Re: That secondary harmonic voltage distribution stuff...

Tesla List wrote:
> Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
> Hi All,
>         I have noticed that the secondary voltage distribution graph for
my coil's
> Fo frequency, as I measured last night, follows the equation:
>         V(dist) = Vmax x dist ^ e
> where;
> V(dist) = The voltage along the secondary with the base being zero.
> Vmax = The maximum voltage (the top voltage in this case).
> dist = the distance along the coil were the base is 0, the middle is 0.5,
> and the top is 1.
> e = the natural log (2.7818...)
> I don't know if this means anything profound or not, but the match is darn
> close...
> Still pondering all this....
> Cheers,
>         Terry


This is an extremely interesting result, since it shows an unexpectedly
different voltage distribution that the mostly-sinusoidal one would
expect from a 1/4 wave theory open resonator! In fact, if your
measurements and approximation formula are close to being correct, fully
25% of the total output voltage would be confined to the uppermost 10%
of the winding(!). Previous wisdom/theory assumed that most of the point
of maximum voltage stress for an unloaded resonator would be confined to
the bottom portion of the resonator, with a maximum of only about 15% of
the total voltage stress appearing across the bottom-most 10% of the

It would be interesting the see if a similar distribution applies to the
case where the resonator is "pumped" from a primary EM field at Fo, and
if, indeed, the distribution becomes more linear as top loading is
added. It may also be that the base-driven CW case may exhibit a
different voltage distribution than the disruptive case during energy
transfer to the resonator during ring-up...

Very interesting results indeed!

-- Bert --