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Re: Method of measuring self C of secondary
Tesla List wrote:
> Original Poster: "Robert Jones" <alwynj48-at-earthlink-dot-net>
> I believe he assumes the equivalent circuit is valid when resonating with a
> comparatively large external C (<1/10Fr). I would expect this to be a valid
> equivalent circuit for such conditions. I did not find any justification
> for such an
> equivalent circuit when the external C has a similar value to the apparent
> C. But I will read the paper again.
Why the restriction? The model must be valid without any extra
capacitor,
or at least without any extra -distributed- capacitor connected to the
top of the coil.
> I also note that as one end is grounded apparent C includes the turn to turn
> C.
Yes, but apparently this capacitance is very small when you consider
all the turns with all these, already small, capacitors in series.
The result is that the "self-capacitance" depends essentially on the
geometry of the coil.
> I wonder if there is a fixed relationship between the two values i.e. 2
> (assuming validity for reasonable frequencies and an isolated coil say
> hanging from the high ceiling).
By symmetry, the capacitors at both sides of the coil must be identical
in this condition. I wonder if the measurement of the first impedance
maximum agrees with this.
Antonio Carlos M. de Queiroz