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Re: Coil Meeting...
Hi Terry,
I have an answer to one of your problems:
> Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
<snip>
> There was one thing that surprised me. We stacked me small coil on
top of
> my large coil with the large torroid and got super good output sparks.
> Since the secondary inductance was higher I would expect this now. However
> we then moved the third coil off to the side to play with the magnifier
> type setup. I thought the original tuning would still work. However, we
> were unable to tune it at all. I will have to think more and have the
> computer help me understand what was going on there. Apparently extra coil
> system require more than just trivial thought to get them to work...
No real mystery. If you calculate Cself of the two coils combined
you find that it is less than the sum of the individual Cself's of
the coils when they are separated. Again I refer to Dr de Queiroz's
modelling of mags. In short, the separated pair will resonate at a
lower frequency than the combined pair.
Tesla never got hold of this rule and there is a good reason why
- the coupling between the secondary and extra coil in the CS machine
was quite enough to muddy the rules. I also discovered from the mini-
CS machine I built that better results will be obtained if the extra
coil is totally uncoupled from the driver system. k between the two
coils when positioned as in the original was about 0.06, quite enough
to lower the overall Q of the secondary/extra system by increasing
its bandwidth due to interactive beating.
Sounds like you had FUN :)
Malcolm
<snip>