Breaktru Forum

eCigarette Forum => Modding => Topic started by: mamu on May 01, 2014, 06:58:37 PM

Title: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 01, 2014, 06:58:37 PM
Got the OKL2-T/20-W12 (http://www.murata-ps.com/data/power/okl2-t20-w12.pdf) in yesterday and got it breadboarded this morning. 

So far, so good with testing (i.e., it's doing what it's suppose to  :laughing: ). 

Size comparison with the Naos Raptor 20A 120W board...
(http://www.mamumods.com/pics/okl2-1.jpg)

Min output voltage (I'm using a 1K ohm POT + 1.43K ohm resister - for a lower min voltage (~3.0v), switch to a 1.5K ohm POT)...
(http://www.mamumods.com/pics/okl2-2.jpg)

Max output voltage...
(http://www.mamumods.com/pics/okl2-3.jpg)

Testing the P-FET for reverse polarity... good to go with protection...
(http://www.mamumods.com/pics/okl2-4.jpg)

Wiring guide...
(http://www.mamumods.com/pics/okl2-t20-wiring3.png)

External parts that I have breadboarded with the OKL (all bought at mouser.com unless otherwise indicated):
20K ohm resistor (CMF5520K000FKEK)

1.43K ohm resistor (RN60D1431FB14)

2x 22uF input caps in parallel (C3225X5R1C226K250AA)

4x 47uF 16v output caps in parallel (GRM32ER61C476ME15L)

1K ohm POT (PT10MH01-102A2020) (use 1.5K ohm POT for min voltage at ~3v)

2x 10A fuses in parallel (RGEF1000)

P-FET (SUP75P03-07-E3)

1S-6S voltage reader (ebay)

3-pos slide switch (1103M2S3CQE2)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on May 01, 2014, 07:50:15 PM
Great mamu. Thanks for sharing.
When I looked at the datasheet the other day, I was thinking 1.5K pot and a 1k fixed resistor may push the high end a bit higher than the max 5.5v
Did you get it as a sample?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 01, 2014, 09:46:43 PM
Awesome
it is priced gewd too
Party mod
Put a fan in front of a rudimentary atomizer and vapor a whole room
if only I lived in Colorado

The penguin approves
(http://img2.wikia.nocookie.net/__cb20110915143150/batman/images/8/8d/180px-The_Penguin_img.jpg)

 :laughing2:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: david4500 on May 01, 2014, 11:29:06 PM
is this the OKL2-T/20-W12P2-C (http://www.mouser.com/ProductDetail/Murata-Power-Solutions/OKL2-T-20-W12P2-C/?qs=sGAEpiMZZMt6Q9lZSPl3RReyOD9tBTeOA9kTVDl24KAGfuu%2fqfFQ1w%3d%3d) or OKL2-T/20-W12N2-C (http://www.mouser.com/ProductDetail/Murata-Power-Solutions/OKL2-T-20-W12N2-C/?qs=sGAEpiMZZMt6Q9lZSPl3RReyOD9tBTeOmjVKmrULLerGx7zlaEAlEg%3d%3d)?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: techguy13 on May 01, 2014, 11:35:08 PM
Nice work!  I've been thinking about getting the T-20 as soon as I saw it and this seals the deal for me.  Time to order a couple to tinker with. 
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: RedLeader77 on May 02, 2014, 12:15:13 AM
Very nice! Being fairly new to modding, i ordered some of these by "Accident". In my attempts to actually use them, most people have told me i need to get a PCB made up for it and that soldering directly to the pads is a bad idea.  You appear to have a different opinion, whats your take?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 02, 2014, 01:25:35 AM
Great mamu. Thanks for sharing.
When I looked at the datasheet the other day, I was thinking 1.5K pot and a 1k fixed resistor may push the high end a bit higher than the max 5.5v
Did you get it as a sample?

No sample, I purchased directly at mouser.

A 1K resistor would push the max output voltage to 7.5v - that may not be good for longevity of some of the components on the converter.  The datasheet says "do not exceed the specified limits of the output voltage or the converter's maximum power rating".

I'm good with 5.5v as a max and my sons too.  We're using 1.0 - 1.5 ohm coils and running around 4.5v - 5v output.  We're a bit on the wushy side of power compared to what some are doing nowadays.  :laughing:

is this the OKL2-T/20-W12P2-C (http://www.mouser.com/ProductDetail/Murata-Power-Solutions/OKL2-T-20-W12P2-C/?qs=sGAEpiMZZMt6Q9lZSPl3RReyOD9tBTeOA9kTVDl24KAGfuu%2fqfFQ1w%3d%3d) or OKL2-T/20-W12N2-C (http://www.mouser.com/ProductDetail/Murata-Power-Solutions/OKL2-T-20-W12N2-C/?qs=sGAEpiMZZMt6Q9lZSPl3RReyOD9tBTeOmjVKmrULLerGx7zlaEAlEg%3d%3d)?

The one I'm using is OKL2-T/20-W12N2-C.  Thanks for asking that, I updated the wiring guide title to reflect which one I'm using.

Very nice! Being fairly new to modding, i ordered some of these by "Accident". In my attempts to actually use them, most people have told me i need to get a PCB made up for it and that soldering directly to the pads is a bad idea.  You appear to have a different opinion, whats your take?

I soldered directly to the pads on the back of the board.  Before putting it in a mod I will be putting a generous layer of gel epoxy over the pads and wiring at the edge of the board.  Just a caution if you solder directly to the pads - use low temp when soldering (< 300 °C).

(http://www.mamumods.com/pics/okl2-5.jpg)

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 02, 2014, 02:31:52 AM
Note: I just realized I had pins 1 and 2 mislabeled in my wiring guide.  That's been corrected.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Iamthebadass on May 02, 2014, 02:36:53 AM
Hey Mamu, great job. Does the Zener provide low voltage cutoff? Have you tested it?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 02, 2014, 05:15:24 AM
ok... just had a duh-oh moment while tinkering with the breadboarded setup some more - with this board I tied the switch to GND, with a zener diode as a low voltage cutoff inline with GND like this that's a no-go.  Removed the zener and corrected the wiring guide.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: dennis15 on May 02, 2014, 08:24:20 AM
 :applaude: Luv it  :yes"
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: rrtwister on May 02, 2014, 08:29:57 AM
I guess I'll have to spring for a board. Haven't heard a thing for several weeks on the sample request.

Nice going mamu  :beer-toast:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: wwwest on May 02, 2014, 08:45:37 AM
What is your opinion on the Raptor and OKL2-T20 mamu. Which one would you prefer? To me both would be way more than I need.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 02, 2014, 10:06:38 AM
It's too early to tell what my preference would be.  Raptor has been an awesome vaping beast from the get-go.  If it weren't oos I probably wouldn't have gotten around to working with this OKL.

I'm still tinkering with the OKL though (ie., it's a work in progress - the reason the title says "tinkering").  I won't be ready to put it in a mod until I'm satisfied I've got it right and with the right components.  So the wiring guide/external components are subject to change.

I also have a few questions about this board and have contacted technical support at Murata for their advice and am waiting to hear back from them.

I've also spent some time since realizing the zener was a no go with the way it was wired in searching for an easy alternative to low voltage cutoff.  I really want that low voltage cutoff.   :yes"

So far with the testing I've done, the OKL is stable and performing really well.  I've also tested with dual 18650 batts in series and a 12V AC/DC power supply - the wiring configuration handles both aok.  With Raptor I had to change out the 7.5K pull-down resistor to a 4.7K resistor to prevent auto-firing at the higher input voltage.

Murata, manufacturer of this board, also make the OKR, and we know how well received and reliable the OKR modules are.  I wouldn't expect anything different with the OKL, so time will tell.




Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 02, 2014, 12:18:59 PM
In my attempts to actually use them, most people have told me i need to get a PCB made up for it and that soldering directly to the pads is a bad idea.

The type of pads used on that board are actually pretty tough, they're the same ones you see on LEDs with a half via on the edge.  They bite into the board material pretty well.  They should be able to take a good amount of stress from a free hanging wire without the pad separating from the board.

I really want that low voltage cutoff.

A 6V voltage detector should be able to handle the job for you.  I did a quick look at mouser for ones that go up to 6V and found some.  Here's one;

http://www.mouser.com/ds/2/348/bd52xxfve_series-e-209417.pdf

There's some others if you search the category of Supervisory Circuits at Mouser narrowed to 6V;

http://www.mouser.com/Semiconductors/Power-Management-ICs/Supervisory-Circuits/_/N-wnws?P=1yxuc7w

I don't know if 6V is high enough, but that's as high as they seem to go.  If you need something greater, might be able to dig up an adjustable one that goes higher than 6V.  Maybe something like this;

http://www.mouser.com/ds/2/405/sbvs187c-261020.pdf


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on May 02, 2014, 01:10:28 PM
Great info Craig. Thanks for sharing with us.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 02, 2014, 02:18:44 PM
Awesome!!  Thanks so much for sharing, Craig!!  :thankyou:

Browsing now - lol another teeny tiny part. My pieces of verobaord are being put to good use these days.   :laughing:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 02, 2014, 02:27:54 PM
There are walls of sorts you have to get over with this stuff.  I know I have one and that's using reflow soldering for major assembly.  I'm really stuck in a hand soldering rut.  I do a little reflow for onesy twosey parts, but just can't seem to get over the wall to do a whole PCB that way.  Anywhere you guys are in working with these parts, I've been there too.  I've just been at it long enough to get over all those little walls.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: DRA on May 03, 2014, 09:06:15 AM
Looks like a decent module. Nice work
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: whoi on May 03, 2014, 04:34:52 PM
mamu, don't forget zener diodes also have an amperage requirement, not just a voltage one, which is why this was probably failing since the draw on the remote is 3mA. Unless I misinterpreted something here...
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 04, 2014, 04:21:24 AM
After a few days of tinkering and testing with a breadboarded setup off and on, I've run into a few glitches.

The loaded output voltage is now higher than the unloaded output voltage.  At max output, loaded voltage is 5.9v - no load voltage is 5.6v.  The load/no load voltages at lower output voltages aren't as extreme as this, but are still reading higher than no load voltage.

Load voltage higher than no load voltage just doesn't make sense. 

Although I was getting no output voltage drop under load during all this testing, I wired up a second OKL and this time connected the +Sense and -Sense pins.  Dialed the pot to max at 5.6v no load, connected an atty and the loaded voltage shot up to 6.1v with the 1st firing, then fluctuated between 5.8v - 6.0v with repeated firing of the fire switch.  It finally settled in at 5.9v.

Other than the strange initial voltage fluctuations, no difference there with the Sense pins connected vs not connected.  So the Sense is failing to compensate for the unwanted voltage increase - was curious if it would.

So... yeah I'm shaking my head by now and thinking well crap - nothing has changed here.... oh wait - the input voltage has gone from 8.4v no load to now 7.3v no load over these last few days since I initially breadboarded the OKL. 

Replaced those batts with a freshly charged set and now no load voltages match load voltage.  So then connected the 12v power supply and yup - no load match load voltage.

Put the 7.3v battery set back in and got the weird higher loaded voltage of 5.9v vs no load voltage of 5.6v.  Same results with and without the Sense pins.

Am letting this set of batts run down to 7v, then 6.5v, then 6.0v, to see what this converter does with load vs no load output voltages with lower input voltages.

This is a summary of what I'm experiencing at max output voltage:
OKL #1 - without Sense pins connected:
Input voltage-----------Output no load----------Output load
7.3v-----------------------5.6v---------------------5.9v
8.5v-----------------------5.6v---------------------5.6v
12v---------- -------------5.6v---------------------5.6v

OKL #2 - with Sense pins connected:
Input voltage-----------Output no load----------Output load
7.3v-----------------------5.6v---------------------5.9v
8.5v-----------------------5.6v---------------------5.7v
12v------------------------5.6v---------------------5.6v

What *appears* to be happening is that the OKL is not stable with regulating output when input voltage is < 7.5v.  This is not good. :(
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 04, 2014, 04:25:41 AM
mamu, don't forget zener diodes also have an amperage requirement, not just a voltage one, which is why this was probably failing since the draw on the remote is 3mA. Unless I misinterpreted something here...

Connected to GND via the on/off control is the issue - I'm not getting the zener breakdown voltage of 5.6v.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 04, 2014, 07:36:43 AM
Mamu its probably your breadboard its behavior is defined in the datas

Its also suggest trying different caps up to 188uf  for the output but says match the input as well
As the battery sags it introducing an impedance
Quote
e. Again, use low-ESR ceramic (Murata GRM32 series) or
polymer capacitors. Initial values of 188 ?F may be tried, either single or
multiple capacitors in parallel. Mount these close to the converter. Measure
the output ripple under your load conditions.

Try with a lipo would be my suggestion and then if same  I would change caps..  But 1st I would make an "air" wired breadboard lol



Quote
Output Current Limiting
Current limiting inception is de? ned as the point at which full power falls
below the rated tolerance. See the Performance/Functional Speci? cations. Note particularly that the output current may brie? y rise above its
rated value in normal operation as long as the average output power is
not exceeded. This enhances reliability and continued operation of your
application. If the output current is too high, the converter will enter the
short circuit condition.
Output Short Circuit Condition
When a converter is in current-limit mode, the output voltage will drop
as the output current demand increases. If the output voltage drops too
low (approximately 98% of nominal output voltage for most models), the
magnetically coupled voltage used to develop primary side voltages will
also drop, thereby shutting down the PWM controller. Following a time-out
period, the PWM will restart, causing the output voltage to begin ramping
up to its appropriate value. If the short-circuit condition persists, another
shutdown cycle will initiate. This rapid on/off cycling is called “hiccup
mode”. The hiccup cycling reduces the average output current, thereby
preventing excessive internal temperatures and/or component damage. A
short circuit can be tolerated inde? nitely.


I like troubleshooting

Quote
Due to large stray capacitance (from 2-25pF per contact point), the inductance of connections, and a relatively
high and not very reproducible contact resistance, solderless breadboards are limited to operate at relatively
low frequencies, usually less than 10 MHz, depending on the nature of the circuit. The relatively high contact
resistance can also be a problem for some DC and very low frequency circuits.
Source http://en.wikipedia.org/wiki/Breadboard
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 04, 2014, 08:24:57 AM
It would be easy to explain voltage drop under load at lower input voltage, but I'm not getting an output voltage drop, Visus, I'm getting an output voltage increase under load with < 7.5v input voltage.

At first I thought well I need to wire in the Sense that would compensate for that voltage increase, but that didn't have any effect.

Full charge batts = no problem
12v power supply = no problem
<7.5v input = problem with unwanted increase in voltage under load

Maybe when Craig checks in he'll be able to explain how a voltage increase under load would happen when input voltage is low.  I have no idea other than its internal to the converter.

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 04, 2014, 09:38:34 AM
The data states a +1% rise if short circuit or drop/impedance
your seeing a +1% rise loaded

Its weird that it would do that but that what it says lol

when no load it is free flowing electrons, happy, when loaded it goes in the short circuit condition +1% or your chip is faulty may be also condition..
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 04, 2014, 02:41:08 PM
Maybe when Craig checks in he'll be able to explain how a voltage increase under load would happen when input voltage is low.  I have no idea other than its internal to the converter.

I'm not sure I understand the problem, but if you're saying output voltage is higher than input, that's a really odd one.  It should not be physically possible for a step down converter to output a voltage higher than input...however...if a converter has a wiring error or some other input-output anomaly, it can do some screwy things. 

Since there is a good amount of inductance inline with the circuit, there can be large voltage spikes that occur during the high speed switching a converter performs (at several hundred thousand Hertz).  In some cases, superfluous voltage spikes can actually fry components within the converter, I've had that happen and it's a major bummer.  When building your own converters, you have to design so those don't happen.

Basic DMMs filter spikes and arrive at an average voltage.  A high end DMM will actually add the influence of those spikes to an RMS reading which will accurately represent perceived voltage.  In some cases, voltage spikes can overcome what a basic DMM can average resulting in an erroneously high reading. 

For situations where noise or voltage spikes are involved, I can't recommend highly enough a decent oscilloscope.  T-Equipment.net has a nice Rigol DSO (http://www.tequipment.net/RigolDS1052E.html?v=7401) (digital storage scope) for $329.  If that's not do-able, even an old analog scope can cover you there and you can find decent ones on eBay for less than $100.

Otherwise, if you're seeing output voltage go up when input voltage goes down, that's not that strange really.  There is an amount of regulation error involved wth these switching converters.  It's actually pretty liberal.  Input voltage does have an effect on output regulation error.  It wouldn't be unusual for output voltage to increase or decrease as input voltage drops, but it shouldn't be more than a tenth or two of a Volt.  If it's more than that, there's something wrong.

Don't forget about a converter's drop-out.  For a step-down converter, you need input voltage a Volt or two above output at all times.


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 04, 2014, 05:23:23 PM
ok... been tinkering again and *think* I've now got a stable OKL.

Although the datasheet says input and output caps are optional and not necessarily needed, I feel they are necessary for a stable input and output for our application.  The datasheet says if using caps, use 44uF for input and 188uF for output.  You're not going to find 44uF MLCC caps or 188uF MLCC caps, so the best option is to parallel a lower value to add the capacitance for the total we need.

Also, with my testing without an output cap it makes no difference whether the Sense pins are connected or not - I'm not getting a stable output with or without the Sense when input voltage drops to <7.5v.  It is important then to use both an output cap and connect the Sense pins to get a stable output voltage else you'll be back to an unstable output under load.

Added 4x 47uF 16v caps (soldered together in parallel) to the output, connected +Sense to Vout and connected -Sense to GND and am now getting stable voltage out under load no matter the input voltage level (min voltage should still be ~6v).

I'm still going to be doing a few more days of testing, but hopefully this wiring is now good to go.  I've updated the OP with the latest wiring guide, but can't edit the parts list to add the output caps.

Here's the parts I've now got breadboarded in addition to the OKL:
20K ohm resistor (CMF5520K000FKEK)

1.43K ohm resistor (RN60D1431FB14)

2x 22uF 16v input caps in parallel (C3225X5R1C226K250AA)

4x 47uF 16v output caps in parallel (GRM32ER61C476ME15L)

1K ohm POT (PT10MH01-102A2020) (use 1.5K ohm POT for min voltage at ~3v)

2x 10A fuses in parallel (RGEF1000)

3-pos slide switch (1103M2S3CQE2)

P-FET (SUP75P03-07-E3)

1S-6S voltage reader (ebay)

This has been a rather *fun* project and a great learning experience for me (I say that with a bit of sarcasm) :laughing: but I think we're good to go.  I'm checking in to adding a voltage detector for low voltage protection for the batts per Craig's recommended parts (thanks Craig!) so will update that when I get the parts in.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on May 04, 2014, 06:06:43 PM
Great mamu. Persistence paid off. Well done. I edited the O.P. w/ the output caps included.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 04, 2014, 06:28:41 PM
Thanks, breaktru.

This one has been a challenge for sure and has def abated my need to tinker with new toys... at least for a loooong time.  :laughing:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 04, 2014, 10:17:46 PM
Woot
Glad you got it
Read and misinterpreted the rise wrong on the +1v 
Quote
Short Circuit Current (17) Hiccup technique, autorecovery within ±1%
of Vout     0.02 A

I look at what we do,  then look at what it says about it.  We short circuit a wire for tasty occurrence.  It said short lol..

Well I got a D+  here must do more school less watching outrageous acts of science lol,,,

 Awesome if it remains stable...
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 04, 2014, 10:36:44 PM
Thanks, breaktru.

This one has been a challenge for sure and has def abated my need to tinker with new toys... at least for a loooong time.  :laughing:

Nooooooo  ya cannot stop we love ya tutorials.    Mucho thanks from so many people..   :thumbsup:


With your popularity--- maybe sky is the limit...

The FDA has approved an ecig manufacturer -- .
Finally medically approved and its the only one and to my knowledge nobody knows this guy.. 
His device is badarse tho, its totally unique..
http://news.yahoo.com/u-e-cigarette-experiment-inspires-medical-device-120928130--finance.html
http://thermovape.com/
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 05, 2014, 03:27:35 PM
One thing to keep in mind is that step down converters really load the hell out of the input caps.  Boost converters load the hell out of the output caps.  So in this case, additional input capacitance is where you should see improvement in stability.  I would give it a try with no additional output capacitance and the two 22uF MLCC caps in parallel on the input. 

The C3225X5R1C226K250AA MLCC caps you're using are the best ones I've found so far, I use them on the output for my boosters, really good performance.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Iamthebadass on May 05, 2014, 04:33:38 PM
So I have one of these on its way right now. I only have 22uf caps so I'm gonna have to tinker and figure out how many works best.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 05, 2014, 06:26:07 PM
I have been doing testing with 2x 22uF (soldered together in parallel) input caps all this time.

The converter is stable with regulating output and no issues when input voltage >7.5v - with and without the Sense and with no output cap - the converter is aok as long as input voltage is >7.5v. 

With Sense connected and with output cap, no issues.  I removed the output cap and I get issues with loaded output voltage being higher than no load output voltage - more especially so when set output voltage >5v.

I have never seen loaded output voltage higher than no load output voltage until now so is weird.

If I set the no load output voltage at 5.6v, I expect to vape at 5.6v, not 5.9v.   It's like the converter is overcompensating and maybe the feedback loop or whatever is off, especially at higher set output voltages.

Someone else may find different results, but this is what I'm getting with my breadboarded setup.

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 05, 2014, 06:38:36 PM


Wire in a button and have a turbo option..  :laughing2:

Good news thats a powerful mod fer sure

Have you run it down to specs @100+W
Not like anyone can vape it there but inspections..

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 05, 2014, 06:48:57 PM
lol no I haven't maxed it yet.  I should and see what happens.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Iamthebadass on May 05, 2014, 07:34:12 PM
I vaped a raptor at 120. It was not fun.

The juice instantly vaporized. All of it. Flooded wicks, still a dry hit.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 06, 2014, 02:28:28 AM
With Sense connected and with output cap, no issues.  I removed the output cap and I get issues with loaded output voltage being higher than no load output voltage - more especially so when set output voltage >5v.

I have never seen loaded output voltage higher than no load output voltage until now so is weird.

If I set the no load output voltage at 5.6v, I expect to vape at 5.6v, not 5.9v.   It's like the converter is overcompensating and maybe the feedback loop or whatever is off, especially at higher set output voltages.

Okay I get it now, you're getting excessive regulation error, but the error is positive as load increases instead of negative as you would expect to see. 

I've actually seen this with my boost converters, but not to that degree.  I've seen no load voltage a tenth or two lower than it is with a light load, but then after that, regulation error goes negative as load increases. 

You're right, it's something going on with the feedback loop and how the converter handles no load.  In my case, it's because the converter goes into a low power mode which causes negative regulation error.  I've since changed the controller configuration to disable that low power mode so it doesn't happen anymore. 

In your case, increasing output capacitance reduces no load regulation error, but I can't tell you why.  Maybe I could tell with a scope.  On my own converters I actually run a 1k resistor from output positive to ground to eliminate the possibility of a zero load condition.  You might try that.  Some parts actually require a minimal loading to stay within specified regulation error.  A 1k resistor will usually cover it.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 06, 2014, 04:44:57 AM
...I've seen no load voltage a tenth or two lower than it is with a light load, but then after that, regulation error goes negative as load increases. 

That's exactly what is happening with this converter.

I did some high amp testing with the OKL.  I didn't max it out - I did 5.5v with 0.4 ohms (76W and 14A) and the converter handled the load aok and I got the expected loaded Vdrop.

But I feel like I'm in the twilight zone with this converter.  I thought the output cap stabilized it, but now with/without Sense and with/without output cap, at around 3-5A Vout loaded is running up to 0.3v (it varies) higher than Vout no load with Vout set >5v.  And this is no matter the input voltage level.  With the high amp testing I just did, there is the expected Vdrop under load.

I tried the 1K resistor across Vout to GND and no effect - with/without output cap and with the 1K resistor no change.

I give up - it is what it is.   :laughing:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 06, 2014, 02:04:22 PM
If you're connecting the adjustment pot through a breadboard, you might try hard wiring it to the PCB with connections as short as possible.  Maybe try a leaded resistor instead.  See if that makes any difference.  But yes, it's a mystery.  You mentioned you emailed Murata technical support about that.  Maybe one of the engineers will get back to you on it.  I have had strange things happen with parts and actually received a response from engineering after sending a query.  Though more often than not, it ends up in the black hole of support requests.  You kind of get what you get with this stuff. 
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 06, 2014, 02:32:51 PM
I'll do that.  In fact, I think I'll wire up all the parts and see what's what.

Still waiting on Murata rep to get back to me.  I've sent him 3 emails now lol.

I tied Sense directly to the atty pos and neg - still same results.

And exact same results with and without Sense connected.  So the Sense doesn't appear to be doing anything.

Of course that's all breadboarded so will wire everything up directly and with short lines.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: techguy13 on May 06, 2014, 05:22:57 PM
I'll do that.  In fact, I think I'll wire up all the parts and see what's what.

That same sort of thing happened to me when I breadboarded the UVT020A0X3-SRZ the other day.  The voltage under load would go high, low and just jump around but once I wired it all together into a small package it started to perform perfectly under load.  I hope it works out the same for you!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 06, 2014, 10:43:51 PM
Thanks techguy.

I'm curious - with the converter you're working with, did you wire Sense (VS) directly at the atty connector?  Or connect to Vout at the board?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: techguy13 on May 06, 2014, 10:56:14 PM
I wired VS as close to the atty connector as possible just to be sure it would work properly.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 07, 2014, 12:12:12 AM
That's what I was thinking of doing for best results so will do.

GE puts out a much better complete and descriptive datasheet than Murata.  Some areas of the Murata datasheet is vague, confusing (to me anyway) or just no info at all.

Hope you posts pics of your build and mod when you get yours done!!  :yes"
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: techguy13 on May 07, 2014, 12:32:22 AM
That's why I decided to go with the GE converter instead of the Murata one, it just seemed to have a more comprehensive datasheet to it.  I will post some pictures of my build as soon as I get enough posts to be able to create a thread.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 07, 2014, 02:31:04 AM
Mundy has the ge too its surprisingly really small
http://www.e-cigarette-forum.com/forum/battery-mods/463904-anyone-used-ge-uvt020a0x3-srz.html
(http://i749.photobucket.com/albums/xx139/Alexander_Mundy/Hybrid%20Project%20X/UVT020A0X3-SRZnexttoDNA20_zps9737d7f7.jpg)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 07, 2014, 10:11:08 AM
A Murata technical engineer finally got back to me this morning.  I sent another email yesterday evening lol - that makes 4 now.  He probably got tired of the repeated emails and thought he better respond to get me off his back.  :laughing:

There were a few questions I had that didn't get answered.  But he said there are 10 ohm resistors internal connecting the Sense pins to Vout and GND, so the DC-DC will work ok if left open circuit but you sacrifice a small amount of output voltage regulation if left open circuit.   

He also said with or without an output cap, should not affect the Sense.  He also said "We guarantee our output voltage regulation at the point where the Remote Sense lines connect into the Vout and GND busses."

I took everything off the breadboard and wired all components directly to the converter and also tied +Sense directly to +atty connector and -Sense directly to -atty connector.

and... success... no more funky Vout... max unloaded = 5.5v, loaded = 5.5v (this was with a load of ~4A) and with higher loads the expected Vdrop.

I'm going to still monitor input voltage level and Vout load/no load just to make sure I don't re-visit the twilight zone with this, but I think I'm finally ready to put it in a mod.  It took me a while to get there and to get it right, but all is good in the end.  :yes"

I updated the wiring guide in the OP (you may need to clear your cache or hit refresh).

(http://www.mamumods.com/pics/okl2-6.jpg)

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 07, 2014, 12:43:50 PM
Sounds like a case where you got hit with the parasitic effect of breadboarding.  The feedback circuits can be sensitive to that.  Good to hear you got it worked out though.

I agree the data sheet is sketchy on that part.  Knowing the function of the sense pads and that they are internally connected would have been nice information to have.  For my own circuits, I'll often pass on parts that don't have a comprehensive data sheet.  Big ding on that one.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 07, 2014, 02:17:33 PM
Breadboard and those crappy meters all wreck havok on precisional.

A good meter, thats mandatory..

