Hackszine.com: Turn an ATX power supply into a lab PSU

Turn an ATX power supply into a lab PSU

With a couple hours of work, it's pretty simple to pull the power supply from an old PC relic and turn it into a pretty decent bench system for powering your electronics projects. The standard ATX power supplys that you find in desktop computers have regulated 5 and 12 and 3.3 Volt outputs with sufficient power for most small project needs. You probably have a few of these just collecting dust in the basement, which means you could have a test bench PSU for quite a bit less than the 80 bucks you'd drop for one on
eBay.

WikiHow and Instructables both have a decent howto on the subject. As always, be careful when working with high voltage electronics. Nobody wants "almost saved $80" on their epitaph, so mind those capacitors.

Convert a Computer ATX Power Supply to a Lab Power Supply
ATX -> Lab Bench Power Supply Conversion

Posted by Jason Striegel | Apr 15, 2008 08:29 PM
Electronics | Permalink | Comments (3)

Comments

Newest comments listed first.

Posted by: Sons on April 15, 2008 at 10:53 PM

Don't do it if you like your electronics

Oh no. And thanks to a lack of sensible, adjustable current limiting such a thing can kill your circuits faster than you can say PSU. And no, the PSU's build-in limit at $BIGNUMBE Amps, or an additional fuse don't count.

A good lab PSU needs to have an adjustable current limit that should be adjusted to the expected current of the circuit (plus a little bit more). If there is something wrong when powering up the circuit the current limiter can safe your electronics, your breadboard, and your wiring. Or when you short something while poking around with your multimeter or oscilloscope. While, on the other hand, your ATX PSU will happily oblige and drive 10A, 20A or more through your circuit, until something gives in. Hint, it is usually not the PSU giving in.

20 or more Amps are even enough to let small wires glow and burn. Even lab cables are usually rated at 16A. So say hello to your little fire hazard on your bench, the destroyer of your expensive electronics and equipment.

Posted by: meh on April 16, 2008 at 11:00 AM

Yeah. What HE said. Rig up a LM317 as a current limiter if you need it, but for me, a good linear power supply isn't all that hard to cobble together. It will also be much more useful in the long run and not have any of the HF nasties that plague cheap chiwanese switching supplies.

Posted by: on May 21, 2008 at 10:12 PM

so is a power supply sufficient for an automobile cd player? they usually run a 10~25 amp, 11.5~14.5v line. i would hate to fry that.