To do any sort of work you need a power supply that provides more than one voltage. For example if you want to power early Williams boards you need +5 and +12v. If you want to power an early Williams sound board you need +12 and -12v.

So at least a dual output version is in order, something like the Circuit Specialist CSI3005X5. But at $130, it's a lot more money than an old ATX supply lying around that would cost you next to nothing to mod as a bench supply.

As for hooking it up, that depends upon the board. Sometimes you can wire into the bypass cap on the power input on the board, sometimes you build a connector that plugs into the power supply.

viperrwk

I've done just fine for years using an ATX PS.

One from a computer I built over 10 years ago. Not a fancy expensive one. Just a basic, cheap one.

I brought 2 sets of wires out of mine, and desoldered and removed the rest. They weren't needed, why keep them?

One set is in a 4 pin plug, with GND, +5, +12 and -12
One set is in a 3 pin plug, with GND, +5 and +12

I built a pigtail for every type of board I want to power up on the bench, and built a splitter for the 3 pin plug, in case I want to power up 2 boards side by side.

Save your money for a rework tool you need, or some parts. I've not found a situation where I needed more than I have.

Ironically enough, I'm looking at converting ATX supplies and adding them to my inventory. Just a matter of narrowing down which one I want to use, and then adding in a small fuse / switch board.

-Hans

I agree. I have never needed anything more outside of those voltages.

I had an arcade power supply I pulled out of an old cabinet, I got for free. It gives me +5,+12 (-5 and -12 as well) adjustable. I just added a switch and a fuse and a new cord as the old one was shot. Attached it to a piece of plywood I had in the stack to give me a nice place to put the boards on.

You can find a new arcade PS for around $20-$30 and prob another $10 for a switch and power cord and fuse setup.

It has a small foot print. I also reused some wire and extra connectors I had so I can just plug the power into the boards without having to use clips.

You need a load on the +12 volt output for the +5 volts work correctly on most AT (or perhaps ATX) power supplies.

The 5 volts is generated and follows the 12 output. With an unloaded 12 volts, the 5 volts will be low.

what are you looking to do? a good bench supply will give you one or more adjustable voltage outputs with adjustable current limiting

don't underestimate the importance of current-limiting when troubleshooting... having an ATX supply as a cheap source of 5/12 is great but some of them can deliver a lot of current on the 5 and 12v rails... many have no output current protection on the 5v rail (almost all do on the 12v rail)

I use this power supply for my bench top testing. Really like it, and it's darn cheap. Works great for Bally MPU, Williams MPU, Dataeast, WPC, etc.
ebay.com link: Artesyn Power Supply 5 1V 3A 12V 2A 5V 350mA 22E008