The bifilar pancake coil at its resonant frequency

[MileHigh]

I found some great clips on the self-resonance of a regular pancake coil and a series bifilar pancake coil from our friend Conradelektro.

https://www.youtube.com/watch?v=fC84W0PIZoE

https://www.youtube.com/watch?v=spQ9yLdb7v4

He clearly did his research and shows two measurement techniques.  Both techniques try to disturb the coil under test as little as possible and to gently coax it into resonance.  His self-resonant frequencies are in the three to nine megahertz range which I believe are in the right ballpark.  So I believe Evostars is loading his coil up too much and getting resonance frequencies in the hundreds of kilohertz range which are really the coil resonating with some form of external capacitance.  Plus what he is doing is yanking "negative" end of the coil to ground with a series of periodic whacks from an IGBT.  That is not exactly isolating the coil from the external electrical environment.

You notice that Conrad can change the self-resonant frequency of the coil by just bringing his hand _in proximity_ to the coil.  Why is that?

The answer leads back to what I have said before.  The inductance of the coil and more importantly the energy it can store is the elephant.  The transient self-capacitance of the coil is like some little shimmering gnat perched on the elephant's back.  More importantly, the fleeting energy that the self-capacitance can store is this tiny tiny minuscule amount of energy before everything goes *poof* and there is an electric arc shorting out two adjacent turns.

The capacitance is sooooo tiny that just having your hand in proximity to the coil changes the self-resonating frequency of the coil.  In effect, you have the few picofarads of the self-capacitance of the coil being affected by the few picofarads of your hand in proximity of the coil.

Notice that the coil always self-resonates in the form of a sine wave.

So, what's so exciting about an elephant with a tiny little gnat on its back that you can only see with a magnifying glass?

[MileHigh]

Another thing that I think many beginners don't realize.  Realistically, the smallest capacitors that you typically can work with to make a functional and reliable circuit are in the nanofarad range.  When you drop into the picofarad range effectively you are lost in the "noise" of the ambient parasitic capacitance.  Just the tip of your finger touching a component represents about a 10 picofarad capacitive load.  However, that is in contrast with using a picofarad capacitor in a sensing application where you are just trying to pick up a high-frequency signal while trying to disturb the source of the signal as little as possible.

[Magluvin]

The answer leads back to what I have said before.  The inductance of the coil and more importantly the energy it can store is the elephant.  The transient self-capacitance of the coil is like some little shimmering gnat perched on the elephant's back.  More importantly, the fleeting energy that the self-capacitance can store is this tiny tiny minuscule amount of energy before everything goes *poof* and there is an electric arc shorting out two adjacent turns.

The capacitance is sooooo tiny that just having your hand in proximity to the coil changes the self-capacitance of the coil.

Notice that the coil always self-resonates in the form of a sine wave.

So, what's so exciting about an elephant with a tiny little gnat on its back that you can only see with a magnifying glass?

I cant agree with what you say about the capacitance. Just because it is minute does not mean it does not function. The only difference between a very tiny capacitance or a larger capacitance, in a resonant LC, is the freq of the resonance and the time it takes to ring off once input is taken away. The larger capacitance should ring longer, but each cycle takes longer to complete than the tiny cap.

If we were to discharge an inductor into a cap, the same inductive charge for each cap, the larger cap will have a lower voltage than the smaller cap. None the less, the tiny cap will take all that the inductor can give, just like the large cap will, just that the smaller cap will be at a higher voltage than the larger cap, of which levels out the playing field as to which cap is more significant than the other

By saying that the capacitance of a bifi coil is so insignificant that it cant be noticed or even compare to a larger cap is nonsense. The tiny capacitance, no matter how small can hold just as much energy as a larger cap. The problem with realization of that is the difference in voltage for each respectively.   Sure you can have 2 caps 100uf and 1uf and compare. But if both are rated and limited to 16v, then yes, the larger cap can and will be a more significant charge at the same voltage level for each. Maybe some people have that stuck in their heads and thats just how it is. But lets use a 1uf at 1kv in comparison to the 100uf at 16v. Now the amount of energy in each is so much closer.

Mags

[synchro1]

The answer to your question is that the question doesn't even make sense.

@Milehigh,

In view of your follow up comments, I find it hard to believe you can't make sense of the question. Since I can't believe you're really that stupid, I have to believe you're a fraud.

Both you and Tinselkoala were banned from posting on the Energetic Forum site by Aaron. This to inform you and your miscreant co-conspirator, that I am in the process of filing a formal complaint to Stephan in Berlin to have you both permanently stricken from posting any further comments on this Web site.

[synchro1]

Together, Tinselkoala and Milehigh have deliberately and methodically "Orange Coned" the bridge to Overunity. This deception has gone on for the eight years I've been commenting on this Web site. I plan to put a stop to it at this time.