Thread: Converting an ATX power supply

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***DISCLAIMER: This is a project with ELECTRICITY!! If you haven't worked with electrical devices before and are unsure of what you are doing, don't do this! You could get hurt. DO NOT work on your opened power supply with it plugged in!!!!***

Now before I even start on this, I'm going to say right up front that this was not an original idea, but rather one that I got from this web site: Converting a PC Power Supply If you follow his direction carefully everything works just fine.

So the very first thing I did was to open the power supply, cut off all the plugs and segregate the wires by color



Now the next thing I did, even though the colors are identified in the web site, was to separate one of each wire and tape it down so I could measure the voltage with my multi meter and identify each wire. While you may not need to do this, there are some ATX supplies out there that do not adhere to the standard color coding that most companies use.



next I drilled out the cover of the power supply and added the binding posts, then I soldered in the 10 ohm wire wound load resistor, this helps the power supply to "latch on," and it also stabilizes the voltage on the 12v rail. You can see it here being held on with the green wire tie.



Next I wired in an LED indicator light so I know when the power supply is on.



For attaching it I didn't do anything very technical, I simply hot glued it into the hole I drilled for it, oh before I forget, I actually savlvaged the LED's, on-off switch and the power cord from the computer I got the power supply, no sense in buying something you can get for free.



Now that I had that all squared away I wired the binding posts with the voltages I had chosen for my power supply, in my case I need an all 12v supply, so I have 2-12v+, 2-common, and 1-12v-. What this will give me is the ability to run 2 12v motors off this supply or a 12v and a 24v.



Now being a frugal New Englander, I can't see wasting the other leads for other voltages, so rather than cutting the wires off at the board like the website said, I chose to heat shrink them together and leave them inside, this will give me the ability to add them in later should I decide I need them.



Now I was fortunate that the computer I found actually had a good on-off switch that was wired directly to the ATX, so the next step is to shorten the wired on that switch to something usable, they were a foot and a half long.



You can actually see the heat shrink on the wires where I soldered them back together.

Now that all of that is done it's time to put it all together and label it all up.



There you have it a finished bench top power supply from an ATX power supply!

And just to prove that this does work heres a video I made to show you

Nice job Im about to replace my power supply I might have to try this.

Where can a cheep person like me find AtX power supplies?

Originally Posted by exquized1

Where can a cheep person like me find AtX power supplies?

Well I find mine on trash day usually, I drive around town and inevitably I will eventually find an old computer in the trash waiting for pick-up,these come out of the compter, if this fails go down to your local transfer station, you can usually find one there, if not try your local industrial park near the office buildings, around back is usually a dumpster, you can sometimes find old office computers here. As you can tell, I'm a bit of a scounger, and I spend quite a bit of time diving into dumpsters and generally poking my nose in where it doesn't belong, but I get the good stuff

K, probably a lame question, but I'm assuming the ones labeled "com" are the neg?

Yup you got it, com is the negative lead on this build.

I stock up on all the power supplies i can when we are recylcing pcs. I have quite a few. I really love the ones for the mini pcs. I have one i hook up for a bench power supply when i am test and soldering LEDs.

Just wondering what the maximum wattage is on that power supply. I just made one but I'm far exceeding the max wattage for the power supply with one wiper motor connected.

My power supply My first power supply completed

I don't know maybe I did something wrong?

Mine is a 250 watt power supply, I've had as many as 3 wiper motors going off of mine at once without issue. Are you perhaps using the wrong resistor?? I'm not big on electronics, the person here to ask is Otaku, when I'm stumped thats who I go to for answers. Sorry I couldn't be a bigger help.