Analysis and Test Results of Voltage Amplitude Control Circuit


Analysis and Test Results of Voltage Amplitude Control Circuit
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I completed most of the testing of the my build of the Analog Voltage Control Circuit (K9).  Only thing missing is the finally amplifier in the circuit which I have not received yet.  I decided to post this now as I plan on moving on to another circuit and do not expect this Q4 amplifier to change the wave train shape.  I attached the analysis and scope shots of signal as it passes through the circuit. I also attached a picture of the test setup which shows Freq Generation card K2, and Analog Voltage Generation card K8 which I used to test K9.  The scope shot shows the output from the card. This is also included in the report.  Note: Green LED on K9 is just a layout place holder for Q4.  Q4 most like will be mounted on an external Heat Sink due to it size and I believe is actually with VIC coils in real system.

I did not use any external signal sources during the testing.  Everything but power was generated on these three cards.  I did run into one problem I had to remove the 47uF capacitor on the A24 Gain Pot as it killed the signal.  Everything else worked as expected as this a fairly simple circuit and the Gain and OFF SET pots were used in the same configuration on the K8 card.  Part of the reason I removed it is this capacitor is label N/A on the K8 circuit.  With the capacitor removed the Pots do the functions described.  You can see this in screen shots in report. Sort of found this by accident as I mention in report as circuit was not working until a moved the test probe.  Then is started working until a notice a loose wire so I stopped and reset everything. Turned it back on it wasn't working again. Spent a couple of hours trouble shooting until a decide to pull the capacitor. Turns out one of things I knocked loose was the capacitor.

My guess this circuit was original setup to pass a higher frequency and block lower frequencies. Then K8 card was added. It appears to be setup on purpose to block higher frequencies as I could not get a 500Hz or higher signal through it. I believe this caused the capacitor on the gain side of that card  to be removed to allow lower frequencies through.  Now I am not sure what the correct frequency is but I did not change anything in K8 circuit.

This are more notes in my documents for these card about both these issues. Both issues caused many hours trying to figure out why the work the way they do. I expect people who understand amplifiers better than I do could give you the math why it works this way.

I think this finishes analog path with the exception of the Digital means piece and I pretty sure it just modifies pulse width of signal for accelerator operation.  As changing frequencies also does this I know pulse width changes moves through these cards with no problem.

I plan on working on cell driver circuit next as that should connect the carrier path and the gate path together on other side of primary from analog path. This is one those things I wanted to know where it was done for a long time. I thing I know how it is done now but I want to see it work.


Re: Analysis and Test Results of Voltage Amplitude Control Circuit
« Reply #1,  »
Very cool.

When you say hours of work troubleshooting that is something we can all relate to here. Good to see how far you've gone already- those breadboard setups look really good too.

When you get to building the VIC let me know if you need help winding the coils. I have an automatic coil winder that does a pretty good job. Also-I recently made a YT video on VIC replication that includes part numbers for the cores and bobbins that get us really close to what Stan had.



Re: Analysis and Test Results of Voltage Amplitude Control Circuit
« Reply #2,  »
May do that though I did get a sewing machine motor and foot pedal to wind coils.  Man in sewing machine store gave it to me for free as he said he had a lot of them in back from old machines.  Now having said that my wife had just purchase a 4K sew machine from him. But I do think for any one who wants to build a coil winder a sew machine shop that repairs them is a good place to get these cheaply.

Best part is I am having fun.  I like building things but I am not a designer.  Though as you can most likely tell from pictures I am a handyman.  I offend wind up walk through hardware store looking for something to solve a problem until I see something that I can make work.  It may not be what it was make for.

It may sound strange but I have been buying most to the parts from amazon.  There has only been a few things I could not find there and as we have prime the shipping is free and usually here in a couple of days.  Some of the more rare items have taken a couple of weeks.  Now in several case I end up with a lot of extra parts but that's OK as offend you can get 3 parts or $7 and you can get 100 in a variety pact for $15 including the 10 of the 3 you needed of.