Project titled controlling direction and speed for DC motor using PWM technique is developed to show how pulse width modulation method can be used for controlling speed and controlling process is managed through personal computer.


Pulse width modulation technique is used this embedded project for controlling speed of motor. Speed variation is used for controlling light by varing current up to few amps. In this circuit 12 and 24 Volte system is used with few design changes.

Pulse width modulation sends signals in the form of pulse which are in square wave which will change from switch on and off , for each pulses there will be time delay which varies from 0 to 100. Using this time delay change in power is transferred to the load.

Controlling direction and speed for DC motors using PWM Technique

Comparing both PWM and resistive power circuit PWM give more efficiency compare to other method. In resistive power system power is wasted for heating series resistors that percent will be saved in PWM.

Other advantage of using PWM technique is it give high torque with given voltage which will overcome resistances in motor. For controlling speed of motor two buttons are used for increasing speed and reducing speed.  Two other switches are used to controlling motor direction from clock wise to anti clock wise. To display speed of motor LCD screens are used.

Whenever there is change in direction or speed variation is seen buzzer will own which works as indication.   


This project is useful for industries and agriculture purpose. In this project main idea is to show how pwm technique is used in controlling speed and increase efficiency compared to other methods.