Mod Antec Tricool case fans

[snbase2]

I want to mod the stock 4-pin molex Antec Tricool 3-speed fans in my Antec 900 case to 3-pin so i can use a fan controller . The problem im having is the fans only have the red and black wire and a separate 3-speed switch. I took apart the switch and as you can see in the pics the switch has its own red, black and yellow wires. If i pull out the yellow wire will i be able to control the rpm's with a fan controller?


http://i24.photobucket.com/albums/c27/snbase2/fan controller/DSCF4674.jpg

http://i24.photobucket.com/albums/c27/snbase2/fan controller/DSCF4681.jpg

http://i24.photobucket.com/albums/c27/snbase2/fan controller/DSCF4678.jpg

 

[philbar71]

How does your fan controller control the speed of the fans? Is it voltage controlled or PWM (pulse width modulation)?

 

[CalcProgrammer1]

I don't think you can get RPM out of the TriCool fans, they don't have the RPM sensor wire. The yellow wire in the switch isn't a sensor wire, it just happens to be yellow like the sensor wire on many other fans.

You can simply wire the red and black wires into a 3-pin connector, omitting the sensor wire completely, but the controller will always read 0 RPM (it will be able to control the fan speed though). If you want to get technical, the RPM sensor wire is often just taken from the negative end of one of the fan motor coils, if you can solder a wire in the right spot you may be able to hack in a sensor wire. The sensor wire's electronic signaling is pretty simple, it connects to ground two times per fan revolution (and is disconnected for the other times). If you have a multimeter or similar measuring equipment you can find points on the fan's board that work this way and solder a wire there for a sensor.

 

[CalcProgrammer1]

I found a sensor point on the TriCool fan! I took the sticker off the TriCool I took out of the rear of my case and was poking around on it with an LED. I found a hidden spot where the LED flashes as the fan spins (this is where the RPM wire is usually tied into). I found it for you, now it's up to your soldering skills to add a wire (it's hidden behind the plastic a bit, but if you don't mind dremeling or cutting the plastic you should be able to tack a wire on with a soldering iron). It works best with the switch on level 3 (all the way on) which is what you'd use with a fan controller anyways.

Solder your sensor (yellow) wire to that solder pad and then use the red and black wires from the Molex connector to make your 3-pin motherboard/fan controller header. Leave the switch on 3 and hide it away (or you can find out the position and solder it but that may be tricky). You should have a TriCool that can be controlled with a fan controller now.