Home made smart fan controller

[Zergling]

I want something that turns on fans when a certain temperature is reached and gradually speeds up till full load at another temerature. Has this been done? The fanstorm kit seems to do this, but I am a bit short on cash and wife would never approve it.

[powergyoza]

Another discussion here http://forums.silentpcreview.com/forums ... php?t=2511
already has some info and links to diagrams of some fan control circuits.

Happy modding!

[ChiefWeasel]

Ive built one of the ones from heatsink-guide, and its very good. Only costs around £2 (~$2 or $3), and you can set the temperature sensitivity. From personal experience, dont use with papsts which click; if the voltage supplied is just below the start up voltage they will click like crazy!

[clamrade]

Does this controller (the simpler one described at heatsink-guide) vary the speed between starting and max, or is it a simple on-off? It wasn't clear to me from the description.

Thanks.

[Mirar]

I have a home-build temperature sensitive quadruple fan controller:


Basic design here:
http://vodka.tky.hut.fi/~jap/Electronics/FanCtrl/
(It's also in the LM317 datasheet along with other fun stuff you can build with it.)

It will not turn on the fans or so, but it will vary the voltage depending on temperature. You don't need the capacitors, they probably do something good in a sensitive environment, but the 12V lines in a computer nor the fans are that sensitive.
The LM317 can handle 1A (=6W at 6V, or 11W at 11V), IIRC. If you use bigger fans, you will need to work with power transistors and stuff.

[ChiefWeasel]

Does this controller (the simpler one described at heatsink-guide) vary the speed between starting and max, or is it a simple on-off? It wasn't clear to me from the description.

Thanks.

The one at heatsink guide varies the voltage continuously from startup to max voltage.