PWM Fans

[moosey]

Basically the post says it all. It would be for a CPU fan on a Intel BX2 motherboard. How are the fan speeds setup, can the user set that up and how?

Thanks

 

[Fullmetal Chocobo]

PWM (pulse width modulation) works by sending 12v to a fan, but not constantly. The pulses of 12v determine the speed of the fan.

EDIT: As far as how to set that up, you should definitely consult the manual first, as it differs for the different BIOS manufacturers.

EDIT 2: Wikipedia info on PWM.

 

[moosey]

Thanks, I'll check those out. I'm still in the processing of ordering my stuff so I was trying to find out if getting a PWM fan would be a good bet for my C2D (trying to keep noise in mind)

 

[Fullmetal Chocobo]

Originally posted by: moosey
Thanks, I'll check those out. I'm still in the processing of ordering my stuff so I was trying to find out if getting a PWM fan would be a good bet for my C2D (trying to keep noise in mind)

In that case, go to the manufacturer page for the mobo, and download their manual. That's one of the first things I do when researching possible motherboards... 😀

 

[Rubycon]

In a true PWM setting, the fan can actually be "programmed" to spin reliably at extremely low speeds. This requires the commutator-less motor driving circuitry and the PWM controller to be matched.

 

[pcy]

Hi,

A PWM fan has fout connectors - theree are the same as for an ordinanry 3 pin fan, and thre forth goes on and off for varying amounts of time. It is used (by circuitry within the fan) to switch the power in the 12V cct on and off at the fan.

The problem is that PWM fans (certainly 120mm PWM fans) are hard to find, and we have had to design a PWM to 3-pin converter as a result.



Peter

 

[moosey]

in this case it would be the zalman 9500at heatsink fan