Re: Tesla Coil Blunders

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jimlux-at-earthlink-dot-net>

more likely the detuning is due to the loading of the sparks/corona/leaders.
Signficant C (pf/cm) and significant R (tens to hundreds of K)



> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<Mddeming-at-aol-dot-com>
>
> > > Original poster: "John H. Couture by way of Terry Fritz
> > > <twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>
> > >
> > >
> > > Tesla Coilers may be making the worst of TC blunders when doing
>
>
>
> Hi John & All,
>         I'm not sure that a known simplification is necessarily a
"blunder".
> The full original formula is:
> f=1/2pi x sqrt(1/(LC - (R/2L)^2))
> taking the derivative of f w/resp to R gives us:
> df/dR=R/(f*(4*pi*L)^2)
> For a coil ~4"  -at-270 KHz, R would have to be>500 ohms to change the
frequency
> even 1%. Since DC resistance is on the order of 20 ohms, the AC resistance
> would have to be 25 times higher to be responsible for even a 1% change.
IMO,
> this is not the culprit.