One dollar variable fan controller

Posted on Thursday, August 29th, 2013 in components, how-to by the machinegeek

Mountaindude has been spending some time lately working on 12V fan controllers and thought he’d share his experiences so far.

“While trying out various computer and network gear, I quite often find the fans too loud. They are of course there for a good reason, but experience tells that the device usually works just fine with less cooling.

Going through a 7805 data sheet for other reasons, I suddenly realized that a 7805 set up in variable voltage configuration should work great as a fan controller. These 12V fans usually run just fine down to 5-6 volts, but at lower RPMs, and thus quieter. Just what was needed!”

You can find project details and schematic at Ptarmigan Labs.

Via the contact form.

This entry was posted on Thursday, August 29th, 2013 at 8:00 pm and is filed under components, how-to. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

4 Responses to “One dollar variable fan controller”

  1. charting says:

    for nice, quiet fans, I hook them up to 5VDC via a USB connector…

  2. kerimil says:

    ohh come on it’s not that dedicated chips are very expensive.. plus as someone has already posted it might be be a better option to reduce voltage. I don’t like the idea of wasting power thorugh 7805

  3. Michael Taylor says:

    kerimil: You mean like a fancy 555/556 based PWM fan-speed controller?

    Of course, as it says at Ptarmigan Labs, Mountaindude built it with junk-box parts on-hand, while a you may not have a PWM controller or a small microcontroller (e.g. ATtiny or PIC10) and (if necessary) pass transistor just lying around.

    It is good for a cheap and quick hack, but a PWM controller based on a dual timer (556) and IRF5x0 MOSFET would be preferable at least in general, with the benefit of reduced thermal dissipation and still low cost.

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