Today the parts for my PWM fancontroller arrived. After a few tedious hours of soldering (which made me look like WL's avatar), the controller was finished. Here is the current version (will do more when I get new parts):



(It's late and I have a bad camera, so don't be mad about the quality ).

As you can see, it's a fairly straightforward design, but because I made some stupid decisions during the purchase of the parts, I ended up having 2 1mm SMD capacitors, which are a real PITA to solder properly .

The fancontroller is PWM controlled, designed for normal 3-pin fans (here is a quick explanation of PWM fancontrol), based on the NE555 timer as an astable multivibrator, which is a design used in some professional fancontrollers as well.
The design is based on this schematic (source):


Theoretically the Mosfet I'm using is rated for 9.2A, meaning I can completely use the capacity of a single Molex line (rated for 5A). Of course, it gets rather hot, even when using one fan, but I'll get a nice big heatsink for it later .
Here you can see it controlling 2 fans:



There are still some improvements I plan on doing:

  • The Mosfet will be fitted with a big heatsink, because it's getting rather hot right now.
  • The layout will be changed, to allow the heatsink and the fan header to fit properly.
  • Of course, the SMD components will be replaced by components that are easier to solder.
  • The final circuitry will be on a printed pcb, which I will also create myself.
  • The potentiometer will be replaced, because it currently lets the fans run at 100% when it's only at 10% voltage. Also, I want one with a big knob .


So far my little fancontrolling experiment. Of course, I'll keep everyone updated as this progresses further. Feel free to ask any questions in the mean time . Hope you all like it.