[RESOLVED] Reusing fan of dead Power Supply

[dee-u]

My power supply just died recently and thought of using its fan for other purposes. How can I provide power to this fan? The label says it is 12volts.

TIA

[MarMan]

Any basic transformer should do it if it provides enough current (some milliamp number).
It is probably DC.

[JuggaloBrotha]

My power supply just died recently and thought of using its fan for other purposes. How can I provide power to this fan? The label says it is 12volts.

TIA

You need to give it a 12V DC line, it's pretty easy to get a 12V transformer that'll output AC/DC

[Lord Orwell]

you didn't specify. Were you wanting to use it as a case fan?

From personal experience i can tell you that there is no set way for the fan to be connected to the circuit board. I've seen the leads soldered, and i've seen plugs. I even had one once that had an external connector that was to run to the motherboard.

i can also tell you that if you have a fan with three or more wires, you still only need to connect the red and black one. a third wire is speed detection, and a fourth by some method provides speed control through pulse-width modulation. I am assuming the fan has some kind of internal relay that interrupts power when this wire goes live. In any case, 4 wire fans are backwards compatible with 3 wire ones that control speed with voltage, and 3 wire fans don't require the sensor wire to be connected.

Most likely a power supply fan will only use 2 wires, but some have smart speed control and have 3.

If you wish to use it in a computer case you will most likely have to splice a different wire on it so you can plug it in. If you want to run it off batteries, a normal cell is 1.5v so use up to 9 of them. If you hook it in your car you should still be ok even though charging boosts voltage up to 13.5 volts. Fans don't have any delicate circuitry in them that could be damaged with that small difference. Any radio shack power adapter can run a fan. etc etc.
Only other thing i can think of to say is hooking a dc fan up backwards will NOT make it spin backwards, and has a possibility of damaging it.

[baja_yu]

The yellow wires in the case give 12 and red wires give 5 volts, black is ground. So just grab a spare power cable inside the case and use that. There should be one ore two of the small ones designated for floppy drive. You can cut off the connector and connect the fan to that. Be sure to isolate the cables properly when you splice them. That's of course if you will be using it inside the case.
You can feed it the read lead instead too. It will spin slower and be quieter. Not as effective though.

[dee-u]

The fan from the Power Supply only have 2 wires, and I did not closely look if the wires have different colors, their colors looked the same to me.

I am still not sure where to use it, perhaps I could place it on top of a CRT TV/Monitor? I just thought their might be some use to it if I can make it spin.

[JuggaloBrotha]

The fan from the Power Supply only have 2 wires, and I did not closely look if the wires have different colors, their colors looked the same to me.

I am still not sure where to use it, perhaps I could place it on top of a CRT TV/Monitor? I just thought their might be some use to it if I can make it spin.

You could use it to make a small portable fan, a 9V battery should run it fine for a while...

[Lord Orwell]

just try it both ways then. Wire in an old power adapter for anything. You won't get full rpms at lower than 12 volts but it will still work. of course this assumes the power supply didn't die because the fan quit...

[dee-u]

I found this old 6volts power adapter for a toy, can I use it to power up the fan which is 12volts according to the label?

[MarMan]

May not run, but it shouldn't hurt. (Certain components can be damaged by an under voltage, I don't think a fan has any of them in it) You can try.

[Lord Orwell]

it "should" spin at half speed. However this assumes there is enough voltage to get it spinning in ther first place.