dc fan controller

Discussion in 'General Electronics Chat' started by chenpenghao, Jan 25, 2012.

  1. chenpenghao

    Thread Starter New Member

    Jan 4, 2012
    i need to design a fan controller that will change the fan speed with a potentiometer using a PV panel as power source. because the output voltage of pv panel is not stable, which ranges from 12V to 24V.
    and the operation voltage of fan is from 11V to 30V.
    how can i make sure the controller can supply 11V-30V to the fan at any time of daylight.
    or state another way, the controller is able to regulate the voltage from 11 to 30V at any level input voltage (12-24V).
    i wanna use a buck boost converter or flyback converter to achieve it.
    but i can figure out how can i deal with the unstable input voltage.
    thanks in advance.
  2. Audioguru

    AAC Fanatic!

    Dec 20, 2007
    Usually PWM is used to vary the speed of a DC motor. Then the torque is always high.
    If the DC voltage is varied then the torque is also varied and the speed control is poor and the fan might not start running slowly.
  3. PaulEE


    Dec 23, 2011
    Linear power amplifiers dissipate a considerable amount of power, also.
  4. Audioguru

    AAC Fanatic!

    Dec 20, 2007
    I used PWM to control ther speed of the motor on an electric model airplane. At any speed of the motor the torque was high and the switching Mosfet was not hot.