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 better breakout board for ATX PSUs.

13/07/2015 UPDATE: PCBs of the new version have arrived. Blog post and store link!

30/06/2015 UPDATE: New version released, x20 PCBs printed and coming in the mail. New source files and details on GitHub (click me!) – available for sale in a couple of weeks

13/11/14 UPDATE: Eagle files have been uploaded, you can find the link at the bottom. Thank you for your interest!

Many people over the internet have already found out the usefulness of having an ATX PSU, often salvaged from old computers, on their bench. It can be quite easily converted into a lab bench power supply (owners of a real one, please don’t kill me).

There are lots of videos on how to add binding posts to your PSU and how not to, but I didn’t like any of these solutions. I tried the first one, but my power supply was so small and tightly packed that wires and binding posts wouldn’t fit right in it.

I then came across Sparkfun’s and Dangerous Prototypes’ ATX breakouts. While I didn’t like the Sparkfun one, the one from Dangerous Prototypes convinced me a bit more.

Yet, I felt like it lacked some features I needed. I wanted some USB ports to power my rPi and charge my Nexus 5, and an adjustable voltage output. Furthermore, my PSU had a 24-pin ATX connector.

While I still consider myself a beginner in the enormous world of electronics, I decided to look up some guides on how to design a PCB (this time I’ve gotta thank you, Sparkfun! Both yours and Adafruit’s libraries and tutorials rock!) and have a try at it.

Fast forward some days later, my very own ATX breakout board was born.

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