gfxgfx
 
Please login or register.

Login with username, password and session length
logo
 
gfx gfx
gfx
19852 Posts in 1275 Topics by 5182 Members - Latest Member: charbuild March 28, 2024, 11:42:23 AM
*
gfx* Home | Help | Search | Login | Register | gfx
gfx
Breaktru Forum  |  eCigarette Forum  |  Modding  |  Topic: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
gfx
gfxgfx
 

Author Topic: Tinkering with the OKL2-T20 20A 110W dc/dc converter...  (Read 325284 times)

0 Members and 15 Guests are viewing this topic.

Online Breaktru

  • Administrator
  • PV Master
  • *****
  • Joined: Nov 2008
  • Location: NY
  • Posts: 3344
  • Karma: +792/-4
  • Gender: Male
  • PLEASE participate in this forum
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #150 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...

Offline deleon209

  • Jr. Member
  • **
  • Joined: May 2014
  • Location: Sacramento, California
  • Posts: 23
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #151 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

Offline Visus

  • PV Master
  • *******
  • Joined: Oct 2013
  • Location: Nexxus
  • Posts: 929
  • Karma: +62/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #152 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


Offline deleon209

  • Jr. Member
  • **
  • Joined: May 2014
  • Location: Sacramento, California
  • Posts: 23
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #153 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.

Offline Visus

  • PV Master
  • *******
  • Joined: Oct 2013
  • Location: Nexxus
  • Posts: 929
  • Karma: +62/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #154 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

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #155 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...

Offline deleon209

  • Jr. Member
  • **
  • Joined: May 2014
  • Location: Sacramento, California
  • Posts: 23
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #156 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.

Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #157 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
« Last Edit: June 09, 2014, 06:24:03 AM by Claviger »

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #158 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

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.

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #159 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"

Offline CraigHB

  • PV Master
  • *******
  • Joined: Nov 2011
  • Location: Reno, Nevada
  • Posts: 2023
  • Karma: +246/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #160 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.

Online Breaktru

  • Administrator
  • PV Master
  • *****
  • Joined: Nov 2008
  • Location: NY
  • Posts: 3344
  • Karma: +792/-4
  • Gender: Male
  • PLEASE participate in this forum
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #161 on: June 09, 2014, 12:57:38 PM »
I ordered the micro view several weeks ago just to play with

Offline Visus

  • PV Master
  • *******
  • Joined: Oct 2013
  • Location: Nexxus
  • Posts: 929
  • Karma: +62/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #162 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/emagin-officially-announces-their-xga096-oled-microdisplay-evf-applications


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



Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #163 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.
« Last Edit: June 10, 2014, 12:19:42 AM by Claviger »

Offline shandy27

  • Sr. Member
  • ****
  • Joined: Jun 2012
  • Location: falkirk
  • Posts: 50
  • Karma: +2/-0
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #164 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.

Offline CraigHB

  • PV Master
  • *******
  • Joined: Nov 2011
  • Location: Reno, Nevada
  • Posts: 2023
  • Karma: +246/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #165 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.

Offline Visus

  • PV Master
  • *******
  • Joined: Oct 2013
  • Location: Nexxus
  • Posts: 929
  • Karma: +62/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #166 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


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:

Offline CraigHB

  • PV Master
  • *******
  • Joined: Nov 2011
  • Location: Reno, Nevada
  • Posts: 2023
  • Karma: +246/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #167 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.


« Last Edit: June 10, 2014, 10:41:50 PM by CraigHB »

Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #168 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.
« Last Edit: June 10, 2014, 11:47:51 PM by Claviger »

Offline Visus

  • PV Master
  • *******
  • Joined: Oct 2013
  • Location: Nexxus
  • Posts: 929
  • Karma: +62/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #169 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
« Last Edit: June 11, 2014, 03:50:56 AM by Visus »

Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #170 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

Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #171 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!
« Last Edit: June 12, 2014, 12:56:26 AM by Claviger »

Offline CraigHB

  • PV Master
  • *******
  • Joined: Nov 2011
  • Location: Reno, Nevada
  • Posts: 2023
  • Karma: +246/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #172 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 :)

Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #173 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.

Offline Chenderson1985

  • Jr. Member
  • **
  • Joined: Apr 2014
  • Location: United States
  • Posts: 5
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #174 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.

Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #175 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?

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #176 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


Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #177 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? 

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #178 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.

Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #179 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.

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #180 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.

Offline cburnet91

  • Jr. Member
  • **
  • Joined: Jun 2014
  • Location: USA
  • Posts: 13
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #181 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

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #182 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.

Offline bob salter

  • Jr. Member
  • **
  • Joined: Aug 2013
  • Location: UK
  • Posts: 12
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #183 on: June 26, 2014, 09:47:41 AM »
Brilliant thread, thank you. Have ordered four of these and an arduino.

Bob

Offline cburnet91

  • Jr. Member
  • **
  • Joined: Jun 2014
  • Location: USA
  • Posts: 13
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #184 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

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #185 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.

Offline cburnet91

  • Jr. Member
  • **
  • Joined: Jun 2014
  • Location: USA
  • Posts: 13
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #186 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.

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #187 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. 

Offline cburnet91

  • Jr. Member
  • **
  • Joined: Jun 2014
  • Location: USA
  • Posts: 13
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #188 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.

Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #189 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)

Offline cburnet91

  • Jr. Member
  • **
  • Joined: Jun 2014
  • Location: USA
  • Posts: 13
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #190 on: June 26, 2014, 07:21:26 PM »
Type of what? Okl2?

Offline Claviger

  • Sr. Member
  • ****
  • Joined: May 2014
  • Location: Hawaii
  • Posts: 94
  • Karma: +4/-1
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #191 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). 

Offline cburnet91

  • Jr. Member
  • **
  • Joined: Jun 2014
  • Location: USA
  • Posts: 13
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #192 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

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #193 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.


Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #194 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.

Offline cburnet91

  • Jr. Member
  • **
  • Joined: Jun 2014
  • Location: USA
  • Posts: 13
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #195 on: June 28, 2014, 02:59:00 PM »
Mamu did you ever figure out the switch wiring

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #196 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.

« Last Edit: June 29, 2014, 08:32:46 AM by mamu »

Offline cburnet91

  • Jr. Member
  • **
  • Joined: Jun 2014
  • Location: USA
  • Posts: 13
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #197 on: June 29, 2014, 12:07:27 PM »
Thank you so much. I'll post my results after I give it a try.

Offline cburnet91

  • Jr. Member
  • **
  • Joined: Jun 2014
  • Location: USA
  • Posts: 13
  • Karma: +0/-0
  • Gender: Male
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #198 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.

Offline mamu

  • PV Master
  • *******
  • Joined: Dec 2013
  • Location: IN
  • Posts: 476
  • Karma: +72/-3
  • Gender: Female
Re: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
« Reply #199 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.

Breaktru Forum  |  eCigarette Forum  |  Modding  |  Topic: Tinkering with the OKL2-T20 20A 110W dc/dc converter...
 

gfxgfx
gfx gfx
Powered by MySQL Powered by PHP Valid XHTML 1.0! Valid CSS!