Re: Inductor Interference

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

Original poster: "Mike Novak by way of Terry Fritz <twftesla-at-uswest-dot-net>" <acmnovak-at-msn-dot-com>

Hey Sam,
Still using those caps I sold ya?
I would suggest, at this power level, to use a helical primary. You can wind
a respectable and well performing primary with 6 gage grounding wire (see
menards ~$.08/ft) on an 8" PVC or acrylic form. With good spacing, you can
pack a TON of inductance in a small space. For lower powered coils, in the
past, I've used insulated speaker wire as the primary... and WITHOUT taps!!!
If you know how much inductance you need, throw the values in wintesla and
find the exact number of turns required, and make the primary of 10 gage
house wire with two or three taps. However, don't use too small of a form
otherwise you'll have some racing arcs and other goblins introduced into
your already plauged system.
An LTR cap would allow you to use your exhisting primary, however, it will
decrease the power throughput. In small, low powered coils, it is best to
use a slightly smaller than resonate cap to get the most power from a given
transformer. Not only that, but the xformer will draw less current also.
But keep in mind, you won't be able to get more than 18-20 inches out of
this coil, so it might be easier to just start over with a larger secondary
and a whole new primary. I'd suggest making a John Freau clone (with the 4"
x 21.5" secondary with 1600 turns) to get the most from your cap bank and
xformer.

-My two cents...


-Mike Novak





----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, January 31, 2001 7:03 PM
Subject: Inductor Interference


> Original poster: "Sam Beck by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<Sam-at-peterbeck-dot-com>
>
> Hey all,
>
> I thought I'd try to redo my 3 inch coil to optimize performance,
> I'm getting 12 inch arcs now.  I'm rewinding the secondary, 3X12 inches,
> with 28 Ga wire.  The spark gap is getting changed from a two-gap RQ to a
> more-than-two-gap SD.  The primary is being rewound on a 30-degree inverse
> conical form.  There is one problem, the resonant frequency of the
> secondary is lower than the space allows for tapping out.  So there are
two
> solutions:
> One-Increase the value of the capacitor.  I don't what the maximum
> amount is for LTR, but if anyone has it, I'd appreciate it.
> Two-Add some extra inductance.  This is what I've been doing so
> far.  The only problem I see is that if I mount the helical extra inductor
> onto the base, directly under the primary coil(and with only 1/2 inch of
> HDPE separating them) with their axes parallel, there could be some kind
of
> destructive or degrading interference as their magnetic fields interact.
> Comments anyone?
>
> Sam Beck
>
>
>
>
>