Step 2: Types of pwm

Three types of pulse-width modulation (PWM) are possible:

1. The pulse center may be fixed in the center of the time window and both edges of the pulse moved to compress or expand the width.
2. The lead edge can be held at the lead edge of the window and the tail edge modulated.
3. The tail edge can be fixed and the lead edge modulated.

Three types of PWM signals (blue): leading edge modulation (top), trailing edge modulation (middle) and centered pulses (both edges are modulated, bottom). The green lines are the sawtooth signals used to generate the PWM waveforms using the intersective method.

About This Instructable


148 favorites


More by shams: How to use a breadboard How to blink{breathing style} LED$ while you are playin re4/mgs/crysis Very simple PWM with 555...Modulate every thing
Add instructable to: