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Re: Off-axis primary inductance
In a message dated 11/23/98 6:01:26 AM Pacific Daylight Time, tesla-at-pupman-dot-com
writes:
> >"I had heard the well circulated wive's tale that off axis L would waste
> >energy. This test graphically proved that it does not.
> >
> >The practical conclusion is that it IS technically acceptable to place a
> >high quality air core tuning coil in series with the Tesla coil primary
> >coil in order to achieve 'fine tuning' without throwing away hard won RF
> >tank circuit energy!
> >
> >Real valuable knowledge gleaned by the actual doing.
> >
> >Robert W. Stephens
>
> This sounds reasonable. Now it makes me wonder about the importance of
> low ESL tank capacitors. If it's okay to have inductance scattered
> anywhere throughout the tank circuit as long as one's coupling is not
> compromised and pri/sec resonance is maintained, why should ESL matter?
> Could it be that only dielectric, and DC plus skin-effect resistive losses
> matter in the tank? Or is capacitor ESL correlated to resistive losses
> in the cap as well?
>
> Gary Lau
> Waltham, MA USA
>
This is all correct. The inductance anywhere in the circuit does not cause
losses because it is reactive, however, the resistance associated with any
inductor will cause losses. The inductance in a capacitor is caused by a large
plate size, but this also means a longer path for electricity to flow through
and thus more resistance. Minimizing inductance also minimizes restistance.
There is nothing wrong with inductance aside from the primary, so long as it
necessary (such as for tuning) and has as high a Q as possible. power lost =
I^2 *R
Matt Behrend