implementing PWM

[Himanshu]

Hello,
           i want to know how to implement pulse width modulation(PWM) on a circuit, what additional components like resistance and capacitor are required.
also i want to know how to implement PWM on 8051 microcontroller.

[pterrus]

I'm thinking about using an LM555 timer IC as a PWM generator.  Hook it up in astable mode like this.  Full disclosure: I haven't actually tried it yet.  But it should work!

[newInRobotics]

Circuit below will generate PWM with variable duty cycle. Change Cap or Pot value to get different frequency.

[Soeren]

Hi,

Change Cap or Pot value to get different frequency.

First it needs to be rearranged a bit
As shown, it's possible (likely even) to short pin 7 to Vcc (Not Vdd, it's an analog device), which will kill the internal transistor driving this pin.


I have attached an example of a PWM circuit that works reliably and relates M/S ratio closely to pot-position.