Re: Parametric pumping for tesla coils?

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

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <teslalist-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
 >
 > Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
<jimlux-at-earthlink-dot-net>

 > It is the idea of charging a capacitor at low voltage, then separating the
 > plates to reduce C, increasing the voltage (keeping Q, charge, constant)
 > that many electrostatic machines are based on (i.e. Wimshurst, etc.)
 >
 > I'm sure that Antonio can shed a huge amount of light on this...

Some electrostatic machines work in this way. The simplest example
are the friction machines, where a small voltage difference created
by friction, that is essentially a "contact voltage" is greatly
increased when the frictioned materials are separated.
The electrophorus is another, where a charged capacitor is formed
when a metal plate is put over a charged insulating plate and
touched. When the metal plate is rised, the voltage on it rises.
More complex "influence machines" still use this phenomenon
to rise the output voltage, but also use positive feedback to
separate more and more charge, generating an output voltage that
rises exponentially as a set of operations is repeated.

As already mentioned, The decrease in capacitance with charge
preserved requires energy. Mechanical energy in the case of the
static machines.

Looking at what I have that combines capacitor-inductor resonance
with influence machines, I see the paper:
H. Wommelsdorf, "Vereinfachtes Verfahren zur Herstellung vielpoliger
Kondensatormaschinen, eine Methode zur Berechnung derselben, sowie eine
Hochfrequenz-kondensatormaschine," Annalen der Physik, 16, 24 February
1905, pp. 334-349.
The text is available at http://www.coe.ufrj.br/~acmq/epapers.html
I didn't study this paper yet.

Antonio Carlos M. de Queiroz