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Re: 3 probably awful beginners questions ;-)



Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <teslalist-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
 >
 > Original poster: "Barton B. Anderson by way of Terry Fritz 
<teslalist-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

 > The rough definitions are:
 >
 > Les:    The effective series inductance of the system.
 > Lee:    The energy storage inductance of the system.
 > Ldc:    The low frequency inductance of the secondary.
 > Ces:    The effective shunt capacitance of the system.
 > Cee:    The energy storage capacitance of the system
 > Cdc:    The low frequency capacitance of the system.
 >
 > Les and Ces is what I'm most interested in as these are the values at Fres.
 > The dc values are what you would measure with say your DMM.

I don't like this modeling. A modeling that should be linear and
that attributes different values for the same components has something
of incorrect. What actually happens is that the simple LC model is not
complex enough to account for all the measured properties. The model
should then have more components, and not the same components with
different values. I think that I have posted something about how to
obtain these models some time ago.

For a beginner, High-order modeling may be very confusing, and
is not necessary.

The essential behavior of a coil is correctly modeled by considering
only its inductance, that is the DC inductance, that can be measured
with a regular inductance meter, and its self-capacitance, an empirical
value that can be obtained by measuring at what frequency the coil
resonates (f=1/(2*pi*sqrt(L*C)).
It corresponds to the unique capacitance of the LC parallel
system, and can't be directly measured with a conventional meter.
(A good approximation may be obtained by measuring the body capacitance
of the coil, suspended high in the air, and dividing it by 2).
In the case of a secondary coil of a Tesla transformer, add to the
self-capacitance the body capacitane of the terminal. The combination
can be measured easily by measuring the resonance frequency of the
entire system.
In the case of the primary coil, the self-capacitance can be safely
ignored, since the primary is in parallel with a much greater primary
capacitance.

Antonio Carlos M. de Queiroz