OKR-T/10, T/6, T/3 schematic circuit

[mamu]

Thanks Breaktru and David.

I haven't had time to play with it more, but I was hoping there would be a way to use a non rated master switch.  I'm not ready to give up yet. 

My goal is to disconnect the converter from firing AND stop idle current drain.  I just need to figure out how to do that without using a rated master switch.  It may not be a true master kill switch, but if it meets my goal I'll be happy with it.

I'm thinking along the lines of working with Vin, on/off control, and the pull-down resistor with a DPST or DPDT switch. 

[david4500]

How about this Mamu...............
Use either a SPST or SPDT like this: Mini Slide
I use this switch on my PTR08100w, OKR-T/10 and PTN4050C mods.

Only AC ratings for that switch, how can you be sure they're suitable for DC?

[mamu]

ok... I give up.  I tried wiring every which way, but no can do without a rated master switch. 

The simplest wiring is with your advice breaktru for a rated SPST switch, but I'd like to place it after the fuse and P-FET, that way it would be protected from the batts' current if something funky happens there.

I googled about rating a switch from AC to DC and this is what I found...

DC Rule of Thumb
For those switches that list an AC voltage rating only, the "DC Rule of Thumb" can be applied for determining the switch's maximum DC current rating. This "rule" states the highest amperage on the switch should perform satisfactorily up to 30 volts DC. For example, a switch which is rated at 10A 250VAC; 15A 125VAC; 3/4HP 125-250VAC, will be likely to perform satisfactorily at 15 amps up to 30 volts DC (VDC).

https://www.carlingtech.com/amp-hp-volts
-----------------------------------------------------------------------
DC CAPABILITY OF AC SWITCHES
It is important to also note that many AC rated switches can be used in applications where less than 30V DC is required, provided current does not exceed the full current 125V AC rating of the switch. In general, the 125V AC rating would be equivalent to the 28V DC rating

http://www.aeroelectric.com/Reference_Docs/Switches/CH_Switch_Training_Manual.pdf
------------------------------------------------------------------------

How about this for a kill switch:

6 amps dpdt slide switch, connect to two sets of terminals in parallel for 12 amps

http://www.mouser.com/ProductDetail/CK-Components/1201M2S3CQE2/?qs=%2fha2pyFadugwNSjKfGlHGNBlv2rz8CMp5wVZ64JEtfeqTdjqEG4CkQ%3d%3d

http://components.arrow.com/part/detail/43424680S5158853N9444

I wonder if there is any advantage to wiring parallel this way...


But then I read this and not sure if it also applies to parallel wiring a DPDT switch...

It is not advisable at all to connect relay contacts in parallel to handle higher load currents. For example, never attempt to supply a 10A load with two relays in parallel that have 5A contact ratings each, as the mechanically operated relay contacts never close or open at exactly the same instant of time. The result is that one relay contact will always be overloaded even for a brief instant in time resulting in premature failure of the relay over time.

http://www.electronics-tutorials.ws/io/io_5.html

[Breaktru]

Yes parallel contacts on a DPDT switch would increase the amp rating but an SPST 3A @ 125v would be sufficient enough to handle our needs (48A @ 7.81V. Were trying to keep the physical size down so a mini SPST would be nice.

Remember we are turning on and off the switch when we are NOT powering the DC-DC converter so there should not be an issue. We are not holding the fire button while switching the on/off switch.

[mamu]

Thanks for that insight, breaktru.  What I understand then is since we're turning the master switch on and off under no current, we're not really asking anything of the master switch other than it allowing current to pass through it to get to the Vin terminal of the fire switch when we press the fire switch. 

Is this correct then - if we have say a 5A rated master switch and 10A or even 20A is simply passing through that switch, it's not going to affect the switch or cause failure?  Would a low amp rated switch have higher contact resistance vs a high amp rated switch? 

I think I'm confused though on how you're rating the 3A 125VAC switch.  From what I've read and linked to in my previous post, that AC switch is still 3A up to 30VDC.  Above 30VDC, the amp rating goes down.

