What does pulse width modulation control primarily?

Pulse width modulation (PWM) primarily controls the duration of the pulse. In PWM, the width of the "on" time within a given period is varied, which effectively modulates the average power delivered to a load without changing the frequency of the signal. By adjusting the pulse width—how long the signal is high versus low—it's possible to control the amount of energy supplied to devices such as motors or LEDs. This technique is widely used because it allows for efficient power control while maintaining other characteristics of the signal such as its frequency constant. Therefore, focusing on the duration of the pulse is key to understanding how PWM functions and its applications in various electronic systems.