I've got a fan from a PC that I want to use on a project. The name plate says it's 20W @ 12V . That's easy to understand but it has 3 wires to the motor which I don't understand. The PC is long gone so I can't test the output unfortunately. Anyone know what they do?
John
In message , John writes
Three wires..
One pos (+12v usually yellow), one neg (usually black) and one is a "sensor" wire.. this one sends a signal to the mother board to shut down if the fan stops rotating thus avoiding overheating of critical components. Not sure how it works though...
If all you need is an "extra" fan, you can connect +ve and -ve to a spare power connector and it should run continuously.
Regards,
The third wire may also be a tacho pulse o/p for speed control
Thanks both. That means I can use it as I hoped. I will check the wire colours when I get home but ignoring the sense wire makes sense for my use.
John
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