[Breaktru]

Turning a switch off or on with a heavy load causes arcing to the contacts which can be detrimental to the switch.
With the switch on and hitting the fire button, you would still need to insure that the switch contacts are rated to the proper amp value of the load so a low rated switch is not advisable. Even if the sw contacts don't burn out, high resistance across the contacts will be in play (voltage drop).

If you look at some of the switch ratings you may see say, 1.5A @ 250V or 3A @ 125V. Using that analogy and doing the math, you will see the lower the voltage the higher the amp rating. This is not an exact calculation. The amp to voltage rating is not necessarily linear. But we can assume that with two 3.7v batteries in series (8.4v) the switch would be safe to use with the converters we are using.

[CraigHB]

The ratings for switches apply only for the amount of power they can switch on and off, not what the contacts can handle when closed.  That would be higher.  Unfortunately, they don't provide ratings for that.

What you can do is measure voltage drop across the switch under load to find how much power is getting lost in the switch.  For example, if you put a 10A load on the switch and measure 50 mV across the terminals, the switch has 5 mOhms resistance and is losing 500mW.  You probably wouldn't want to see more than a half watt lost in the switch at maximal loading.  Any more than that and the switch is probably going to burn out.

[Breaktru]

I knew good ole Craig would come thru and set us on the straight and narrow path 

[CraigHB]

Hehe, assuming that is in fact the straight and narrow path

[david4500]

Thanks for all the switch info everyone

[mamu]

I knew good ole Craig would come thru and set us on the straight and narrow path 

For sure. 

Craig has given me many "aaha I get it now".  He is like our pot of gold at the end of the rainbow - previous and valued.

Hehe, assuming that is in fact the straight and narrow path

lol

That's good news that the contacts can handle higher power than what the switch is rated for.

Seriously Craig you're a blessing.  You're always willing to help us and share and are patient with us and your explanations and advice are very much appreciated. 

[memoevapor]

Seriously Craig you're a blessing.  You're always willing to help us and share and are patient with us and your explanations and advice are very much appreciated. 

What Mamu said 

[mamu]

A few questions if you have time, Craig.  I think as David said paralleling a DPST or DPDT switch is a great idea if we should need it.

Would a higher amp rating then of 12A from a 6A DPST or DPDT switch when paralleling also include a higher amp rating for the contacts?  Or would the contacts still be the same?  Would the contact resistance change with this parallel configuration and be an advantage for less resistance and thus less voltage drop under load?

Also, is there any advantage to wiring this way...


vs this way?


It doesn't seem like it would matter, but in my search last night I saw these 2 different types of wiring configurations and it got me to wondering if there was a reason for wiring one way vs the other.

[Ctarno]

So I know this has been said before but which hamond 1590 box is correct in size. Mine is way to narrow and short. I am not happy

[david4500]

1590g takes some creativity to get everything to fit, grinding corners, chopping battery sleds... go with the 1590b if you want more room to work with. it's slightly higher in height and about half an inch longer & wider.

[Ctarno]

Thank you. People here are much nicer than"fb" group!

[david4500]

T6 1550P 18350s

Another switch question:

Bottom slide switch is wired to break the series link for use as an on-off. I chose this as a convenience of my layout. Would the resistance of the switch be significant enough that I shouldn't have it in the middle of the battery series? Are there any issues I should be aware of with this switch placement?

Switch used:
http://mouser.com/Search/ProductDetail.aspx?R=1101M2S3CQE2virtualkey61170000virtualkey611-1101M2S3CQE2
http://www.ck-components.com/14394/1000_4jun13.pdf/

[Breaktru]

Nice going David 
Thanks for sharing your photos

[Bwrairden]

I've seen one schematic here that uses a spst master switch that breaks the negative to all components. Is this acceptable? And would a .5 amp 30v DC switch be suitable?

[Visus]

Sweet mod David  clean

when you switch on or off they do not have to balance so there is no load on it.
Oh hey there they say, didnt know you were here too 
no different then puttin series batts in a flashllight

I think break linked to 3A version so if that one is fine your golden
those screws would drive me batty.  meh',  your extra 20 secs not mine haha 

[david4500]

Thank you.

Magnets will be replacing screws. Spray painted them to match the box. Will epoxy them when I get around to it.

[CraigHB]

Bunch of stuff so I'm not going to try to quote anything, sorry if this gets confusing.

