Noman, MuhammadJaleel, MuhammadAhmad Muaz Tufail2014-09-232014-09-232014-07https://escholar.umt.edu.pk/handle/123456789/1271In present days the power semiconductor devices have completely revolutionized the control of drives especially in the area of control usage of Thyristors IGPT’s power MOSFET etc., has increased. The project reveals the digital closed loop control system for speed control of DC motor using PWM technique. The digital circuit can be interfaced with microcontroller, so that the speed can be controlled by Micro-controller even more easily. PWM technique to the digital circuit drives the component correspondingly, speed will change. The project basically consists of Micro-controller (AtMega-16), Motor driver (TLP-250), Dot matrix LCD (JHD-164) display, Rotation feedback sensor (optical encoder), MOSFET’s (irf-740), Resistors, and Capacitors. We program the Micro-controller to take the input values from the user, and then rotate the motor by placing 25% to 40% duty cycle pulse on the motor. The motor is rotated at X RPM speed, can be detected by using feedback sensor and micro controller. If the speed is above the specified speed then the micro controller continuously reduces the duty cycle till the speed comes to a predetermined level. If the detected speed is less than the pre determined speed then the micro controller continuously increases the duty cycle till the determined level. The micro controller keeps on tracking the determined speed by varying duty cycle in a closed loop control system.enBS ThesisElectrical EngineeringThesis