Lets say you want 12v...

[VTEC_Inside]

My venture into the world of RC has lead me to re-discover something I already knew. A computer PSU makes a great 12v source with decent amperage capacity.

Older AT power supplies with a hard switch are simple, but tend to be lower amperage and not as smart as an ATX supply.

I've got an AT supply under my workbench that I use when I need 12v, but I'm in the process of making a nicer one out of an ATX supply.

Anyway, just thought I'd mention it in case anyone else had a use for 12v source, but didn't want to spend a lot to get one.

[hotrodalex]

I used a PSU to run a car stereo deck connected to the floor speakers in my room. Good stuff.

[VTEC_Inside]

I used a PSU to run a car stereo deck connected to the floor speakers in my room. Good stuff.

How many amps can your PSU put out on the 12v rail?

All the AT supplies I have are pretty weak, <10amps. The ATX supplies I have laying around are all 12+ amps.

The bugger as I'm finding out is that ATX supplies aren't stupid. They shut off on their own VERY easily if a short is suspected. Some won't even turn on unless there is a load on the 5v rail, and even then you better hope you hooked up what you wanted to the 12v first. Most also have sensor wires paired with the others so you best not just hack off the connectors to start.

The 430w PSU I'm toying with is a particular pain in the ass, very finicky. A 10w10ohm resistor on the 5v makes sure it turns on every time, but its still very sensitive to loads on the 12v. I've got more resistors coming since my local shop let me down. The most favorable arrangement (IMO) is 2 of these resistors in series, followed by 2 in parallel. That loads up the 5v enough and doesn't result in too much heat from any of them.

[hotrodalex]

I used the PSU from the old Mac we had, so I didn't have any problems. Just clipped a few wires off the harness and connected them to the stereo (12v, the "on" wire, and a few grounds) Might have had something connected to the 5v, can't remember.

[VTEC_Inside]

Hmm, not sure if that PSU would follow the same rules as an ATX then. Did it have a physical switch in the first place?