First, welcome on the thanks.  I enjoy talking about this stuff and the forum gives me the opportunity.

For the first photo, you're doing the same thing but different.  I don't see any advantage there and it's more trouble to wire.

You can think of a switch like a resistor, two switches in parallel halves the resistance and doubles power tolerance.  However, similar to fuses, there are derating considerations.  Since the ability of something to handle current always comes down to heat, there's more heat with both poles adjacently connected.  However, you still come out way ahead, just not as far ahead as two individual switches.

When you see a rating like 24V/3A, that's actually a power rating in terms of Volts and Amps.  It additionally indicates the switch's voltage limit and maximal current at that voltage.  The power rating of a switch determines the maximal amount of power you can control while still meeting the switch's MTBF (longevity).  Ratings are mainly about MTBF since the contacts wear due to arcing and eventually fail to conduct after a number of cycles.  The more power the switch is controlling the faster that happens.  You could exceed the rating with a sacrifice in longevity.  You could largely exceed the rating with a large sacrifice in longevity.  It's not pass or fail like an absolute maximum rating you'd see in a data sheet. 

Switch ratings mostly come down to the characteristics of the contacts.  This does not necessarily determine the amount of current a switch can handle though it comes into play.  You could have a switch with a high MTBF and power rating by way of a large mating area with high performance materials, but if the paths running to that area are small, the switch may overheat with currents largely over those stated in the ratings.  The opposite could be true, large paths, but small mating area.

Switches don't always have ratings in terms of  Amps and Volts.  Sometimes they use VA which is a power rating like Watts, but includes the power factors you see with loads like motors and transformers.  When a switch has a rating in terms of Amps and Volts, it's a safe assumption the switch can handle a higher current with a lower voltage.  When power does not exceed the specification, the limitation for current flow is simply a matter of resistance between the switch's terminals.  As long as power is within tolerance, the base current a switch can handle is typically much higher than the Amps you might see stated in a rating.

There's no way find how much current a switch can carry from its data sheet.  They just don't provide that information.  They only provide the rating for how much power you can control.  When power is not exceeded, it's a matter of how much current it takes for the internal paths of the switch to get too hot.  It's something you have to measure for yourself as I mentioned previously.

[mamu]

Thanks for the explanation Craig! 

[Ctarno]

Is there a way to do this or something like this on a single battery? Regulated with awesome performance? Please for all that is holly don't say buy an SVD or something like that. Lol

[Bwrairden]

Hey guys, new to the forum and to mod building. About to try my first one and just wanted to check and make sure I've drawn a good schematic. Any input would be great. Thanks.

[Visus]

Is there a way to do this or something like this on a single battery? Regulated with awesome performance? Please for all that is holly don't say buy an SVD or something like that. Lol

http://breaktru.com/smf/index.php/topic,215.0.html

[Breaktru]

Hey guys, new to the forum and to mod building. About to try my first one and just wanted to check and make sure I've drawn a good schematic. Any input would be great. Thanks.

Yup. That will work, less the PTC protection

[Bwrairden]

Yup. That will work, less the PTC protection

I read mamu's post about fuses on ECF and it makes my head spin.

I take the t10 max wattage at 80% effiencency for a total of 62.5w, divided by min input voltage = 3.4v. 62.5/3.4= 18.38 amps.  Seems huge.

Then I read here that you recommend (2) 5 amp fuses in parallel. That sounds right to me.  But I want to understand why.

What am I missing?

[mamu]

I read mamu's post about fuses on ECF and it makes my head spin.

I take the t10 max wattage at 80% effiencency for a total of 62.5w, divided by min input voltage = 3.4v. 62.5/3.4= 18.38 amps.  Seems huge.

Then I read here that you recommend (2) 5 amp fuses in parallel. That sounds right to me.  But I want to understand why.

What am I missing?

Min input voltage for the T10 is 6v.

