This is a bench-top power supply built to power my various electronics projects. It is built from a PC Power and Cooling Silencer 470 watt PSU.
Here is the stock PSU:
Power ratings:
28A at 3.3V
32A at 5V
26A at 12V
.8A at -12V
Here is the inside of the PSU. It is pretty crowded in there as it is.
Next I installed a switch on the front to turn it on and off:
I then cut all the connectors off.
I installed 5 banana jacks on the front: Ground, 3.3V, 5V, 12V, and -12V.
I then connected the wires to crimp-on connectors, which can be screwed to the back of the banana jacks. Blue is -12V, red is 5V, orange is 3.3V, and yellow is 12V. I used up to 3 wires per connector, and up to four connectors per jack in order to get the maximum possible current flow.
Switch:
Power LED:
Leads connected to the power jacks:
Switch connected:
In order to start, modern ATX power supplies require a load on them, so I used these ohmite resistors to put load on the 5V and 3.3V rails.
The 5 Ohm resistor on the 5V rail got quite hot, so I built a heatsink for it out of some scraps:
Completely assembled:
Powered on:
I've thought about doing something like this for awhile. Good execution and good motivation for me to make my own.
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P.S. You are doubtless aware, but for the benefit of the casual hobbyist considering building something like this: any voltage combo not using ground will be current limited by the leg of lesser ampacity; e.g. the 23V setup is limited by the -12V rating of .8 amp
Nice build. I've been using old power supplies for a while for experimenting but never made one this professional looking. I am curious why you put a switch on it as it seems to already have a switch below where the power cable plugs in. It also might be advantageous to note for those planning on doing this that the purple wire is a constant 5 volts even when the power supply is turned off. I always keep this wire handy because if I accidentally short two wires and it switches off, taking the purple wire to ground through a resistor for a split second seems to reset it. Might not work on all power supplies though.
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