Craig said he will sell you his for like 10 bucks in a deleted post but I was upset so he sold it to me for 15 lol...
I am now proud owner of  a  sebastian omnitrix ben 10 meter..
Its in the mail.  lol

 
No really at least freak yourself out confiding with knowing,  it aint your equipment..

Inductance is a tricky unit just ask a joule thief.   :yes"
So ya know your routed wiring is perfect now with two of  those in-line..
If you saw how fast they drain caps you know what I are chats about, its uber fast
that loss cannot be good for holding down the volts stable
using caps on the output if using meter I would say since golden here
if not using a meter none are needed
but ya need a good DMM to know if true

I would bet a margarita in Monaco thats whats what



Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 07, 2014, 04:31:18 PM
I don't think it was the meter, Visus.

Sounds like a case where you got hit with the parasitic effect of breadboarding.  The feedback circuits can be sensitive to that.  Good to hear you got it worked out though.

I agree the data sheet is sketchy on that part.  Knowing the function of the sense pads and that they are internally connected would have been nice information to have.  For my own circuits, I'll often pass on parts that don't have a comprehensive data sheet.  Big ding on that one.

I agree - there is a world of difference between Murata and GE and TI datasheets in how well written and comprehensive they are.  I don't have an electronics background so I learn as I go and good datasheets help me a lot there.

What I'm torqued about though (with myself) is I never once considered it might be the breadboard causing issues and I should have as I've ran down that road before.  I especially didn't realize the feedback loop would be affected by it.  First time I've worked with Sense and a feedback loop.

aah well.. it was a journey and a good learning experience for me. If I get hit with something like this again though, somebody just shoot me.  :laughing:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 07, 2014, 04:35:26 PM
double post
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 07, 2014, 04:57:25 PM
Craig said he will sell you his for like 10 bucks in a deleted post but I was upset so he sold it to me for 15 lol...

Hehe, you'd have to pry it from my cold dead hands, it's this one; http://extech.com/instruments/product.asp?catid=48&prodid=284 and I got a really good deal on it so that one's going to be around for a long time.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 07, 2014, 05:10:21 PM
I have a Fluke.

Funny story with how I got it.  A good forum friend sent it to me a few years back when I posted pics of testing something (can't recall what I was testing now) with my cheapie Radio Shack multimeter.  Said a modder needs a good DMM and he felt sorry for me with using a Radio Shack one.  lol.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Chenderson1985 on May 07, 2014, 05:25:19 PM
I am very new to modding. I have only built a DNA 30 and an Altoids can PV from a vamo pcb. I ordered on of these chips and got it in today. Before I start on this I don’t know if I fully understand your wiring diagram Mamu. I see that there is a 20K Ohm resistor on connections 1 and 2. Do I need to connect these two areas? This will be my first undertaking with a chip like this so any advice would be very appreciated.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 07, 2014, 05:28:38 PM
I don't have an electronics background so I learn as I go and good datasheets help me a lot there.

90% of what a data sheet contains does not require any technical expertise, it's just a matter of saying this does this and that does that.  Sometimes they get really technical, but most of what you need just to hook up a part is either there or it isn't.  In the case of the OKL, it just isn't there.  They didn't even provide a typical application circuit which is like the most basic aspect of any data sheet.

Quote
What I'm torqued about though (with myself) is I never once considered it might be the breadboard causing issues and I should have as I've ran down that road before.  I especially didn't realize the feedback loop would be affected by it.  First time I've worked with Sense and a feedback loop.

I've been nailed by that before, it happens.  When I do breadboard work, I do a mix of PCB and breadboard connections.  Breadboards alone just cause too many strange problems and then like you found out, you spend a bunch of time chasing your tail.  Though they can work well for some things

A good rule for breadboarding is if it's a high impedance signal, put it on a PCB.  If it's low impedance signal, a breadboard is fine.  The high impedance stuff is what's sensitive to the effects of a breadboard.  Things like digital buses or logic signals or, like you found out, feedback circuits are high impedance. 

But yeah, it's a learning experience.  I learn new stuff every time I start a new project and I've been doing electronics for decades.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on May 07, 2014, 05:35:02 PM
I've always experienced problems w/ breadboards so I usually solder most everything. If I'm testing part values that may need to be changed, I solder on alligator clips.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 07, 2014, 05:39:47 PM
I have a Fluke.

Funny story with how I got it.  A good forum friend sent it to me a few years back when I posted pics of testing something (can't recall what I was testing now) with my cheapie Radio Shack multimeter.  Said a modder needs a good DMM and he felt sorry for me with using a Radio Shack one.  lol.

Flukes are probably the best meters out there, but they're pricey.  A Fluke with the same functionality as my Extech would probably be close to a grand.  I can handle a couple hundred bucks for a good meter, but a grand is way out of my price range.  Anyway, that's awesome someone gave you a Fluke, they're all expensive.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 07, 2014, 06:13:42 PM
I am very new to modding. I have only built a DNA 30 and an Altoids can PV from a vamo pcb. I ordered on of these chips and got it in today. Before I start on this I don’t know if I fully understand your wiring diagram Mamu. I see that there is a 20K Ohm resistor on connections 1 and 2. Do I need to connect these two areas? This will be my first undertaking with a chip like this so any advice would be very appreciated.

The 20K resistor in this circuit pulls high the on/off control which turns the converter off, preventing it from auto-firing.  Without this pull-up resistor, the converter would always be on, always firing - with and without pressing the fire switch.

One end of the 20K resistor is connected to pin 1 and the other end of the resistor is connected to pin 2.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 07, 2014, 10:08:20 PM
I have a Fluke.

Funny story with how I got it.  A good forum friend sent it to me a few years back when I posted pics of testing something (can't recall what I was testing now) with my cheapie Radio Shack multimeter.  Said a modder needs a good DMM and he felt sorry for me with using a Radio Shack one.  lol.

I was hoping there data sheet and tech talk did not tell us wrong since the OKR is stable without caps. 
I built Breaks welder and was surprised at how fast those meters drain a cap
I put it to effect here what may happen on  feedbacks +a breadboard
"whats in between the atomizer"

Meh

Fluke FTW  ;hubba;

My company gives ya one when we turn journeyman in the third rail dept.
I made journeyman via a retirement/seniority by transferring out of third rail into the treasury dept and missed out on the fluke.
I so wanted the fluke but we get an engineer shadow if accuracy needed with flukes and gizmo's..
They no play around with cash collects and he gets the goodies..
Became a glorified parts changer  :laughing:

I owe ya a margarita in Monaco --  :thumbsup:




 

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 08, 2014, 04:35:03 PM
lol Visus - I may take you up on that margarita.  :laughing:

I've always experienced problems w/ breadboards so I usually solder most everything. If I'm testing part values that may need to be changed, I solder on alligator clips.

That's a good tip breaktru with using alligator clips.  Just bought some spares to have plenty on hand.

Thinking back on this, it was just strange that for over a day the OKL worked correctly until the input volts <7.5v - so I associated that with the OKL.  Then put an output cap and tied in Sense and everything aok for a while.  Then got funky again - so associated that with the OKL too.  Strange stuff.

OKL is doing great now and has been stable with the output with the direct connections.  So it was def the breadboard. 

Am curious now if I tied Sense directly at the converter instead of directly at the load, but aint gonna mess with it anymore.   :laughing:  Is good to go as is.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 09, 2014, 12:54:54 AM
Am curious now if I tied Sense directly at the converter instead of directly at the load, but aint gonna mess with it anymore.

You can probably do that if you want, the only difference is the regulation point is where the sense pickups are so you would get the added voltage drop of the wiring between the board connections and the atomizer connector.  It's probably not enough of a drop to be concerned about.  Maybe a couple mOhms of wiring which results in an extra 40mV at 20A.  It would save you the trouble of running wires to the atomizer connector for the sense pickups. 

Probably not worth the trouble this time, but if you build another one, you could just jump the sense connections to the Vout and ground pads on the board, or just leave them disconnected since they're already connected internally.


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on May 13, 2014, 01:03:25 AM
hi manu i was wondering which one did you get? because when i go to the  site theres two different kind of this chip.. one of them is sold out..

http://in.mouser.com/Search/Refine.aspx?Keyword=OKL2-T%2f20-W12
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 13, 2014, 02:41:31 AM
The title of my wiring guide in the OP has the one I use - OKL2-T/20-W12N2-C
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on May 13, 2014, 02:59:22 AM
yah i saw the sorry i came back here to delete my post but it was to late you already saw my post..eheh sory..

by the way mamu is the  wiring on the fist post is UPDATED?  are you using the sense connection?

thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 13, 2014, 03:43:35 AM
lol that's ok, zotek.

Yes, the wiring guide in the OP is current.

Based on what the Murata engineer told me - the output voltage regulation is guaranteed at the point where Sense connects - I tied the Sense pins directly at the atty connector.

You'll be able to start a new topic when you have a few more posts.

The APTS020A0X43-SRZ - TLynx - by GE seems to be the counterpart to this OKL2 board with similar specs and pinout and wiring configuration and also both are smt.

I've been vaping on and off with my "out of the box"  :laughing: OKL2-T20 setup and it's doing a great job of it - stable and consistent.


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on May 13, 2014, 09:45:00 AM
thank you so much manu for your reply..i just ordered 5 pcs of the chips..hehehe ive been waiting for the NSR020A0X43Z for a while..and im done.lol do you think you can push this chip to 6v?.

and aslo have you tried this chip?  http://in.mouser.com/ProductDetail/GE-Critical-Power/NSR040A0X43Z/?qs=sGAEpiMZZMt6Q9lZSPl3RZ%252b%252bVUVDyW2OaruvwtMC5Tg%3d
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 13, 2014, 11:04:46 PM
Great write up. Interesting to see behind the curtain and read all the frustration I am sure went into this for you!

Ordered a complete set to build one mod, this will be my first :P

mamu, you rock!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Chenderson1985 on May 15, 2014, 06:05:38 PM
Thank you Mamu for taking the time to make a wiring diagram for this chip. It helps people like me learn a new skill.

https://www.dropbox.com/s/bzdfp16y1qdxb58/2014-05-14%2019.46.56.jpg
https://www.dropbox.com/s/0h7w1weicimmr47/0514140024.jpg
https://www.dropbox.com/s/4in9zv57j8m4zb4/0514140033.jpg
https://www.dropbox.com/s/sxcgxjuk4invznl/2014-05-13%2022.12.45.jpg
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 15, 2014, 06:53:06 PM
Thank you Mamu for taking the time to make a wiring diagram for this chip. It helps people like me learn a new skill.

https://www.dropbox.com/s/bzdfp16y1qdxb58/2014-05-14%2019.46.56.jpg
https://www.dropbox.com/s/0h7w1weicimmr47/0514140024.jpg
https://www.dropbox.com/s/4in9zv57j8m4zb4/0514140033.jpg
https://www.dropbox.com/s/sxcgxjuk4invznl/2014-05-13%2022.12.45.jpg

What box is that Chenderson?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Chenderson1985 on May 15, 2014, 07:01:44 PM
https://www.parts-express.com/hammond-1591bsbk-abs-project-box-black-44-x-24-x-13--320-706
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: memoevapor on May 15, 2014, 07:44:49 PM


For situations where noise or voltage spikes are involved, I can't recommend highly enough a decent oscilloscope.  T-Equipment.net has a nice Rigol DSO (http://www.tequipment.net/RigolDS1052E.html?v=7401) (digital storage scope) for $329.  If that's not do-able, even an old analog scope can cover you there and you can find decent ones on eBay for less than $100.]


Craig, how many channels do you suggest for our modding purposes? I have a very limited modding budget. I've been looking at this DSO HERE (http://www.ebay.com/itm/Hantek-6022BE-PC-Based-USB-Digital-Storag-Oscilloscope-2Channels-20MHz-48MSa-s-/221270085136?pt=BI_Oscilloscopes&hash=item3384b98e10), what are your thoughts on this one? :popcorn:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: memoevapor on May 15, 2014, 08:26:30 PM
NICE Mod Chenderson1985! :rockin smiley:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: memoevapor on May 15, 2014, 08:46:00 PM

and aslo have you tried this chip?  http://in.mouser.com/ProductDetail/GE-Critical-Power/NSR040A0X43Z/?qs=sGAEpiMZZMt6Q9lZSPl3RZ%252b%252bVUVDyW2OaruvwtMC5Tg%3d

That is one powerhouse of a chip according to the Data Sheet DataSheet (http://apps.geindustrial.com/publibrary/checkout/NSR040A0X?TNR=Data%20Sheets|NSR040A0X|generic)! 5.0V @ 40Amp = 200Watts. Could do some serious sub ohming there!  freaked_out:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 16, 2014, 01:56:47 AM
thank you so much manu for your reply..i just ordered 5 pcs of the chips..hehehe ive been waiting for the NSR020A0X43Z for a while..and im done.lol do you think you can push this chip to 6v?.

and aslo have you tried this chip?  http://in.mouser.com/ProductDetail/GE-Critical-Power/NSR040A0X43Z/?qs=sGAEpiMZZMt6Q9lZSPl3RZ%252b%252bVUVDyW2OaruvwtMC5Tg%3d

It would be at your option to push it to 6v.  I usually stay within specs.

I've not tried the 40A module, but I think someone on ECF posted about using it.  I think 20A is way plenty for me.  :laughing:

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 16, 2014, 02:10:22 AM
Thank you Mamu for taking the time to make a wiring diagram for this chip. It helps people like me learn a new skill.

https://www.dropbox.com/s/bzdfp16y1qdxb58/2014-05-14%2019.46.56.jpg
https://www.dropbox.com/s/0h7w1weicimmr47/0514140024.jpg
https://www.dropbox.com/s/4in9zv57j8m4zb4/0514140033.jpg
https://www.dropbox.com/s/sxcgxjuk4invznl/2014-05-13%2022.12.45.jpg

Well done and congratz, Chenderson!!

I love the clicky 16mm ss button.  I don't know about the P-FET being mounted on the back of the OKL though, the Drain is connected to the tab plus it's not a good idea to have metal from one part touching metal of another part.  It must not be causing issues if you're vaping with it, but maybe an insulating layer like electrical tape or Kapton tape between the OKL and the the P-FET would be a good idea.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on May 16, 2014, 03:28:02 AM
It would be at your option to push it to 6v.  I usually stay within specs.

I've not tried the 40A module, but I think someone on ECF posted about using it.  I think 20A is way plenty for me.  :laughing:


can you make it mamu?..ill pay.lol
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 16, 2014, 01:44:29 PM
Craig, how many channels do you suggest for our modding purposes?

Most of the time you only need one channel.  Though the times you need both channels, it's nice to have them.  In some cases you may want to compare signals which is not something you do all that often, probably about the same need as two DMMs which happens sometimes as well.  You can get by with a single channel if the option is nothing, but pretty much all benchtop scopes start at two channels. 

Quote
I have a very limited modding budget. I've been looking at this DSO HERE (http://www.ebay.com/itm/Hantek-6022BE-PC-Based-USB-Digital-Storag-Oscilloscope-2Channels-20MHz-48MSa-s-/221270085136?pt=BI_Oscilloscopes&hash=item3384b98e10), what are your thoughts on this one?

I can understand the need to avoid spending several hundred dollars on a proper benchtop scope, but those "use your PC" ones do have some issues.  Generally they're pretty limited on the bandwidth, but that one is 20 MHz which is actually fine for most stuff.  Though sometimes you're concerned with high frequency noise which a 20 MHz scope won't be able to see.  Other than that, the signals you may be interested in are usually well below 20 MHz.

The sample rate is a bit low on that, 48 MSa.  The Rigol scope I linked to is 1 GSa.  That means resolution will be limited so your waveforms may be a bit choppy looking in the display. 

You kind of pay your nickel and take your chances with those PC based scopes.  I would recommend a proper scope, but if it's that or nothing, it's better than nothing.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: memoevapor on May 16, 2014, 09:24:02 PM
Thanks Craig! I appreciate your time, expertise, and most of all patience with a noobe! :thankyou: Just a few months ago I MIGHT have been able to pick a DSO out of a line up of parts, but I would not have been able to tell you what it did....LOL. Thank you VERY much!!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 17, 2014, 03:26:16 AM
Mamu! You are wonderful for helping us out. I built my first mod today using this write up. Trying to stuff it all into a 1590g Hammond box is proving to challenging Lol.

A couple questions though. Why are you adding caps to the in/out? The spec sheet says they are not required and when I was test firing mine today it seemed to work fine without them.  Just don't want to leave them out if they are crucial pieces.

Holy Vape @ 5.5 volts on a .45 ohm fogger v4!!!! As fantastic a wicking design the fogger v4 is, it never had a chance at keeping up with 70 watts Lol.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 17, 2014, 01:30:59 PM
Thanks Craig! I appreciate your time, expertise, and most of all patience with a noobe!  Just a few months ago I MIGHT have been able to pick a DSO out of a line up of parts, but I would not have been able to tell you what it did....LOL. Thank you VERY much!!

Welcome, one comment I wanted to make in that previous post was you can actually do pretty well with a used analog scope.  You can find good ones on eBay under a hundred dollars.  The storage function is nice to have, but it's not actually a critical feature.  Inexpensive DSOs like the Rigol I linked to are a pretty recent thing.  They used to be cost prohibitive for a hobbyist, like several thousand dollars.  I got by on a 100 MHz analog scope for decades of work at home up until a few years ago when inexpensive DSOs became available.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 17, 2014, 02:32:24 PM
Mamu! You are wonderful for helping us out. I built my first mod today using this write up. Trying to stuff it all into a 1590g Hammond box is proving to challenging Lol.

A couple questions though. Why are you adding caps to the in/out? The spec sheet says they are not required and when I was test firing mine today it seemed to work fine without them.  Just don't want to leave them out if they are crucial pieces.

Holy Vape @ 5.5 volts on a .45 ohm fogger v4!!!! As fantastic a wicking design the fogger v4 is, it never had a chance at keeping up with 70 watts Lol.

Your first mod is with the OKL2-T20?  That's impressive - congratz!!

Yeah, the converter will work ok without external caps, just like the OKR, so it's at your option to add them or not.

I like to have at least an input cap on these converters to help buffer the shock/stress on the batts and module from frequent and repeated firing.  I think it gives increased stability and longevity to both the batts and the converter.  We fire these converters sometimes up to a hundred times a day each and every day.

I find it interesting that between the Murata converters and the side-by-side comparable GE converters, the GE converters require an input cap while Murata states an input cap is optional.

But even then Murata recommends external caps... p. 4, note #1 from the OKL2-T20 datasheet...

Quote
All models are tested and specified with external 188?F ceramic output capacitors and a 44 ?F external input capacitor. All capacitors are low ESR types. These capacitors are necessary to accommodate our test equipment and may not be required to achieve specified performance in your applications. However, Murata Power Solutions recommends installation of these capacitors.



Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 17, 2014, 02:39:43 PM
Thanks for the reply.  Time to go add my input caps :)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 17, 2014, 02:54:33 PM
I like to have at least an input cap on these converters to help buffer the shock/stress on the batts and module from frequent and repeated firing.  I think it gives increased stability and longevity to both the batts and the converter.  We fire these converters sometimes up to a hundred times a day each and every day.

I would recommend that as well.  Step-down converters really load the hell out of the input caps.  It's less of a concern for boost converters, they heavily load the output caps.  For a booster I would recommend additional output capacitance, if any at all.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: jrweber02 on May 17, 2014, 05:37:06 PM
Got the OKL2-T/20-W12 (http://www.murata-ps.com/data/power/okl2-t20-w12.pdf) in yesterday and got it breadboarded this morning. 

So far, so good with testing (i.e., it's doing what it's suppose to  :laughing: ). 

Size comparison with the Naos Raptor 20A 120W board...
(http://www.mamumods.com/pics/okl2-1.jpg)

Min output voltage (I'm using a 1K ohm POT + 1.43K ohm resister - for a lower min voltage (~3.0v), switch to a 1.5K ohm POT)...
(http://www.mamumods.com/pics/okl2-2.jpg)

Max output voltage...
(http://www.mamumods.com/pics/okl2-3.jpg)

Testing the P-FET for reverse polarity... good to go with protection...
(http://www.mamumods.com/pics/okl2-4.jpg)

Wiring guide...
(http://www.mamumods.com/pics/okl2-t20-wiring3.png)

External parts that I have breadboarded with the OKL (all bought at mouser.com unless otherwise indicated):
20K ohm resistor (CMF5520K000FKEK)

1.43K ohm resistor (RN60D1431FB14)

2x 22uF input caps in parallel (C3225X5R1C226K250AA)

4x 47uF 16v output caps in parallel (GRM32ER61C476ME15L)

1K ohm POT (PT10MH01-102A2020) (use 1.5K ohm POT for min voltage at ~3v)

2x 10A fuses in parallel (RGEF1000)

P-FET (SUP75P03-07-E3)

1S-6S voltage reader (ebay)

3-pos slide switch (1103M2S3CQE2)







Was wondering if a 22k ohm would work instead of a 20k ohm on pins 1 and 2 can someone explain how mamu decided 20k ohm I get that if there isnt a res there then it will auto fire wheather button being hit or not just bot sure how 20k ohm was decided im trying to pic thing up to make my own style build and maybe down the road post it up and share like mamu and breaktru do
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on May 17, 2014, 08:13:07 PM

can someone explain how mamu decided 20k ohm

That value is given in the datasheet on page 17 Remote On/Off Control (Negative).....

From Datasheet: "The On/Off pin should be pulled high
with an external pull-up resistor (20K ohms)."
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: jrweber02 on May 17, 2014, 08:33:17 PM
Thank you break must have skipped over that while going thru the sheet but this forman has helped tremendously on my road of modding and I thank everyone in here
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 18, 2014, 12:43:21 AM
The low voltage detector IC for UVLO is too teeny tiny for me to work with.  I ordered 3 different ones and they are all too tiny I can't even mount them on a stripboard as the pins are too close together, so they require a proper PCB to mount on. 

I'm doing the next best thing then and installing a low voltage indicator with the OKL2-T20.

I'm using the LTC1440 to monitor batt voltage - it has an ultralow 4uA standby current.

I wired it for a 6.2v low voltage indicator.  If the batt's voltage is >6.2v, the red LED does not light.  When the batt's voltage is at or less than 6.2v, the red LED lights telling me it's time to charge the batts.  The red LED has a sharp 6.2v turn on - no tweens and no dimming. 

Here's a link to the datasheet: http://cds.linear.com/docs/en/datasheet/144012fd.pdf (http://cds.linear.com/docs/en/datasheet/144012fd.pdf)

Here's the schematic...
(http://www.mamumods.com/pics/ltc1440-wiring.png)

Here's what it looks like breadboarded... the voltage is set at 6.2V on my DC power supply, the red LED lights...
(http://www.mamumods.com/pics/ltc1440-1.jpg)

Here's what it looks like with everything tucked under the IC...
(http://www.mamumods.com/pics/ltc1440-2.jpg)

Here's the parts list... you could use 1% resistors if you choose, but I used 5% without issue (maybe I was lucky? :laughing:)...
(http://www.mamumods.com/pics/ltc1440-3.jpg)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 18, 2014, 03:01:46 AM
ERMAHGHERD <3 mamu, fantastic development right there.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 18, 2014, 03:48:14 AM
Was wondering if a 22k ohm would work instead of a 20k

Yes, it would.  That value is not critical, should be able to range from 10 to 47k without issue, it's only a pull-up or pull-down resistor depending on the regulator part number (postive or negative logic for the control pin).

The low voltage detector IC for UVLO is too teeny tiny for me to work with.  I ordered 3 different ones and they are all too tiny I can't even mount them on a stripboard as the pins are too close together, so they require a proper PCB to mount on. 

Sorry to hear that part didn't work out for you mamu.  You may have to get into making PCBs at some point.  I don't know if you've looked into it, but I'm sure you'll wonder why you didn't try it sooner once you get into it.  The hardest part is getting a clean toner transfer to the copper clad.  After that there's no trick to it.  You can reflow solder your parts onto the board in a frying pan, no problem.

Oh, BTW, if you plan on trying your hand at making PCBs, don't throw away those Elle magazines.  They're made with the best toner tranfer paper I've ever seen, even better than the stuff you buy made for that purpose.  I have a whole stack of those mags I save for making PCBs.


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on May 18, 2014, 06:42:16 AM
The low voltage detector IC for UVLO is too teeny tiny for me to work with.  I ordered 3 different ones and they are all too tiny I can't even mount them on a stripboard as the pins are too close together, so they require a proper PCB to mount on. 

I'm doing the next best thing then and installing a low voltage indicator with the OKL2-T20.

I'm using the LTC1440 to monitor batt voltage - it has an ultralow 4uA standby current.

I wired it for a 6.2v low voltage indicator.  If the batt's voltage is >6.2v, the red LED does not light.  When the batt's voltage is at or less than 6.2v, the red LED lights telling me it's time to charge the batts.  The red LED has a sharp 6.2v turn on - no tweens and no dimming. 

Here's a link to the datasheet: http://cds.linear.com/docs/en/datasheet/144012fd.pdf (http://cds.linear.com/docs/en/datasheet/144012fd.pdf)

Here's the schematic...
(http://www.mamumods.com/pics/ltc1440-wiring.png)

Here's what it looks like breadboarded... the voltage is set at 6.2V on my DC power supply, the red LED lights...
(http://www.mamumods.com/pics/ltc1440-1.jpg)

Here's what it looks like with everything tucked under the IC...
(http://www.mamumods.com/pics/ltc1440-2.jpg)

Here's the parts list... you could use 1% resistors if you choose, but I used 5% without issue (maybe I was lucky? :laughing:)...
(http://www.mamumods.com/pics/ltc1440-3.jpg)


never mind.lol..i got it.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 18, 2014, 08:39:28 AM

hi mamu just wondering why do you need this for? if probely stupid question but im to lazy to make calculation right now..so if your battry gets to lower than 6.2 how many volts  left in your battery each?(single bat)

The bully in school would beat you up for this question. lol
I have laid some but whoa that wins an award...  :thumbsup:

Craig stop recommending those lil bitty things, you make it seem like us noobs can do em  :wallbash:  wow if Mamu says their that tiny whoa..
I was gonna try em too phew.. almost check a guys certification almost before recommend lol  im kidding but .......

Awesome Mamu thats an easy peasy there

So it will blink bright when vape sag then pop on constant when fully @6.2v -- kewl
$5.61 parts count your richums  :thumbsup:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 18, 2014, 11:15:10 AM
I know, Craig - I really should learn to do it.  It would be great to have a tiny board and have all smt parts and then just run the wires. 

It's even easier since oshpark.com (http://oshpark.com) will make the PCB for you based on your design and the prices they charge aren't bad - just need to upload your design file and there ya go.

lol Visus - I really did try to work with the voltage detector, but with pins 1,2,3 less than a half mm apart, it was too difficult.  And there aren't any in a bigger size at the cutoff volts I need - lol I spent a few hours looking.

And this is how tiny it is... don't drop one, you'll never find it  :laughing:
(http://www.mamumods.com/pics/voltdetector.jpg)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Jasen on May 18, 2014, 01:02:29 PM
That's small even before you factor in the picture, for me anyway, is about 2:1
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on May 18, 2014, 01:34:06 PM
I know, Craig - I really should learn to do it.  It would be great to have a tiny board and have all smt parts and then just run the wires. 

It's even easier since oshpark.com (http://oshpark.com) will make the PCB for you based on your design and the prices they charge aren't bad - just need to upload your design file and there ya go.

lol Visus - I really did try to work with the voltage detector, but with pins 1,2,3 less than a half mm apart, it was too difficult.  And there aren't any in a bigger size at the cutoff volts I need - lol I spent a few hours looking.

And this is how tiny it is... don't drop one, you'll never find it  :laughing:
(http://www.mamumods.com/pics/voltdetector.jpg)

The LTc sizing  is how I imaged it in my head from doobe's drawing that is uber tiny and to think it cut volts loaded

This is how imagined it should be wired:

(http://i860.photobucket.com/albums/ab167/doobedoobedo2/mosfetswitchwithvoltageprotection_zpscf2df0e9.jpeg)

Fixed the wiring
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 18, 2014, 03:40:49 PM
It's even easier since oshpark.com (http://oshpark.com) will make the PCB for you based on your design and the prices they charge aren't bad - just need to upload your design file and there ya go.

