PC Fan Controller Circuit


Posted on Feb 5, 2014

This PC fan controller circuit is designed with discrete components and is used to control 12 V fans that have a current consumption lower than 200mA. With the components values presented in the circuit diagram, the voltage won`t drop below 7V. If the fan won`t start at 25 °C then temporarily replace the temperature sensor KTY10 with a 1. 8k © resi


PC Fan Controller Circuit
Click here to download the full size of the above Circuit.

stor and reduce the value of R7. If the PC fan has a speed too high then increase the R7 value. T1 and T2 transistors compare the fixed potentional from R3-R4 common point with the temperature dependent potentional of R1-R2 common point. It may be useful to connect a 25k © potentiometer instead of R2 and to adjust it until the PC fan is at the correct speed and to measure its resistance and then replace it with a fix resistor with the same value. Place the temperature sensor in the warm air of the fan. When the PC is connected the speed rotation of the fan will be pretty high because of C1 but will decrease at a minimum value. Measure with a thermometer the air temperature close to the sensor. When the temperature reaches 35 °C the controller circuit will start to work. If this won`t happen modify the value of R2 or adjust a potentiometer placed instead of R2. When the temperature increases so will the rotation speed of the PC fan. The maximum speed will be lower than the one obtained without the control circuit.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    CDV700 Geiger Counter
    how to use in-built adc of avr
    2500w phase control
    in making incandescent lamps
    2X15 Watt stereo amplifier using TDA4935
    Dynamic Microphone Preamplifier using C945 transistor
    dvi to par digital video interface with lcd
    60kv ignition coil driver circuit
    Coil Winding machine counter with Atmega8 and Reed relay
    dtmf circuit
    Reverse engineering an MB Electronic Simon game



    Top