Over the last week we re-visioned the ATX power supply breakout board in KiCAD, free of the confines of Eagle’s 100mm by 80mm cell. We chose the ATX board because it’s already at the limit of the free version of eagle, and it’s filled with big connectors that can’t be miniaturized.
This version builds on the already popular ATX Breakout Board v1.1, but adds new features and hackability. Stuff that simply wouldn’t be possible without the unlimited routing area available from the open source alternative to our usual program.
Features of the ATX Breakout Board V2:
- Adjustable positive and negative power rails
- Fuse blown indicators on every rail, complementing the line good LEDs
- Ground terminals on every rail
- 1.25A polyfuses on all power rails, including the adjustable ones
- 2nd ATX jack for easier enclosure design
- 2×8 0.1” header connected to all the power rails and the control lines of the PSU, including the adjustable ones.
- Open source, designed in KiCAD open source software
Expect a full report on our KiCAD experience tomorrow. More about the updated design below. Comments and suggestions are always welcome, leave them in the comments here, or head to the forum.
This breakout board can recycle a common ATX computer power supply into a bench lab supply. It breaks out all of the rails to screw terminals that also take a banana plug in the top for quick connections.
As in previous versions of the ATX board, each rail has 1.25 amp fuse. LEDs that indicate that voltage is good on each rail. Version 2 adds an additional LED on each rail that lights when a fuse is blown. This is implemented with a PFET and a few resistors.
Since we designed version 2 in KiCad, the size limitations of Eagle were no longer constraining us. We added ground (GND) terminals to each of the output lines. Now there’s redundant ground connections like the original breakout prototype. Sjaak will be so happy about this.
Some people want to put the breakout in the top of a case and connect the ATX jack from below. In this version we added an additional ATX connector footprint to make it easier to do that.
For complete hackability, we broke out all the output rails and ATX PSU control lines to a 2×8 0.1” pitch header.
Schematic and PCB were designed with KiCad EDA, download the latest project files from our Google Code project page.