Computer Fan speed Controller

[Gayan Soyza]

Has anybody tried this circuit? Its an Automatic Fan Speed Controller for PC's.
Designed under a MOSFET.very simple.just adjusting the Gate Voltage through THERMOSTAT & V/R to control the Output.this works fine.I added to my PC (System Fan) & for my Amp.Here is the original link you can get more information from that........... try it.

http://www.heatsink-guide.com/content.php?content=control.shtml

cheers

 

[Sceadwian]

It's a horribly simple circuit.. It waste the energy it doesn't send to the fan as heat in the fet. Modern PC's use a fixed frequency PWM with a variable duty cycle to control the power getting to the fan, easy enough to do with a simple 555, and depending on the PC significantly more efficient.

 

[Gayan Soyza]

It's a horribly simple circuit.. It waste the energy it doesn't send to the fan as heat in the fet. Modern PC's use a fixed frequency PWM with a variable duty cycle to control the power getting to the fan, easy enough to do with a simple 555, and depending on the PC significantly more efficient.

Ya its correct PWM more efficient than this.but with descretes it's the only cct I found.I alredy made this 555 as usual.it's controling well.