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Author Topic: implementing PWM  (Read 1096 times)

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Offline HimanshuTopic starter

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implementing PWM
« on: January 27, 2012, 09:43:42 AM »
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.

Offline pterrus

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Re: implementing PWM
« Reply #1 on: January 27, 2012, 10:10:14 AM »
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!

Offline newInRobotics

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Re: implementing PWM
« Reply #2 on: January 27, 2012, 12:47:21 PM »
Circuit below will generate PWM with variable duty cycle. Change Cap or Pot value to get different frequency.
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Offline Soeren

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Re: implementing PWM
« Reply #3 on: January 27, 2012, 02:26:18 PM »
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.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


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