Get More Out Of Your Thermaltake Fan

Date Written: February 5, 2002
Written By: Jason Rabel
Company: Thermaltake

Get More Cooling For Free (Again)!:

After posting the Volcano 7 Fan Tip, people started writing about if it was possible to wire up a switch to the fan sensor to go between the sensor control and full speed. In theory it sounded possible, so I decided to try it out on my Volcano 7 fan to see if I could wire in a switch.

The temp probe is a fairly simple device that controls the fan speed. As the temperature increases around the probe (gets hotter) the resistance through the probe decreases, which tells the fan to spin faster. When it gets colder, the resistance increases through the probe which tells the fan to slow down. I clipped off the probe from the fan and connected it to my Ohm meter to see what kind of resistance I would get. Sticking it in the freezer for a few seconds maxed out the resistance around 8-10k Ohms. Actually clipping off the probe also let me know how the fan operated in relation to resistance, some sensors react the opposite way as I described above.

For those of you who don't know the Thermaltake fan spec's, here they are:

• 2900RPM @ 25°C (77°F) / 46CFM

• 5000RPM @ 35°C (95°F) / 53CFM

The first step was to take the fan off the heatsink, and when you flip it over you can separate out the power wires from the probe wires. For this mod all you really need is some spare insulated wire (the smaller the better), a soldering iron, and at minimum a SPDT switch. The mini switch below that I had laying around is actually a DPDT, but it doesn't really matter because we are only going to be using one side.

Since I clipped off the probe to check the Ohms, I decided it would be easiest to mount it near the switch just for simplicity's sake. Though later I realized this wasn't the best way to do it, but I will explain after I go through the necessary steps.

First you want to solder a long wire to the middle of your switch, this is the common line that will lead back to one end of the temp wires on the fan (that the probe used to be attached to). I like to use heat-shrink tubing to prevent any shorts, though it is not necessary if you are careful, perhaps electrical tape could serve the same function.

Anyhow, now that we have the center wire connected, depending on which way we flip the switch will depend on whether it runs through the top or bottom connector. So on one end I soldered in the temp probe, and on the opposite end just another regular wire. The opposite ends of both of these wires you want to solder together and connect to the other temp wire on the fan. This will complete the circuit and now depending on which way you flip the switch will depend on if the current runs through the sensor or just straight through for max RPMs...

However, if you notice far right picture above, we have a slight problem. The solder points are right at the edge of the fan and are too thick to get everything flush! ACK!

Go On To Page 2 For Plan B -->