and also plz plz rate my instructable well
Hi every one.Today i'll show you how to make a PWM(pulse width modulation) out of a very famous chip 555(lm,ne any one will do) with some other parts offcourse.This is really simple and it is very handy if you want to control your leds,light bulb,servo motor or dc motor(brushless also works).
My pwm can only change the duty cyle from 10% to 90% it cant do nothing more!
Step 1: What Is PWM
Step 2: Types of pwm
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.