Is Zalman FAN MATE 1 using PWM?

Clippet · Post by **Clippet** » Mon Jun 02, 2003 6:57 am

I recently read some discussions in this forum about fan controllers which use so-called PWM. It worked a bit like turning the 12V power on and off rapidly to make the fan "see" a lower voltage and thereby spin slower. PWM apparently solves the problem with a high-wattage rheostat that is normally used.

Almost every one of the postings about this topic seems to point to that PWM is not recommended for controlling fans as silent as possible, due to "clicks" and other strange sounds that arises in the fan.

A well-known simple fan controller is the FAN MATE 1 from Zalman. The simple question is: does this controller use PWM?

From looking at the pictures in the review on this controller here on silentpcreview.com, it seems like it uses som big variable resistance instead of PWM.

IceFire · Post by **IceFire** » Mon Jun 02, 2003 8:39 am

It is just a rheostat.

Post by **MikeC** » Mon Jun 02, 2003 9:06 am

IceFire wrote:It is just a rheostat.

Technically, it is a voltage regulator that uses a transistor. Here's our recent brief review.

Clippet · Post by **Clippet** » Mon Jun 02, 2003 1:51 pm

Thanks for the help on this topic. Now I can use these controllers without worrying about PWM

Does this circuit always guarantee a range of 5.5V to 12V on all fans? It seems so reading the specs on Zalman's homepage. Fans have different resistances (and so amps).

Post by **MikeC** » Mon Jun 02, 2003 2:03 pm

More like 5V to 10.5~11V -- on all fans.

Clippet · Post by **Clippet** » Tue Jun 03, 2003 1:01 pm

Yes but to me the most interesting with it, is that it will be that range on all fans