For sure, Osh Park is like my most valued supplier on the internet.  Just amazing the prices.  PCBs are like throw-aways for me if I want to change something, no biggie to re-order.  So yeah, that makes it even easier if you order out for PCBs.  The only problem is there's about a week lead time for the 2 layer boards, about 2 weeks for the 4 layer boards.  But hey, how much is your time worth.

I do a mix of boards I make myself and ones I order out.  The simple one layer boards that only contain a few components I do myself since I can make those pretty quick and easy, the more complex 2 and 4 layer projects I order out.

The software is not a biggie though there's a bit of a learning curve that can lend to some frustration.  CadSoft offers a limited free version of Eagle that can do anything you need for small 2 layer projects and it's a professional level program; 

http://www.cadsoftusa.com/download-eagle/?language=en
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on May 18, 2014, 04:40:24 PM
The LTc sizing  is how I imaged it in my head from doobe's drawing that is uber tiny and to think it cut volts loaded

There's probably 100 transistors on the little chip die for that tiny part.  Since currents are very low normally, they don't need big pathways for currents in there.  I think the limit is about 50mA on the reset pin so that detector could power an LED, but that's about it. 

The intent is only to provide a logic signal to another chip so it doesn't need to put out much power.  The currents required to supply signals like that are generally negligible.  The power consumption on that part is very small, it draws only about 150nA as in billionths of an Amp.  A watch battery could power it for 100 years, of course the battery would expire long before that.

The processes used to make chips are pretty amazing.  Some chips use current pathways only atoms thick.  They've actually hit the physical limit there and a new technology is required to move forward.  Right now, chip dies are as small as they can be and still conduct electricity.  There's all kinds of theories on things like quantum states and optics in further reducing the size, it's all pretty far out there.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on May 23, 2014, 02:03:48 AM
@mamu What size box do you use? I got one its Hammond 1591ATCL Translucent Polycarbonate Project Box -- Inches (3.9" x 2" x 0.8") . Got it on amazon. Do you recommend a size? This one seems a little small but this is my first time building a mod period so idk whats a good size. Im familiar with modding as I used to do xbox 360 and install mod chips and such so Im not new to everything exactly
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 27, 2014, 01:36:05 PM
@Deleon209 - Fitting everything into a 4x2x.8 box is tough :P Good luck, I have mine in a box that size, and the 18650s have to be hand wrapped and taped to the contacts, no battery tray will fit.

@mamu - You weren't kidding about how hard this hits. I had to turn voltage down to 3.9 output, where i am used to using fresh VTC 5s on my mechs. Anything over 3.9 v on any of my tanks overwhelms their ability to wick, and I am talking about some great wicking tanks, Taifun GT, Kayfun 3.1, Expromizer etc.  Fantastic mod!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on May 27, 2014, 03:20:31 PM
@claviger
What's a good box and size? Dimensions or link would  be much appreciated. I usually order my boxes from Amazon but if you know a cheaper site in USA with cheap shipping let me know. Thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 27, 2014, 05:41:50 PM
I would suggest 4.5x2.5x1 ish boxes. Hammond 1590B series is in that ballpark. It will still be a tight fit, but give enough room to get a box in for batteries.

digikey, mouser, amazon all have them.

The other route would be fastech using one of these for cheap as chips nice aluminum boxes:

1 x 100*76*35mm Aluminum External Enclosure Case for Electronics DIY black
1 x 100*66*43mm Aluminum External Enclosure Case for Electronics DIY black
1 x 100*76*35mm Aluminum External Enclosure Case for Electronics DIY gold
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on May 27, 2014, 05:59:15 PM
Thanks I've ordered a few boxes before I finally found out what was the right size. Now I gotta order another one and wait. This will be my first boxmod then I got 5 raptors waiting so I'll build this one then move onto those.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on May 27, 2014, 06:24:25 PM
I got some fatdaddy vapes mod Connector 510 but I got a graveyard of parts so I have some topcaps for a hammer Chi you nemesis and I wanted to know if I could just use those and solder to it like I would a reg 510??? I'd rather use a copper contact one then a basic 510.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 28, 2014, 02:56:26 AM
You absolutely can use them. Just look up how to solder to steel if they are steel to ensure a good contact.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: JUICYOHMS on May 30, 2014, 11:19:25 PM
Very Nice...I'm getting ready to build a Box mod using this chip, but would like to use the same pot & knob the the AXIS box mod uses...Does anyone know which kind it is or have a part number handy for that particular POT/KNOB setup...
Thanks in advance for any help & these diagrams are very helpful.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Jasen on May 31, 2014, 12:27:56 AM
Juicy, the fire switch on the axis mod just looks like a anti vandal switch. The POT knob may just be just that, a knob that might fit any number of POT's.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 31, 2014, 01:37:29 AM
Juicy - I used these on my OKL2.  Used a 2.2k ohm pot and 1.43k resistor for the circuit, gives right around 2.5 - 5.6 volt control. Looks very similar to the Axiz mod pot, works great, fantastic quality, will be using them in all box modes that I make in the future, both for my own and for others!!

Yes they are pricey.

http://www.digikey.com/product-search/en?v=716&FV=fff40004%2Cfff80335&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

Parts list for my 20amp mod:
http://www.digikey.com/product-detail/en/P16NP222MAB15/P16NP-2.2K-ND/1587862
https://www.fasttech.com/p/1258801
http://www.fatdaddyvapes.com/shop.html (The new one with 22mm washer)
Radio Shack switch :P
1.43k resistor
4x22u caps (2 input, 2 output)
20 gauge
On/Off slide switch

No screen, no reverse polarity protection, no voltage cut.  Some of the better modders may be able to fit it in that box, but I could not. Great mod for myself, but wouldn't give to anyone else.

What amazes me, is that at 3.7 volts my Kayfun hits easily as hard as it does off a Penny Mod (pure copper mech with the lowest recorded drop) using a fresh charged VTC-5!  In fact, the only tank I have that can consistently wick fast enough over 4 volts is my Expromizer.  .69 and .74 ohm builds respectively.  VV mods have now replaced all my mechanicals! 

After typing the above I decided to try my Stillare at .28 ohms dialed up to 5.5 volts........ really bad idea raged:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on May 31, 2014, 03:12:36 AM

Check out the XXIX 29 mod by BCV 18650 no voltage drop at all.
What amazes me, is that at 3.7 volts my Kayfun hits easily as hard as it does off a Penny Mod (pure copper mech with the lowest recorded drop)

I love that hot hot vape! Deserty flavors though a hot fruit vape isnt tasty
After typing the above I decided to try my Stillare at .28 ohms dialed up to 5.5 volts........ really bad idea raged:

Check out the XXIX 29 mod by BCV 18650 no voltage drop at all and I love that hot hot vape! Deserty flavors though a hot fruit vape isnt tasty  freaked_out:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: JUICYOHMS on May 31, 2014, 03:22:18 AM
AWESOME GUYS...MUCH APPRECIATED FOR THE DETAILED & QUICK RESPONSES...:-)
\M/
Sincerely...
JU-C
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 31, 2014, 06:45:52 AM
I revised the OKL2-T20 wiring guide to more of a schematic type and already I get a request to bring the old one back lol.

I don't like the huge Hammond cases, so I used my Sam case (2x C battery box - 83mm x 57mm x 30mm) and it's fully loaded with P-FET, fuses, low battery indicator, voltage reader, Keystone contacts, fatdaddyvapes new 510 connector, etc.  :yes"

The OKR board and wiring would have fit much easier in Sam - Raptor maybe - but with some creative packing and wiring, I got the OKL2 to fit - just barely.

What I've noticed most about this OKL2-T20 is that the batts last forevah between charges!!  Much much longer than vaping same voltage, same coil, as with my Raptor and my OKR mods. 

After the funky start I got with the breadboarded feedback loop, it's turned out to be quite a champ in the vape dept.

This is called space management :laughing: ...
(http://www.mamumods.com/pics/sam-okl-1.jpg)

I sanded then swirlified the case using a 1" mandrel and scotch brite pads on the drill press...
(http://www.mamumods.com/pics/sam-okl-2.jpg)

More hand friendly for me than the big Hammond cases...
(http://www.mamumods.com/pics/sam-okl-3.jpg)

(http://www.mamumods.com/pics/sam-okl-4.jpg)









Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: JUICYOHMS on May 31, 2014, 08:42:12 AM
Question about the chip description on MOUSER. They offer this in a Neg Pol Seq  &   Pos Pol Seq....As MAMU stated the Neg Pol Seq was used for this design.
But Does someone know which would be more preferred, what the difference is and could you use either if stock gets low on one or the other?
Thanks again...
\M/
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 31, 2014, 03:18:55 PM
Neg/Pos doesnt change much except the ON/OFF switch wiring.  The details on it are in the datasheet if I recall correctly, it's not a huge change.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on May 31, 2014, 03:33:20 PM
(http://i195.photobucket.com/albums/z226/tcclaviger/IMG_20140531_092741_zpsddc078c1.jpg) (http://s195.photobucket.com/user/tcclaviger/media/IMG_20140531_092741_zpsddc078c1.jpg.html)

(http://i195.photobucket.com/albums/z226/tcclaviger/IMG_20140531_092758_zps76e066b0.jpg) (http://s195.photobucket.com/user/tcclaviger/media/IMG_20140531_092758_zps76e066b0.jpg.html)

Not much of a Hammond box fan myself already. They have a somewhat awkward H/W/D ratio for me. Plenty of other boxes out there that feel better in the hand!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on May 31, 2014, 04:51:08 PM
Nice Claviger. Thanks for sharing
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on May 31, 2014, 05:24:42 PM
Nice box kinda reminds me the size of my DPM box I had. I'm thinking of using the Hana mod clones box. Only one battery tho but it's Prewired with battery contacts and 510 ready to go.  There about $20ea but I gotta buy $200 worth so idk maybe if more people want I will get some. Only thing is only 1 battery (http://i.imgur.com/j06RQF8.jpg) (http://i.imgur.com/DY47tMf.jpg)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 31, 2014, 08:53:52 PM
I keep dreaming some day we'll have a teeny tiny OLED like the DNA that displays watts, ohms, volts, batt status, and it's already programmed for use and we just hook it up with our buck converter.  We'd be able to have the works and in a smaller case.  The demand for that would be huge.

I kept dreaming of a quality ss never fail 510 connector and at what I could afford and that came true, so who knows. 


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on May 31, 2014, 11:47:33 PM
Well, so much for having put a low battery indicator in Sam.  I placed the LED above the fire button so I would be sure to see it when it lights and hadn't had a problem with seeing it when it lights, but this time I wasn't paying attention to it or checking the voltage reader was kinda chain vaping and saw the red LED too late - neg batt = 2.6v, pos batt = 3.1v.  ugh.  That neg batt really takes a beating when input volts is low.

On a bright note - I got THIS (http://www.ti.com/lit/ds/slts252k/slts252k.pdf) today to tinker with - programmable UVLO.  sweet!

and tiny footprint for a 16A 88W module...
(http://www.mamumods.com/pics/221-1.jpg)





Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 01, 2014, 03:20:44 AM
Brilliant find!  Allows reduction in component count off the PCB :P

That data sheet on it is incredibly thorough, even for TI!  Definitely building this one!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on June 01, 2014, 03:52:54 PM
Nice looking part.  TI always makes the good stuff.  I'm waiting on a 4 switch buck-boost controller they're supposed to be releasing soon.

TI always publishes really nice data sheets.  Them and Microchip always publish the best ones.  My two favorite component makers are TI and Microchip because they make stuff that works well, but also because they have really good data sheets.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on June 01, 2014, 04:10:36 PM
I keep dreaming some day we'll have a teeny tiny OLED like the DNA that displays watts, ohms, volts, batt status, and it's already programmed for use and we just hook it up with our buck converter.

The thing is the components you need for a gauge set are going to cover what you need for a whole controller board.  Just add a digital pot and develop the MCU program, you're good to go.  So, if anything, you would possibly see complete controller boards that utilize a power module like that one.  People are making them already, but they're selling the whole mod, not the board a la carte. 

It's possible you might see a gauge set like that from a hobby supply, but they tend not to miniaturize things the way you need for an e-cig.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 01, 2014, 06:03:38 PM
Nice looking part.  TI always makes the good stuff.  I'm waiting on a 4 switch buck-boost controller they're supposed to be releasing soon.

TI always publishes really nice data sheets.  Them and Microchip always publish the best ones.  My two favorite component makers are TI and Microchip because they make stuff that works well, but also because they have really good data sheets.

The datasheet for this converter is awesome - I've read through it at least 6x now to make sure I didn't miss anything and think I've got it figured out. 

I emailed TI tech support with a few questions and am waiting to hear back.

Although it has programmable UVLO (I'm setting it at 6.4v and testing with that), I don't know if there is something onboard that also stops idle current drain after that low volt cutoff. 

The datasheet took me back to the days when working with TI's PTR08100 converter - almost word for word with the inhibit pin.  I never used the inhibit pin with that converter though.  I wonder if anyone used that inhibit pin and with an N-FET to control it like the datasheet suggests or if an N-FET is really required.  The OKL2-T20 datasheet suggests an N-FET to control inhibit but I'm not using one and the converter is working aok.  I don't know enough about N-FETs controlling the inhibit pin though to say what the difference is with and without using one.

I did buy the suggested BSS138 though and it is soooooo teeny tiny and not doable, but I think I found a compatible one in a TO-92 package - ZVNL110A (http://www.mouser.com/Search/ProductDetail.aspx?R=ZVNL110Avirtualkey52230000virtualkey522-ZVNL110A)

This is the way I did the schematic for the N-FET:
Drain to inhibit pin
Source to ground
Gate to fire switch
Fire switch to ground

I haven't tested it yet though to see if that is correct.




Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on June 01, 2014, 08:43:45 PM
Its a still drawing mamu

"When the Inhibit control
is active, the input current drawn by the regulator is significantly reduced."

Substantial:
"The hysteresis voltage, which is the difference
between the ON and OFF threshold voltages, is set at 500 mV"
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on June 01, 2014, 09:00:19 PM
It reads to me as tho you can use it as on/off  or uvlo and not as both. 

time to breakout board a supervisory if using the inhibit.  woot

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on June 01, 2014, 09:23:29 PM
The enginners might give you some crap if you tell them you're using a mechanical pot with one.  The intent with the power modules is to fix the voltage with a normal resistor.  They don't design them for use with a variable resistor in mind, though there's never a problem when you do it.  The engineers still don't like it.

The part is still going to draw some current when disabled by the UVLO.  You'll have to measure it when you get one on the bench, shouldn't be so much that it will over-discharge the battery before you can attend to it.  The spec might be in the data sheet and it may be liberal.  You might find it draws less than specified when you actually measure it.

Concern about idle draw depends on how you fire the atomizer.  If using a switch on the main supply, the point is moot.  If using a tactile on the inhibit pin, idle draws becomes a consideration and possibly a problem.  If draw is under a mA, you're probably fine.  Consider a battery has at least a few mAh left when flagged so a draw of 1mA will give you a few hours to change out the battery before an over-discharge occurs.  If you get draw down to 100uA, then you have a couple days to change out a battery.

I didn't read the data sheet, but I expect the transistor performs the same function as a switch.  Though what the transistor does is mitigate the voltage bouncing that occurs when switch contacts make and break.  It may or may not be a problem for the regulator's logic circuits, but if it is, you can debounce the switch with a couple resistors and a capacitor.  Probably the same number of parts either way.  I would just go ahead and try a tactile there without any debouncing.  If it works without issue, it works.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on June 01, 2014, 09:52:51 PM
Craig it states do not use a pull up to debounce probably because it is dual use its either inhibit or UVLo pin.

It also had 500mv is always on if using the inhibit pin to help with soft start-up regardless if uvlo is active or not,  it didn't have the amperage listed..

So breaking vi would be my way of wiring using uvlo, so when she wont fire I know take out the batts but with using vi they are not being drawn anyway ..  :laughing2:


great find by Mamu I searched and searched, no other boards have a programmable uvlo in a package size we can use..
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 01, 2014, 11:18:28 PM
Thanks guys!

lol at the engineers getting cranky.  I won't tell them I'm using a POT then.  :laughing:

I'm going to try if first with just a push button switch then and see what's what.  Thanks for the explanation, Craig!

I was so hoping there was something onboard that would shut off the idle current drain after cutoff.  My logical self knew it, but my I really want this self is in denial lol.

A modder at ECF has a lipo mod with the Raptor.  He went on a 2 week vacation without the mod and came back to find the lipo batts drained and toast.  So a master kill switch is def needed with mods that use the inhibit and have lipo batts.

Visus - it's both inhibit and UVLO.  Read the datasheet p.8 Terminal Functions - Inhibit and UVLO.

When it says don't use a pull-up, it's talking about not using an external pull-up resistor as there's already an internal one.

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on June 02, 2014, 12:20:33 AM
Thanks Mamu just rambling trying to see with post if this all is making sense to me
nope
I was thinking also just throw in a nc tact sw using uvlo @8.5v shutdown as off/on
then Craig explained the switch debouncing and my brain exploded lol

Found standby current draw
Input standby current Inhibit (pin 11) to GND, Track (pin 10) open 5 mA
then when uvlo active
Input low current (IIL ), Pin 11 to GND -235 µA


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 02, 2014, 02:49:59 PM
So about the OKL2-T20.

After having it for awhile I have tried a few different matched sets of batteries with varying results, figured I would post them here. All batteries were bought in pairs and have been used on a rotational basis for the past 2 months keeping them fairly even in discharge/charge counts.  All the tanks I use I am also testing using apples to apples setups at .69 ohms single coil using 26 gauge kanthal a1, so the load is constant regardless of what i vape from.

2 x Sony VTC 5 2600 mah - Last two full days. I pull them and charge them every other night.  All three times I have done so, they have come out at exactly the same voltage. Usually they are around 3.4 volts each when pulled the second evening.

2 x AW 1600 mah - Have only used these once as they do not discharge evenly. From a full 4.21 charge they lasted me only about 8 hours and discharged at an alarmingly different rate. Once came out at 3.32 volts the other went down to 2.28! I did not expect them to die so quickly, and only pulled them when I noticed a change in the vape (sounded wierd).

2 x MNKE 1500 mah - Lasted about 10 minutes, had issues with the load. Didn't bother checking voltages as they did not function properly and went straight back to my wifes "approved for Volcano Lava Tube use only" stack.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on June 02, 2014, 06:29:01 PM
A modder at ECF has a lipo mod with the Raptor.  He went on a 2 week vacation without the mod and came back to find the lipo batts drained and toast.  So a master kill switch is def needed with mods that use the inhibit and have lipo batts.

Using a main power switch to fire the atomizer does simplify things, but then you're limited to a high power switch.  When using a regulator's enable/disable pin, there's always the idle draw you have to consider and it can be a real PITA to deal with.  It can be a source of issue if using a permanently mounted battery or if you simply don't want to remove batteries when the mod is not in use.

When they design these regulator modules, the intent for the enable pin is only to control the standby/shutdown function of the regulator.  There's not always a lot of consideration put into how much power is consumed when the regulator is not active.  Mostly these parts are used for devices running off utility power, not batteries.  Some regulators will drop current demand into the micro-Amps when in standby or shutdown, others into the milli-Amps.

They usually list current demands in various regulator states, let me see if I can find it for that part in the data sheet.  Okay, taking a quick look at the specs it looks like the standby current draw is 5mA.  Looks like what they've done is sacrificed a shutdown mode for the UVLO function on that inhibit pin.  So, that's going to be high for a discharged battery, but again, you should measure on the bench.  Sometimes those specs are liberal.

To resolve idle draw issues, you can use a main power switch to fire the atomizer and only use the inhibit pin for the UVLO.  You can always use a MOSFET and tactile if there's a problem in using a high power switch.  For a MOSFET switch, there's virtually zero current draw in the off state.  Well there is a little, but it's so small you can consider it zero.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on June 02, 2014, 06:49:38 PM
woot
I hit it on the nail, it says what you stated earlier about uvlo current draw probably being very low demand when uvlo is active
it has high mid and low current states listed

Input low current (IIL ), Pin 11 to GND -235 µA


when taking state license relaying data sheet and code are huge part of test
super fun when someone ask or need quest work on hopefully right when posting but your here to clear the way

i need to put page number  but never look at it , just scroll scroll oh there it is lol






Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: strugelabs on June 02, 2014, 11:16:47 PM
Will these 1.43k ohm resistors work instead of the ones mamu recommends/uses? http://in.mouser.com/ProductDetail/Vishay-Dale/RN55D1431FB14/?qs=sGAEpiMZZMukHu%252bjC5l7YYphdDAKSU4lHek%2fL%252berSWY%3d
They are out of stock everywhere for the ones mamu has used. :/
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 03, 2014, 01:09:52 AM
Nice find , strugelabs.  The resistor is good to go.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 03, 2014, 01:19:34 AM
I started a thread for this new converter: PTH08T221W - 16A 88W w/ UVLO... (http://breaktru.com/smf/index.php?topic=1261.msg14909#msg14909)

I didn't realize until breadboarding and seeing how it has to be configured with an NC switch that it might be a big pita just to get programmable UVLO. *sigh*
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: strugelabs on June 03, 2014, 01:24:35 AM
Great to hear! Also what does the amperage of the button mean? Do i need a higher amperage button for more watts my mod pushes out? Or does that have nothing to do with it whatsoever?  :beer-toast:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on June 05, 2014, 06:30:43 AM
ok so i put mine altogether and when i hit the master switch it gets so hot it melts the solder off the mosfet connection?? any ideas??
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on June 05, 2014, 04:01:05 PM
That's no deal.  You have a wiring error somewhere causing a short circuit.  Could be a failed or defective component, but more likely a wiring error.  You should probably replace that transistor.  When one melts the solder on the pins it's due to excessive current flow.  Likely the temperature of the junctions inside exceeded tolerance and it's a dead solider now.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MumsVapes on June 05, 2014, 04:55:58 PM
I'm new to all of this and thank you Mamu and all the rest of you guys for the pointers and tips on this topic. I've wired up the chip with all your guys recommended parts and it's working good from3.3-5.5 volts. My question is under a load of .42 ohms I'm seeing about a 1 volt drop when firing. I expect some voltage drop but a 1+volts? On my mechanical mod it is no where close to Half that. My question is is there something I can do in order to correct this? And what should I use? Thanks for all your knowledge
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on June 05, 2014, 05:37:09 PM
Here's my pics. Well after forgetting a certain sense wore I got the volt meter to display the battery voltage but it keeps refreshing and showing the voltage??? But now I can't get it to fire and show the output volts maybe the fire switch it's bad?
http://imgur.com/a/JWjxE
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on June 05, 2014, 05:47:10 PM
I couldn't tell you if there was a wiring error judging from the photos but the 1S6S DM that you are using pulses. It pulses for readings for 6 batteries and a total voltage of all batteries. I stopped using those 1S6S a long time ago. There are much better DM's available like THIS (http://www.ebay.com/itm/Mini-DC-2-5-30V-LED-Panel-Voltage-Meter-3-Digital-Display-Voltmeter-V20D-NI5L-/400690810002?pt=LH_DefaultDomain_0&var=&hash=item5d4b088c92)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 05, 2014, 06:56:21 PM
I'm new to all of this and thank you Mamu and all the rest of you guys for the pointers and tips on this topic. I've wired up the chip with all your guys recommended parts and it's working good from3.3-5.5 volts. My question is under a load of .42 ohms I'm seeing about a 1 volt drop when firing. I expect some voltage drop but a 1+volts? On my mechanical mod it is no where close to Half that. My question is is there something I can do in order to correct this? And what should I use? Thanks for all your knowledge

Only thing I can think of that your batteries are getting heavily loaded and they are sagging so low that the output of the OKL drops to maintain the 2 volt difference between input and output.  What batteries are you using and what voltage is the output set at?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: strugelabs on June 05, 2014, 07:02:44 PM
Breaktru have you ever used the drok volt meters? its the one i ordered. Ill post a link below.

http://www.amazon.com/DROK-Surface-Digital-Voltmeter-Detector/dp/B00C58QIOM/ref=pd_sim_sbs_e_9?ie=UTF8&refRID=1MVG7GQJR40DF8VAYKJT
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on June 05, 2014, 07:46:49 PM
Thanks now I know not to use those. And everything I used was from mamus list of parts so nothing different.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on June 05, 2014, 08:31:19 PM
Thanks now I know not to use those. And everything I used was from mamus list of parts so nothing different.

It's not they are bad meters, just irritating
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on June 05, 2014, 08:34:37 PM
Breaktru have you ever used the drok volt meters? its the one i ordered. Ill post a link below.

http://www.amazon.com/DROK-Surface-Digital-Voltmeter-Detector/dp/B00C58QIOM/ref=pd_sim_sbs_e_9?ie=UTF8&refRID=1MVG7GQJR40DF8VAYKJT

I can't say I used that exact meter but have used similar 3-wire meters. Just know that they need a power souce. Black to negative, white or green to voltage being read (output) and red to battery positive
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on June 06, 2014, 01:58:07 AM
i removed capacitors works fine now...is that really that bad to run that way???
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 06, 2014, 01:32:13 PM
i removed capacitors works fine now...is that really that bad to run that way???

Are you referring to the voltmeter as being bad to run that way?  There's nothing "bad" about the voltmeter pulsing, it's just the way that voltmeter works and has been used in hundreds of mods over these last years as that's all we had.  But the new voltmeters are preferred nowadays for the smaller size and steady on display. I really hadn't payed attention to them as I have a stash of the 1S-6S.  But I need to update my guide to just say "Voltmeter". 

If you're referring to the caps as being bad to run that way - it's good that you took them out so not to cause any more damage to the electronics.  Your picture shows the caps wired in series, well not really since you have nothing wired on either end but only where they connect in the center. 

The caps are suppose to be wired in parallel like you did with the fuses.

(http://www.mamumods.com/pics/I5.jpg)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on June 06, 2014, 02:37:56 PM
@mamu
I was referring to the input/output caps after I removed it fires fine now. But after what you said from the pic it's probably because I didn't do them right. I was Confused on how to do them parallel and solder properly. Do you have a pic of how the capacitors look wires for the input and output? The 4x ones in parallel really threw me off.  Doh:  that and the wiring for them I'm a Lil confused about to. I tried to look at your pics to see exactly but the schematic changes the way it's ran and the old one makes it look like it's separate from the connection. When I get home from work I'll post a pic to show you what I mean.
Thanks everyone for the help on here I appreciate it.
My first box tho I went for this one first before a okr. Now that I got the hang of it somewhat I'm gonna start making one of each type possible to really master this.

A few questions to.
Go with the black panel or clear to see the LCD ??


http://imgur.com/beCFLnQ
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on June 06, 2014, 02:54:19 PM
@mamu
I meant was it bad to run it without the capacitors not the 1s-6s. It's fine that it pulses I got used to it. For some reason though I can't get I  to display the output voltage when I fire it. It works but it doesn't.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on June 06, 2014, 03:20:05 PM
Caps are opposite of resistors, they subtract in series and add in parallel.  So putting them in series would make them less effective.

In any case, input and output caps are optional for the OKL, it already carries them on the board.  You can run additional ones or not.  Too much capacitance on output can impact regulator performance.  There is a limit and it's specified in the data sheet.  For low ESR caps like the ceramic ones, it's only 1000uF if you look under capacitive loading in the data sheet.  Input is less sensitive to additional capacitance than output, but I wouldn't go overboard there either.

I would probably not run additional caps if they are not required.  No sense adding to the part count and expense if you don't have to.  In doing my own PCB designs, it's not unusual for me to alter the design when possible to eliminate a part here or there.  Part counts always add up fast.

My general attitude is never add parts if you don't have to.  The more simple a design and the fewer parts it requires the better.  That's not to say you should eliminate parts if you have a need for them.  Additional output and input capacitance can be a benefit, but t's not possible to say how much without some bench testing.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on June 06, 2014, 03:25:28 PM
I know parts start adding up fast $$$ I lost track of all the stuff I ordered and it was $300. I got plenty of parts but just saying if I could knock that down a Lil why not
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on June 06, 2014, 03:41:14 PM

http://imgur.com/beCFLnQ


Looking at your internals, I would strongly suggest using heat shrink over your bare wires. Especially in a metal box. Things can get moved around if banged, dropped, etc...
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on June 06, 2014, 03:52:03 PM
Mines a plastic abs box. Also I was gonna use some liquid electric tape on the metal parts. It's not done I just was putting it in there to see where to place it best and how I'm gonna run it.

