Author Topic: change pulse width of a signal  (Read 9688 times)

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Offline EteslaTopic starter

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Re: change pulse width of a signal
« Reply #25 on: February 05, 2017, 03:01:33 pm »
David Hess, I like your idea. I am completely new to ramp generators, but it looks like I can make on from a 555 that would work. Im not sure why you still need to integrate the signal for feedback, and I'm not sure how that feedback would "control the slope"... Im assuming this is to eliminate the problem of high frequencies potentially having either a very very small on-time or no on time at all (because the capacitor will not have charged to the comparators "trigger" voltage.), and or the low frequencies completely charging the capacitor giving a larger than desired duty cycle...

Overall I just ordered a few 4047's as they seemed to be built for my task in monostable mode. I will experiment with most of your methods until those chips get here, and will post on this topic with my results if I find anything interesting.

Thank you all for your help!
 

Offline David Hess

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Re: change pulse width of a signal
« Reply #26 on: February 05, 2017, 03:51:39 pm »
Using feedback is just an easy way to maintain a precise duty cycle while the frequency changes.  It is sometimes used to "true up" a source to have a 50% duty cycle without dividing by 2.  There is a Linear Technology application note which uses it but I was not able to find it.
 


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