Microcontroller based Closed Loop Speed Control of DC Motor using PWM Technique

Speed control of DC motor is very important especially in the fields including industrial applications, robotics and so on.So, speed control of DC motors at different load conditions is a prominent field of research in order to achieve a robust system.This paper presents the design and implementation of microcontroller based speed control of DC motors which emphasize the design of PWM control using ICs like SG3524, TL494 in the field of motor speed control.For PWM generation microchip PIC16F877A microcontroller is used.The feedback loop is created by using ADC which is available in the microcontroller IC.This ADC reads the voltage level of the motor and correspondingly the voltage level of the motor can be maintained at a fixed level.A driver circuit is used to drive the motor.Hence, a closed loop motor speed control circuit is designed and the total amount of power delivered to the motor is varied depending on load conditions.In this technique, the regulation of motor's speed is realized by changing the voltage of the motor which is adjusted by the duty ratio of PWM.