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How can I power my fans externally? Answered


I'm trying to run my 12v DC fans externally. Is there a way to do this? Is there such thing as a power supply specifically for 12v fans? I'm thinking the only way to do this is to cut up a 12v power supply that I can get from the shops. Is there another way to power them? Is there anything that can externally supply the correct voltage (12v) to these fans?

Thanks, really appreciate any help.

4 Replies

Josehf Murchison (author)2014-02-14

Make sure the fans are 12 volts, some cooling fans are 5 volts.

Any 12 volt DC supply will power them.

If the fans are 5 volts any 5 volt DC supply will do.

Next some fans are multi speed and they have a red, black, and yellow wires.

For multi speed fans you may need a control circuit usually controlled by a thermistor and a comparator.

The thermistor senses the heat and speeds up the fan.

Some of these you can by pass the control circuit with a switch to the red and yellow wires.

The last fan hook up uses a two wire fan red and black wires and a thermistor and comparator circuit to turn on the fan. These sometimes will also be able to control the speed of the fan.

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Vyger (author)2014-02-14

If you are talking about 12 volt computer fans then you can use an old computer power supply to power them with no trouble, You can even hook up a fan controler and monitor and control the RPM. You don't have to cut up a power supply, just plug it in and hook the fans to it.

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Tickles14 (author)Vyger2014-02-14

I seriously didn't even think about that. Thanks, I'll do that. What amount of watts will I need for one 12v DC fan?

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petercd (author)Tickles142014-02-14

About 2W, the fans range from 0.15A to 0.25A @ 12V, you could even use one of those variable voltage 12v 1A psu's, unless you're running a bank of 10 fans.

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