Power Supply Snafu

Yesterday, I went to turn on my power supply to power my latest tinkering, and I let the magic smoke out. Apparently at least 3 capacitors and 2 transistors blew from my visual inspection inside. It had lasted me many long years of tinkering, and I happened to have an extra ATX supply laying around from my last computer upgrade.

I opened it up, found that it already contained a load resistor across the +5V supply, something that I remember was needed for the power supply to work correctly.. A little testing and I found I had to drop the green wire to ground to get it to turn on. I drilled a few holes in the top to make room for my binding posts, wired one each to the -12 (blue), GND(black), +3.3(orange), +5(red), +12V(yellow) terminals.

In addition, I hooked up the brown (sense) wire to the 3.3V wire. I also decided to throw the whole circuit onto a separate switch on the top of the supply, so I hooked the green/black up to a SPST switch on top. I kept the wires long to allow easier future modification.

After turning it back on, I found out my rails were easily sitting within 5% of the advertised voltages.

The end result: My lab is now back up and running with my new power supply, and I now have a lot more scrap parts from my previous supply. Now back to making a pin-out of my nixie tubes for my clock (more on that later)


(Future upgrade plan: add a variable voltage from 0-24V using -12/+12 - drawbacks - space within the supply itself, possible add a small bot on top to host the circuitry. For now, I will use a small breadboard 4-25V, 1A variable supply. I have)