Re: 1500-3000 turn coils

["Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Tesla list wrote:
> 
> Original poster: "Dan Kunkel" <dankunkel-at-hotmail-dot-com>

> my intution tells me that cap size and inductance is not a linear
> relationship. especially when you consider the outer turns of a conical or
> flat spiral coil...each consecutive turns affords more inductance than the
> previous.

The shape of the primary coil can affect its inductance and the coupling
coefficient with the secondary. Essentially nothing else.
 
> aside from reduced sprak gap losses from more primary turns, are there any
> other areas that contribute to longer sparks associated with a larger
> primary? i had originally read that more turns in the primary allowed more
> effecient transfer of energy between the coils, or something about superior
> coupling (12-15 turns being the "sweet spot").

Increased coupling can result in more energy being transferred to the
secondary in less time, or at least in less oscillation cycles. This
really may lead to smaller losses in the gap.
When the coupling is high, there is a series of discrete optimum
values for the coupling coefficient, that cause a maximum of voltage
to appear at the secondary terminal with no energy at the primary.
These "magical values", are, however, not directly related to the number 
of primary or secondary turns. The geometry of the coils is what
determines it.

Antonio Carlos M. de Queiroz