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Author Topic: how i change the duty cycle in monostable 555?  (Read 3498 times)

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thanosgen

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how i change the duty cycle in monostable 555?
« on: June 15, 2009, 23:19:50 PM »
hi.i want to ask something.i need two ways to tell me to make the monostable 555 circuit to change the duty cycle,
without change the R and C.or tell me two practical circuits to do this...

i believe something with pin 5 etc...

kam

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Re: how i change the duty cycle in monostable 555?
« Reply #1 on: June 16, 2009, 07:29:51 AM »
Hallo thanossgen,

You want to change the duty cycle without changeng the RC circuit? That wold not be possible. You need to change the R to change the duty cycle.

A circuit that does just this, changing the duty cycle while the frequency is steady, is this one:

http://pcbheaven.com/projectpages/PWM_Fan_controller_using_a_555/