The bifilar pancake coil at its resonant frequency

[nelsonrochaa]

I hope it is safe for me to post now.

TinMan, MH, you are both right as usual. There is significant capacitive coupling between the two individual half-coils of the bifilar winding, and there is also significant capacitive coupling from the open end of the L1 coil to Ground, through space.

The issue of the proper placement of the CVR is still under discussion and experimentation. I tend to agree with MH on that issue but "traffic continues".

I also want to make it clear that the schematic above is not mine, I just made the ground connections explicit in my edit. The original comes from Partzman, and his coil parameters are listed on that version of the schematic. He has been working on this for a long time, and I and some others are quite new to the program and are still coming "up to speed" as it were.

In my own work with that circuit thus far, I have found that there can be a _huge_ difference in performance depending on whether 50 ohm ordinary resistors, or ~10 ohm non-inductive resistors, are used for the L2 "load".  I'm hoping someone will "donate" a 50 ohm NI resistor to me so that I can eliminate at least one variable in that problem.



Mags, I would recommend against getting a combined scope/AWG, as the AWG function in those units is a compromise and generally has low power/voltage output and takes up processing and controls that are better left to the scope function alone. Two separate units will of course cost somewhat more but will be _far_ more versatile in your laboratory use.  Even a "cheepo" DDS AWG stand-alone is likely to be better and easier to use than the AWG built into the scope. But I'm just going by what people are saying on a test equipment forum, I have no personal experience with a combo unit like that.

In answer to your question.... in my experience, yes.

Welcome again  nobody will eat you man Sure is safe  as always have been
Give now your best to show and recognize that at the end of 91 pages on this thread , the bifilar pancake coil have some value and "special" characteristics of great value  .

Nelson Rocha

"The easiest person to fool is yourself" -- Richard Feynman

[tinman]

TinMan, MH, you are both right as usual. There is significant capacitive coupling between the two individual half-coils of the bifilar winding, 

and there is also significant capacitive coupling from the open end of the L1 coil to Ground, through space.

In all honesty,how much could that capacitive value be?--that small ,it would almost be non existent.
How to check--easy. Disconnect L2,and see how much current you can get to flow through the open L1,using this capacitance that is suppose to exist between the end of L1 and ground.
Bet you come up with 0,as i did.

I hope it is safe for me to post now.

Well,it has nothing to do with me any more.

The issue of the proper placement of the CVR is still under discussion and experimentation. I tend to agree with MH on that issue but "traffic continues".

After seeing MHs post,i went straight to the bench,and tested again with the CVR placed at the input.
Everything else left the same,i seen no difference in the input power,nor across the load resistor.
You will of course,need to isolate your scope grounds from the FGs ground ,as i have done.


Brad

[Magluvin]

Mags, I would recommend against getting a combined scope/AWG, as the AWG function in those units is a compromise and generally has low power/voltage output and takes up processing and controls that are better left to the scope function alone. Two separate units will of course cost somewhat more but will be _far_ more versatile in your laboratory use.  Even a "cheepo" DDS AWG stand-alone is likely to be better and easier to use than the AWG built into the scope. But I'm just going by what people are saying on a test equipment forum, I have no personal experience with a combo unit like that.

In answer to your question.... in my experience, yes.

Ok. Ill look. Thanks   That one is +-3.5v at 100ma and the one below is the same but only 50ma.   Like is there an amplifier that could be added?


So in your experience yes...  so this may be what Tesla was speaking of in how you guys are going about it. Why other would he specify given freq and potential.  Does the freq go up as the potential is lower or higher? Thanks

Mags

[TinselKoala]

Welcome again  nobody will eat you man Sure is safe  as always have been
Give now your best to show and recognize that at the end of 91 pages on this thread , the bifilar pancake coil have some value and "special" characteristics of great value  .

Nelson Rocha

"The easiest person to fool is yourself" -- Richard Feynman

Hello Nelson, I am glad to see that you are paying attention and reading along.

Another of my favorite Feynman quotes is this one:

"It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong."

There have been some recent experimental results reported elsewhere that might interest you.

[nelsonrochaa]

Hello Nelson, I am glad to see that you are paying attention and reading along.

Another of my favorite Feynman quotes is this one:

"It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong."

There have been some recent experimental results reported elsewhere that might interest you.

Like i already told many times i'm learn all time  even when suck experiments are not new did you make the same?

https://youtu.be/I_eja4gmpcY?t=211

https://youtu.be/Te7NcDY-afQ?t=100


Nelson Rocha