Is there a way to use 3-pin CPU fans outside of a computer?

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Nathan113

Commendable
Dec 12, 2016
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I disassembled a slim PC and it had a very nice turbine CPU fan (takes air in from the bottom and blows it out the side). It has a 3 pin connector for power.

From my understanding, The red wire is positive, while the black is negative. There is a white wire which I understand is the fans tach cable to communicate with the mobo.

Is there any way I can use this outside of a computer inside a 12V system? I'm working on a motorcycle project and this would be perfect for cooling in the small space I have.

I'm looking to either have it run full blast when I open a switch or hook it up with a dial to control the speed. Is any of this possible with this type of fan?
Thanks in advance for any help.
 
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Yes, the mobo can tell it how fast to run, but in this case, it should always run at full speed and a bit more, if it's at 14V.
It shouldn't die at 14V, there are a lot of fan killing videos on youtube and all of them last over 20V.
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Yes red and black 12v would give you full speed. You could use a potentiometer to vary the voltage to it and slow it down.

Keep in mind that most car/marine/whatever 12V dc can idle as high as 14V sometimes so a basic L7812 12v voltage regulator would help keep the power in line.
 
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I have attempted hooking it up to straight 12V, but the fan would shut off after a second of spinning. I believe its a safety shut off deal. It spins fast, but off after a second. How do I keep it spinning?
 
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a 12V Motorcycle Battery. I just hooked it up again and it spins fast, but than drastically slows down and holds a slow speed.
 
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I used a computer fan in a custom made guitar amplifier head I built to cool the vacuum tubes in the amplifier. I didn't need it to run at full speed (noisy) so I just used a 6 volt transformer, rather than a 12 volt source. The DC voltage controls the speed, not the amps. Sounds like something may be wrong with your fan.
 
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Has nothing do with AMPS. A device will only DRAW the AMPS it needs. That's why a 40AMP rail on a power supply doesn't blow up a hard drive, even though it pulls 0.9AMP.

Voltages on the other hand, as I stated, a 12v DC marine/car/motorcycle battery is usually in the 14-16V range, and this could be cause the behavior with the fan.
 
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If the battery is indeed supplying more than 12v DC wouldn't the fan simply run faster than it would at 12 V? If the OP has a multimeter, it would be easy to determine the voltage of the battery. As the battery discharges, the voltage would go down.

 
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After a little bit of research after hearing what everyone had to say, I found that fans use more amperage to start up, then use less. So that is why it spins fast, then slows down. Perhaps something with the communication between fan and mobo has to do with the speed?

I appreciate everyone's help here.
 
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Yes, the mobo can tell it how fast to run, but in this case, it should always run at full speed and a bit more, if it's at 14V.
It shouldn't die at 14V, there are a lot of fan killing videos on youtube and all of them last over 20V.
 
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