Fan Speed Controller - Build your Own

Silvon,

I leave my fans at full speed simply because I have no reason to turn them down. I have a gaming rig too. When gaming, just turn them up to full speed.

Keep in mind that this is a VARIABLE resistor, so you can turn the fans up or down depending on the use.

5 volts is the minimum, because any less and the fan just shuts off.
In your case, I would stick with a 120 ohm potentiometer, as you will see the best results with that.
That allows you to leave the fans at full speed (12v) when gaming, or turn them down to 5v for quiet afterward.

If you get a 100ohm pot, then you could only turn it down to, say 7v, which will not be a slow (quiet) as 5v.

Make sense?

~Lordbob

Silvion said:

Makes perfect sense, thanks a lot for clearing that up LB, appreciate it heaps!

No problem.

Would be cool if you posted pics of it finished!

It is pretty cool to know my guide helped some random guy I have never met before do the same sort of mod I came up with

~Lordbob

Silvion said:

Haha will do, might take me some time to make it though, i'm a novice (obviously) so learning as i go, enjoying it heaps

Plan is to make fan controller like yours, mount it in 5.25" bay to control 6 fans, thinking about adding another switch to turn on/off leds for each fan.. but one at a time i think xD
Yeah found your tutorial through google. I've used heaps of information from it, Couldnt find anything else useful apart from your tutorial, so grats :)

Thanks a lot for helping me out

If you need any help with the wiring, etc feel free to PM me or post here. I check the forums at least once a day, so I will see it and reply fairly quickly (assuming I am not in class).

In regards to the fan controller bay, I can tell you right now that you can only really fit 4 across (assuming you can't find pots smaller than mine). You might want to consider using either 2 rows of 3, or some other lineup.
Also figure out how to mount the LEDs in the fan bay (there are nice little LED holder that should work fine).

The fan bay itself could prove problematic. I know mine was an absolute bitch to build, so I hope you have a better way than I did.

~Lordbob

Excellent tutorial,thanks !

xXTyMeador73Xx said:

This is exactly what I'm looking for. great instructions, easy to follow, simple construction. The problem is that i have a ridiculously powerful fan. it runs from 7-14.5V dc and draws 440 mA (.44 amps). i would like to drop it to 7V with the pot turned all the way down, and 12V with the pot all the way up (using a 12V rail obviously) the problem is that i need a potentiometer with 19.5 ohms (i would settle for 20 ohms) resistance. All i can find with this resistance are things called "trimmers" and not actual potentiometer's like the one you used. do you have any ideas as to where i could find one?

You can also look for variable resistors, those are the same as potentiometers and sometimes easier to find.
It shouldn't be too hard to find that potentiometer, but I don't know where you have been looking.

~Lordbob