Understanding Motor Speed Control Using PWM

Pulse Width Modulation (PWM) is a powerful technique for controlling the speed of electric motors, especially in DC and BLDC types. This article explains how PWM works and how to implement it.

🔌 What Is PWM?

PWM modulates the width of voltage pulses sent to the motor, changing the average power delivered without altering voltage level.

• High Duty Cycle : More power, higher speed
• Low Duty Cycle : Less power, lower speed

⚙️ Why Use PWM?

• Efficient power control
• Minimal heat loss
• Smooth speed transitions
• Low-cost implementation via microcontrollers

🔧 Hardware Requirements

• Microcontroller or motor driver IC
• Power MOSFETs or transistors
• Flyback diode
• PWM-capable power supply

🧪 Sample PWM Code (Arduino)

int motorPin = 9;

void setup() {
  pinMode(motorPin, OUTPUT);
}

void loop() {
  analogWrite(motorPin, 128);  // 50% duty cycle
}