Hotwire a PC power supply?

[Push Eject]

That's a pretty great how-to. Do that, Luf'

Push Eject

[Bugeater]

Thanks! I was thinking about looking for that page today for a project I am building.

Wayne
Bugeater Brewing Company

[keggermeister]

I'm pretty sure that most cpu power supplys have built in circut breakers. I use one at work for bench testing car parts. The one i use would put out almost 5 amps before tripping. After shorting or overloading the circut it would come back on in a few seconds.

Make sure that it is rated for Rat Pad!

[Lufah]

Alright I got the power supply working. Now anyone know how the wiring for a 24VDC fan works? It has four wires instead of the two.

Red=ground

Blue= -12VDC

White= ???

Purple= ???


It runs with just the -12 and the ground wired up, but seems like I should be able to get more out of it if I hooked one of the other wires to the +12. Nothing seems to change when I try it tho.


Thanks for helping the clueless.


Travis

[codewritinfool]

Alright I got the power supply working. Now anyone know how the wiring for a 24VDC fan works? It has four wires instead of the two.

Red=ground

Blue= -12VDC

White= ???

Purple= ???


It runs with just the -12 and the ground wired up, but seems like I should be able to get more out of it if I hooked one of the other wires to the +12. Nothing seems to change when I try it tho.

Thanks for helping the clueless.

Travis

Lufah,

If it is working with red = ground and blue = -12VDC, AND it is a 24V fan, just hook the red to the +12VDC and leave the blue at -12VDC. Don't hook up the other two wires, just insulate them. Also, no ground connection. You just want 24V of potential across the fan, and that's how you get it. Caution though, read the following:

If it is a CONDUCTIVE housing, you may have problems if one of those two wires is common with the case of the fan AND there is a return path from the case to ground on your power supply.

If it is in a plastic housing, probably no problems at all.

Try it.

[Lufah]

Yup that worked. Holy shit is that going to be a hell of a stir plate!


Thanks again


Travis

[codewritinfool]

I've never built a stirplate, but I was just thinking about the physics of it...

The maximum speed of the stirplate is probably determined by the strength/coupling of the magnets and the viscosity of the fluid.

Faster motor = not necessarily a faster stir because the two magnets are no longer tightly coupled.

Anyone with a stirplate know for sure?

[Push Eject]

I gave up on my homemade stir plates and bought two when I kept throwing stir bars...

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