Abstract: This paper presents simulation and hardware implementation of constant speed dc motor, using Thyristor Bridge, which operates in two quadrants. The firing angle is controlled by PID controller and is given to Thyristor Bridge which intern control the armature voltage of dc motor. Pic microcontroller PIC16F877A is used to implement PID controller. Variable resistor is used to set the speed of motor. This project is done for 0.5Kw motor. Motor gives constant speed for the variation in input voltage.

Keywords: PID controller, fully controlled thruster bridge, PIC 16F877A.