Also there's only two capacitors so there's only like 1 way to do them really since there's only metal on two sides of the cap..   If someone can poet a pic showing me how you do yours in parallel.
Also I seen a Lil tray on mouser for adding multiple caps you just slide then in. It holds about 3-4 caps and it's stacked on top of each other. Pretty cool idk if that would solve the problem  or not. I'll post pic if I find it again
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on June 06, 2014, 04:37:47 PM
@ Deleon you must tell me where to find that enclosure I so wanna an infinity box mod.  I just learned how to make an infinity mirror, and wanna infinity button area and that box would be the sauces..  Thanks

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on June 06, 2014, 05:18:13 PM
What's a infinity box mod? Or infinity anything Ive never seen one or heard of it. Post a pic. What I did was get a plastic black Hammond enclosure and a clear enclosure and swapped the covers on them. U could also get a metal enclosure and a clear one and use the clear door on the metal one.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on June 06, 2014, 07:35:59 PM
Thank ya lol didn't see it to be that, thought it was a new enclosure I have not seen yet --duh'.  :thumbsup:


No one has an infinity mod yet or enclosure,  I wanna make it so when I vape, it will light up either the whole mod or just the area around the button with an infinity mirror.  Great for parties mod type mod..  Huge douche yeah  i vape mod  :fun:...

It wont have as much depth but will be just as cool..
https://www.youtube.com/watch?v=FT2PmyD9fJU
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 06, 2014, 08:40:47 PM
I've been adding 2x 22uF parallel input caps and leaving off the output caps.

This is what the datasheet says about caps for the OKL (p.4 Note #1)...

"All models are tested and specified with external 188?F ceramic output capacitors and a 44 ?F external input capacitor. All capacitors are low ESR types. These capacitors are necessary to accommodate our test equipment and may not be required to achieve specified performance in your applications. However, Murata Power Solutions recommends installation of these capacitors."

...Also there's only two capacitors so there's only like 1 way to do them really since there's only metal on two sides of the cap..   If someone can poet a pic showing me how you do yours in parallel

For ceramic caps, stack one on top of the other, silver ends matching, solder the silver ends together on each side.  Then if you can't attach the caps directly at the board, solder a piece of wire to the silver ends.

Like this, but I soldered the caps directly to the board so didn't need a wire on each silver end...
(http://www.mamumods.com/pics/221-5a.jpg)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: deleon209 on June 08, 2014, 06:10:02 PM
@mamu  :thankyou:
Now I see thanks idk why I do didn't think of that way I just figured the Caps all he had to touch each other.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 09, 2014, 05:58:15 AM
I know you were looking for something like this mamu. 40 bucks, but allows for all kinds of fun features if you get creative with it.  Arduino is not terribly hard to learn and you will be able to do things like build in all the function of DNA/SX chips and then some!

Doing some rough math based on what I can find for power draw while running simple code, a single 3000 mah 18650 will run it for 461 hours so while power draw is not negligible, it is not a deal breaker!  Thinking this device tied to a OKL2-T20 with microview controlling the on/off pin. Then you could still use a analog pot if you want and have the microview read voltage or use a digital pot for control.

Anyway, just thought I'd mention it as a possible solution for a nearly ready to go OLED for DIY mods.

https://www.kickstarter.com/projects/1516846343/microview-chip-sized-arduino-with-built-in-oled-di
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 09, 2014, 08:50:55 AM
This has become a bit frustrating for me.  I was asked to do a schematic version of the wiring for this converter.  I thought well ok I hadn't done that before but sounded like a good idea and I can take the time to do that if that's what people want, but I'm receiving more and more requests to bring back the picture wiring guide.

So I brought back the picture wiring guide.  For those who wanted the schematic wiring guide it is here... OKL2-T20 wiring guide (http://www.mamumods.com/forum/index.php/topic,721.0.html)

I've already spent way too much time on this, so this is final.  And my comment in a previous post wasn't a knock on anyone as I wouldn't do that, it was me shaking my head that I obviously can't please everyone.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 09, 2014, 08:53:38 AM
I know you were looking for something like this mamu. 40 bucks, but allows for all kinds of fun features if you get creative with it.  Arduino is not terribly hard to learn and you will be able to do things like build in all the function of DNA/SX chips and then some!

Doing some rough math based on what I can find for power draw while running simple code, a single 3000 mah 18650 will run it for 461 hours so while power draw is not negligible, it is not a deal breaker!  Thinking this device tied to a OKL2-T20 with microview controlling the on/off pin. Then you could still use a analog pot if you want and have the microview read voltage or use a digital pot for control.

Anyway, just thought I'd mention it as a possible solution for a nearly ready to go OLED for DIY mods.

https://www.kickstarter.com/projects/1516846343/microview-chip-sized-arduino-with-built-in-oled-di

That is really really cool!  Kind like a dream come true I was wishing for.   :yes"
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on June 09, 2014, 12:29:41 PM
https://www.kickstarter.com/projects/1516846343/microview-chip-sized-arduino-with-built-in-oled-di

That's a really cool part. 

Should be able to put it into a sleep mode when idle that draws very little current.  That's something the MCU handles and they all have that mode available. 

For use in a mod, you could strip the enclosure probably.  Also should not be a problem to interface a digital pot with it, provided you can handle the assembly.

Though it's a bit pricey, but already having the display saves a lot of work and expense.  Probably couldn't make one yourself a whole lot cheaper. 

Wish I could find those displays they use in those, really hard to find tiny surface mount ones like that in small quantity, the off-the-shelf ones all use those damn FPC cables.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on June 09, 2014, 12:57:38 PM
I ordered the micro view several weeks ago just to play with
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on June 09, 2014, 03:06:08 PM
@ Break and Craig, Clav
Anyone else that can power and educate these displays, they are awesome


(http://www.oled-info.com/files/eMagin-XGA096-OLED-XL-img_assist-349x192.jpg)

http://www.oled-info.com/emagin-officially-announces-their-xga096-oled-microdisplay-evf-applications


Industry:
http://www.oled-info.com/tags/oled_display_modules


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 09, 2014, 11:35:17 PM
Ok all interested, I had a bit of an epiphany today!  Not sure it will work but the OKL2-T20 has a bunch of features that would mesh with the Microview perfectly.

It can set output voltage based on an analog input voltage signal. That means you can use the microview and a up/down button to adjust voltage and forgo the POT if you wanted to.  If you wanted to make a box mod to end all box mod power races, the OKL2 also has sync available via an external pin, so you could use one of the Microview PWM channels to feed the synchronization signal to paralleled OKL2s for 40 amps of potential output power!!!

Also, brainstorming/searching last night, I found a very simple OHM measurement circuit and code that are verified to work, so there is that.  Then I found that you can measure voltage via an analog input, so there is that. From there it is a simple piece of code to figure out watts.  A step further and if you are using the Microview to control the OKL2 voltage vs the extra input pin it has, you can do VV/VW with the microview paired with an OKL2, in theory, pretty easily!

All in all, once the code is written and the first sample built, this may end up being an easy drop in solution for the DIY VV/VW with literally unlimited power potential available. 

There is a tiny $10 arduino, the Pro Micro which as a built in USB, that has all the same functionality but is missing the display. The displays on the Microview I found for $2.10 from china, exactly the same display.  The code to drive it is readily available. So what is missing? The IO board for the dispaly, also, readily available for under $4. It would seem, you could build a very close aproximation of the Micro view for $16.10 plus shipping and some soldering !!!!

One other pretty sweet feature...

You can measure the VCC voltage supplied to Arduino referenced to a very accurate 1.1 volt internal signal.  That means you could power Arduino off of the 18650s, and it can monitor input voltage so if voltage ever falls below X (whatever you set it at) it will not fire the atomizer, but will still let you use the interface so you know it is working, just needs a recharge.  It can also give you realtime monitoring of input and output voltages so you can watch what the sag is on both input and output.  Now to figure out how to recharge the 18650s via the onboard USB... last piece I am not sure about. Charging solution worked out using a very simple circuit to charge series 18650s safely.

All the arduino capabilities eliminate the need for nearly all the external parts of the OKL2 setup. 

Recap: $20 in batteries, $12 OKL2, $16 Arduino micro pro usb, $20 for extra whatever.  Roughly 58 bucks that can kick the crap outa any commercially available box mod!

eh eh, pretty neat!

TL/DR: My inner nerd is raging and excited at the possibilities of a tine arduino / OKL2 hybrid box mod lol.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: shandy27 on June 10, 2014, 05:38:49 AM
I found a 0.5" display for £15 from chine including the interface board for the arduino micro.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on June 10, 2014, 08:32:20 PM
@ Break and Craig, ClavAnyone else that can power and educate these displays, they are awesome

That first one is just a color OLED with really tiny pixels.  Those transparent ones are also color OLEDs but they have a transparent substrate.  Both are pretty amazing.  I've seen the transparent color OLEDs in action and they are extremely cool looking.  They've actually been around for a few years now.

The problem with OLEDs for me personally when used in an e-cig mod is they are not readable in direct sunlight.  I had that problem with the first mod I built, went to look at it outside and I couldn't see the display.  Now I stick to an FSTN display that is perfectly readable in direct sunlight.  Unfortunately it seems FSTNs are falling out of favor for OLEDs so I may never see one smaller than the one I'm using now.

In terms of using the Micro View, I didn't read a data sheet on it, but I expect it gives you access to all of the MCU I/O pins.  In that case you're only limited by what you can do with any function provided by the MCU.  After that, the limit is your imagination.  You should be able to do whatever you want with it, even interface a Bluetooth or an accelerometer if you want.  You could put a GPS and Bluetooth chip in there which would allow you to track your e-cig using a phone app.  That's something I could really use, always misplacing the damn thing.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on June 10, 2014, 09:52:58 PM
Yeah the second one on industry page supposedly has whats called 1000nits and is the new bright oled viewable in sunlight.

They state
Quote
Such a high brightness OLED offers unparalleled clarity in direct sunlight.
hope its true, but real world sometimes offers less than corporate ad statements.

That tiny color unit would be the bees knees in mini mods lol my infinity mirror idea e cig,  it can do it...

A few pages down theres a resistive touch unit that also is cool

http://www.oled-info.com/osd-displays-announce-15-resistive-touch-pmoled-display
(http://www.oled-info.com/files/images/osd-touch-1-5-inch-pmoled-img_assist-300x169.jpg)

If I had ur skillset I would have some of the silliest mods if time permitted,  that skill-set demand must be exhaustive if working for the man, sole p,  or inc.  :laughing:  So much tech today

Sorry went ot just ramblin  :laughing2:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on June 10, 2014, 10:22:59 PM
Yeah the second one on industry page supposedly has whats called 1000nits and is the new bright oled viewable in sunlight.

That's a pretty bold statement for anything powered by low currents.  The brightness of sunlight hitting a surface is probably tens times greater than the brightest OLED displays I've seen as of yet.  Advertisers do like to make unfounded claims so you have to take it with a grain of salt, maybe on a cloudy day, but that would be the extent of it.  Though I could be proven wrong about that, wouldn't be the first time.

In any case, if someone makes a display that can run on supply currents under a few hundredths of an Amp and still be well visible in direct sunlight, I'll use it, I don't care what type it is.  At this point, it's only FSTN and it runs on very low currents, under a mill-Amp, though they require backlighting when there's low ambient light and backlights draw around 20mA.

If a display draws much over 20mA, I can't use it.  Well I suppose I could, but that's a lot of current relative to the rest of the logic circuits.  Hehe, I'd need two power converter's, one for the display and one for the atomizer.  A high power LED flashlight is visible in direct sunlight, but those draw Amps, not milli-amps, that's the rub.  If power consumption is not an issue, I'm sure it's possible to make a sunlight visible OLED.  But then who's going to use a display that consumes 5 Watts unless it's for a billboard or something, certainly not for anything battery powered.


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 10, 2014, 10:30:12 PM
1st version of the code is written to do the following (still need to get it display on an LCD instead of the computer monitor :) );

Monitor battery voltage and display it on the screen when the fire button is in the off position.
Monitor Atomizer voltage and display it on the screen when the fire button is depressed.
Check the resistance of the coil when a 2nd button is depressed or switch thrown depending on your hardware. the fire button is pressed and released 3 times.
calculate the wattage of your vape and display it on the screen when the fire button is depressed.

Will be expanding on it to provide more function such as battery charge % and hard lock out of the OKL turn on circuit when battery voltage is equal or lesser than 6.4 volts.  This would provide the ON - ON - ON then straight off like the provari without the oscillating that dc-dc converters get when the battery is nearly dead.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on June 11, 2014, 03:37:30 AM
Clav that will rule in the high power hobby modding world

 freaked_out:

 ;hubba;

IDK if you know, Craig taught us when using a display it usually has capacitive touch function so that as well..

http://breaktru.com/smf/index.php/topic,1037.msg10785.html#msg10785
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 11, 2014, 03:58:33 AM
Enjoy. Drop in arduino code to do all things a mod must do at a minimum imho. More will come later, but that is what I got done in a couple hours of self education :P
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 11, 2014, 03:59:16 AM
//Developed in a day by Rob Smith 2014.  Distributed under GNU public license, share this as you please and I don't care about credit :P
//Version 1.2
//Tested to work only a simulator and not on a real Arduino, however it should work just fine.
//LCD is for a 16x2 using the standard LiquidCrystal displays (LCDs) based on the Hitachi HD44780 (or a compatible) chipset, which is found on most text-based LCDs.
//Ohm measurment circuit is designed to run from the +5v to a 50 ohm resistor to analog input 1 then to the atomizer then to the arduino ground. Never should this circuit be active during firing of the atomizer DC-DC converter.
//Use a MOSFET or transistor to turn this circuit on and off using the ohmPin.
//Sleep functions should now function at a rest timer of 5 seconds.
//Displays Battery voltage and atomizer resistance when the fire button is not depressed and displays atomizer voltage, wattage, and amperage used when fire button is depressed.


// Added Libraries
#include <LiquidCrystal.h>
#include <avr/sleep.h>

// set pin numbers:
const int firebuttonPin = 7;     // Connected to fire switch on the Box from pin 2
const int ohmPin = 8;            // Sets the pin used to enable the OHM meter circuit to digital output 8
const int powerConverter = 6;    // Connected to inhibit/enable/on-off of the DC DC Converter connected to pin 4
const int ledPin = 13;           // Internal LED to verifyt he circuit is activating for trouble shooting connected to pin 13
const int analogPin = 0;        // potentiometer wiper (middle terminal) connected to analog pin 0, outside leads to ground and +5V
const int atomizerVoltage = 1;  // declares the analog pin 1 as the voltage output of the DC-DC converter to be read
const int batteryVoltage = 2;   // declares the analog pin 2 as the voltage output of the battery pack
LiquidCrystal lcd(12, 11, 5, 4, 3, 9);
int wakePin = 2;                 // pin used for waking up

// Variables
int buttonPushCounter = 0;   // Counts the number of button pushes
int buttonState = 0;         // State of Fire Button
int ohmpowerState = 0;       // State of the Ohm circuit power signal on-off
int lastButtonState = 0;     // Last state of the push button
int raw = 0;                 // variable to store the raw input value
int Vin = 5;                 // variable to store the input voltage controlled 5v supply from the arduino 5v pin output
float Vout = 0;              // variable to store the output voltage the voltage being read after it passes through the atomizer coil
float R1 = 50;               // variable to store the R1 value which is a 50 ohm resistor
float R2 = 0;                // variable to store the R2 value which is the resistance of the atomizer coil
float buffer = 0;            // buffer variable for calculation
float Vbatt = 0;             // Assigns a variable for battery voltage
float Vatty = 0;             // Assigns a variable for atomizer voltage
int sleepStatus = 0;         // variable to store a request for sleep
int count = 0;               // counter

void wakeUpNow()             // here the interrupt is handled after wakeup
{ // Wake up action
  digitalWrite (powerConverter, LOW); // Keep the DC-DC converter output turned off
  }

void setup() {                        // put your setup code here, to run once:
  Serial.begin(9600);
  lcd.begin(16, 2);                   // set up the LCD's number of columns and rows
  pinMode (firebuttonPin, INPUT);     // Set pin 7 as fire button input
  pinMode (ledPin, OUTPUT);           // Set Pin 13 as LED output
  pinMode (ohmPin, OUTPUT);           // Set Pin 8 as the FET G output on pin 8 to enable the OHM meter
  pinMode (powerConverter, OUTPUT);   // Set Pin 6 as DC-DC converter output
  pinMode(wakePin, INPUT);
  //attachInterrupt(0, wakeUpNow, LOW); // use interrupt 0 (pin 2) and run function wakeUpNow when pin 2 gets LOW
}

void sleepNow() {                      // here we put the arduino to sleep
  set_sleep_mode(SLEEP_MODE_PWR_DOWN); // sleep mode is set here
  sleep_enable();                      // enables the sleep bit in the mcucr register so sleep is possible. just a safety pin
  attachInterrupt(0, wakeUpNow, LOW);  // use interrupt 0 (pin 2) and run function wakeUpNow when pin 2 gets LOW
  sleep_mode();                        // here the device is actually put to sleep!!  THE PROGRAM CONTINUES FROM HERE AFTER WAKING UP
  sleep_disable();                     // first thing after waking from sleep is disable sleep.
  detachInterrupt(0);                  // disables interrupt 0 on pin 2 so the wakeUpNow code will not be executed during normal running time.
}

void loop() {                                                                                   // put your main code here, to run repeatedly:
 // Fire button code
  buttonState = digitalRead (firebuttonPin);     // Monitor the Fire button for closed circuit
    if (buttonState == HIGH) {                   // When fire button is closed and ohm circuit is turned off
    digitalWrite (ohmPin, LOW);                  // Disables the Ohm Meter Power circuit
    delay (100);                                 // Delay the fire function to prevent ohm circuit and fire function being active at the same time
    digitalWrite (ledPin, HIGH);                 // Turn on the ledpin
    digitalWrite (powerConverter, HIGH);         // Turn on the DC-DC converter output
   
    // Voltage to atomizer monitoring code
      Vatty = analogRead(atomizerVoltage);               // Reads the voltage of analog pin 1 to determin the voltage going to the atomizer
      float Avoltage = Vatty * (5.0 / 1023);             // Convert the raw value being read from analog pin 1 into a voltage value
         
    // Display the output power of the DC-DC converter in Watts
      Vatty = analogRead(atomizerVoltage);               // Reads the voltage of analog pin 1 to determin the voltage going to the atomizer
      int Watts = (Avoltage * Avoltage) / R2;            // Convert the power going the atty to watts using voltage squared divided by resistance formula using the value of resistance found above in ohm meter
   
    // Display the output current of the DC-DC converter in Amps
      Vatty = analogRead(atomizerVoltage);               // Reads the voltage of analog pin 1 to determin the voltage going to the atomizer
      float Amps = Avoltage / R2;                        // Convert the power going the atty to Amps using voltage divided by resistance formula using the value of resistance found above in ohm meter
         
   // Display meter ouptuts
      lcd.clear();
      lcd.home();
      lcd.print("Atty volts: ");                //  to display the voltage on the LCD
      lcd.print(Avoltage);
      lcd.setCursor(0, 1);
      lcd.print("W: ");                        //  displays the wattage on the LCD
      lcd.print(Watts);
      lcd.setCursor(7, 1);
      lcd.print("A: ");                        // displays the wattage on the LCD
      lcd.print(Amps);
     
   // Set the count timer to zero to reset the 5 second idle sleep function
      count=0;   
      }

buttonState = digitalRead (firebuttonPin);     // Monitor the Fire button for closed circuit
      if (buttonState == LOW)  {               // Monitor the Fire button if it is anything besides Open
      digitalWrite (ohmPin, HIGH);
      digitalWrite (ledPin, LOW);              // Keep the led turned off
      digitalWrite (powerConverter, LOW);      // Keep the DC-DC converter output turned off
         
    // Votlage remaining in battery code
      Vbatt = analogRead(batteryVoltage);      // Reads the voltage of analog pin 2 to determin the voltage going to the battery
      float Bvoltage = Vbatt * (5.0 / 1023);   // Convert the raw value being read from analog pin 1 into a voltage value
      int Bpercent = (Bvoltage - 3.2) * 100;       
   
    // Ohm Meter code
      ohmpowerState = digitalRead (ohmPin);
      if (ohmpowerState == HIGH) {
      raw = analogRead(analogPin);    // Reads the Input PIN, this circuit is set to a on-off switch to cut the 5v supply voltage unless depressed in order to keep the Arduino isolated from the DC-DC converter output voltage to prevent damage to Arduino
      Vout = (5.0 / 1023.0) * raw;    // Calculates the Voltage on th Input PIN by dividing the max voltage (5) by the number of steps the Arduino can handle (1023) and then multiplies the resulting increment by the raw input value from analogRead pin
      buffer = (Vin / Vout) - 1;      // Creates a variable requried for the math to get ohms instead of volts by dividing Vin (5) by Vout from the argument above and subtracting 1
      R2 = R1 / buffer;               // Divides R1 (10 ohms) by the variable created above (buffer), the result is the resistance of R2 (atmoizer)
     
    // Display meter outputs 
      lcd.clear();
      lcd.home();
      lcd.print("Battery %: ");       //  display the voltage on the LCD
      lcd.print(Bpercent);     
      lcd.setCursor(0, 1);
      lcd.print("Ohms: ");            //  displays the resistance in ohms on the screen
      lcd.print(R2);                  //  displays the resistance in ohms on the screen
     
   // display information about the counter
      Serial.print("Awake for ");
      Serial.print(count);
      Serial.println("sec");
      count++;
      delay(1000);                    // waits for a second
     
   // check if it should go to sleep because of time
      {
      if (count >= 5) {
      lcd.clear();
      lcd.print("Entering Sleep");
      delay(100);                     // this delay is needed, the sleep function will provoke a Serial error otherwise!!
      count = 0;
      sleepNow();                     // sleep function called here
      }
    }
// compute the serial input
//    if (Serial.available()) {
//    int val = Serial.read();
//    if (val == 'S') {
//    Serial.println("Serial: Entering Sleep mode");
//    delay(100);     // this delay is needed, the sleep function will provoke a Serial error otherwise!!
//    count = 0;
//    sleepNow();     // sleep function called here
//    }
//       if (val == 'A') {
//       Serial.println("No u"); // classic dummy message
    }
  }
}

Edit: Version 1.2 has cleaned up code, functional sleep and recover from sleep state. Pin 2 and Pin 7 must be connected to the same switch to trigger a transistor to set the normally high pin 2 connected to arduino's RX pin to low when Pin 7 goes high (switch closes) otherwise once it goes to sleep you cannot wake it!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on June 11, 2014, 07:07:26 PM
Hehe, you lost me at "void wakeUpNow()".  My C skills suck, I can use it if I have to, but I mainly program in assembly, as tedious as it is, it just seems so much simpler for me.  The bright side is I get really efficient code that way.  I really need to work on my C skills, it's the industry standard, but assembly is the CraigHB standard :)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 11, 2014, 11:31:23 PM
lol Craig, the hilarity of the whole thing is that I have endeavored to teach myself C/C++ for probably... a decade, but no project came along that really gave me a need to do so, so I didn't.  This however, has forced my hand, so off to www.google.com school I go heh.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Chenderson1985 on June 12, 2014, 12:40:26 AM
I need help! I keep breaking the 20k resistor on this setup. It will fire for a little while then it just stops. When I test the resistor it is reading 14.4k, What am I doing wrong. Someone please help.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 12, 2014, 01:01:25 AM
Strange Chenderson.  Assuming you have resistor in the right spot I would assume the resistor is either too low a wattage rating or there is a loose connection somewhere else in your circuit causing a short on the enable circuit.

When it is working, have you tested your voltage out under load and the voltage coming fromt he switch to ground to see what they are at?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 14, 2014, 06:44:49 PM
I've been working on the LVC (low volt cutoff) circuit for the OKL2-T20 off and on these last couple of weeks and finally got my ducks in a row with it.  I was getting forgetful of paying attention to the low volt LED indicator I had installed with my OKL2 mod and thought I ought to get this done and installed in my mod before I trash my batts. <eek> lol

(http://www.mamumods.com/pics/okl2-t20-wiring-lvc.png)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 15, 2014, 02:46:58 AM
Love the solution you came up with, I plan on implementing it in my MCU controlled OKL2. Could you not simply relocate the Master Switch after the PFET and then have it connect above the zener/below the 20k to have a full master and avoid the idle drain? 
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 15, 2014, 06:03:22 AM
Love the solution you came up with, I plan on implementing it in my MCU controlled OKL2. Could you not simply relocate the Master Switch after the PFET and then have it connect above the zener/below the 20k to have a full master and avoid the idle drain?

Yes of course, but then you'd need a rated master switch to carry the amp load.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 15, 2014, 06:09:26 AM
Good point. Your way allows use of an on/off latching switch, pretty good idea mamu!

Can't wait to get my 2nd OKL2 in the mail. Going to push the limit on it a bit and see how high it will output. I suspect 5.5 is a conservative limit.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 15, 2014, 07:58:10 AM
An idle current kill can be done, but it would take another N-FET in addition to the N-FET for on/off control and it would need to be rated for current.  Negative logic converters take some work around for LVC and idle current kill.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on June 26, 2014, 05:17:42 AM
Hey, I'm pretty new to all this. I've made a few simple mods with zmax chips and dnas but this has turned into a whole new ballgame. The trouble I'm having is auto firing without the switch being pressed. I'm following mamu's older wiring with the in and out caps before the zener and all were added because I haven't got a chance to get the rest of the new parts. I read in another forum that the 20k resistor on the on/off and V-in prevent the auto fire so I've tried 3 seperate ones with same results. Any help would be greatly appreciated. Thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 26, 2014, 08:52:20 AM
Hey, I'm pretty new to all this. I've made a few simple mods with zmax chips and dnas but this has turned into a whole new ballgame. The trouble I'm having is auto firing without the switch being pressed. I'm following mamu's older wiring with the in and out caps before the zener and all were added because I haven't got a chance to get the rest of the new parts. I read in another forum that the 20k resistor on the on/off and V-in prevent the auto fire so I've tried 3 seperate ones with same results. Any help would be greatly appreciated. Thanks

Check to make sure that the 20K (and not 20 ohm or 200 ohm) resistor is soldered properly to Vin and on/off.

Check to make sure you are using a NO switch, not a NC switch.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bob salter on June 26, 2014, 09:47:41 AM
Brilliant thread, thank you. Have ordered four of these and an arduino.

Bob
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on June 26, 2014, 10:39:33 AM
Mamu this is the switch I have http://www.madvapes.com/30-ml-16mg-10915.html and for the resistor I'm pretty sure I have it soldered right. Is there really a wrong way to connect it. If I'm not mistaken resistors don't have polarity
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 26, 2014, 11:05:37 AM
Mamu this is the switch I have http://www.madvapes.com/30-ml-16mg-10915.html and for the resistor I'm pretty sure I have it soldered right. Is there really a wrong way to connect it. If I'm not mistaken resistors don't have polarity

The switch you linked is an NO switch so is ok unless it is defective in that when not being pressed the contacts are touching.  Check continuity or if you have another switch you can try it to see.

How exactly did you wire the switch for each leg?  If you didn't use an N-FET at the on/off pin, then one leg of the switch is wired to on/off pin and the other leg of the switch is wired to ground (batt negative).  If you used an N-FET at on/off double-check to make sure Gate, Drain, and Source are wired correctly.

Right - there's no polarity for resistors, what I mean is make sure the resistor is securely soldered with no loose connection or cold solder joint.  If the OKL2 is auto-firing and the switch is wired ok and not on when not pressed, then it seems that the board is not recognizing the 20K pull-up resistor is attached.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on June 26, 2014, 11:14:07 AM
So if not using the n -fet I should wire the switch from on/off to ground instead of v - in. I have another okl2 board I may try that. I tried finding your old wiring guide to see if anything was wired differently but on every forum it's updated.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 26, 2014, 11:57:32 AM
So if not using the n -fet I should wire the switch from on/off to ground instead of v - in. I have another okl2 board I may try that. I tried finding your old wiring guide to see if anything was wired differently but on every forum it's updated.

