Cheap fan control without microcontroller

Discussion in 'Digital Circuit Design' started by RodSTAR, May 8, 2017.

  1. RodSTAR

    Thread Starter Member

    Jan 3, 2008
    15
    0
    Hello electronics guys, I want to turn on an AC or DC fan when a heatsink reaches a certain temperature determined by a potentiometer, and then fan speed to be some quite proportional to temperature. I bet or I'm sure this situation has already been solved anywhere anytime, but I want to know where to find the circuit or if is there already any cheap kit (on eBay or something) to do this. I could easily do this with a microcontroller, but I want some cheaper solution.

    Regards
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    15,853
    4,628
    A simple 12f series pic could do this fairly cheap.
    You would need a thermal sensor also and the output device would depend on the nature of the motor.
    Max.
     
  3. ian field

    AAC Fanatic!

    Oct 27, 2012
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    ATX PSUs used to have a neat little sub panel with a couple of transistors and a thermistor on a fly lead clamped to the heatsink.

    Nowadays its fully integrated into the main PCB - but if you can be bothered hand tracing the circuit.

    Its a good basis for the control circuit, you can buffer the output for what current you need.
     
  4. dendad

    Well-Known Member

    Feb 20, 2016
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  5. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    PWM signal using 555.
     
  6. DickCappels

    Moderator

    Aug 21, 2008
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  7. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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