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Re: Harmonics



Tesla List wrote:

> This WAS how I thought a Tesla coil worked a while ago, too. However, new
> discusions and thoughts have lead me to believe this is NOT how a spark gap
> driven Tesla coil works. 
>...
> I think a better picture of a spark gap driven Tesla coil would be a hammer
> and a bell. Your hammer is the primary circuit and the bell is your
secondary
> coil. The bigger the hammer, the "harder" the bell rings, which is one
reason
> why I like using a big cap and high RF currents as opposed to a high voltage
> and a small cap.
> Comments and flames welcome because they are only going to help me
understand
> Tesla´s coils better.

The swing idea is correct for a CW coil, where a resonator is driven by
an electronic oscillator at his resonance frequency, and the resonator
voltage amplitude increases in almost linear way until breakout. 
The hammer idea is not correct, because there is no instantaneous energy
transfer anywhere in a Tesla coil.
You can imagine a capacitor-discharge coil as a CW coil where the
primary circuit tries to act as the electronic oscillator for the first
RF
cycles after the firing of the spark gap. But as the energy in the
primary is
limited, as energy is transferred to the secondary resonator the energy
in the primary decreases. This results in the amplitude of the primary
oscillations decreasing almost sinusoidally, and the amplitude of the 
secondary oscillations increasing almost cosinusoidally. The amplitude
variations continue if there is no breakout, with the secondary energy 
returning to the primary circuit by the same mechanism. 
In normal opeartion, breakout occurs before the first complete energy 
transfer, and the spark gap opens as soon as the primary energy is
completely,
or almost, transferred.

Antonio Carlos M. de Queiroz