Correct - without the N-FET the fire switch needs wired to on/off on one leg and ground on the other leg.  Wire it that way and let me know if that solves the auto-firing.

I updated the wiring guide with a note for wiring the switch if not using an N-FET. 
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on June 26, 2014, 12:04:08 PM
still same auto firing. I checked every connection on the board and through the whole circuit and cant find any bridges or cold solder joints. I'll completely baffeled. I'm not getting any battery sagging or drop offs on any voltage level. Everything is working perfect except for the fact that its auto firing. I've also tried with another switch i have, an anti-vandal switch and same problem. Went as far as switching a few parts out for new ones and no avail.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 26, 2014, 07:02:50 PM
@cburnet91 - Positive logic vs Negative, are you 100% sure about the type you have?

Had my Arduino mod fall on its side two days ago and was firing for at least 5 minutes (possibly up to an hour). I now have a Kayfun 3.1 with nothing left of the insulator under the positive post, it literally liquefied it.  Not only that but I had a transparent chimney and M tank on it, both of which are not just visibly damaged but they are no longer cylinders, more like wavy crazy melted plastic slag.  The Kayfun is currently a dead short, 0.0 ohms measured on my DMM, my Arduino mod, and my HCIGAR ohm tester.... 



This led to an inadvertent test of three things:
1: Does the OKL2 correctly deal with a short circuit situation by turning off voltage output, and rechecking periodically for a safe condition? (yes, I measured the Kayfun's resistance with two devices following the incident and it is a dead short).
2: Do batteries survive without being damaged when the OKL2 is in a short circuit protection state? (yes, the batteries are fine and still being used).
3: If the box setup is pushed to the absolute limits will everything survive? (yes, with the exception of the atomizer lol)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on June 26, 2014, 07:21:26 PM
Type of what? Okl2?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Claviger on June 26, 2014, 07:34:12 PM
I dont and didn't use a NFET thus far on my mods.  I wire from On/Off to switch, switch to ground.  20k resistor from On/Off to Vin, thats it, pretty simple.

If its not working and all the connections are good, either the internal resistor is bad on the OKL or the only other thing I can think of which logic type it is, fire when On/Off is low (Negative) or fire when On/Off is high (positive). 
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on June 26, 2014, 07:39:12 PM
This is the exact chips I ordered http://www.digikey.com/product-detail/en/OKL2-T%2F20-W12P2-C/811-2960-1-ND/4738833 and I used the 20 resistors that mamu put in her wiring guide
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 26, 2014, 10:25:19 PM
This is the exact chips I ordered http://www.digikey.com/product-detail/en/OKL2-T%2F20-W12P2-C/811-2960-1-ND/4738833 and I used the 20 resistors that mamu put in her wiring guide

That one is the positive logic module (has a P in the part number), the one I worked with is the negative logic module (has an N in the part number).  So yours requires opposite switch wiring to turn on and off the converter.  Read the datasheet in the Remote On/Off Control section where it defines on and off for positive logic vs negative logic.

I have its baby brother the positive logic OKL2-T12 here and will get it breadboarded to see how the switch should be wired.

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 26, 2014, 10:33:51 PM
@cburnet91 - Positive logic vs Negative, are you 100% sure about the type you have?

Had my Arduino mod fall on its side two days ago and was firing for at least 5 minutes (possibly up to an hour). I now have a Kayfun 3.1 with nothing left of the insulator under the positive post, it literally liquefied it.  Not only that but I had a transparent chimney and M tank on it, both of which are not just visibly damaged but they are no longer cylinders, more like wavy crazy melted plastic slag.  The Kayfun is currently a dead short, 0.0 ohms measured on my DMM, my Arduino mod, and my HCIGAR ohm tester.... 



This led to an inadvertent test of three things:
1: Does the OKL2 correctly deal with a short circuit situation by turning off voltage output, and rechecking periodically for a safe condition? (yes, I measured the Kayfun's resistance with two devices following the incident and it is a dead short).
2: Do batteries survive without being damaged when the OKL2 is in a short circuit protection state? (yes, the batteries are fine and still being used).
3: If the box setup is pushed to the absolute limits will everything survive? (yes, with the exception of the atomizer lol)

Good to know all is well with that mishap, Claviger.

Thank goodness you had an aluminum case to absorb the heat.  If that Kayfun was firing for that long of a time plastic would have melted.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on June 28, 2014, 02:59:00 PM
Mamu did you ever figure out the switch wiring
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on June 29, 2014, 07:34:25 AM
Mamu did you ever figure out the switch wiring

Got the OKL2-T12 positive logic module breadboarded this morning and tested various wiring configurations.

The goal with the positive logic module is to pull on/off control low (to ground) to turn off and high (to Vin) to turn on, which is opposite of the negative logic module.

So... you have 2 options with the positive logic module.

One option is to keep the wiring as is with the 20K pull-up across on/off control and Vin, wire one leg of an NC fire switch to the on/off control pin and wire the other leg to ground.  In order to turn the module on and off with this wiring configuration and not get auto-firing you need an NC switch, not an NO switch.

The other option is to use the 20K resistor as a pull-down resistor and wire the 20K resistor across on/off control and ground, wire one leg of an NO fire switch (the one you have from madvapes) to the on/off control pin and wire the other leg to Vin plus batt +.  With this wiring configuration, on/off control is pulled low to ground (off) when the fire switch is not pressed and pulled high to Vin (on) when pressing the fire switch.

I tested with various resistors from 1K all the way up to 50K and they all keep the module pulled low (off) when not pressing the fire switch.  So it doesn't seem to matter what ohms resistor is used as a pull-down resistor.  This was short-term testing though. 

ETA: a zener tied to on/off control does not work with either option above.

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on June 29, 2014, 12:07:27 PM
Thank you so much. I'll post my results after I give it a try.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on July 02, 2014, 12:01:55 AM
@mamu
Wired it up and it worked great. The voltage reading was acting a little strange though.
Maybe because i didn't use the inputs caps at first. When i wired it in my box it kept shorting out.
I would notice the voltage continously drop when fired and then smoke from the ground on battery holder.
Figure its a short somewhere from it being such a tight fit. Still trying to figure out an easier way to wire it in the box.
Question: On your wiring guide you mention to use 20 gauge or lower wire on pins 2,4,5... 4 being the ground, do I use
20 guage on all the ground connections or do i use 24 gauge and wire it all to one single 20 gauge wire.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on July 02, 2014, 02:30:47 AM
Input caps - with or without - wouldn't cause the issue.

Definitely find the source of the short and fix it.

20ga for both positive and negative for input (batt + and batt -) and for output (atty + and atty -).  24ga for all else.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on July 02, 2014, 03:52:33 AM
it works fine with a 1.4 ohm single coil on my trident rda but on a .5 ohm dual coil on my crown is when I get the voltage constantly dropping.
it never fires passed 4.6 then goes all the way down to 3.6 very fast then the voltage reader starts flickering. I also noticed that it doesn't go
all the way down to 3.5, its more like 3.6 and only goes up to 5.2 volts. Could it be the battery holder im using. I'm also using the pre soldered thin wire
that's already on the battery holder. Thanks for all your help by the way. Sorry for so many questions.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on July 02, 2014, 04:27:37 AM
Also, are the sense connections necessary and if so should I use 24 gauge for that also
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on July 02, 2014, 04:52:37 AM
Could it be the battery holder im using.

Probably.  You need a solid connection to the battery when using more power.  The cheapo battery holders with the 24 gauge wires are not going to cut it.  Likely the wires are overheating causing big voltage drops and then the controller board conks out due to low input voltage.  More power requires more heavy duty wiring and connections, there's no cheating on that.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on July 02, 2014, 05:14:29 AM
So in theory replacing those I'd say 26 gauge wires with 16-20 gauge should make an improvement if not fix the issue. Anyone know the lowest ohms this board can go.
Its a 20 amp chip so i'm guessing around .3 at 5.5 volts?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: cburnet91 on July 02, 2014, 06:33:57 AM
So I made my own battery holder using brass for the contacts and soldered 18 gauge wire to it and the voltage is not dropping. So far so good. Not noticing anything gone wrong through the circuit beside the 510 (fat daddy vapes spring loaded) getting hot when firing at high volts for extended periods testing but I'm sure thats from the atty getting so hot.
Man this thing chucks the vapor. Only thing left to figure out is why my minimum voltage is 3.6 and highest is 5.28-5.3
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 17, 2014, 08:28:41 PM
Hello, I'm new to the forum and wondering if anyone can help me. I am working on my build however it is autofiring so I check the 20K resister as I read here that that is the most common issue. When I check it with a meter it reads 14.7K and when I check a brand new one it reads 19.8K. I believe the 19.8K is ok but what would make the one in my test layout read 14.7K? ANy help would be great.

Thank You.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on July 17, 2014, 09:21:02 PM
I check the 20K resister as I read here that that is the most common issue. When I check it with a meter it reads 14.7K and when I check a brand new one it reads 19.8K. I believe the 19.8K is ok but what would make the one in my test layout read 14.7K? ANy help would be great.

Thank You.

Welcome to the forum.
Did you check the 20k out of the circuit and not in the test layout?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 17, 2014, 09:23:54 PM
No not yet. I am removing it right now. Will let you know.

Thanks for the quick response.

Thank You.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 17, 2014, 09:50:44 PM
Off the circuit it reads 19.1K
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 17, 2014, 09:51:27 PM
Sorry 19.9K
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on July 18, 2014, 05:19:10 AM
I believe the 19.8K is ok but what would make the one in my test layout read 14.7K? ANy help would be great.

A 1% 20k resistor can range between 19.8K and 20.2K and still be within tolerance, so your resistor is good. 

You typically can not get good readings on a resistor when it's in a circuit because there may be other paths for the current to follow creating a parallel resistance.  In some situations you can get a good reading with a resistor in-circuit, other situations you can't, just depends on the circuit.

You have to check resistors before you install them.  The only thing that damages them is an overload so once a properly rated resistor is installed, it's good for the duration.  Active components like transistors can fail and passive components like capacitors can fail, but it's almost unheard of for a resistor to fail.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 18, 2014, 09:07:28 AM
Thanks Craig,

So now that we know the resistor is good  any ideas on why it was autofiring? My assumption is that I had a bad connection between pins 1 and 2 with the resistor. My next step is to go back to breadboard and see if I can put it all together (again) and test from the breadboard. I started straight out of the gate putting it together mainly because I read about the volt twilight zone readings the breadboard was causing. But my thought is that if I go back to breadboard and it all works I can then start soldering it down again.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on July 18, 2014, 10:51:59 AM
Either the resistor had a bad connection at Vin and/or at on/off for the OKL2 to be auto-firing or you have the positive logic OKL2 (OKL2-T/20-W12P2-C).  I worked with the negative logic version (OKL2-T/20-W12N2-C) which requires a pull-up resistor from on/off to Vin.  The positive logic version needs a pull-down resistor from on/off to ground.

...Only thing left to figure out is why my minimum voltage is 3.6 and highest is 5.28-5.3

With a 1K pot plus 1.43K resistor you should have a range of 3.5v - 5.5v depending on the tolerance of the pot and resistor.

If you have a 1.43K resistor 1% tolerance connected between +Trim and an outer leg of the pot, you should be getting 5.5v output when the pot is turned all the way to 0 ohms.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 18, 2014, 10:58:50 AM
Thanks Mamu,

I did recheck my mouser order and this is what I received OKL2-T/20-W12N2-C. So I guess the on/off - vin had a bad connection. I will update once I breadboard and see if I can fire with the button.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on July 18, 2014, 11:10:44 AM
Just a thought - are you using the N-FET at on/off?  Did you make sure to put a 1K resistor across gate and source?  Without that pull-down resistor the fet won't turn off and the converter would auto-fire.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 18, 2014, 11:41:24 AM
I did use the n-fet and had the resister there.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 19, 2014, 12:20:49 AM
Thanks for all of your help. It must have been a bad connection at the 20K because I rewired everything onto my homebrew PCB and wired it all up and PRESTO....... BOOM..... (Edited for Craig ;bow;) we have vape. Now time to put it in the box.

Thanks again for all of your help. WIthout people like you I would never have even attempted this. Kinda strange my first Box MOD is going to be a 100w monster......

Thanks again :)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on July 19, 2014, 03:33:00 AM
Oh man, don't say "BOOM" when talking about e-cigs, I thought you were about to say your battery exploded, anyway, good to hear all is well.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on July 19, 2014, 05:55:18 AM
Woot  glad you accomplished your goal

Great build up to success,  I also thought %&^*..

OT mouseover

Craig I always say boom,  yeah direct short makes no sense to noobs but when you have seen a hefty 15A short blow a hole thru steel no other word will get across to people who have no idea how much energy  are in these e cigs..  30A whoa  60A OMG

Yeah the media loves that word so I guess I could say, you may have a horrible outcome and  need hospital services if you proceed  :laughing2:

IDK maybe ill not say anything anymore and let it be.. 

As a journeyman we yell and bully our know it all helpers into knowledge, one freakin mistake can take out a whole splicing chamber of people when dealing with live 32k amps.  It has happened, very rare, (good training) but--it blew the clothes and skin off a coworker, he luckily lived to talk about it.  The fireballs luckily went str8 up about 200ft,  a train unfortunately was in the system drawing ~15k amps 600vdc, if two trains 32k, it had stopped about 60 ft from it and the breaker kept resetting and the fireball kept booming until control  shut it down from their board..  My co worker had made a huge mistake and was caught in a splicing bunker with the million5 (MCM5)  shorted to structure on the elevated system,  he was frying and made the decision to jump to his demise, another co worker hero'd, he moved the line wagon under him and had started raising the platform before he was under him,  he fell about 4ft onto the platform..  Whats wild,  our platforms usually wont raise from the trucks inside controls in gear,  this truck was broken and the tower and outside controls busted and it should have only worked from the inside controls in park, it had worked while in gear.  Miracle oh yes..  No other linewagon works this way,  it was in the waiting line to be serviced for repair.  This was  about a window of ~15 secs of movements.  Another wild addition to this story,  a news crew was filming a story at a restaurant next to where it happened and caught the whole incident.  Its used to this day (1987') as an industry wide training video of what will happen..  Horrible video but he lived..  The hero co-worker just knew the tower would raise and it did he said he didn't even think about it as it would not.. 

A touche to this story,  the linewagon was fixed and a month after it was fixed the tower raised on its own going under a bridge sending the chauffeur to the hospital for years.  It was retired lol...

No time for mistakes or inaccuracies and we put these things next to our faces. :laughing:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on July 19, 2014, 10:17:40 AM
No time for mistakes or inaccuracies and we put these things next to our faces.

Yeah, it kind of puts a whole new spin on safety.  It's one thing for a battery to explode on the charger, another if it happens in your face.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 19, 2014, 03:13:07 PM
Safety is no joke and everyone (including me) needs to consider that when dealing with power. Education is a must and knowledge is POWER. Edited post to ensure no one else gets the wrong idea.

Thanks Again.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 20, 2014, 11:38:06 AM
Thanks to you all I now have my mod just about complete and was wondering if using a 11.1 Lipo battery would be acceptable for this build? I did read the specs on the OKL2 and it says "Operating voltage range Minimal 4.5 Volts, Typical/Nominal 12 Volts, Maximum 14 Volts,". The reason I ask is I fly RC Helicopters and have about ten (10) 11.1v Lipo batteries, 2 6S Balance Changers as well as a slew of other Lipo batteries and connectors. I like to use Lipo whenever possible because of it's power to weight ratio and just because I am set up for them it makes things easier for me. As always thanks again for your input.

Thank You. 
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on July 20, 2014, 01:40:10 PM
Yes, you can use a 3S LiPo if you like.  Though the 60C ones are pretty volatile.  It's safer to use the 20C ones.  The higher the drain limit the faster they release energy if a fault condition occurs.

You must have some kind of short circuit protection when using a LiPo.  Since the OKR-T/10 provides current limiting and overload protection, you should be covered.  Ensure your wiring is sound and no internal faults can occur there.  Even so a fuse is never a bad idea as a backup.

Generally the round cells are safer than the LiPos for a few reasons.  For one, LiPos are only encased in a thick foil where the round cells are encased in a steel tube.  This makes LiPos vulnerable to physical damage which is much more hazardous in terms of exploding cells than a short circuit. 

Another reason the round cells are safer is because the high drain ones use a less volatile chemistry than the LiPos, that is Lithium Polymer versus Lithium Manganese.  A fault is less likely to cause "thermal runaway" which is the technical term for a cell catching on fire and blowing up.  If thermal runaway does occur, the reaction happens slower.

Since round cells are typically used for personal electronics where the "S" LiPos are typically used for RC models, a lot of R&D is put into the round cells to make them generally safer in terms of their volatility and failure rates.  Little effort is put into the hobby LiPos to make them safer. 

Comparing chemical volatility, LiPo is safer than LiCo, but more hazardous than LiMn.  The drain rating also has an impact there since it determines the maximal rate the cell can release energy.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 20, 2014, 05:42:06 PM
Thanks for the info. I do have a fuse at the batt and it is a 20c rated 3S.  Also I made a PCB for the layout and only have wires where absolutely needed I hope this will minimize wiring mishaps. I was concerned about stressing the other components but I think by what you are telling me I should be ok there. I may give it a shot and watch it for a while to see if it performs as expected.

Thanks Again.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: werkkrew on July 21, 2014, 10:39:50 AM
I have a question about the primary diagram in the OP.

In browsing the entire thread I have seen some separate diagrams which included reverse polarity protection, low-voltage cutoff, and a low voltage LED indicator. 

Are these integrated into the main diagram right now?  They appear to be but I am not 100% sure.

Also, what does the switch in this circuit need to be rated at?

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 21, 2014, 11:37:37 AM
I have confirmed that using the current diagram there is reverse polarity indicator light. As well if a zener is used then there is also low voltage cutoff. Also I believe I read through this forum that the switch needs are very low due to the fact of it's placement and that the master switch if used only stops it from firing and does not turns off the system and idle drain still occurs. Please feel free to correct me if I am wrong here .

Thank You.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on July 22, 2014, 02:27:19 AM
Juicy - I used these on my OKL2.  Used a 2.2k ohm pot and 1.43k resistor for the circuit, gives right around 2.5 - 5.6 volt control. Looks very similar to the Axiz mod pot, works great, fantastic quality, will be using them in all box modes that I make in the future, both for my own and for others!!

Yes they are pricey.

http://www.digikey.com/product-search/en?v=716&FV=fff40004%2Cfff80335&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

Parts list for my 20amp mod:
http://www.digikey.com/product-detail/en/P16NP222MAB15/P16NP-2.2K-ND/1587862
https://www.fasttech.com/p/1258801



http://www.fatdaddyvapes.com/shop.html (The new one with 22mm washer)
Radio Shack switch :P
1.43k resistor
4x22u caps (2 input, 2 output)
20 gauge
On/Off slide switch

No screen, no reverse polarity protection, no voltage cut.  Some of the better modders may be able to fit it in that box, but I could not. Great mod for myself, but wouldn't give to anyone else.

What amazes me, is that at 3.7 volts my Kayfun hits easily as hard as it does off a Penny Mod (pure copper mech with the lowest recorded drop) using a fresh charged VTC-5!  In fact, the only tank I have that can consistently wick fast enough over 4 volts is my Expromizer.  .69 and .74 ohm builds respectively.  VV mods have now replaced all my mechanicals! 

After typing the above I decided to try my Stillare at .28 ohms dialed up to 5.5 volts........ really bad idea raged:


can you please post your guide? because i wanna setup the same thing..why do u need output caps? thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 23, 2014, 12:34:39 PM
I was wondering if someone could help me with a change I would like to see in the OP for my own mod? When the 3 position switch is set to VIN it turns on the LCD and displays the current Battery Voltage (VIN) and stays on. However, when I change the 3 position switch to VOUT nothing is displayed until I hit the fire button. I was wondering how difficult it would be to turn on the LCD when selecting VOUT so that you could see the voltage set by the Pot? If I have something wired wrong or this does not make sense please let me know and I will do my best to clarify.

Thank You.

(Edited) I don't want the OP to change just wanted to say that I used the OP for my mod so that is what I have currently.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on July 23, 2014, 02:11:37 PM
Theres literally no way without using a digital pot/controller and mcu/oled/etc to show you the v-out voltage set or  change acid.

Totally seperate setup. 
Even clavigers fancy arduino setup wont until you pulse the atomizer then of course it will every fraction of a sec display and keep that on the screen but thats just the last pulse, its a picture of vout  when you vape again it may change..  A  build like Craigs will do what you want and it will stay put but yeah very difficult.



Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 23, 2014, 02:20:04 PM
Thanks for the quick reply. Sounds like it is what it is.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on July 23, 2014, 02:28:37 PM
Yup it needs a brain. 
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on July 23, 2014, 04:05:37 PM
A  build like Craigs will do what you want and it will stay put but yeah very difficult.

Yes, the atomizer data is "sticky" for my mods.  But that also brings a point of contention.  You have to power the atomizer to get a new reading.  Not a big deal, a quick tap on the trigger will do, but still there's not really an on-demand option for checking resistance.

In any case to get stored readings, you have to use a device to store data.  The one and only way to do that is with a micro-controller and all the business that involves using one.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on July 23, 2014, 11:03:42 PM
can please someone help me.im building a box but i dint want to use fuse,reverse polarity LED lights..can someone post  wiring diagram? and part needed ?thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on July 24, 2014, 05:05:06 AM
can please someone help me.im building a box but i dint want to use fuse,reverse polarity LED lights..can someone post  wiring diagram? and part needed ?thanks

If you're not going to add a fuse or p-fet, wire Vin to the batt + contact on the batt holder.  If you're not going to use the n-fet, wire on/off control to one leg of the fire switch and wire the other leg of the fire switch to ground.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on July 24, 2014, 09:44:02 AM
If you're not going to add a fuse or p-fet, wire Vin to the batt + contact on the batt holder.  If you're not going to use the n-fet, wire on/off control to one leg of the fire switch and wire the other leg of the fire switch to ground.

hi mamu thank you for your reply..i have another question,, can i still use zener diode? and i still need 4x 47uF 16v output caps in parallel on vout? im little confuse because in your parts list it says 4x 47uF 16v output caps in parallel (GRM32ER61C476ME15L)..and i dont see those caps on the diagram picture. thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 24, 2014, 03:15:49 PM
I have a really dumb question. I built my mode and I know what everything is for and how it works except for the N-Fet. Can someone tell me what the N-Fet is for and why I need it? Just trying to educate myself a little in the process.

Thank you.
BFBCAcid
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on July 25, 2014, 11:25:51 AM
hi mamu thank you for your reply..i have another question,, can i still use zener diode? and i still need 4x 47uF 16v output caps in parallel on vout? im little confuse because in your parts list it says 4x 47uF 16v output caps in parallel (GRM32ER61C476ME15L)..and i dont see those caps on the diagram picture. thanks

To use a zener you need the N-FET wiring at on/off control.

I initially used output caps, but the output is stable without them (just not on a breadboard  :laughing:) and for our load purpose they aren't needed so eliminated them.

I have a really dumb question. I built my mode and I know what everything is for and how it works except for the N-Fet. Can someone tell me what the N-Fet is for and why I need it? Just trying to educate myself a little in the process.

Thank you.
BFBCAcid

The N-FET acts like a switch to drive/control on/off (but without the bounce that push button switches sometimes have which can cause problems).  My purpose for using it though is to convert this negative logic module to positive logic via the positive Gate of the N-FET so I can use a zener for low voltage cutoff.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on July 25, 2014, 12:24:58 PM
Thanks Mamu,

Now I understand.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BOFH on July 28, 2014, 10:48:19 AM
Thanks for all the information mamu.

Im trying to finish off a SX350 mod at the moment(need some time to upgrade my printer now the parts have arrived) but once that's done id like to make a real mod.

As Raptors seem to be made from unobtanium at the moment im looking as using this for my first real mod.

So quick question, I noticed the PTR08100W can be pushed over its spec'd 5.5v up to 6v using a slightly lower fixed resistor with the pot.  Is that possible with this chip im guessing about a 1.3k fixed resistor should be about the right value when the pot is zerod for 6V.  Wondering if anyone has tried or is the 5.5v a hard limit? 

Thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on July 28, 2014, 11:30:11 AM

So quick question, I noticed the PTR08100W can be pushed over its spec'd 5.5v up to 6v using a slightly lower fixed resistor with the pot.  Is that possible with this chip im guessing about a 1.3k fixed resistor should be about the right value when the pot is zerod for 6V.  Wondering if anyone has tried or is the 5.5v a hard limit? 

Thanks

If you look at the past mods I made w/ the 08100w, you will see that I have an approximate output range of 3.6volts to 6.14volts using a 200 ohm pot w/ a 220 ohm fixed resistor.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BOFH on July 28, 2014, 11:42:14 AM
Thanks Breaktru

That was where id got the idea from.  Is it possible to do the same thing with the OKL2-T20 and push it over the 5.5V spec (to around 6v) using a lower resistor and still maintain reliability like you did with the PTR

Thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on July 28, 2014, 04:00:33 PM
The OKL2 is pretty new to all of us so no one knows yet how reliable it is if taking it above spec.   The datasheet says not to exceed max specified output voltage or max power rating, but I don't think a half volt higher than max spec'd would be a big deal as long as you stay within 110W and 20A.  But you do these things at your own risk of course.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BOFH on July 28, 2014, 05:54:24 PM
Thanks mamu

Guess I'll have to have a go and see what happens.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: werkkrew on July 29, 2014, 07:01:12 PM
Are the fuses in this circuit necessary?  If so, what do they provide exactly?

According to the product datasheet:

Quote
These converters also include under voltage lock
out (UVLO), output short circuit protection, overcurrent
and over temperature protections.

I don't want to leave them out if they are very important to the safety of the mod but I don't have much space to work with.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BOFH on July 30, 2014, 08:19:15 AM
Are there any specific requirements for the Zener or will any do.

Found this one on Mouser http://uk.mouser.com/ProductDetail/Vishay-Semiconductors/1N4734A-TR/?qs=sGAEpiMZZMtQ8nqTKtFS%2fJrR9ou1I1aD%2f58PHwJ%2f8k4%3d will it do the job?

Werkkrew

You never have to have fuses.  But if something goes wrong with your batteries and one goes nuclear or the protection in the circuit fails it could save wrecking everything else.  So they are generally a good idea from a safety perspective as shorted batteries are not fun.  If you are really tight on space maybe you could use two of these http://uk.mouser.com/ProductDetail/Littelfuse/0501010WR/?qs=sGAEpiMZZMtxU2g%2f1juGqVticcWmDLIrN%252bPfJ%2fEGQCw%3d . Downside is if they blow you will have to replace them.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: werkkrew on July 30, 2014, 09:22:56 AM
I'll try to squeeze the re-settable ones I have in there.  Random question, how do these fuses fail, and how do you reset them?  That will help me figure out placement in the box.

http://www.mouser.com/Search/ProductDetail.aspx?R=RGEF1000virtualkey65000000virtualkey650-RGEF1000

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BOFH on July 30, 2014, 09:48:16 AM
Explanation of how they work here http://breaktru.com/smf/index.php/topic,691.msg5429.html#msg5429

They reset themselves, you don't have to so can go anywhere in the mod.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on July 30, 2014, 01:33:33 PM
Random question, how do these fuses fail

PTC fuses do not have infinite lifetime.  As the number of trip occurrences goes up, normal resistance also goes up.  At some point the fuse will stay permanently tripped.  Physically bigger fuses last a lot longer and can tolerate thousands of trips without any change in normal resistance.  The really small SMD ones can wear out after a small number of trips, as low as 50.  The SMD ones in a 1206 package or larger are good for a few thousand.  The big leaded ones are good for a lot more. 

Wikipedia has a short article that explains the mechanics of a PTC fuse; http://en.wikipedia.org/wiki/Resettable_fuse
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ModManCooper on August 04, 2014, 09:37:48 AM
Hey all my first post on the forum.  I have built about 15 boxes using the okl2 chip and love it! I am curious on what other dc to dc converters are out there that could be used in our hobby.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ModManCooper on August 04, 2014, 09:39:54 AM
Minus the obvious like Naos Raptors and the okrs  ;cheers;
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on August 04, 2014, 06:23:44 PM
I am curious on what other dc to dc converters are out there that could be used in our hobby.

