Re: Capacitive Magnifier?

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

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

Tesla list wrote:
 
> Original poster: "harvey norris by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <harvich-at-yahoo-dot-com>

Some comments:

> > Check CSN,I think somewhere in commentary background
> > in the end of CSN, Paper showing 4 various
> > modification of transmitter (2 of them are of
> > transformeless type).
> I beleive you may be refering to  CSN notes on Sept
> 19th, showing 6 different magnifier schemes. 

The pictures in the September 19 page show coils
labeled "secondary", apparently meaning that there
are also primary coils and capacitors, not shown.
The same drawings apears in page 200 of my book.
Fig. 4 shows a magnifier with a transformer
driver and a capacitor across the secondary coil,
as is necessary for correct operation as a 6th-order
system. Note that Tesla says that this was found to
be the best configuration, but that he doesn't know 
how to dimension the coils (what is now known).
Figs. 5 and 6 indeed show "capacitively coupled" magnifiers,
but with a transformer in the driver.
The picture that shows some transformerless structures
is in page 403 in my book. 
These networks are quite complicated, but look
as 6th-order systems (ignoring the capacitors associated
with the resonators and the strange double grounding
in the first drawing), or transformerless magnifiers.
The idea there is stated as "to use two capacitors, one
charged by the power supply and other via the spark gap
from the first" (not clear what is the advantage). 
Note the equation of energy conservation on page 402
(Marincic commentaries, 21 June).

> The reason for stating that
> transformerless is a "bad" description for all of
> these schemes is the fact that undoubtably Tesla's
> extra coil would have been situated "inside" the very
> large secondary he employed, thus even if the coils
> have direct line connections, there will still be
> inductive influences between the systems. 

Possibly. Even in my experimental circuits some
magnetic coupling was present between the coils, but
if the coupling is small the operation is unaffected.
It is even useful for fine tuning by moving the coils.

> In figures 5 and 6 it is found best
> to make extra coil 3/4 wavelength and the secondary
> 1/4 wavelength FOR OBVIOUS REASONS.

This is not obvious at all once the correct equations
are derived. There are many possibilities that work,
and with all the third coil operates in "1/4" wave
mode. A "3/4" wave mode is also possible, but I don't
see advantage in having two voltage maxima along the
third coil.

Antonio Carlos M. de Queiroz