custom PWM fan controller

wjogert

2[H]4U
Joined
Sep 11, 2007
Messages
3,108
I wanted to show off the custom PWM controller that I designed to control 3-wire fans.

It runs 2 fans from a single PWM signal and is capable of running extremely high current fans. I am using it to drive my Zalman CPU cooler and a 1.3A Orion 120mm hi-velocity fan.

It was designed to adjust the fan voltage between ~4V to 12V (minimum voltage depends on the motherboard PWM range). This keeps the fans quiet, but never completely off so that fan failure alarms can still be set.

I will have to post the pics later (stupid work firewall is blocking all the image hosting sites and I don't see a file attachment option).
Board is 2.5" X 1.75" and has standard connectors for all of the connections (petite and sexy, lol).
 
Last edited:
Finally got the pics uploaded. Here is my little handmade prototype.
If I build anymore, I will have the PCB manufactured with soldermask and silkscreen.

 
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