Simple DC Motor Controller using 555 Timer IC

Driver is the actual circuit that drives DC motor and switching circuit decides how DC motor should be driven. So actually, switching circuit is the main circuit that controls the motor. Now there are two parameters of DC motor that can be controlled

1. Speed

2. Direction

Changing the direction of DC motor is very simple just reverse the supply given to DC motor.

For varying speed of DC motor you have to vary the applied DC voltage. One well known method widely used in industries is Pulse Width Modulated (PWM) speed control of DC motor also known as chopper control. In this method PWM is applied to DC motor and as the width of pulse varies average voltage applied to motor varies and so the speed of motor also varies.



In this project I have used standard H-Bridge circuit as a DC motor driver and astable multvibrator (using IC-555) as a PWM generator. IC-555 generates PWM with the base frequency of 100 Hz. This PWM is applied to H-Bridge driver through DPDT switch which decides direction of rotation either clockwise or anticlockwise.


The DC motor controller that I have given here can be used in controlling small or medium DC motors of Drilling machine, portable DC fan, small water pump etc.