Any converter with the right input and output range.  These POL modules as they're formally called are widely produced and generally used a lot in electronics.  The buck modules (step-down) are by far the most common compared to boost or buck-boost.  The higher output parts we need for an e-cig are less common, but they seem to have picked up in offerings over the last few years.

New models trickle out slowly but surely so you have to sort of keep your eyes peeled on what makers are offering.   Texas Instruments is a big maker and so is Murata.  GE has some good offerings as well.  There's many more brands than that, but those guys probably have the widest product range.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ModManCooper on August 04, 2014, 07:45:45 PM
Thank you for the response!! I posted on the main page about the 40a raptor. Any advice would be extremely appreciated!!!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on August 10, 2014, 12:38:12 AM
I was wondering does the OKL2-T20 20A 110W converter step down? I tried to read the datasheet but must be missing it or it can't do it? If so how can I tell?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on August 10, 2014, 02:18:05 AM
I was wondering does the OKL2-T20 20A 110W converter step down? I tried to read the datasheet but must be missing it or it can't do it? If so how can I tell?


Read features on the specs sheet it tells you there..

it can step down from 5.5v to all the way in the gutter @ 0.69,  it cannot step up. 

A booster/step up regulator has a hard time stepping down the okl is a buck converter it steps down from a set voltage from input usually thats at least 1v lower than input.  8.4v input, becomes dialable from 0.69-5.5v output.


Programmable output voltage from 0.69-5.5Vdc



It cannot step up





Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on August 10, 2014, 02:55:03 AM
Thank you for the response VISUS but I'm still lost.

Maybe I didn't ask the correct question. Say I have an ATTY and it's built to 2.0 ohms and with the setup here I set the voltage to 3.5v, would I be vaping at 6.125 watts? I guess I'm asking what would the chip do at this point. Likewise (I know I shouldn't do it but it's just a question) if I build an Atty at .25 and set it to 5.5 would I vape at 121 pushing the chip or would it only give 110W as the specs say?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on August 10, 2014, 01:41:47 PM


Yes 6 watts

Yes 121 watts


Section Output on the spec sheet

Most modules will exceed their spec sheet values but it may harm the module if done frequently.  We pulse them and that makes our use of them a little different.  If built proper, hypothetically it may last a few lifetimes pulsing at even 130watts or just a day,  using it where  it never turns off a continuous use at 130 watts maybe last a year or two or just a few minutes, thats hypothetically of course...

Its absolute maximum limit is ~32Amps ~176watts

Section input on the spec sheet
What is really  cool it will only ask the battery for 8-15amps to do 20 amps depending on input voltage like at 5v it will only ask the batteries for 13-15amps while output is at 20amps It will change due to battery power lowering and sag.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on August 10, 2014, 04:28:03 PM
Your range of power is dependent on atomizer resistance and limited by the regulator.  So for example if you set up a voltage range of 3.5 to 6V;


There's also the limitation of your battery.  Demand on the battery is output plus losses divided by lowest battery voltage.  That would be about 120W divided by 6V or about 20A.  To support maximal power output for the regulator, you need a battery than can handle a 20A drain.  However, maximal output current load for the regulator is 20A so you can also run into that limitation.  Output current at 5.3 Volts with a 1/4 Ohm atomzer is over 20A.

I think the reason you are confused is there are a number of limitations that come into play.  You have to look at which limitation occurs first.  For the regulator, you have a maximal demand of 110W or 20A, whichever comes first.  Then there's the voltage range which is dependant on the regulator and how you set things up.  Then you have atomizer resistance and the maximal drain the battery can support.  All of these factors have to be considered when looking at output range in terms of power, voltage, or current.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on August 10, 2014, 04:42:27 PM
Now I am confused too.

When I read the data sheet it says its maximum input amp request is 15.85 at output 20A
It also says 32A is the absolute maximum current before shutting itself down.
Meh the 08100 says 50 watts is its maximum and I use it frequently at 70-80 watts have done 90watts no issues

What gives there

Meh' cannot get the right screenshot sizing

Page 3 Input
http://www.murata-ps.com/data/power/okl2-t20-w12.pdf

(http://www.webpagescreenshot.info/i3/53e7dd56210a85-40656908)


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on August 10, 2014, 04:59:03 PM
I have not studied the data sheet for this part, but if there's a stated maximum for input current, then that applies as well.  It further convolves calculation of output range, but that's how things go with electronics.  There's always a number of factors you have to consider.

In that case, maximal input power is going to be maximal input current of 15.85A times minumum battery voltage of 6V which is about 95W.  Less losses that brings maximal output power down to about 85W at minimal battery voltage.

You can typically exceed ratings to an extent, but you risk reliability doing that.  You may be able to fudge that maximal input current value somewhat.  However, absolute maximums stated in the data sheet are in fact absolute.  If you exceed those even by a tiny bit, the part will fry.  For optimal reliability, you should not exceed ratings.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on August 10, 2014, 05:15:14 PM
Cool I was hoping I was reading that right,  I have said it in other places  :facepalm:

phew lol

Yeah their underrated specs are I figure for maximums in safety for the module and other electronics its connected with so it doesn't become a fused buss bar lol

So it does need those 2v above output to operate so unless using a 3s batt it will never exceed the boards specs.. woot

Lol aha most shoulda just wired a OKRt10 or Ti08100 if using 2s batts  :laughing2:

the fine print  big eyes overlook wanting that huge number..

3s batts FTW
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on August 10, 2014, 05:21:47 PM
Yes, another issue that comes into play is regulator "drop-out".  For dual series cells, ouput voltage can be rather close to input voltage.  In that case, regulator drop out can cause a limitation in output voltage range.  Step-down converters tend to have a lot of drop-out.  For example, a regulator with a drop-out of 1.5 Volts has a maximal output voltage of 4.5V with a minimal battery voltage of 6V which is the typical minimum with two series cells. 

You can resolve the drop-out issue quite nicely by using 3 series cells.   That also gives you the full output power range for the regulator since minimum there is 9V and at 16A max input current, that makes the full range of output power available.

It's actually pretty common for things to seemingly get out of hand when calculating maximums and minimums for circuit specifications.  It's something I've burned a lot of brain cells over at times.  There's even more factors like variations in temperature and manufacturing tolerances that have to be considered.  It all gets quite complex when you want to accurately predict the capabilities of a circuit.  However, most of the time you can just neglect those more subtle factors to get a good enough idea.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on August 10, 2014, 09:58:45 PM
Thanks to both of you this is fantastic information and great tech talk for others that may want to know. Thanks again.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Thearlaich1965 on August 14, 2014, 06:31:19 PM
Just getting back to the forum and found this thread. I'm anxious to read it from beginning to end. :)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: joshgg81 on August 18, 2014, 09:38:38 PM
Ok hi im new here   wanted more power so Im building my own.  Im reciving the positive logic version of the okl2-t20 . I have a few questions  1. As I read earlier with this version I can not do a low voltage cut off   
                    2. I would like to do an on board pass through charger with this mod  and was wondering what would be best to use and how to wire it in.

       Thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on August 18, 2014, 11:13:53 PM
Josh,
You can do a low voltage cutoff by selecting the proper Zener for you application my understand (Could be wrong) is that if you want a cutoff at 6.2 volts the you need a 5.5 Zener? Read the entire thread here and I think you will find it. I believe it talks about Zener (5.5) + .7 or .6 something to that effect gives you a cutoff of 6.2 or 6.1 respectively.

Now for my question anytime the top of my P-FET (MOSFET) touched the outside of the box it blows? Isn't that hole supposed to be attached to ground? And if do being my box is ground is that a problem? Any help is appreciated.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on August 18, 2014, 11:18:32 PM
Ok hi im new here   wanted more power so Im building my own.  Im reciving the positive logic version of the okl2-t20 . I have a few questions  1. As I read earlier with this version I can not do a low voltage cut off   
                    2. I would like to do an on board pass through charger with this mod  and was wondering what would be best to use and how to wire it in.

       Thanks

I had the positive logic 12A OKL2 and not the positive logic 20A OKL2 and couldn't get a voltage reading from the zener as I had breadboarded it, but from what I've read from other modders working with the positive logic OKL2 20A you can add a zener and wire it exactly like the Raptor 20A or OKR-T10 wiring.

So try that and let us know if it works - put the pull-down resistor across on/off control and ground, then do the remaining wiring for on/off control and Vin like with the Raptor 20A or OKR-T10.

It takes special wiring to do a pass through with series batts, not as simple as with parallel batts.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on August 18, 2014, 11:24:49 PM
Josh,
You can do a low voltage cutoff by selecting the proper Zener for you application my understand (Could be wrong) is that if you want a cutoff at 6.2 volts the you need a 5.5 Zener? Read the entire thread here and I think you will find it. I believe it talks about Zener (5.5) + .7 or .6 something to that effect gives you a cutoff of 6.2 or 6.1 respectively.

Now for my question anytime the top of my P-FET (MOSFET) touched the outside of the box it blows? Isn't that hole supposed to be attached to ground? And if do being my box is ground is that a problem? Any help is appreciated.

He's referring to the positive logic version, not the negative logic version I had worked with and a diagram for.

The metal tab on the back of the mosfet is also Drain (and is directly connected internally to the middle leg or whichever leg of the mosfet is Drain) - for reverse polarity wiring, Drain is connected to + batt. Absolutely isolate that tab from any metal touching it or any negative connection.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: joshgg81 on August 18, 2014, 11:30:59 PM
Ok awsome I will give that a shot and let youhow it turns out thanks alot
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on August 19, 2014, 04:39:12 AM
The metal tab on the back of the mosfet is also Drain (and is directly connected internally to the middle leg or whichever leg of the mosfet is Drain)

Check that in the part's data sheet, came across a PMOS recently where the exposed die (metal pad) was on the source.  It was a Texas Instruments part.  Almost screwed up on that, was just about to send a board off to the fab and then realized it was different on that one. 

That metal pad is actually what the chip is mounted to.  It's the pin that's tied to it, not the other way around.  There's a metal pad like that on either side of the source-drain channel that makes the connection.  They can expose either one for heat sinking.  Usually it's the drain, but it doesn't have to be. 
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on August 19, 2014, 05:05:36 AM
I assumed that he is using the p-fet most modders are using with the Raptor for reverse polarity - SUP75P03-07

(http://www.mamumods.com/pics/sup75.png)

I've switched from using that one to a smaller d-pak size p-fet...
(http://www.mamumods.com/pics/ipd.png)


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on August 19, 2014, 10:02:52 AM
Thank you for your response. I may be moving to the PAK as well.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on August 23, 2014, 05:12:34 PM
Sorry to keep asking questions but I have a strange issue that I thought someone may be able to help with. I've been vaping my mod with no issues for a few weeks. One day I was vaping and noticed that when I turn the POT all the way up I was only getting a reading of 2.x volts. If I turned all the way down I was  3.5 like expected. So I took the atty off and measured it with a meter and sure enough I was getting 5.5 at high and 3.5 at low when I adjusted the POT. So I assume under load something is going on. I checked almost all components and they seem ok. My guess is that it is somewhere between the Trim (Board) connection, 1.43K Resistor and the pot or at the 510, but I am new so guessing is not a good thing. Any help on where to look would be appreciated.

Thank Again.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on August 27, 2014, 03:06:57 PM
So I figured out my problem and wanted to pass the info along. I used the below Battery Holders in my mod and they seem to be dropping voltage like crazy not providing adequate voltage to the chip at high voltages (5.5) with low Ohm builds (.3). Even though I cut the cheap wire at the terminals and went with 18G wire from the battery box to the fuse / chip.

Now for my next questions. What are you all using for a battery tray so I can test something different in my setup.

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2146231_-1 (http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2146231_-1)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on August 27, 2014, 06:45:06 PM
Keystone holders are best.
You have loses w/ the holder that you have. It is especially noticeable as the amperage demand increases.

See: Battery holder contact resistance measurements (http://breaktru.com/smf/index.php/topic,1226.msg14200.html#msg14200)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: BFBCAcid on August 27, 2014, 08:25:01 PM
Thanks Breaktru, Off to the web I go.

THank You...... As always
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bob salter on September 01, 2014, 12:48:13 PM
I inadvertently bought the positive logic board. I know how to fix the switch wiring. I'm using lipo batteries so don't need the pfet. Is there any way to add uvco to it?

Bob
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on September 01, 2014, 04:14:08 PM
For low voltage cutoff using a zener diode, wire the positive logic Vin and on/off control like the Raptor and OKR-T10 are wired.  I haven't tested this, but from what I'm hearing this is working for those who have the positive logic OKL2-20.

Also, for lipo batts, use a 6.2v or 6.4v zener.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bob salter on September 01, 2014, 04:24:05 PM
brilliant thank you. Will report back when completed

Bob
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: nicvape on October 28, 2014, 02:15:47 PM
Hello.
First I want to thank Mamu for this post . It is very helpfull.
 And second , I have breadboaded my OKL2 and every seems to be ok with no load ( 3.58 V min and 5.55 V Max).
But when I load the output , I have a huge volt drop ( almost 2 V !!!)
Sense + is on Vout and Sense - on Gnd
I don't know if the poor quality of my breadboard can be involved or if it is something else . I am a little lost.

Please excuse me if my english is not correct, it's not my native language
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: DireHavok on November 02, 2014, 05:41:33 PM
Ok not sure if I damaged chip. I have wired to the mamu diagram, less pfet and nfet. I did however wire pos sense to vin not vout. Remote is not activating output. If 20k res is removed I have fluctuating output...no idea if damage has been done...I have 2 more chips gonna re try...

Is the nfet needed or is that just for master switch?

**EDIT**  I have the w12n2-c which if not mistaken is a negative logic..and guessing remote lead needs to be moved to ground instead of Vin
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on November 02, 2014, 06:15:34 PM
Ok not sure if I damaged chip. I have wired to the mamu diagram, less pfet and nfet. I did however wire pos sense to vin not vout. Remote is not activating output. If 20k res is removed I have fluctuating output...no idea if damage has been done...I have 2 more chips gonna re try...

Is the nfet needed or is that just for master switch?

**EDIT**  I have the w12n2-c which if not mistaken is a negative logic..and guessing remote lead needs to be moved to ground instead of Vin

Need the N-FET if you want to use a zener for low volt cutoff.  Without the N-FET you cannot use a zener.  If not using the N-FET, wire one leg of the switch to on/off and the other leg to ground.

You cannot wire +Sense to Vin and expect the converter to work correctly.  The Sense pins are for supplying the converter feedback for output voltage, not input voltage.  Plus +Sense is internally tied to Vout so you've essentially made a direct connection between Vin and Vout by hooking +Sense to Vin.  I just don't understand why you would do that.




Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on November 02, 2014, 06:18:44 PM
Hello.
First I want to thank Mamu for this post . It is very helpfull.
 And second , I have breadboaded my OKL2 and every seems to be ok with no load ( 3.58 V min and 5.55 V Max).
But when I load the output , I have a huge volt drop ( almost 2 V !!!)
Sense + is on Vout and Sense - on Gnd
I don't know if the poor quality of my breadboard can be involved or if it is something else . I am a little lost.

Please excuse me if my english is not correct, it's not my native language

Yes, it could be the breadboard.  Been there done that lol.

But it could also be the batt contacts, high internal resistance of the batts, inefficient input/output wiring, high amp load - anything that adds high resistance to the circuit.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: DireHavok on November 02, 2014, 06:36:08 PM
Need the N-FET if you want to use a zener for low volt cutoff.  Without the N-FET you cannot use a zener.  If not using the N-FET, wire one leg of the switch to on/off and the other leg to ground.

You cannot wire +Sense to Vin and expect the converter to work correctly.  The Sense pins are for supplying the converter feedback for output voltage, not input voltage.  Plus +Sense is internally tied to Vout so you've essentially made a direct connection between Vin and Vout by hooking +Sense to Vin.  I just don't understand why you would do that.

Wiring the sense wrong was seeing wrong location...stupid mistake...I have several nfets just need small board to use it.  Why is zener not usable for on/off? Is it because its a negative logic chip
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: nicvape on November 03, 2014, 12:19:18 AM
Yes, it could be the breadboard.  Been there done that lol.

But it could also be the batt contacts, high internal resistance of the batts, inefficient input/output wiring, high amp load - anything that adds high resistance to the circuit.

Ok. Thanks for your answer. I'm waiting for my battery sled from vape3D and I'll optimize the position of components and the length of wires
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: screwfunk on November 17, 2014, 05:27:38 AM
Quick question for Mamu or anyone else with the know how. I cannot source the 1.43k resistor locally. They have everything else around it, 1.3k, 1.5k but no 1.43k. Is there anything I can do to change this or use something else in its place?

Sam
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: wa9w00d on November 17, 2014, 06:06:37 AM
Hi Sam,  You could put a 30k in parallel with that 1.5K.  Get you pretty close.

Wayne
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on November 17, 2014, 12:01:20 PM
Quick question for Mamu or anyone else with the know how. I cannot source the 1.43k resistor locally. They have everything else around it, 1.3k, 1.5k but no 1.43k. Is there anything I can do to change this or use something else in its place?

Sam

1.3K would give 6V output max and 1.5K would give ~5.2V output max.  Both are close enough to the converter max specs and would be ok, but if using the 1.3K, either don't exceed 5.5V max output or don't exceed 20A, 110W.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: wicked_tattoo on November 18, 2014, 10:14:18 AM
I have been trying to get a build going with this chip for 3 days now.  raged: I went and bought a breadboard to see if I can trouble shoot it that way. I got it all rewired and it now hums when it gets power???? I am using the Mamu guide but trying to first get it to function without all the safety (similar to a HexOhm) just to see what I can make happen. I am really not sure what I am doing wrong. Any suggestions on how to set something up similar to that type of build? Thanks all

So no reverse polarity protection, no caps, just a n-fet and a 1.43k resistor for the pot.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: wicked_tattoo on November 19, 2014, 12:28:46 AM
Anyone?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on November 19, 2014, 05:37:50 AM
I have been trying to get a build going with this chip for 3 days now.  raged: I went and bought a breadboard to see if I can trouble shoot it that way. I got it all rewired and it now hums when it gets power???? I am using the Mamu guide but trying to first get it to function without all the safety (similar to a HexOhm) just to see what I can make happen. I am really not sure what I am doing wrong. Any suggestions on how to set something up similar to that type of build? Thanks all

So no reverse polarity protection, no caps, just a n-fet and a 1.43k resistor for the pot.

Which version of the OKL2 are you using? OKL2-T/20-W12N2-C or OKL2-T/20-W12P2-C
How many series batts are you using? 2 or 3. Are your batteries up to the task?
Is the battery sled and connections okay?
What resistance coil and output voltage are you using?
Have you measured battery voltage at Vin with the fire button pressed under load?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on November 19, 2014, 09:13:36 AM
A humming/buzzing sound indicates the converter is being overloaded/overworked.  Could be from a too low ohm coil build, could be output voltage set too high for the coil you're trying to use, could be source volts/current not adequate, could be high circuit resistance interference.

Here's a very very basic wiring guide for the OKL2-T20 negative logic version...

(http://www.mamumods.com/pics/okl2-t20-basic-wiring.png)



Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on November 19, 2014, 03:17:07 PM
what is n-fet for ? is it to avoid battery for draining when box mod is unuse? thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on November 20, 2014, 12:13:23 PM
what is n-fet for ? is it to avoid battery for draining when box mod is unuse? thanks

For the OKL2-T20, the N-FET is used as a switch/driver for the on/off control plus convert this negative logic board to positive logic in order to be able to use a zener diode for low voltage cutoff.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on November 20, 2014, 03:15:52 PM
can i use zener with out it and switch? thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on November 20, 2014, 03:34:17 PM
can i use zener with out it and switch? thanks

No, you cannot use a zener without the N-FET for the negative logic version.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: zotek on November 23, 2014, 08:59:08 PM
i dont get this one 4x 47uF 16v output caps in parallel (GRM32ER61C476ME15L)

that is this for? thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: LeeM on December 17, 2014, 11:28:36 AM
can anyone please help me out with wiring a switch on a positive board rather than the negative?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: LeeM on December 17, 2014, 12:44:49 PM
A humming/buzzing sound indicates the converter is being overloaded/overworked.  Could be from a too low ohm coil build, could be output voltage set too high for the coil you're trying to use, could be source volts/current not adequate, could be high circuit resistance interference.

Here's a very very basic wiring guide for the OKL2-T20 negative logic version...

(http://www.mamumods.com/pics/okl2-t20-basic-wiring.png)

carried on reading, and if i have the positive board could i use this a basic diagram but rather than wiring the switch to ground i wire it to battery positive?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on December 19, 2014, 03:48:32 PM
LeeM - wire the positive board just like the Raptor 20A, except keep the same trim resistor and POT as for the negative logic version.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: wallie88 on March 02, 2015, 02:11:35 AM
I just got a okl t20.  I've  put it together and it is autofiring. I really don't  know what I'm doing, I'm just trying to fallow along as best as I can. I know it's hard to say without any info but if any of you have to guess what do you think is the problem? Is i have the 20k resistor on 1 and 2.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on March 02, 2015, 05:19:20 PM
Did you use the positive logic OKL2-T20?  The wiring here is for the negative logic.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: wallie88 on March 02, 2015, 11:18:32 PM
Thank you. It's is the posistive logic t20.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on April 05, 2015, 09:52:38 AM
Hi again everyone! I hope you've all had great couple of months!!

I'm back at it. My hiatus lasted a little longer than anticipated, but I started work on an OKL2-T20 yesterday. This will be my first mod with this board. So far, I've gotten all of my leads attached to the board, tucked away, and wrapped up.

Things are definitely going more smoothly than my first box, lol. It really helps to have done this before. It still requires a lot of patience and imagination, but having already made several mistakes and learned from them, this should prove to be a much more pleasant experience!

Here are a few pics of how I wired the board:

(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20/IMG_20150404_215442_zpsabp2zyow.jpg)

(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20/IMG_20150404_225209_zpsd37wezb0.jpg)

(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20/IMG_20150405_003728_zpsdl51b0cz.jpg)


I know a lot of people want to see how everyone does this, so I've tried to take some decent progress pics, all of which I will upload to a new thread for this build. You can see that I've soldered the caps directly to the pad (or maybe you can't see...but I tried, lol) Lots of people ask about this, so I'll try to have more clear pics on the thread.

If you have any questions or comments, feel free to let me have it! I have very thick skin, so don't hold back!! I'll try to help in any way I can. If I don't have an answer.... well.... that's why we have Craig hangin' around! :P

I'm really excited to get back to building! I've gotta run to Lowe's this morning to pick up some epoxy and whatnot, but as soon as I'm back.... it's on!  :rockin smiley:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: eveshka on April 09, 2015, 04:14:30 AM
This setup looks nice.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: everett464 on April 17, 2015, 04:06:37 AM
I just wired up an OKL T20 and I am getting a clicky sound at the low end of the pot - no fire, just clicks. At .52 ohms I was able to fire somewhere around 4 volts, at 1.6 ohms it didn't fire until 4.5 or so.
Any ideas? It's a negative logic board, wired as per mamu's guide, without caps, diodes, etc.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: everett464 on April 18, 2015, 03:38:17 AM
Ok folks, I've figured it out (after wiring a second board the same exact way). Not only did I forget the resistor on the pot leg, but I wired my pot backwards. Sincerest apologies. I appreciate the help. Doh:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on April 18, 2015, 04:27:51 PM
Well, that happens even to those of us that have been doing electronics projects for ages.  The first thing I look at when I have a problem is my wiring.  The vast majority of the time I find something there I did wrong.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SoLongSidekick on April 22, 2015, 05:39:53 PM
Hey so I was hoping to get some quick help. I'm trying to design a PCB that I will open source that you can just solder the OKL2 on, solder in your through-hole components, jumper the rest and you're done. I normally just jank all my stuff together by hand so I am not very good at this so I need some help haha.

Are you guys just tying all your GND lines together or actually attaching them to something? Also, I want to use an seven segment display, if I'm not mistaken I need to mount pin1 to the +Sense and pin2 to the -Sense right?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: dc99 on April 22, 2015, 09:53:28 PM
Something like this? Theres a few been designed
https://www.oshpark.com/shared_projects/rn413IO3
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SoLongSidekick on April 23, 2015, 01:06:34 PM
Something like this? Theres a few been designed
https://www.oshpark.com/shared_projects/rn413IO3

Pretty much, but I'm hoping to cram it in a 1590G enclosure so I'm not sure if that one will work.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: dc99 on April 23, 2015, 04:23:37 PM
Should be easily doable with the right sled. I have a few I got from a guy on ebay that slide the batteries way to the right. David4500 has a real nice one on shapeway. http://www.shapeways.com/product/LQTRK7PNZ/18650-dual-holder-staggered-v1?li=search-results-1&optionId=55531890
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: CraigHB on April 23, 2015, 04:24:33 PM
Are you guys just tying all your GND lines together or actually attaching them to something?

Not sure exactly what your asking, but typically with PCBs and grounds you use a "ground plane".  In your PCB design software you should be doing a copper fill on the bottom to serve as ground and run your circuit traces on the top side.  Any ground connections you need for components on top should connect to the ground plane through a via.  You usually can't avoid a few traces cut into the ground plane, but it's best to avoid that as much as possible.  The more solid the ground plane the better.

Ground planes are important for reducing electrical noise and it also makes it more convenient to route your component connections.  Ground connections are the most common ones and they can be picked up from a ground plane easily with a via or array of vias for high current connections.

With home made PCBs doing two sided boards with vias can be rather involved.  It's possible, but not really worth the effort when you can get them fabbed for cheap from places like Osh Park.  For a home made single sided board you can use a copper fill to act as your ground plane.  Doesn't work all that well since you have to cut it up pretty heavily to route component connections.  It's much better to use a ground plane with a two sided board.


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SoLongSidekick on April 24, 2015, 05:29:36 PM
Not sure exactly what your asking, but typically with PCBs and grounds you use a "ground plane".  In your PCB design software you should be doing a copper fill on the bottom to serve as ground and run your circuit traces on the top side.  Any ground connections you need for components on top should connect to the ground plane through a via.  You usually can't avoid a few traces cut into the ground plane, but it's best to avoid that as much as possible.  The more solid the ground plane the better.

Ground planes are important for reducing electrical noise and it also makes it more convenient to route your component connections.  Ground connections are the most common ones and they can be picked up from a ground plane easily with a via or array of vias for high current connections.

With home made PCBs doing two sided boards with vias can be rather involved.  It's possible, but not really worth the effort when you can get them fabbed for cheap from places like Osh Park.  For a home made single sided board you can use a copper fill to act as your ground plane.  Doesn't work all that well since you have to cut it up pretty heavily to route component connections.  It's much better to use a ground plane with a two sided board.

Yeah sorry I should have been way more clear. I understand how it works on fabbed PCBs, I was wondering how you did the ground when wiring by hand. Did you just attach the ground wires directly to the case (if metal) wherever convenient? Or did you have them all meet at a central point and just connect to each other?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: everett464 on April 24, 2015, 05:45:34 PM
I ran through this last week - started this thread with some pics.

E

http://www.reddit.com/r/OpenPV/comments/32pwu2/ground_wire_bundles_okl_t20/
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SoLongSidekick on April 24, 2015, 06:07:34 PM
I ran through this last week - started this thread with some pics.

E

http://www.reddit.com/r/OpenPV/comments/32pwu2/ground_wire_bundles_okl_t20/

Thanks for the resource, but it still doesn't mention exactly how/where they're connecting the GND wires. It looks like he's just connecting them all at one spot and not connecting them to the case, but I just want to be sure.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: everett464 on April 24, 2015, 06:27:52 PM
He is me, and in that instance, the ground circuit is tied to the box through the atty - just like most of these boxes.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SoLongSidekick on April 24, 2015, 06:28:52 PM
He is me, and in that instance, the ground circuit is tied to the box through the atty - just like most of these boxes.

So you just run all the ground lines together and terminate them at the - atomizer contact?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on April 24, 2015, 07:15:50 PM
It depends on where and how your parts lay.
I would run a heavy gauge gnd wire from the battery (-) to which ever is closer, the 510 or Pin 4 on the board. If the 510 is closer than from 510 to pin 4 or vice versa. All the rest of the gnd connections are light gauge and can be connected to the nearest ground point as mentioned above.