[joshleeman]

Was mistaken on the parts yeah those are not the parts you want. you can read I obviously skimmed it or cannot lol  woot another OKR build incoming--
I'll help ya with parts list if ya want..

fuse
http://www.digikey.com/product-detail/en/AGRF500-2/AGRF500TR-ND/1113329

battery holders
http://www.digikey.com/product-search/en?pv32=189&FV=fff40006%2Cfff80022&k=keystone&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

220 ohm 1/4watt resistors
http://www.digikey.com/product-detail/en/MFP-25BRD52-220R/220ADCT-ND/2059126

4.7k ohm resistor
http://www.digikey.com/product-detail/en/NFR25H0004701JR500/PPC4.7KBCT-ND/614262

5.6v Zener
http://www.digikey.com/product-detail/en/1N5232BTR/1N5232BFSCT-ND/458917

200ohm trimmers choose the one you like
http://www.digikey.com/product-search/en?pv1=291&FV=fff40004%2Cfff80338&k=trimmer&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

22uf 16v Capacitors choose the one your comfortable with using
http://www.digikey.com/product-search/en?pv14=9&FV=fff40002%2Cfff8000a&k=22uf&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

Mosfet
Not sure so many to choose but I would use the one in Mamu's raptor build
Re: Tinkering with the Naos Raptor - 20A, 120W dc/dc converter...
« Reply #124 on: March 07, 2014, 05:49:18 AM »

Switch
http://www.digikey.com/product-detail/en/1103M2S3CQE2/CKN5051-ND/483721

Meter
I use this one --it comes in red green or blue
https://www.fasttech.com/p/1222902
 
OKR T10
http://www.digikey.com/product-search/en?vendor=0&keywords=okr+t10

You are awesome!!!  Thank you so much for doing this, I'm sure it will help out many more ppl than just me.  This stuff is incredibly overwhelming at first when you have zero experience building electronics.  Thank you thank you thank youu!!!!!

[blkbd]

I have a noob question, I will be building a unit like in the above schematic with a OKR-T6 and already have a 500 ohm pot in junk drawer. Is there a way to compensate for the 500 ohm so the whole pot will be useful instead of maxing out at half way? 

[david4500]

You won't max out half way, your high output voltage (about 6v) will be reached at the end of a full turn. What will change is your low voltage output at the full opposite turn. It will be about 2.2v with a 500 ohm pot, instead of about 3.4v with a 200 ohm pot.

The value of the fixed resistor (220 ohm) between the trim pin & potentiometer sets your high voltage. The combined value of the potentiometer (200 or 500 ohm in your example) and the fixed resistor sets your low voltage.

Page 4 of the OKR-T/10 spec sheet has a formula you can use with the different resistance values and the output voltage. An online algebra calculator makes for easy figuring.

http://www.mathpapa.com/algebra-calculator.html

[david4500]

Hey guys, new to the forum and to mod building. About to try my first one and just wanted to check and make sure I've drawn a good schematic. Any input would be great. Thanks.

Really nicely laid out drawing. Best of luck with your first mod.

[mxrdrver]

Ok, I'm building a box mod with a OKR-T10 inside of a Hammond 1590G. I'm using BreakTru's schematic that uses Pin#1 because I screwed up and ordered 2A push button switches. His schematic says to use a on/off switch between the +battery contact and Pin#1, I would assume to prevent battery drain when the mod is not in use. Looking at what I have, inside the 1590G, I don't have room for a on/off switch. I was curious, if I used the zener diode that Mamu talked about, would that prevent total battery loss without using a on/off switch?

[Jasen]

MX, Welcome
Actually I believe the switch is just a master power switch to prevent accidentally firing it in your pocket.
Did you get a standard slide switch or a mini slide switch, the mini switches are pretty small, roughly 1/4x 1/4 x 1/2 w/o panel mount tabs.

[mxrdrver]

Thanks. I've been lurking around here for a couple weeks. Not wanting to post anything until I've had a chance to read throught the miles and miles of information.

I don't have any switches yet. I was hoping to get away without using one. That's why I was asking about the zener. I'm not too concerned about the mod firing accidentally. My main concern was being able to use the 2A push button switches I have.

