How to Design and Implement a PWM Motor Control Circuit

How to Design and Implement a PWM Motor Control Circuit

Pulse Width Modulation (PWM) is one of the most effective techniques used to control the speed of DC motors . It is widely used in applications such as robotics , fans , pumps , electric vehicles , and industrial automation . This article provides an in-depth guide on how to design and implement a PWM motor control circuit from scratch, covering essential components, design principles, and practical implementation. What is PWM? Pulse Width Modulation (PWM) is a technique of controlling the average voltage supplied to a load (in this case, a DC motor) by rapidly switching the power on and off. The duty cycle of the signal determines how long the switch remains on in a given period. Duty Cycle (%) = T O N T O N + T O F F × 100 \frac{T_{ON}}{T_{ON} + T_{OFF}} \times 100 For example: 0% duty cycle = always OFF (motor off) 50% duty cycle = ON half the time (motor at half speed) 100% duty cycle = always ON (motor full speed) Why Use PWM for Motor Control? Efficient speed control (minimal heat loss) Lower power consumpt…