Keep wiring as short as possible. Go for the shortest run.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SoLongSidekick on April 24, 2015, 07:18:11 PM
It depends on where and how your parts lay.
I would run a heavy gauge gnd wire from the battery (-) to which ever is closer, the 510 or Pin 4 on the board. If the 510 is closer than from 510 to pin 4 or vice versa. All the rest of the gnd connections are light gauge and can be connected to the nearest ground point as mentioned above.

Keep wiring as short as possible. Go for the shortest run.

Great to know, thanks! The last piece I'm missing (I'm hoping to have a "no shit" moment) is the other ground points. I get that connecting to the box is not the way to go, so would the best route be to connect every line that goes to ground to either the 510- or PCB-, or could I run them to both depending on which one is closer to the particular ground line I'm working with?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on April 24, 2015, 07:26:11 PM
The other ground points can be connected to the nearest heavy gauge point. They don't all have to be connected to the same point. You can use the closes 510, pin 4 or the batt (-) for the neg light gauge points. Each can be at a different heavy gauge connection points.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SoLongSidekick on April 24, 2015, 07:27:42 PM
The other ground points can be connected to the nearest heavy gauge point. They don't all have to be connected to the same point. You can use the closes 510, pin 4 or the batt (-) for the neg light gauge points. Each can be at a different heavy gauge connection.

Awesome thanks for the help guys! Last question, I'm assuming it would be ok (for example) to just connect a wire I need to ground directly to the negative battery terminal where the heavy gauge wire connects?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SoLongSidekick on May 05, 2015, 02:15:57 PM
I think I have the wiring all figured out after receiving help from you guys; so a thousand thank you's for that. Now I am going over everything to see if I can save any space anywhere. I looked high and low for an SMD fuse that matched the specs of the fuses listed in the first post but I had no luck. What I was able to find were these: http://www.mouser.com/Search/ProductDetail.aspx?R=2920L500%2f16MRvirtualkey57610000virtualkey576-2920L500%2f16MR.

Would I be able to wire 4 of those 16V 5A guys in parallel? I rarely work with fuses so have very little experience with them.

My plan is to mount any SMD version of the listed components I can find on an SMD proto board and place it directly under the OKL board.

Does anyone see any reason I wouldn't be able to use this P-Channel MOSFET? http://www.mouser.com/ProductDetail/Infineon-Technologies/SPD50P03L-G/?qs=sGAEpiMZZMshyDBzk1%2fWi9Xn%2fBYY8cyRFNbcNaxpP1M%3d

Since the N-Channel is so small I'm not going to bother trying to fin an SMD version.

Any help on the above is greatly appreciated. Hopefully this can help anyone trying to use a 1590G in the future.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: screwfunk on May 17, 2015, 10:54:54 AM
I thought I would share really quick on how I wire up the OKL. It really helps me to make it compact and clean. I solder the mosfet legs directly to the chip like so. It makes for a rather thin build. I just strap the fuses to the top and away we go. You cant really see it but the drain leg is folded upwards and I have it folded over and soldered to one side of my fuses.

(https://c2.staticflickr.com/6/5454/17775642366_4e5b9c4e2b.jpg)[/url]
(https://c2.staticflickr.com/6/5464/17179451714_6e697b3e48.jpg) (https://flic.kr/p/t5LPbw)
(https://c2.staticflickr.com/6/5325/17181591883_51d6be4e9c.jpg) (https://flic.kr/p/sb6btm)OKL
(https://c1.staticflickr.com/9/8717/17802385141_d07fd47ed0.jpg) (https://flic.kr/p/sbh9EP)
Hope this helps...

Sam (https://flic.kr/p/t88SSR)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on May 17, 2015, 11:26:01 AM
I thought I would share really quick on how I wire up the OKL. It really helps me to make it compact and clean. I solder the mosfet legs directly to the chip like so. It makes for a rather thin build. I just strap the fuses to the top and away we go. You cant really see it but the drain leg is folded upwards and I have it folded over and soldered to one side of my fuses.

Hope this helps...

Sam

Very good Sam. I luv compact parts and wiring layouts.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SoLongSidekick on May 20, 2015, 02:32:39 PM
I thought I would share really quick on how I wire up the OKL. It really helps me to make it compact and clean. I solder the mosfet legs directly to the chip like so. It makes for a rather thin build. I just strap the fuses to the top and away we go. You cant really see it but the drain leg is folded upwards and I have it folded over and soldered to one side of my fuses.


Sam

That's outstanding, thanks for posting! So are you not using the twin parallel caps from Vin to Gnd?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Poppy26 on May 20, 2015, 04:32:38 PM
Thanks Sam for posting. Very helpful
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: screwfunk on June 05, 2015, 02:50:48 AM
@SoLongSidekick

Check out the second picture. on the right hand side right next to the fet. That little square package with two black wires hanging out to the left. That is the Dual caps.

Sam Champlin
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: krazymonkeys on June 30, 2015, 07:46:06 PM
I was curious if any of you ever tried out using PTFE resistance wore for load testing these mods? You can get wire that's wrapped in fiber glass that withstands over 1000* F in many different ranges of resistance.  May not be truly necessary, but when doing your initial test builds and finding out what works, it's nice to have a much more easily configurable load that you can't melt or otherwise destroy. Beats risking an atty or components.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on July 05, 2015, 03:11:34 PM
Going to try this one myself here. Question though: Is it ok to use the n-fet posted  without the zener diode? As in as just using it as the switch activator?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: lakethomason on July 09, 2015, 03:45:54 AM
Wow! I was reading this thread a year ago, can't believe it's still alive. You guys are awesome.

I just have a few questions

1. What happened to mamumods.com/forum !!?

2. Input caps! I have this feeling in the back of my head that I read the answer somewhere in here, but ctrl f 'caps' on every page brought no answers :( ... What gauge wire is recommended for the output caps? 20?

Now that summer is here (again) I'm here to finish my 1590g okl t20 box!

cheers
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on July 09, 2015, 11:19:55 AM
Going to try this one myself here. Question though: Is it ok to use the n-fet posted  without the zener diode? As in as just using it as the switch activator?

Yes, is ok - the zener is not required for the circuit to work correctly.

Wow! I was reading this thread a year ago, can't believe it's still alive. You guys are awesome.

I just have a few questions

1. What happened to mamumods.com/forum !!?

2. Input caps! I have this feeling in the back of my head that I read the answer somewhere in here, but ctrl f 'caps' on every page brought no answers :( ... What gauge wire is recommended for the output caps? 20?

Now that summer is here (again) I'm here to finish my 1590g okl t20 box!

cheers

I turned the forum off quite some time ago.

Caps are optional for this converter.  I use input caps, but there is no need for output caps.   No conduction current flows through the cap, so very thin gauge is aok.  I solder resister legs to the ends of the cap, then heat shrink the works.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: lakethomason on July 09, 2015, 02:02:53 PM
Ah, thanks for the reply mamu! Are you on reddit much? I'd give you gold for sticking to this thread for so long! ;D

From your comments, I made my own P version okl 20 diagram, would you mind checking it out?

https://drive.google.com/file/d/0B4bLHfNgUpiNNXJxWFlNYUFzNkdVVXhyZUgxank4WFVScEhn/view
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on July 09, 2015, 07:30:14 PM
Yes, is ok - the zener is not required for the circuit to work correctly.

Thanks Mamu!   Should have this done sometime Saturday!   :rockin smiley:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: lakethomason on July 10, 2015, 03:53:32 AM
Just got my jumbled mess of wires all together and good news is, it works!

Bad news is that my output is a little odd.

When my poteniometer is cranked to the max, the output only reads at about 3.37 volts, while cranked down, it reads 0.68 volts.

Its odd because thats about a 2.5 volt difference, which is the same as the 3.0 to 5.5 it should be reading at.

I have the 1k potentiometer thats listed in the parts in the OP, and I have the correct resistor on there.

Anyone have a clue as to what could be going wrong?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on July 10, 2015, 08:38:41 AM
Sounds like you may have an open portion of the resistance sweep in your pot. A voltage output of 0.69V indicates "OPEN".
Try another pot.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: lakethomason on July 10, 2015, 04:14:37 PM
Thanks breaktru!

Somehow the pot worked this morning! Got it reading a solid 5.5 when cranked up.
My only problem now is autofiring :/
Unfortunately I'm using the positive okl t 20 chip, I read through mamu's advice and wired 20k from on/off to ground, and I wired the the button from on/off to vin. I don't have sense wired yet.
Any idea what i'm doing wrong here :/

EDIT: Aaaaaaand I'm an idiot.
I have the negative version. Had the positive before, thought it didnt work, used the negative version that I bought a few months ago thinking it was another positive version. Time to wire this baby up for reals.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on July 11, 2015, 09:28:28 AM
EDIT: Aaaaaaand I'm an idiot.
I have the negative version. Had the positive before, thought it didnt work, used the negative version that I bought a few months ago thinking it was another positive version. Time to wire this baby up for reals.

Shit happens. We've all been there too

There could be dead spot on the pot.. hence the 0.68V output.
When you get it rewired up, try moving the pot very slowly to see if you hit a dead spot.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: lakethomason on July 17, 2015, 04:56:24 AM
Guys, I did it :D

The lid had to be ground down to the max, which is entirely my fault.
..and I had to electric tape everything because I was still getting some weird short.
 and I still don't have a knob for my potentiometer..

But I did it! I have more pics if you guys want more ;)

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on July 20, 2015, 10:03:29 AM
Nice setup Screwfunk!! I'm definitely going to put as much as I can on the board next go-round.

**edit** You too, lakeT! Looking good!!

I had to take a little time off for family funks, but I'm back in the saddle now. I got everything wired up and into the box before my little hiatus, but I still needed to tie in my grounds and tidy things up.

When I picked back up, I ran into an issue. I wasn't getting any power output. When I checked with the dmm, I had 8.4x volts across my sled, but it just wasn't getting to the board....  Being out of the game for so long again, I wasn't really in my groove. I started pulling parts out to check for cold solder joints (i've never had a cold solder joint), and I just didn't see anything wrong.

So.... I took a step back, breathed for a few minutes, fixed me a cup-a-joe, and my brain started working again. I realized that I was sticking the probes of my dmm down in between the battery terminals and the sled contacts. I noticed that if I moved to the outside of the contacts (not touching the batteries themselves), I wasn't getting power across. Since I did get 8.4x volts touching the (+) of one battery and the (-) of the other, I knew that the two contacts connecting the batteries in series were good, so it had to be either the positive end of the series or the negative end. Turns out I wasn't getting good contact at the positive point.

I pulled the batts out, bent the contact out a little, stuck them back in, and viola! Power!!

Moral of this story.... Troubleshooting 101: Always start with your battery holder (as I've read here many times).

It looks like crap now because I had to splice components back into the circuit, but I've almost got it all back together. I hope to finish it up tonight after work. I'll get some pics up when I'm happy with what I've got.

Good luck everyone! And don't get discouraged!! Things are usually simpler than we're making them out to be.  ;cheers;
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on July 21, 2015, 09:18:35 AM
Okay... I got everything tied back in last night, and she fired right up.

Problem: My Vo range is abnormally high, 6.05V-7.xx.

When I get home this evening I'll see what I can do. It was late when I finished up, so I shut her down while I was ahead. Any progress is good progress, right?

My pot is epoxied into the enclosure already, so that's gonna be a real pita if I need to swap it out, but I'll manage. I have a couple different pots in my stash, some 200ohm and some 1kOhm, for different boards, but I really thought I used a 1k. I keep them in separate bins. Would a 200Ohm pot cause the voltage range to run that high? I'll pull out my dmm tonight and test the pot to make sure.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on July 21, 2015, 10:05:23 AM

Problem: My Vo range is abnormally high, 6.05V-7.xx.

Would a 200Ohm pot cause the voltage range to run that high?


Yes 200 ohm pot is too low. Also your fixed resistor is either too low or not wired in correctly.
Even with the wrong pot zeroed out, the fixed resistor alone comes into play giving you the top end of the voltage output range.
Hint: The lower the ohmage the higher the output voltage and visa versa.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on July 21, 2015, 10:15:35 AM
Yes 200 ohm pot is too low. Also your fixed resistor is either too low or not wired in correctly.
Hint: The lower the ohmage the higher the output voltage and visa versa.

Awesome, thanks man!! I didn't even think about my fixed resistor. I'll check everything when I get home from work.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on July 21, 2015, 08:40:39 PM
That was it. I forgot to put the fixed resistor back in the circuit....

3.5-5.5Vo

Now I've just gotta tidy up, and I'll be done with this one. Thanks again Breaktru! It always pays to have a little outside perspective!

 :rockin smiley:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on July 21, 2015, 08:53:59 PM
Great. Good to hear it's working now.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on July 23, 2015, 10:03:16 AM
Great. Good to hear it's working now.

Thanks man. It definitely feels good to finally finish what I started back in April.

I thought I'd upload a few pics for you guys. You'll have to excuse the nasty mess of wires. As I said in an earlier post, I got a little frustrated while troubleshooting and cut the components out, just to find out that it was completely unnecessary
 :wallbash:

So... what you're seeing is a bunch of excess wire from splicing everything back into the circuit. I'm not planning on selling this one to anyone, so I wasn't too worried about looks. As long as it vapes, it's good. I have all the parts (minus an enclosure) to build another like it, so I'll be starting on that sometime soon.
Although, I've gotta get a new soldering iron. I was trying to change the tip, and it twisted and broke right off.... Luckily, I have a nice butane torch with a soldering attachment, so I could make the final few solders to finish this one up.

This first pic is from a couple months back, before everything was cut out.
(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20/Day_3%203_zpslsvsxdif.jpg)

(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20/July22%204_zpsuf5uqntm.jpg)

(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20/July22%203_zpsgkejg8e7.jpg)

(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20/Top_zpsr1hsroxy.jpg)

Side by side with my Raptor mod.
(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20/sideBySide_zpskshvm0gt.jpg)

This is an inside view with some text boxes I added at work yesterday. I thought it might be helpful to some of those who haven't finished one yet.
(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20/Inside%20with%20text_zpspinxxoj2.jpg)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on July 23, 2015, 11:27:17 AM
Really came out rather well  :rockin smiley:
Nice looking pot too
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: vaperkarma on July 23, 2015, 11:34:22 AM
good one bamanered. looking good guy  :thumbsup:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on July 23, 2015, 12:03:11 PM
Thank you much, fellas!  :beer-toast:

I can't wait to get started on the next.

**edit** I'd REALLY love to try an MCU build. I've been doing some reading on it, but I don't know that I'm quite ready to start one. I've got some C++ experience, so that should definitely help. I just like to do as much research as I can before I get started on anything.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on July 25, 2015, 01:45:39 PM
I read through this thread several times in anticipation of of he arrival of my okl2-t/20s with my PWM PCB components. Well they arrived yesterday and I've got the box wired up, had some issues that it wouldn't fire at all even though voltage was entering and exiting the chip as expected, until I removed the positive sense from the positive terminal to Vout ( I now realize its supposed to be connected to either the positive 510 or Vout -_- durrr). Anyway, now its working great but I have a high pitched squeal when I turn it up past about 50%. I've searched this and couldn't find much about it. Is this normal?

I haven't gone all out with it yet(left the fuses, caps, pfet and diode out), just went for the minimalist, working mod and plan to add the caps, fuses, and everything else in when I have more time, so I'm not sure if that could be the cause since I didn't use the capacitors?

Thanks for any help, and thank you Manu for the awesome, easy to follow diagrams! Its greatly appreciated
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: hill115side on July 25, 2015, 01:56:00 PM
Hello guy

I did go off and design a PCB board for the T20 and others as well.  Just wanted to show you what I can up with.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on July 25, 2015, 02:00:56 PM
Hello guy

I did go off and design a PCB board for the T20 and others as well.  Just wanted to show you what I can up with.

Is that for a 1590g? Are you selling the boards or have unpopulated ones available anywhere? Looks pretty nice!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on July 27, 2015, 10:42:41 AM
I did go off and design a PCB board for the T20 and others as well.  Just wanted to show you what I can up with.

Looks good Hillside.  :thumbsup:
I'd definitely be interested in getting my hands on some, too. Let us know.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: hill115side on July 30, 2015, 08:27:37 PM
Send me a pm with your Number and I will reach out.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on August 07, 2015, 03:25:20 PM
I found this the other day, so I thought there's no way I'm not sharing this with you guys.

https://squareup.com/market/modpcb

Someone has designed and is selling pcb's for the OKL2-T20, the Raptor, and for PWM mods. Check it out. You just solder your board to the pcb, along with some smd parts, and you're done. Pretty effin neat. They're only 15 bucks a pop. I know I plan to grab a few to play around with soon. They even link to another site (link below) that sells CNC Aluminum enclosures with a 1590G 'tallboy' specifically designed to hold one of these setups.

http://modcrate.myshopify.com/

Enjoy!  :beer-toast:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on August 07, 2015, 03:30:41 PM
Oohh crap... Sorry Hillside!! I just saw your post.... I didn't mean to dump on you like that :(
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on August 26, 2015, 10:43:42 AM
I've been working on a new one here and there over the past few weeks, and I've just about got everything ready to go in the box. I've slowed way down on this one, and have been trying to take my time to produce a nicer, cleaner end result. I'm also trying to put it all into a 1590G sized CNC enclosure that I got from ModCrate, which is a royal pain in the arse. I could have easily left out some of the extra components like the Pfet and the Nfet, and went with a very basic schematic, but I wanted to do it right. I like the challenge anyway.

I'm gonna post a couple pictures below, so you can see how it's coming along. In the pics you can see a part that I've designed and uploaded to Shapeways for printing and ordering. This part is a drop-in switch holder that holds the two switches in the circuit and the reverse polarity indicator LED. I really think this is gonna add a nice touch when it's all said and done. I've also started designing some other things, like a bezel for the same switch that functions just like the digital voltmeter bezels that many of us use. I'm not using that one in this mod, but I'm really excited about using it in the next one.

Well... here goes nothing. Keep in mind that I haven't cut my holes in the enclosure, or finished up the wiring. I've just got things sat in there to see how it's all fitting. This is an extremely tight fit!! Let me know what you think.


(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20%20version2/20150825_193043_zps42j7r617.jpg)


(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20%20version2/20150825_214437_zpsxwbsqc9f.jpg)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on August 26, 2015, 11:10:57 AM
Nice going bamanerd. Great work so far  :rockin smiley:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on August 26, 2015, 11:47:30 AM
Thanks man  :beer-toast:

It definitely gets better with each iteration.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on August 30, 2015, 02:03:57 AM
Where do you fit the 510 and button in that thing?!? I've been considering an OKL 1590G build but from the looks of it I'd have to use a tiny tactile switch rather than a 12-16mm momentary :/
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on August 30, 2015, 10:08:19 AM
Where do you fit the 510 and button in that thing?!? I've been considering an OKL 1590G build but from the looks of it I'd have to use a tiny tactile switch rather than a 12-16mm momentary :/

Hahaha! Yeah.... it's an extremely tight fit. It's been a real challenge trying figure out how to make it all fit.

You're absolutely right. I had already planned to use a tactile switch in this one, so I wasn't too worried about that, but the 510 has been causing me a great deal of concern. I got my hole cut for the 510, and everything sat in there last night. Just as I suspected.... the 510 sits right on top of the board. Like flush, right on the board. This is a FDV v3 that I had in the drawer, and after days of moving and squeezing and soldering and resoldering.... I finally ordered a V3 Shorty last night, once I realized that this one definitely isn't going to work in this setup.

I feel sure that shorty 510 will work just fine. It should be here by Wednesday or Thursday, so I'll let you know as soon as I get it and stick it in there. This is gonna be a really nice looking mod once I get it all done, so it's definitely worth the extra effort to me. So.... just something to think about. If you have the time and the patience, give it a go! I think you'll really be pleased with it.

One thing that I'm super pleased with is my switch holder that I designed. Last night I got the switches and my reverse polarity LED placed in there with the excess wire tucked underneath, and filled it with epoxy. It came out great!! I will definitely be using this from now on.


Here's a pic of the space situation with the 510.

(http://i64.photobucket.com/albums/h186/Snypercell/OKL2-T20%20version2/SpaceSituation%201_zpsnxrbbuqs.jpg)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on August 30, 2015, 10:34:54 AM
I was able get more clearance for the 510 by grinding down the lower corner and sliding everything down.
You may be able to leave the top part of the corner so you can mount a magnet.
I used a dremel w/ the bits shown attached below...
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on August 30, 2015, 11:03:45 AM
Those are my go to bits too, breaktru, for dremeling those corner posts of a Hammond box.  The bottom one I also use for thinning inner walls if needed.

bamanerd and MonkeyTokes - it's doable to fit the OKL2-T20 in a 1590G, plus all the works like fuses, RPP, voltmeter, as well as a mitec 12mm switch (it has very little depth so is doable).

It's also doable to fit the works in a tiny 1550P with some intense dremel work on the inner side walls and dremeling the underside of the corner posts, leaving a lip to glue magnets in.

My motto... make it work!  :laughing:

These are Raptor 20A mods, but both boards are similar size.

1590G...
(http://www.mamumods.com/pics/avani1.jpg)

(http://www.mamumods.com/pics/avani2.jpg)

1550P...
(http://www.mamumods.com/pics/avani3.jpg)

(http://www.mamumods.com/pics/avani4.jpg)

(http://www.mamumods.com/pics/avani5.jpg)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on August 30, 2015, 11:18:39 AM
For the 1590G - do like breaktru says and dremel the underside of the lower corner post so you can seat the sled on the bottom inner wall.  Leave just few mm of the post so to glue a magnet in.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on August 30, 2015, 11:28:49 AM
For the 1590G - do like breaktru says and dremel the underside of the lower corner post so you can seat the sled on the bottom inner wall.  Leave just few mm of the post so to glue a magnet in.

I was thinking about doing that. I wasn't sure what the best bit would be, though. Your pictures really help, breaktru. Thanks very much, both of you!!

I LOVE those 'P' boxes, Mamu!!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on August 30, 2015, 02:59:55 PM
I'm surprised you guys go through the trouble to notch out the box rather than the battery holder itself. I also use the little tungsten carbide bits on my aluminum boxes, though mainly to modify the lip around the lid to fit the nut for the switch and such.

Those are some really nice looking boxes though Mamu! I'm gonna check out those switches, for some reason it hurts my soul to see people resolved to using the little DNA tactile buttons in a Hammond box as a fire button :/

Bamanerd, that is a really nice job. I'm diggin' the switch holder as well! Did you 3D print that, get it made through shapeways or? I've still got a few OKLs on hand, I think I'm gonna give it a go and worst case just move it over to a B box if I can't swing it with what I've got on hand. Sadly I'll probably have to get a FDV connector(I'm not a fan) or modify one of my varitubes to fit. Hell, I barely can fit my TO-220 mosfets in a 1590G while using the "vaping underground mosfet PCB" from osh park without the connector touching. I'll definitely post some pics if it goes well.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Morphoys1979 on September 02, 2015, 11:40:12 AM
Hi Guys, thank you to Take Part of your Forum, that´s awesome.
Since one Week my OKL20 Negative Version is running very well in my 1590B Box. I only have one Problem with the LVC and I don´t know what is the issue. I wired everything up like the Mamu Diagram shows including all Safety Parts etc. When the Battery-Power reaches 7.4 Volts input Voltage, my output Voltage goes slowly down. I adjusted 3.65 Volt, for my 0.4ohm atty. So when I reach 7.4 volt Battery Power the Output goes slowly down to 2.8 Volt and the ship makes a noise like zzzzzzz. Not loud but i Can hear it. Above 7.4 Volt Input everything is as it should be. Can someone help me with my Problem.

Thanks to everyone who can help.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on September 02, 2015, 11:56:36 AM
I'm not sure I completely understand, but I do know the noise you're refering to. My OKL boxes make that noise when the batteries are nearly too low to even fire the mod. Is it 2.8v  under load from your .4ohm atomizer or just a voltmeter/multimeter? My guess would be if you turn the potentiometer up slightly so the output voltage is back up to 3.65v the noise should go away.

Its not a fix but it should do the trick. I think the chip just kind of whines when voltage is low
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on September 02, 2015, 12:02:32 PM
How old are the batteries you're using? That buzzing is the chip being under powered. With a .4 ohm build, if the batteries aren't in really good condition it can cause your input voltage to drop significantly while firing, which will cause this. I have an old set of VTC 4's that does that exact same thing.


@MonkeyTokes Yeah, i designed it and uploaded it to Shapeways for printing. You can search for it using my screen name (I think) or my shop name on there, Infamous Mods. I have a few on there. Two 1590B sized ones and the one 1590G. I also have a nice switch bezel for the outside of the box on there (like the screen bezels we've been using).

I'm working on some other things in my spare time, too. Once I get them printed and tested, they'll be available. Also, keep in mind that all of these switch holders are designed for these switches http://www.mouser.com/Search/ProductDetail.aspx?R=1101M2S3CQE2virtualkey61170000virtualkey611-1101M2S3CQE2 (http://www.mouser.com/Search/ProductDetail.aspx?R=1101M2S3CQE2virtualkey61170000virtualkey611-1101M2S3CQE2), but should work for anything that is that size or smaller. It works for both two position and three position switches alike. I have one of each in the one pictured.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Morphoys1979 on September 02, 2015, 12:41:18 PM
Hi Monkeytokes and bamanerd,
I tried different Batteries, VTC5, Efest 35amp, Samsung 25R, and is the same Problem. It happens under Load and also with 0.7ohm and 1.2ohm atty.
Without Load everything is fine with adjusting the output. Under Load the output breaks down slowly. Everytime when the Input Voltage goes under 7.4 Volts I can do nothing else as change Batteries. I also have a Raptor build and there works everything as it should. There is a cutoff at 6.4 volt and I´m Lucky. In my OKL Build I´m loosing a lot of Battery - capacity and thats bad. When I recharge the VTC5 with my opus 3100 they start at 3.7 volt and take 1000mAh. With the Raptor-Mod they start loading at 3.2 Volt and take 2200 mAh that is a big difference. Could it be that there is another mistake in my OKL Mod.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on September 02, 2015, 02:14:39 PM
I'm really not sure man. I'm really not super knowledgeable about all of this. I only know the problems that I've encountered. I do know that my OKL2-T20 also hits LVC at higher average voltages than my Raptor does. If I'm running a higher resistance build, say.... .6+ ohms, then it will discharge to about 6.8-7.2V before LVC.

If I'm running bare minimum, .3ohms, then it can start LVC anywhere between 7.4-7.7V depending on the batteries I'm using and the voltage I'm vaping at. A quick fix is to just dial it down a little, and keep on vaping at slightly lower voltages incrementally. Maybe there's a higher internal resistance in this build. I don't know.

I feel sure that if you give the guys some time to look it over and think about, someone who knows this stuff inside and out will respond with some insight when they get a chance. The guys around here are really helpful. Tchuss!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on September 02, 2015, 02:23:11 PM
Awesome! I'm in the process of putting together my first shapeways order now for a couple DNA boxes for a local shop, I'll definitely check them out and maybe add a coupe to my cart for the rest of my OKL boards! By chance do you know of a DNA bezel on shapeways for the screen that also has two holes for the up and down butto? Something like the picture below? In I my expierence their search engine is a bit wonky. Looking for DNA bezels got me all sorts of custom enclosures and what not. Really I should finally invest in a 3D printer so I can learn to do it myself but that's another expensive commitment.

Morphoys - my only thought is maybe you used a different part than the ones in mamu's diagram? If so that may cause the results you're getting. Personally the only components i use aside from the OKL itself are fuses and capacitors. No low voltage cut off or reverse polarity protection so I'm not exactly sure what else it could be. Maybe a bad mosfet? Sorry I cant be if more help, im sure someone with a bit more expierence with this chip will be able to give you some tips.

