Get a 3-pin fan to use PWM?

If its for a cpu cooler, and plugged into the cpu cooler socket then just use speedfan (http://www.almico.com/speedfan.php ) to control it, i use it to manage my radiator fan, tell speed fan the desired temps you would like and it will only ever turn the fans up when u reach that temp or above it. Same goes for other fan headers.

But each mother board is different, i have 6 fan headers and only 2 of them are controllable via software, so it will just be a matter of testing.
 
PaulyD said:
As above really

PWM requires 4 pin cable and header, no way around it unless using software (as above) or get a fan controller
Click to expand...

Actually that's not quite correct. Certainly, the most common PWM implementation used in PCs has 4-wires, but it's perfectly possible to run PWM on 3 wires (the mCubed TBalancer does this) - you just need a PWM generator to vary the pulse width on the positive wire. I built a couple of 3-pin PWM controllers and they worked as advertised, the only issue being the fans 'jerk' at very low speeds whereas the 4-pin ones stop. All you need is a timer chip and a MOSFET to power the fan.

http://www.bit-tech.net/modding/2001/12/03/pwm_fan_controller/1
 
WJA96 said:
Actually that's not quite correct. Certainly, the most common PWM implementation used in PCs has 4-wires, but it's perfectly possible to run PWM on 3 wires (the mCubed TBalancer does this) - you just need a PWM generator to vary the pulse width on the positive wire. I built a couple of 3-pin PWM controllers and they worked as advertised, the only issue being the fans 'jerk' at very low speeds whereas the 4-pin ones stop. All you need is a timer chip and a MOSFET to power the fan.

http://www.bit-tech.net/modding/2001/12/03/pwm_fan_controller/1
Click to expand...

WJA96 - you are a wealth of information and i'm glad you corrected me! :cool:

Didn't even think about the MCubed TBalancer and I have one myself :o
 
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