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Re: Isotropic secondary capacitance
From: DR.RESONANCE[SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent: Wednesday, September 10, 1997 5:26 PM
To: Tesla List
Subject: Re: Isotropic secondary capacitance
To: Malcolm
Thanks for the tip on Corum's work addressing this area. I will dig out
his book and review.
I spent a leisurely afternoon discussing some of your recent posts
(addressed to me) with the plasma physics group at Univ. of Wisconsin ( a
wild and mad professional group if there ever was one). Energy can lump
itself at one end. Not the particles but the waves which contain the
energy -- if only for a brief instant prior to reflection. A common
example would be a blum line (lien if you are German) in which energy is
charged into a line typically with a Marx generator and then a sudden short
circuit is induced at one end. Opposite end sees 2 x applied E.
More importantly we were discussing resonance transformer behavior and
especially why it usually takes two or three cycles to achieve full output
potential. My opinion was this standing wave behavior is required to build
resonance. I was wrong. The actual factor here is the dynamic
characteristic of the plasma field (even ions which are not visible as the
sparks we love). It seems the capacitance of the entire field requires
charging and this essentially electrostatic charging of the field process
requires two or three full cycles of energy from the oscillation
transformer.
They were in complete agreement with your accessment of primary capacitance
required to charge the load, ie, secondary system with its distributed cap
and the cap of the plasma field.
With regard to sticking your hand in bath water analogy one professor
replied, "A lot has to do with how rough your hand is". This would relate
friction as the electrical equiv. of resistance, so the answer would depend
on the resistance and Q factor of the system.
Congrats on your newest coil performance and don't fall in the tub.
DR.RESONANCE-at-next-wave-dot-net
>
>
> From: Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
> Sent: Wednesday, September 10, 1997 12:13 AM
> To: tesla-at-pupman-dot-com
> Subject: Re: Isotropic secondary capacitance
>
> Hello Dr RESONANCE,
>
> > From: DR.RESONANCE[SMTP:DR.RESONANCE-at-next-wave-dot-net]
> > Sent: Monday, September 08, 1997 11:43 AM
> > To: Tesla List
> > Subject: Re: Isotropic secondary capacitance
> >
> > To: Malcolm
> >
> > If you measure the Fres of one of your coils, then measure its
inductance,
> > does this calculated value of Cdist agree with the value you would
obtain
> > by solving the Fres (equation for resonance) for capacitance?
>
> Medhurst agrees with the resonance and lumped-L check I've done on
> _all_ coils I've wound to well within 5%. (2% in a majority of cases).
> In short, yes. The real battle in finding a formula that worked was
> in defining the essence of Cself. Of course one runs into interturn
> capacitance for _ungrounded_ coils which was thrown out because it
> failed to work for a grounded upright single-layer coil. Medhurst
> applies strictly to this particular case.
> The artificial model I came up with forces both current and
> voltage distribution to match this case (until it is refuted by a
> better one of course :)
>
> > In one of your coils, how close is the measured value (in % margin
> or error)? Does it vary much between PVC insulated wire and magnet
> wire?
>
> I have found no case yet where Cself depends on the insulation. As I
> say, all my research suggests the _overall effect_ of Cself is
> isotropic. To get a feel for its true nature, I refer you to the
> Corum's series of diagrams showing the progression from cavity to
> open resonator. Picture the C distribution of the line wrt to its
> surroundings in all those cases and you see Cself :)
>
> Regards,
> Malcolm
> <snip>
> > >
> > > There is indeed!! You'll be pleased to know that after a three month
> > > search while researching a TC article for a magazine, I found it. It
> > > is Medhurst's formula:
> > >
> > > C = HD pF where D is coil diameter in cm and H is a factor that
> > > follows the law:
> > > h/d = 2 H = 0.51
> > > h/d = 5 H = 0.81
> > > Interpolation is linear for this h/d range. H bottoms out at 0.46 for
> > > an h/d = 1 (which as fate would have it was the final form Tesla's
> > > extra coil took :) The tabulated values for H remove the complex
> > > mathematics from the formula.
> > >
> > > Malcolm
> > >
> > >
> >
> >
> >
> >
>
>