Pulse Width Modulation Based DC Motor Closed Loop Speed Controller

Abstract

Regulating the speed of a DC motor using a microcontroller and the pulse width modulation (PWM) technique is the primary objective of this project. Every robotics project relies heavily on DC motor control. Rotating a DC motor with high or low speed limitations is necessary in many applications. We employ the PWM approach for this purpose. In a pulse width modulation (PWM) circuit, the average on time may be adjusted from zero to one hundred percent by adjusting the on-to-off ratio, which results in a square wave. This allows for the delivery of power to the load to be varied. Compared to a resistive power controller, a pulse width modulation (PWM) circuit is more efficient. When set to 50% load power, the PWM uses approximately 50% of full power, with nearly all of that power going to the load. In contrast, a resistive controller uses about 71% of full power, with half of that power going to the load and the other 21% going to waste heating the series resistor. Pulse width modulation has the added benefit of allowing the pulses to reach the entire supply voltage. This allows them to generate more torque in a motor by more readily overcoming the internal motor resistances. An on-board computer, coded using embedded C instructions, is utilized in this project. The on-board computer may talk to the input and output modules. In order to show the current speed of the DC motor, the LCD acts as the output module. The speed of the motor may be adjusted using the control buttons.