Question about vibration motor circuit

Discussion in 'General Electronics Chat' started by yuvi1, Feb 17, 2014.

  1. yuvi1

    Thread Starter Member

    Feb 1, 2013
    hi all,

    i have 2 questions about this circuit that i took from this page :

    if i read this circuit correctly , i see that it drives a vibrator motor (of a cellular phone) with a PWM signal and a dc voltage , so my question is , why the PWM signal cannot drive the motor itself ? it's because it doesn't have anough current to drive the motor ? and my second question is, why is it wrong to drive the motor just with the dc voltage (without a pwm signal) ?

    thank !
  2. alfacliff

    Well-Known Member

    Dec 13, 2013
    a lot of those motors are burshless motors, and will not work on dc alone.
  3. shortbus

    AAC Fanatic!

    Sep 30, 2009
    The PWM allows you to control the speed/intensity of the motor. And since PWM is usually a "signal level" used to switch a "power level" voltage it may not be a high enough level to run the motor.