[Visus]

Its a normally closed switch on pin 1 unless you have model e version
noone buys model e version so nc switch ya need to use it.

the diode you would need would be huge without a mosfet
you need to buy another switch anyway

[Ctarno]

Hello again what is the best way to make the holes in the hamond die cast aluminum case. Do I just use a dremmel or would a drill be better? And does anyone know the circumference of the holes needed? Just have to drill and way we go

[blkbd]

Hello again what is the best way to make the holes in the hamond die cast aluminum case. Do I just use a dremmel or would a drill be better? And does anyone know the circumference of the holes needed? Just have to drill and way we go

Drill is always better for clean round holes, Don't have the diameters needed but someone will chime in as this has been the best forum I have found for helpful vapers.

[Ctarno]

Single coil or dual? Tried both on a okr and don't know what I like. What are your opinions?  And lastly .6 should be lowest for daily use, yes?

[mxrdrver]

Ok, finally got the time to sit down and breadboard everything. I'm using an OKR-T/10. It took me a couple hours to figure out how everything hooked in. Since I was using an 2amp push button switch, I opted to use pin#1 remote. Something that I wanted to bring up, was that all of the diagrams I've seen showed power(+)   from battery to pin#2. I used Breaktru's schematic as the basis for my build. Every time I put power to the circuit, the atty would auto-fire without pushing the on/off button. I went round and round with this trying to find the problem. Then, only when I only supplied power to pin#1 did everything work properly. Was I reading the schematic wrong? I could swear that I saw in Breaktru's schematic that power is supplied only to pin #2 when using pin#1. Here's a picture of everything breadboarded.

[Breaktru]

If you used the schematic shown below and it fired without hitting the fire button it sounds like the fire but is not Normally Opened but a Normally Closed switch.

[mamu]

With Breaktru's schematic and using pin 1 - you need a NC switch and no pull-down resistor.

But it looks like you're using one of E-Switch's 12mm 2A ss switches which is an NO switch.  You'll need a 1K - 4.7K pull-down resistor across pins 1 and 3 to turn the OKR off.  I don't see a pull-down resistor on the breadboard.

[Breaktru]

I think the explanation was a bit confusing but looking at the breadboard, Pin 1 is not wired to anything making it like my schematic above. That's why I mentioned the N.O. switch.

If it's a 2A @ 48v switch then it should be good for:
4A @ 24V
8A @ 12V
12A @ 9V
16A @ 6V
Again as I mentioned before, the results stated are not linear but it will suit our needs.

[mxrdrver]

Ok, I didn't realize they might be normally open. Looking back on the order sheet, they are indeed NO switches. I also picked up several 5A horn style push button switches from MadVapes. Looking back at their description, they don't say if they are NO or NC. I just hooked one of those up, with power to pin#2, and it autofired. ?? I don't know what's going on. All I know, the way I have it hooked up to pin#1 works.

[mxrdrver]

Now that I switched over to the NC horn style switch, I think I won't use pin#1 after all. Just waiting on a couple 5A fuses and I can get it all installed. Thanks for the help.

[Visus]

Now that I switched over to the NC horn style switch, I think I won't use pin#1 after all. Just waiting on a couple 5A fuses and I can get it all installed. Thanks for the help.

Pin2 is no pin not nc;  its a  direct on/off since the module will fire with power uninterrupted to pin 2 its the less parts/wires pin lol...
But they do produce a different version module,  version"e"   pin1 will only fire the device with  positive logic regardless if pin 2 is direct wired

[JUICYOHMS]

Hello Guys...

Has this or could this chip be used with success in place of the OKRT10?

     Murata LSS-T/10-W12-C  (.6-6v @ 10amps/60watts)
$11.50 ea.
     DigiKey Part# 811-1811-ND  (506 available)

[CraigHB]

If you look at the data sheet it says it's an obsolete part;  http://www.murata-ps.com/data/power/lss-t10-w12.pdf   That's always discouraging.

Anyway, looks pretty much the same as the OKR-T/10, maybe just an older version of the same thing.  So yeah, you could probably use it without any problem.

[david4500]

I would like to use a tactile instead of a slide switch for the voltmeter. Not sure what circuity would be needed to do so.

simpler solution to for what i wanted to do, on-on-off  push button:

http://www.digikey.com/product-detail/en/50-0088-00/542PB-ND/935975
http://www.digikey.com/product-detail/en/50-0041-00/529PB-ND/611178