Author Topic: electronics help  (Read 1770 times)

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electronics help
« on: May 30, 2009, 18:46:18 pm »
So I have 50 % duty cycle signal that is driving an and gate , this signal is phase locked to another frequency via a frequency divider . This "other" faster frequency is always 50% duty cycle and that will never change

What I wish to do is control the duty cycle of this normally 50/50 duty cycle frequency . It will be opreating in the ranges of 1khz to 50 khz

I wish to control the duty cycle from a range to 0 to 100% so I can drive my and gate with this signal .

I am just not smart enough to figure out how I should do this , somebody plz help me .

« Last Edit: May 30, 2009, 19:19:27 pm by Dankie »

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Re: electronics help
« Reply #1 on: May 30, 2009, 19:52:44 pm »
If the signal is a function of the "other" faster frequency which is always a 50% square wave....just slowed down by a frequency divider, you will not be able to adjust the duty cycle w/o adjusting the "other" frequencies' duty cycle

I suggest you use a cd4047 in the "compliment gating" mode....and use a 555 timer to the gate pin. Just make it so both circuits are in parallel (common electrodes) and have the output of the 555 go through a large resistor (1-2 Mohms) and an LED (if LED lights up the signal is too high of a voltage)

To change the gating duty cycle all you have to do is make r1/r2 variable resistors and you can change them independently to make any duty cycle u wish!
http://i175.photobucket.com/albums/w152/Jdub6d9/555ast.gif

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Re: electronics help
« Reply #2 on: May 30, 2009, 20:02:43 pm »
god dammit

I cant believe there is not some sort of IC that can do this

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Re: electronics help
« Reply #3 on: May 30, 2009, 20:43:19 pm »
There maybe...however, every IC chip ur signal goes through lags/degrades the signal more and more.

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Re: electronics help
« Reply #4 on: May 31, 2009, 03:45:08 am »
haha I decided to drop this idea

I will only use mutiples of the frequency , either divided by 4 or 8 .

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Re: electronics help
« Reply #5 on: June 05, 2009, 16:46:36 pm »
its getting there , let me offer you a discount on a new pwm lol .

All my wire customers will .

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Re: electronics help
« Reply #6 on: June 05, 2009, 19:14:55 pm »
its getting there , let me offer you a discount on a new pwm lol .

All my wire customers will .

awesomeness