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Another clever trick from the world of electronics – Pulse Width Modulation is a simple method for controlling analog devices via a digital signal. It’s also a very efficient way to drive motors, lamps, LEDs, & more.

If you’ve ever faded an LED with an Arduino – you’ve used PWM. But you don’t need a microcontroller to generate a PWM signal. The ever-versatile 555 timer chip can be configured to modulate its output duty cycle in response to a potentiometer – with the help of some relatively simple circuitry. Or for a more robust solution, consider the DC to Pulse Width Modulator kit suitable for sending up to 6.5A of current and built around the Motorola SG3525 – a chip dedicated to the art of PWM.

Oh and – I’d be denying my own nature if I didn’t mention at least one audio-related application. Indeed, PWM comes in very handy for generating simple sound from a microcontroller – melodies too!

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Collin Cunningham

Born, drew a lot, made video, made music on 4-track, then computer, more songwriting, met future wife, went to art school for video major, made websites, toured in a band, worked as web media tech, discovered electronics, taught myself electronics, blogged about DIY electronics, made web videos about electronics and made music for them … and I still do!

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