Re: Location of Primary relative to Secondary???

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

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Dan,

Typically the bottom turn of the secondary starts out about even with the
flat primary plane. You should make this
adjustable. When you adjust the coupling between primary and secondary, it
will simply be raising or lowering the
secondary. Moving the secondary further away from the primary reduces
mutual inductance and thus coupling. Everyone
has their own method of performing this adjustment, but the constant
between the methods is to adjust the coupling
in small increments so that the coil can be run at full power producing the
longest sparks under smooth operation
without unwanted racing arcs or other damaging sparks.

I use to adjust coupling at lower powers, but I seem to be leaning towards
simply running at about 3/4 power and
starting out with the secondary at a low coupling (secondary is far enough
above the primary to cause low
coupling), then begin lowering the secondary (increasing coupling) in small
increments (1/2"). When racing arcs
start, I begin raising the secondary (reducing coupling) in small
increments (1/4") until the coil runs without
error. Finally, run it at full power and make any slight adjustments necessary.

Take care,
Bart

Tesla list wrote:

> Original poster: "Daniel McCauley by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>
>
> Regarding pancake primary coils?
>
> Where should the secondary coil reside relative to the flat plane of the
> pancake primary coil?  Should it be level with the base of the secondary
> coil or is this something that has to be adjusted during operation.
>
> Thanks again.
>
> Dan