Author Topic: EPP Control Unit  (Read 3575 times)

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EPP Control Unit
« on: April 23, 2010, 04:36:01 am »
I've been looking at this portion of the demo cell circuitry and it appears to me that the pulse selector switch is labeled backwards i.e. the basic pulse is set by the 555 then is multiplied by each 7490 chip.  If this is true what else might be backwards in the basic circuit diagram?  I'm referring to figure 9XB variable pulse generator schematic.  Or is my understanding of how the circuit works incorrect...


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Re: EPP Control Unit
« Reply #1 on: April 23, 2010, 04:40:32 am »
Yea I noticed that, but as far as I know they are divide by 10 on the initial frequency from the 555... Maybe someone with more circuits experience than myself can give a better understanding...

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Re: EPP Control Unit
« Reply #2 on: April 23, 2010, 07:07:20 am »
That are divide by ten, he firstly generate a frequency and than divide by ten by 100x by 1000 ... or other 2x 4x  ...

I tried that already, is useful... it gives you very low to high frequency range, with 50% duty cycle