If it were my mod I'd pull it apart and check your wiring and part numbers and values.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Morphoys1979 on September 02, 2015, 02:46:11 PM
Thanks Guys, maybe I should take the LVC out of the Box and change the wiring for this and take a look what happened. It is just bad, because it is fully assembled and that sucks. I`m just dissapointed about the less Vaping time compared to my Raptor. Sorry for my bad English, I´m German so that is a big challenge to be around here  :laughing2:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: bamanerd on September 02, 2015, 03:29:35 PM
Sorry for my bad English

No worries! Your English is actually really good. I don't think too many people would even notice that it's not your first language. You should hear/see the way some Americans speak....

My ex-wife is German. She lives in Schweinfurt, Bayern. What part of NordRhein Westfalen do you live in?


@MonkeyTokes I don't know man. I've never built a DNA, so I've never searched specifically for DNA parts. I do completely agree that their search function is cracked out, though!! lol

I REALLY want to get a 3D printer, too. Like bad.... but yeah... they're quite expensive. I really like the one that Dremel has recently come out with. It's about 900-1000 bucks. Costco has one that starts at 600ish. I've heard it's not bad. Something to look into.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Morphoys1979 on September 02, 2015, 05:47:28 PM
Hi Guys just want to give my feedback to you about my LVC Problem. I have taken out the 5.6v zener diode and now it runs. D'ont ask me why, cause in my Raptor build it works fine, but in my OKL board it sucks. Thanks to be Part of your community. I will go on to learn more about Modding  freaked_out:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Morphoys1979 on September 02, 2015, 05:54:25 PM
@ bamanerd
I live in Duisburg, that is near Düsseldorf and Cologne. Thanks for compliments to my writing in English, sometimes I feel like my English is not clear.

But learning by doing is the best, same with modding.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on September 09, 2015, 05:37:58 AM
Glad you got your mod working again! I wouldn't really sweat the English, a lot of times people who speak English as a second language speak English better than those whose first language is English :p

Bamanerd have you ever looked into an opebsource or  DIYkit for a 3d printer? They seem like a bit more work for the setup and getting everything working right but once you get it going they seem to work about as well as a $500-800 3d printer and you save $300ish. I feel like itd pay for itself pretty quickly just as something to play around with and test designs rather than ordering a sample from shapeways and waiting for it to be delivered then make adjustments and reorder it again and so on.

Anyways, one of my friends OKL mod started to auto fire, it worked for probably a month before with no problems. they said they were using it at 60% with a .5ohm coil but there is a clear burn spot on the board. Any ideas what the component is that has melted (see circled component in picture) and what could cause this to happen? I've got a new OKL on hand but I'd rather know what caused it before I waste it, ya know?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on September 09, 2015, 08:39:17 AM
MonkeyTokes - that's an N-channel MOSFET.  It's part of the switching circuit for the converter.  Surprising that it would fail, but does happen.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on September 09, 2015, 08:50:45 AM
If there was a burn spot on that part, maybe got a blast of current or short across it.  I'm not sure if reversed battery would cause that if there was no P-FET protecting that part of the circuit, but it might be a possibility.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on September 09, 2015, 09:17:23 AM
Thanks Mamu, that's what I was thinking, or exceeding 20A and the fuses not working for some reason. He assured me the batteries were in correctly but even I've put them in backwards before so who knows. He did say it worked for a 10 or so puffs before it started auto firing so I'm not even sure that's possible with the batteries reversed. Whatever it was definitely burnt it out good!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on September 16, 2015, 11:04:59 AM
Anybody ever figure out what needs to change in the wiring for the positive logic version? Would i just wire the switch to positive instead of negative?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on September 16, 2015, 05:41:33 PM
Yes - just wire it like the OKR and Raptor.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on September 17, 2015, 12:07:12 AM
Right but following the negative logic diagram results in the mod constantly firing and stops when the button us pressed. Well so people have said. Mine just makes a strange clicking sound.

I was just wondering if anyone has found a definitive way to wire them up to function properly.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: lakethomason on September 19, 2015, 12:48:59 PM
Hi mamu :3

First and foremost, thank you so much for your help and dedication to this thread! You. Are. Awesome.

I don't know if you're interested, but murata recently released an okr t 30 chip that looks decently similar to the okl t 20 with a removable heatsink. Right here : http://www.mouser.com/ProductDetail/Murata-Power-Solutions/OKR-T-30-W12-C/?qs=sGAEpiMZZMvNM%2fd3q5fCV8lqr4%252bbPfYq25w3WAz%2fTQc%3d

My friends and I are 3d printing a couple box mods and I was wondering if it would be wired similarly to the okl t 20

I read the data sheet a few times but I'm no electrician haha. I figured out what pot I would need through some research, and the step down resistor would be the same as the okl t 20 positive version (which I accidentally got the first time and am using now)

Perhaps on a slow day you could check it out?

Thank you :D
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on September 19, 2015, 03:02:23 PM
hey lakethomason... the OKR-T30 would be wired similar to the OKR-T10.

From reading the datasheet, external components for the OKR-T30 are the same as the OKR-T10.  The only unknown component would be the pull-down resistor.  I would start with a 5K first, then 1K.  Go with the highest that keeps the enable pin pulled low (off) as that would use the least amount of idle current.

POT - 200 ohms
RTrim - 220 ohms
zener diode - 5.6v, or 6v if using lipo
Input cap - optional, if using use a 22uF, 16v MLCC
bridge all Vout
bridge all Vin
bridge all gnd

I would highly recommend 3S for this converter for best efficiency and vaping longevity.  You really won't get best results with using only 2S.

Hope this helps!

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on September 19, 2015, 04:06:24 PM
Nice buck reg

Like Mamu says if you go 2s you'll only get 5v out to 510,  its swallows 2v off the top.
"Vin must be a minimum of 2V higher than Vout."

Its no where near the okl for our use IMO,  it will only give ya 30 amps @ +25c temp correction,  so if ambient is 25c add 25c and it will derate if not vented and even vented it still is derating huge without a fan..

The awesome part at full load 30A it only draws 13.2A  @3s..  Thats awesome.. 

But the OKL will do 30A easy and will not derate in warm/hot weather as fast..  But if it derates who can tell 160watts from 110 watts anyway both are hawt unless u got  huge gauge coil in there, like a 8wrap dual 32/24ga clapton or such.   :Thinking:  IDK why anyone vapes over 80 watts lol..  I get overnic'd just thinkin about it..
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: lakethomason on September 19, 2015, 10:03:01 PM
Okay, so I did some more research and have a few more questions..

First @Visus, you're saying that the okl can handle 30 amps better than the okr t 30? Perhaps I'm misinterpreting you. Why don't you think that 'its no where near the okl for our use"? Are you saying that the okr 'needs to heat up' before 30 amps can be achieved or something?

and @mamu,  that does help! Immensely, thank you. Do you think this chip could be used well in a box mod? I could put 3s in the box, but would I run into output issues if I removed the heatsink? Even if I kept it on?
And this will probably sound noobish, but what do you mean by bridging?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on September 20, 2015, 06:47:25 AM
Ya the okl is bad to the bone heres an extensive testing of it review..


http://vapingunderground.com/threads/okl-t20-chip-review.63318/

The chip you found is great in applications providing cfm's,  it is cutting some power to get that 30 amps for ya..  I am not savvy on the watts burn conversion to heat but its snatching 2v always and only asking at full load 13.2 amps(awesome) it is a total different build on the chip than the OKL.  For example my 08100 only grabs .89v over load, runs cool as a cucumber up to ~110watts..

The OKL t20 will put out 32A 189 watts at a 2s load.  @ 2s the OKL is awesomely efficient..
The t30 will become a hot box in your hand as soon as you get @~20A and will run warmer than you want at even lower loads..

The raptor series have 40A - 60A chips they are a much better choice IMO @ 2s/3s and @ 5v load it is ~96% efficient,  thats baddest to the bone..  The OKL's are not as effiecient as the raptor series until 3s and even then not ~96%..  It also only pulls .80v over load at max load out if 5v, it's even lower if below 5v its really an awesome cool running chip.. 

http://www.geindustrial.com/products/embedded-power/naos-raptor
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on September 20, 2015, 08:06:20 AM
The datasheet for all these OKR converters list it needs 2v higher input over output, but CapeCad over at ECF proved it's more like .8v - .9v.  Some of the overhead depends on the power you're requiring of it, circuit resistance, and batt sag - which is true for all these converters we work with.

Here's what I mean by bridging those connections..
(http://www.mamumods.com/pics/okr-t30.png)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on September 20, 2015, 10:20:15 AM
Thats great info Mamu ya 2v is huge I thought for a switching reg,  moving it back to old  regs that definitely are hot as hades grabbing definitely 2v under load.  I guess its saying build it giving it room lol...  I do like the okl 5.5v uvlo,  with the lgs at 2s it would not need a safety circuit as the lg's HE series runs comfortable down to 2.5v..  Meh I still like the raptors better if was to wire a high power reg but Ti also has a really good high amp reg with great specs but it is only usable above 3s http://www.ti.com/lit/ds/symlink/pth12040w.pdf..

I would wanna try that OKL t30 700mhz frequency tho see what it vapes like  :laughing2:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: lakethomason on September 20, 2015, 10:52:14 PM
Thanks for the info guys!

So if the okr t 30 is a bit mediocre, what would be the most badass chip I could put in a box? I'm looking for max wattage and something that wont overheat haha. Batteries are variables, we could go any way at this point, lipo 3s or li mn 2s. Something that's not the dna 200 chip for $80 :P

Bonus: We figured we could put wireless chargers paired with lipo batteries in our boxes, how cool would that be??

Also! What are the max voltage and wattage youve found the okl to be? If we marketed our boxes with these numbers should we change up the fuses as well?

And uhh.. what lipo batteries/website do you recommend I use?

<3
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: mamu on September 21, 2015, 06:12:19 AM
I wouldn't say that the OKR-T30 is mediocre.  Murata doesn't make mediocre stuff. :)

Modders have been making mods with the OKR line of converters for years now and they have stood the test of time.

You need to figure out what it is you want from the converter, lakethomason, and go from there. 
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on September 21, 2015, 06:41:43 AM
IMO

Check out David4500 555 PWM or Doobe's MCU PWM mod,  both can handle huge wattage.  There not any regulators under size humongous that can do what their boards in wattage can..  If your batteries can handle a ~1000 watt load their boards can do it with the right mosfets..  Basically if you go above 200 watts you also have to design an atomizer than can do it repeatably as it will melt and blow the top off almost all atomizers on market today...   

If you want plug and play ready to run regulator ease the Raptor series edition boards with Mamu's tutorial posts are hard to beat but stlll only up to ~400 watts.

I posted some badarse 3s lipo batts in parts for mods section ~35-70Aburst..

Most regulators are underated by a huge margin,  they have their reasons for doing that but we run them in seconds not always on so they will outlive us running above board specs..   The okl has a 14million hour always on life expectancy at their spec rating,  well the way we use them in under 10 sec bursts you can probably double that life expectancy lol.. 

@ 2s you cannot beat the OKL T20 overclocked it will do 32A,  the 20A 120 watt Raptors will do up to ~45A overclocked..

My uber opinion is; "there is not anything high power you can build that is not redundant to the Dna200"  other than David's and Doobe boards..  Your cost will be right at the ready to run Dna200 to build most high power regs..   
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on September 25, 2015, 09:18:41 AM
@Visus what do you mean by over clocking??
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on September 25, 2015, 07:19:22 PM
@Visus what do you mean by over clocking??

Termed for using it above or below min-maximum data sheet spec..

Used as a slang like as in computer overclocking get a bigger fan and/or heatsink no harm or foul.
Since we don't use it continually on just pulsing,  it works favorably..   
Data sheets do list the overclocking/above data sheet min-max setting limit...
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: lakethomason on October 05, 2015, 02:04:23 AM
Hey mamu, I basically built your okl t 20 box with the 20 amp fuses and all. Would I be able to run this thing at 32 amps @ 189 watts like visus says the chip can handle? I've been real close to the .275 ohm max at 5.5 volts, always been too afraid to test it haha
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Visus on October 05, 2015, 02:29:07 AM
Lake, You fused it to low to truly overclock it. 
Maybe it will,  some resettable fuses do not trip str8 away but if you try chain vaping it, it may..


Read the data sheet, not Visus, I go by the data sheets,  they tells ya when and what the chip will do..

32 amps max and the chip shuts down..   :wave:
-------
Mamu has said, 'she just buys the right chip to desired wattage and builds it to data sheet min-max specs not its absolute max of overclocking,  she no play around with that biznuss..  I do though if it goes boom I build another, none have failed yet  :laughing2:

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: MonkeyTokes on October 08, 2015, 09:12:43 AM
Thanks for the info guys!

So if the okr t 30 is a bit mediocre, what would be the most badass chip I could put in a box? I'm looking for max wattage and something that wont overheat haha. Batteries are variables, we could go any way at this point, lipo 3s or li mn 2s. Something that's not the dna 200 chip for $80 :P

Bonus: We figured we could put wireless chargers paired with lipo batteries in our boxes, how cool would that be??

Also! What are the max voltage and wattage youve found the okl to be? If we marketed our boxes with these numbers should we change up the fuses as well?

And uhh.. what lipo batteries/website do you recommend I use?

<3

I think the 40A or even 80A delta boards may work for ya. Personally 200watts is more than I need and can see anyone else needing but I suppose its cool to have. I have one of the 40A Delta's and it is surprisingly small. Way smaller than expected! I don't have any empty 1590Bs at the moment but from what I can tell if you slide the 510 towards the lid a bit it will fit in with a 3D printed 3x 18650 sled or even better with a 3s lipo. It leaves little room for really anything else besides the supporting components and pot, unless you use a small tactile switch instead of a 16mm button. They also have an onboard heatsink for passive cooling so theres that.

I can also recommend david4500's "dualparamos V1.4" PWM boards, though I've recently had issues with the traces on 3 of 6 of the boards I ordered. I also have used TheModFather's mini PWM boards which work pretty well, but again, I've had about as many fail as I've had work well but for their price, its worth a shot.
I can also recommend david4500's "dualparamos V1.4" PWM boards, though I've recently had issues with the traces on 3 of 6 of the boards I ordered. I also have used TheModFather's mini PWM boards which work pretty well, but again, I've had about as many fail as I've had work well but for the price its worth a shot. I also recommend using the vaping underground TO-220 mosfet PCBs with the mini PWM set up.

Regardless, It does hold true that there is no DC-DC converter that has a footprint even quadruple the size of a pwm board that can output nearly the same power.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on January 01, 2017, 11:53:35 PM
Hello all, new here. I just started building with the OKL2-T20 it is the N. My issues is its auto firing soon as I put in the second battery, its dual 18650. I used this wiring diagram. I would greatly appreciate any help with this.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on January 02, 2017, 12:41:47 AM
You need a 15K resistor on the mosfet. But I may be wrong.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on January 02, 2017, 12:48:23 AM
Its regulated and its a P-Fet not a mosfet. I know when building all my unregulated boxes, I would use a 15k resistor on the mosfet. I have seen several diagrams and see none with a 15k resistor on the p-fet.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on January 02, 2017, 12:50:59 AM
Its regulated and its a P-Fet not a mosfet. I know when building all my unregulated boxes, I would use a 15k resistor on the mosfet. I have seen several diagrams and see none with a 15k resistor on the p-fet.

True, but you don't even need the p-fet in that configuration.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on January 02, 2017, 11:01:21 AM
Anyway, is your fire switch soldered?  You may have used too much heat on it if it is.

All your grounds at the 510? Any of them loose?

Did you test this outside the box before you installed it?

I don't see anything wrong with the diagram , although I would rather use a fuse than a p-fet

The only things that should be causing auto-fire may be:  bad soldering at key locations, or,   exposed areas contacting the box shorting it out, or over-heating the chip/parts while soldering.


Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on January 02, 2017, 12:44:36 PM
Yes the switch is soldered and it looks to be good. All grounds are done at the 510, none seem to be loose. Yes I'm testing this outside the box. Only thing that is in the box is the 510. Could the problem be the resistors I am using? The are the small SMD ones. I used for both the 20k and the 1.43k. I'm attaching a photo of the 1.43k and the 20k is about the same size. I do have those coming in that have the long legs on them. I appreciate your help SDADDY.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on January 02, 2017, 01:30:55 PM
Using SMD version of the resistors is fine. Shouldn't be an issue as long as everything is wired properly. Again, you may have just burnt one.
You did attach one leg of the pot to the center leg, yes?

Desolder the firing switch, see if that does anything. After that, the only suggestion is replacing the resistors, which you are already on.

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on January 02, 2017, 01:59:28 PM
Center leg on what? sorry not sure of what you are meaning.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on January 02, 2017, 02:34:11 PM
The 20k resistor is that what is suppose to keep it from auto firing?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on January 02, 2017, 03:33:10 PM
The 20k resistor is that what is suppose to keep it from auto firing?

It's on the same circuit, so it could be your problem.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on January 09, 2017, 07:39:13 PM
Got it all figured out. The seller sent me the Positive instead of the Negative board. He was shipped the wrongs one and didn't catch it. So he is making it right. I did figure how to wire it though and its working nice. Instead of running the 20k resistor to the vin from the on/off pad. Run it from the on/off pad to the Negative pad. Then run the on/off wire from the pad to the on/off switch. Then from there to the fire switch, then from there to the Positive on the battery sled. I got 3 of the + boards. So I'm keeping the one I got wired up and he is sending me 2 new - ones. I re done this diagram to show how I wired the OKL2-T20 P board.

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on April 17, 2017, 03:35:36 AM
Hi , I am new to the forum and modding , been reading and educating myself and feel quite confident to start my first build . Quick question , how do you identify the pol - and pol + okl2 chipsets ? People do make mistakes with your order and after using it you find that it's not what you ordered , that sucks .
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on April 17, 2017, 04:06:37 PM
This is how you can tell the difference in the two boards.
L21120 - is Positive
L20120 - is Negative.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on April 17, 2017, 04:55:04 PM
Thanks chopper71 , is this number on the package ? I am waiting on the negative pol from Mauser , should be getting this week .
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on April 17, 2017, 05:31:39 PM
The number will be on top of the board. That's the best way to make sure. I'm posting a example where it is. This is the neg board.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on April 18, 2017, 07:38:50 AM
-@ Chopper71 ,thank you kindly . Is there anyone on this forum that knows where to find pcb for okl2 like hill1 15side was selling  ? I think it was in this post #349 ?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on April 18, 2017, 08:48:04 AM
Ebie this is where I get my PCB board to make mine. You can get either the board a lone or the whole kit.

http://puffervape.com/index.php?cPath=33_92
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on April 18, 2017, 05:19:20 PM
Wow , seriously neat builds with these pcb boards , I kinda like the "less is more " thingy . Have to get from those pcb boards for my projects . I must build four mods , what worries me now is the fact that I have to educate myself more to solder those tiny components  , too expensive to mess it up with crappy soldering , well Google is my friend and YouTube my mentor lol . Thanks Chopper71 for your speedy replies , have you built of these pcb boards personally ?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on April 18, 2017, 05:24:23 PM
Seems like I will be building a mod as per mamu's diagram and a few mods using puffervapes okl2 kits, pretty excited , now to sell the pcb boards to the government
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on April 18, 2017, 06:34:22 PM
Wow , seriously neat builds with these pcb boards , I kinda like the "less is more " thingy . Have to get from those pcb boards for my projects . I must build four mods , what worries me now is the fact that I have to educate myself more to solder those tiny components  , too expensive to mess it up with crappy soldering , well Google is my friend and YouTube my mentor lol . Thanks Chopper71 for your speedy replies , have you built of these pcb boards personally ?

Yes I have and you will want to get a hot air rework station. Plus some good solder paste. Yes YouTube and Google is very good friend to have  :).
You are welcome and I hope you can make something nice.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on April 21, 2017, 12:22:55 PM
Question , can i use the IRLB3034 N-FET instead of the ZVNL 110 N-FET ?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on April 21, 2017, 11:21:48 PM
Question , can i use the IRLB3034 N-FET instead of the ZVNL 110 N-FET ?

I believe that is the same N-FET I use.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on April 22, 2017, 04:19:09 PM
In the diagram mamu stipulates the zvnl with a 1k ohm resistor , will it be ok to use the irlb3034 with a 15k ohm resistor in its place ? Sorry for not being clearer in my previous post .
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on April 23, 2017, 01:57:59 PM
In the diagram mamu stipulates the zvnl with a 1k ohm resistor , will it be ok to use the irlb3034 with a 15k ohm resistor in its place ? Sorry for not being clearer in my previous post .

I was wrong, I use the zvnl as well. Just checked and that is the one. I would not suggest using anything else but what is shown.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on April 25, 2017, 08:42:34 AM
Is there any other n fet i can use other than the specified one ? The two main suppliers in South Africa dont have it in stock . I must buy from the US .
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on April 25, 2017, 09:03:10 AM
You can just leave off the fet and the diode. Neither "must" be used. The fire button works through the board and not directly with the power source.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on April 26, 2017, 02:41:54 PM
My first mod , as per mamu's diagram . Thanks Mamu and all other forum members for educating me , it's been quite a journey . I am waiting for the 510 connector from a vape store that is getting it from the US , then it will be complete , and ready to be vape . I couldn't resist building it to this point . My next build will be the okl2 from Puffervape , I just like the layout and simplicity of less wires to hide . Thanks to all that contributed to this thread , u guys rock .
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: chopper71 on April 26, 2017, 03:49:29 PM
My first mod , as per mamu's diagram . Thanks Mamu and all other forum members for educating me , it's been quite a journey . I am waiting for the 510 connector from a vape store that is getting it from the US , then it will be complete , and ready to be vape . I couldn't resist building it to this point . My next build will be the okl2 from Puffervape , I just like the layout and simplicity of less wires to hide . Thanks to all that contributed to this thread , u guys rock .

Very nice, I really like how you did that.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on April 26, 2017, 04:25:15 PM
Great first mod ebie. Congrats
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on April 28, 2017, 02:22:01 PM
Thank you guys for a great forum and the speedy replies, considering our time zones. Government has approved the Puffervape okl2 PCB build. Will be ordering month end. Will post updates on the build.    :thankyou:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SoLongSidekick on May 03, 2017, 02:47:35 PM
I should be able to figure this out but I just can't think straight right now. Will this work with an OKL build? http://www.modmeter.com/v2.php
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on May 24, 2017, 03:13:38 PM
@ SDaddy , how can i get in contact with David4500 , i want to purchase a pwm pcb from him . Thanks
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on May 24, 2017, 05:33:13 PM
You can try his Facebook group.   https://m.facebook.com/MosMaxElectronics

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: ebie on May 25, 2017, 05:55:18 AM
Thanks SDaddy
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: david4500 on May 27, 2017, 11:25:32 PM
Hey there fellas. I've also got a FB group, just search for "MosMax Electronics Group" :)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: kentsfield on January 21, 2018, 06:37:59 PM
Heya folks,

I really need some help. I build a mod with an OKR-T30-C PSU and connected it like shown in the attachment.

The 12V power are coming from an external power supply.

Well, without a load, the output voltages are stable between (i think?) ~3V and almost 12V. But as soon as I attach an atomizer to the 510 port (0,4 ohm coil), the OKR module starts oscillating/buzzing pretty bad. Its very loud and even the wires are "vibrating", also the power supply im using (45A on 12V). Its very strange, that other parts start oscillating too. I never had this problem before.

I am using a 250 ohm trimpot, connected to trim- and trim+. Also two 22uf tantulum capacitors between VIN and GND. I don't use the sense wires because I don't know how and the datasheet of the OKR is pretty confusing imho.

Any ideas or suggestions?

Thanks in advance!
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on January 21, 2018, 08:00:31 PM
OKR-T/30-W12-C

I don't even see a diagram on this forum for this chip, other than yours

What diagram did you use to build it?

It's missing Alot of information.
Title: OKR-T/30-W12-C
Post by: Breaktru on January 22, 2018, 10:09:08 AM
Heya folks,

I really need some help. I build a mod with an OKR-T30-C PSU and connected it like shown in the attachment.

The 12V power are coming from an external power supply.

Well, without a load, the output voltages are stable between (i think?) ~3V and almost 12V. But as soon as I attach an atomizer to the 510 port (0,4 ohm coil), the OKR module starts oscillating/buzzing pretty bad. Its very loud and even the wires are "vibrating", also the power supply im using (45A on 12V). Its very strange, that other parts start oscillating too. I never had this problem before.

I am using a 250 ohm trimpot, connected to trim- and trim+. Also two 22uf tantulum capacitors between VIN and GND. I don't use the sense wires because I don't know how and the datasheet of the OKR is pretty confusing imho.

Any ideas or suggestions?

Thanks in advance!

Assuming that your wiring is correct, Usually buzzing is an indication that the battery or power supply is not capable of providing the current that you need.

Here is the Data Sheet: https://power.murata.com/data/power/okr-t30-w12.pdf (https://power.murata.com/data/power/okr-t30-w12.pdf)

Here is a build video:
https://youtu.be/4BMMx6iRyew (https://youtu.be/4BMMx6iRyew)
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: kentsfield on January 22, 2018, 01:50:24 PM
Hi Breaktru,

thanks for the reply. I used the video provided by you as a "building guide" and basically, the handmade schematic above is the same, as the guys in the video uses.

I have also read the datasheet a few times, the only plausible reason for that problem could be the hiccup mode, as described in the datasheet.

The power supply should be more than enough sufficient, but I will hook a power meter up and see what my PSU really outputs.

EDIT: I really think its the PSU. I have now connected ALL 12V cables from different rails and ALL GND cables (if there are any rails), and still - oscillation. When I hold the fire button for about 5 to 10 seconds, the PSU shuts down, allthough there should be 30A (not 45, Sorry).

Anyway, Ill think I just get hold of a proper 12V PSU with enough Amps and try it again.

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on January 22, 2018, 05:01:26 PM
Can you put a voltmeter on the OKR input voltage pins or on the PSU output and see if the voltage drops when firing with a load.
Also if you have an amp meter, check the PSU amperage under load.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: kentsfield on January 23, 2018, 04:03:00 PM
Hi Breaktru,

i will test this. But today I used a server PSU I had laying around here. 12V, 59A. Should be MORE than enough. Well, no oscillation and buzzing anymore. But - Nothing really happens. The internal volt meter shows 0.01V max., and nothing really happens. There is a normal, very light buzzing coming from the OKR module, but that's normal. It doesn't matter how high I set the trimpot, nothing happens.

I will extract the ammeter/voltmeter combo with shunt from my 3D printer and re-wire it to the server mainboard in order to see the input voltage, but I think this time it's not the PSU's fault. those server PSUs are built for longevity and extreme precision.

Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on January 23, 2018, 04:51:08 PM
Do you have a volt meter to see if there is 12v present at the PSU output?
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: kentsfield on January 24, 2018, 04:31:24 AM
Hi,

Yes- clean 12V, with or without load.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: FlameOut on January 24, 2018, 12:02:07 PM
Are you getting the 12V at the OKR input pins since using the server PSU.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: kentsfield on January 24, 2018, 04:16:57 PM
Yes, I measured the voltage output from the server PSU without the OKR attached, 12V. Then, with OKR but not turned on - 12V (measured on the OKR VIN and GND pin), with load (OKR on) - also 12V.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: kentsfield on January 28, 2018, 01:49:17 PM
it works now. I can't really tell why, I checked all connections (allthough I did this already a few times), strenghtened a few soldier joints, until it somehow works now  :thumbsup:
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: Breaktru on January 28, 2018, 02:55:45 PM
Yeah, it could have been a cold solder connection.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: captainmac40 on September 30, 2018, 04:18:47 PM
Hi! I'm seek about some information or diagram to sync 2 OKL2-T20 to have an 40A capable output.
Do you have something ?
Thanks !
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: SDaddy on September 30, 2018, 05:32:07 PM
Hi! I'm seek about some information or diagram to sync 2 OKL2-T20 to have an 40A capable output.
Do you have something ?
Thanks !

The OKL2-T20 is a 20a board. You would need a different board to go to 40a.

You might want to look at the DNA boards.
Title: Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
Post by: captainmac40 on September 30, 2018, 06:00:33 PM
Quote
The OKL2-T20 is a 20a board. You would need a different board to go to 40a.

You might want to look at the DNA boards.

Yes I know it's an 20A board, I know also he as an sync pin to sync 2 or more same board. But I don't know how can sync. With an PWM signal ?

That's my question.

I know the DNA board also but the okl is an piece of my arduino based project.

Thanks !