Gated Pulse Frequency Generator Functional Description


Gated Pulse Frequency Generator Functional Description
«  »Last edited
The attached document is the result of analyzing the circuit for this card.  It is another step in my understand of how the electronic works and what it actually does.  Like the one I did for main frequency generator card it lists all the inputs and outputs and shows what the card does to them. I am doing this as Ronnie mentioned he did not understand how system worked until we looked at all the modules in detail. 

The card has one main function it sets the pulse width for all the frequencies signals coming from the Main Frequency Generator and those on the Accel input (the gate function) and allows the width to be manually controlled from pot on front panel. The circuit sets a minimum width that cannot changed. Stan has stated changing pulse width effect rate of gas production.

It does provide switch to turned off cell and provides input to allow other modules to do this.

As far as I can tell it does provide the GATE (no signal space) seen it the VIC signal.  I thought given the name of the card it was added here but it is not.  I think gate here was meant to set size of opening (pulse width) like a gate in fence.

NOTE: If you plan on building these cards you need the front panel controls.



Re: Gated Pulse Frequency Generator Functional Description
« Reply #1,  »
If there is one thing i know about complex analog pro types' is that they tend too have idiosyncrasies that only the author understands.

my work today demonstrates this quite well ;-D


Re: Gated Pulse Frequency Generator Functional Description
« Reply #2,  »Last edited
I built a bread board version of the Gated Pulse Frequency Generator and hooked it up to the Variable Frequency Generator board I had built earlier. I then ran a series of test to see how it actually works.  I included test results in my original analysis document (2 pages of test write up and 2 pages of O-scope screen shot to show what output looks like and how in changes when adjusting control POT.  I replaced original document with new version and renamed to show that it now includes test results.

Quick summary:  This circuit primary function is to generate a Gate wave train with it own frequency and period.  The main function of the POT is change these values. They both change at the same time.  Its does NOT pass through the input signal from Frequency Generator board in fact the wave train changes very little from different input frequencies. I checked from 5Khz signal to one a 5Hz.  For these tests I did not change base frequency in the Variable Freq Gen board as I wanted enter to made changes in test configuration to make comparison of change I made easier to see.

So still looking for place where the carrier frequency and the Gate signal are combined at this point I beginning think where Gate signal enters the VIC as one of the Frequency Generator outputs goes to K10.

I did have some problems caused by using bread board but even those turned out to be useful as it gave me more information on how board functions and some of its limitations. I documented all this in test results.

I am glad I am building and testing these circuits as I am finding analysis I made while close, it is not good enough.  Testing the board show me exactly what does as I can see the output on the o-scope and also see what happens when I make changes to inputs and changes using local controls.

Re: Gated Pulse Frequency Generator Functional Description
« Reply #3,  »
I finally found where the gate signal and the carrier signal are combined.  It is done in the Phase Lock Circuit input/output you can see this in Figure 7 of WO 92/07861 at top you see in boxes A and G which are both inputs to Phase Lock Circuit what I have been missing it is also in output to the Cell Driver it is even Labeled "Gated Signal to Cell Driver Circuit".  This is only place I found that shows the 2 signals being input logic gate together.

Found this as I was rereading this  WO document after building a couple of the frequency circuits and getting ready to build analog circuits.  I was checking to see where all their outputs go as some of drawings do not show this clearly and some of the redrawn circuits have dropped the labels and just show connections as lines.  Also to be honest I did not expect it to be in Phase Lock Circuit which I have only glanced at so far, though it does look very similar to Variable Frequency Generator Circuit.

I was surprised how almost all it now makes sense as I can see where the circuits do what is described. Writing my own description of what the frequency and analog circuits do was a big help in that understanding.  I have posted those for frequency circuits with test results in this forum and have drafted ones for analog circuits which I will also post after I build and testing them so I an clean up error in my understanding before I post them.

I was going to post image of Figure 7 but need to figure out how to do that.


Re: Gated Pulse Frequency Generator Functional Description
« Reply #4,  »
Thank you for your clarification of this in plain English Earl it does help a lot
and is greatly appreciated I am sure it help people up take , but reading your words. 

Look forward to more sensible diagram showing the 
Gated Pulse Frequency Generator Board with it
sensor feed back interups , acellerator inputs
going to the  PPL

I feel people can all try to put this together and get it out to builders
with you words and diagrams helping

Great Work