Controlling Power with Pulse Width Modulation

You can perfectly control a motor's speed or an LED's brightness just by slicing up time.

This is done by a tiny computer brain called an STM32 microcontroller. It uses a feature

called Pulse Width Modulation, or PWM. Instead of changing the voltage,

the chip sends power in super-fast pulses. The magic is the "duty cycle"—the percentage of time

the pulse is on versus off. A long "on" time means more power, making a light brighter

or a motor faster. A short "on" time means less power, dimming the light or slowing the motor.

So next time you see a light dim smoothly, remember it's a tiny chip playing

with time, millions of times per second.