New ATX Breakout Board PCBs (with some improvements!)

Hello everyone, I’ve got some good news today!

I released a newer version of my ATX Breakout Board. After receiving a lot of requests, I also printed some PCBs (10x blue, 10x red) and will print more after thorough testing of the current revision.

Features and additions added from the older version:

  • Thickened many traces, removed pin headers in the middle of the board and added one behind each binding post (up to 5 output pins per voltage line, with no risk of burning any traces).
  • Added resistors to the USB ports (on the back of the board). You may want to use them for USB identification, as they are cheaper and easier to find than the TPS2513. Adafruit link for more info: https://learn.adafruit.com/minty-boost/icharging
  • Moved LM317 so that you can mount it horizontally + used a footprint with longpads, should you want to solder wires to an external voltage reg + heatsink.
  • Prototyping area added at the top left of the board. Not sure if it will ever come useful, but I had some empty space there. You have easy access to the 3V3 and 5V lines.
  • Moved/rearranged several parts (pot, switch, LEDs) in order to draw shorter and cleaner traces.

New parts list:

  • C1, C3: 0.1uF 0805 SMD capacitors.
  • C2: 1uF 0805 SMD capacitor.
  • F1, F2, F3, F4: 1812 SMD PTC resettable fuses. (Littelfuse ones should work just fine, I used Bourns instead which are a bit larger).
  • J1: 24-pin ATX connector.
  • JP1, JP2, JP3, JP4, JP5, JP6: 5-pin headers, male or female as you prefer.
  • JP7: 3-pin header (voltmeter output).
  • LED1, LED2, LED3, LED4, LED5, LED6, LED7: 0805 SMDs, choose the color you want but make sure to use appropriate resistors. You may not want full brightness and sure enough you don’t want magic smoke.
  • R1, R3, R4, R5, R7: 3.3K ohm, 0805.
  • R2: 330 ohm, 0805 (value may change – double check LM317 voltages or calculate your own).
  • R8: 10k ohm, 0805.
  • R9: 9/10W power resistor, not needed in my case.
  • R6: 1.2k ohm, 0805.
  • R10, R15: 43k ohm, 0805.
  • R12, R14, R17, R19: 51k ohm, 0805.
  • R11, R16: 75k ohm, 0805.
  • T1, T2, T3, T4, T5, T6: binding posts with 4mm hole. You may want some red ones for the positive lines and a black one for GND.
  • U1: LM-317, through hole.
  • U2: TPS2513 from Texas Instruments. If you don’t have it, install resistors R10-R19 for the same functionality (not both!).
  • VR1: 2k ohm, PCB mount potentiometer, 9mm (click)
  • X1, X2: USB female connectors, through hole.
  • SW1: 8x8mm pushbutton (got mine from Tayda.)

I bought all of my components from Tayda Electronics, except for the ATX connector and the PTC fuses (check Sparkfun or eBay!)

Time for some pictures:

Sexy, aren't they?

Sexy, aren’t they? Also, colors!

The whole batch.

The whole batch.

And here’s a fully assembled one (terrible soldering on fuses and LM317 because I recycled them from a previous build):

An assembled board.

An assembled board.

 

PCBs will be available in the store and on Tindie soon.

Cheers!

 

Building a 3-channel, high power RGB LED driver

Hey guys,

I built another board, which is a 3-channel (RGB) LED driver based on an inexpensive chipset called PT4115 (you can find them on eBay or Aliexpress).

The circuit is very simple and looks like Sparkfun’s PicoBuck. However, I used beefier components and a different chip. You may say it’s pretty much the same thing, but I made it to learn some more about PCB design.

Datasheet here. LED current is set through a sense resistor. The output current I is equal to 0.1/Rs. I wanted ~300mA for each channel so I chose a 0.33 ohm resistor. If you want 350mA, choose a 0.27ohm resistor.

Each channel can be controlled via PWM (you can solder male/female headers on the board), for example with an Arduino.

You can input up to 30V and control 3W/10W/20W LEDs.

The bare boards.

The PCBs.

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