Author Topic: Gated Pulse Frequency Generator Schematic  (Read 35424 times)

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Re: Gated Pulse Frequency Generator Schematic
« Reply #40 on: April 02, 2011, 04:46:29 am »
Just want to let everyone know that this circuit doesn't work. I built it today and couldn't get anything at the at the output, not sure what the issue is with this circuit.
research truth tables for XOR, NOR ( in stans fig 6) and XNOR

I think we need XNOR logic to make the signal get through to the 74122

Was that the chip you used when you built the non functional circuit?

I think the patent drawing was drawn wrong on those logic ICs, the only time a NOR gate allows a signal high is when all inputs are LOW and this cant happen with VDD on each of the pins continuously !

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Re: Gated Pulse Frequency Generator Schematic
« Reply #41 on: April 02, 2011, 04:49:46 am »
Don or anyone, do you have the pinout connections for figure 12 on the 4017 chips?

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Re: Gated Pulse Frequency Generator Schematic
« Reply #42 on: April 02, 2011, 04:50:36 am »
I used the 74122, I even bypassed the NOR gates and still nothing at the output. There must be some values wrong for the components the connect to the 74122.

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Re: Gated Pulse Frequency Generator Schematic
« Reply #43 on: April 02, 2011, 09:30:59 am »
Ok guys I withdraw my previous statement. I had a faulty 7404 on my Variable Frequency Generator, it wasn't allowing the pulses to go down to 0v and this was causing the 74122 not to output anything, but i have it all working now and it works GREAT!!!!

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Re: Gated Pulse Frequency Generator Schematic
« Reply #44 on: April 02, 2011, 10:54:29 am »
ok my hopes are back up again....i just picked the first coponents i found to check it again but now the waveform remains the same thru a transformor :)

Hi Newguy
I have question to You . Is Q4 connected corect in this sim?
andy

nope Andy its not :(  you'll have to look over me sometimes... im not an electronics guy and nite shift messes with me lol  Do we know the values for the cell driver components  ? ill b try n to fill in the circuit with at least all the  correct variables in the cell driver .... i cant find a transistor configured exactly like the pnp ones on fig 5  does anyone know wat they are or if they are pnp and npn transistors?
« Last Edit: April 02, 2011, 13:45:10 pm by newguy »

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Re: Gated Pulse Frequency Generator Schematic
« Reply #45 on: April 02, 2011, 14:58:45 pm »
when the arrow direction point to the base is pnp. when the arrow point to the emiter is the npn.

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Re: Gated Pulse Frequency Generator Schematic
« Reply #46 on: April 02, 2011, 15:06:49 pm »
ok here is the waveform or something closer to wat i was expecting to see, all ive done is superimposed another signal onto the gate signal.The idea i thawt i guess is to fill every other pulse with the gate signal.Ive got the frequency and adjustment close but not perfect if anyone is interested or will state an opinnion.The cell driver circuit variables are there  but not not hooked up ,you can see wer the scope is attatched the reisister that hooks up the cell driver part.. i just guessed at the components wich aint good but should be able to be replaced with ease if someone knows the rite parts. again i thawt the idea was to fill every other pulse of the superimposed signal with a gate signal.Im just tryin to learn for now so an oppinion would be nice :)   I dont have the frequency and gate adjustment matched to fill just every other pulse yet.

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Re: Gated Pulse Frequency Generator Schematic
« Reply #47 on: April 02, 2011, 15:27:18 pm »
Ali, the frequency generator circuit (fig 12) is the same as the 8XA thats already posted somewhere on this site.The chips are 7490 and not 4017.
Don