Re: More Coupling...

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

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

HI Scot,

Coupling is directly proportional to proximity or distance. Make the spacing
between secondary and primary and you significantly reduce the coupling (and
increase as you move the 2 closer). Helical primary's can be high coupling
simply due to the proximity of each wrap in parallel proximity to the
secondary. Obvisously, a helical primary inner diameter can be increased so
that the coupling coefficient is ok for a Tesla Coil, but a more compact
design is to build a flat primary which can be closer in proximity to the
secondary and therefore "compact" as compared to the previous.

We have all thought of strange and odd shapes for our primary's,
secondary's, toroids, etc... but many of us lay down at night and only think
about it. Few actually build their coils to their "pre-dream" thoughts. I
say spend the the $40 and let us know what happens (if your asking?).

For example, John Freau just posted regarding his sync gap phasing using a
cap and variac (90 degree shift!). We've all tried to look at this but John
got a cap, got variac, and did it. Makes me want to do the same since I've
got a couple 10A variacs and various caps laying around here there.

I looked at this in Microsim and didn't get the same results John is getting
(and therefore never tried it - a lesson learned). Must check experimentally
because models used threoretically can be incorrectly used - must verify all
!!!

Bart



Take care,
Bart
-----Original Message-----
From: Tesla list <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Saturday, December 09, 2000 11:04 AM
Subject: More Coupling...


>Original poster: "BunnyKiller" <bigfoo39-at-telocity-dot-com>
>
>Hi All...
>
>while reading all of the coupling threads, I began to wonder about the
>coupling of
>a helical primary and if anyone has done any experimenting on the distance
from
>the secondary. ( e.g. instead of having a helical primary say 2" from the
>secondary , how about having it 6 or 8" from the secondary?)
>
>would this extra distance decrease the coupling or would it matter?
>
>it seems most of us use the 1-2" distance of primary/secondary distance to
>prevent
>pri/sec flashover. ( this is on conicals and flats)
>
>another thought .....   what do yall think about a parabolic curve instead
of a
>conical? you would have the reduced coupling near the secondary form
( inner
>turns of the primary would be nearly flat or conical)) but in addition a
>helical
>style coupling factor at the outer edges of the primary?( more parallel to
the
>secondary)
>
>if any of you have any input to this id like to hear from yall before i
>spend 40$
>or so on tubing to try this ;)
>
>Scot D
>
>
>
>