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Re: LC III

Original poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx>

----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Wednesday, March 30, 2005 4:51 PM
Subject: Re: LC III


> Original poster: Paul Nicholson <paul@xxxxxxxxxxxxxxxxxxx>
>
> Hi All,
>
> Antonio wrote:
>  > This story of "coherence" is very strange,
>
> Yes, the Corums sometimes referred to the 'coherence time',
> which I would normally take to be the time taken for a signal
> to travel through a resonator, bounce off the far end, and
> return to the start, ie the round trip time.  During that period,
> the source sees only the characteristic impedance.  Once that
> period has elapsed, the standing wave is fully formed.

That is only true if the source is equal to the characteristic impedance.
For all other conditions part of the signal is reflected at the source.
If the reflected signal is in phase with the original signal the amplitude
grows exponentially.
eventually reaching a steady state condition which is the standing wave.

Possibly what the Corums where try to say is: For a high Q resonator the
signal is reflected numerous times. During that time the source must remain
in phase. If the coherence time (phase changes with time) of the source is
less than the time required to build up the standing wave then the standing
wave will not continue to build i.e. the voltage gain is limited by the
coherence time of the source. The forgoing is correct as a general comment
about resonators including lumped ones. If I remember their paper correctly
they implied it was a property only of a transmission line which is
incorrect and I don't see what it has to do with an impulse Tesla Coil.
Mathematically  the amplitude of a resonator is determined by the
convolution of the impulse response of the resonator with the signal as time
functions. If the coherence length is less than the width of the impulse
then the convolution integral will sum to a lower value.

The Corums stated that the three peaks in the spectrum proved their
transmission line theory which was also incorrect.
They also seemed to think that the amplitude in the secondary increased
after quench again incorrect.
The over all impression I was left with was that did not understand how a
Tesla coil worked though they did get the wave properties of the secondary
correct.

Robert (R. A.) Jones
A1 Accounting, Inc., Fl
407 649 6400