Wednesday, April 03, 2013

ATX Bench Power Supply

As you may have noticed, lately I’ve been learning electronics. My budget is not unlimited and was wiped out by my purchase of a Rigol DS1102E Oscilloscopeover Christmas. I needed a bench power supply of some sort for my experiments and while I’d love a real variable bench power supply I started to think of using a surplus (I have a bunch salvaged from dead PCs) PC ATX power supply as a substitute for the time being.
There are tons of such projects out there on the internet but most involve hacking open the power supply and I didn’t think that was the way to go. I considered getting a cheap ATX adapter from Monoprice and breaking out the voltages onto a PCB but then I came across the Dangerous Prototypes ATX Breakout Board.
It was only $13.80 plus $3.80 shipping from Hong Kong (via Seeed Studio) which was reasonable and quite a time saver. I happened to have an old used project enclosure laying around in my junk pile (I have no idea where I got it from) that would fit an ATX supply so I set to work.
I laid out the ATX mounting profile, chain drilled the outline and chiseled out the waste.
Finally an excuse to use my die filer!
Filing the outline.
The ATX supply mounted to test fit and function.
Just enough room in the project box.
The box didn’t have a front panel so I made one from aluminum. The box had feet on the sides and bottom but I decided that mounting it vertically would be best so I removed the feet on the bottom (now side) of the box)
I had to add a piece of angle in the middle top to support it.
The breakout board mounting laid out. The large holes are for clearance for the binding posts.
Test fitting.
I had considered mounting it flush but decided standoffs would be safer and easier.
A rectangular hole was nibbled out. It’s almost as if I knew how to make square holes in panels
Remaining wires tucked into place. I can pull one out the side if I need a Molex connection for a project.
In hindsight I should have made the rectangular hole slightly further up as the wires needed to be massaged into the sharp bend. I protected the wires from the hole edges with some spiral wire loom.
Not bad, the board works well, has tiny little power indicator LED lights and this will be a useful bit of equipment for my hobby. If the ATX supply blows up I can just pop in a new one. I’ll need to get a binding post for the –5V as my supply has that voltage (I wish they included it). The only real change I’d make, for my setup is to have the Molex connector come out the bottom of the board – this would have made the assembly much cleaner. Maybe I’ll make my own board someday.

1 comment:

Anonymous said...

And maybe a bit more than 1.5 amps of power.