
PWM or Pulse width modulation is the method of controlling input voltage with digital position feedback signals through a series of on-off pulses. Pulse-Width Modulation is commonly used for speed control of a motor. The wider the pulses the higher the average input voltage and the narrower the pulses, the lower the input voltage.
On actuators with an internal PCB, PWM is usually not allowed as it will damage the components on the board.