Re: Racing Sparks

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "david baehr" <dfb25@xxxxxxxxxxx>

Original poster: "Lau, Gary by way of Terry Fritz 
<twftesla-at-qwest-dot-net>" <Gary.Lau-at-compaq-dot-com>

The problem of racing sparks running along the secondary is not yet fully
understood, but the ways to stop it are.  They are:
1. Reduce the pri-sec coupling.  Trouble is, some efficiency is lost when
coupling is reduced.
2. Install several creepage disks along the length of the secondary, to
make the surface length of the secondary longer.

Creepage disks have been employed by only a few people, not including
myself, and good results have been reported, allowing the use of higher
coupling.  I suspect the reason this is not more commonly used is:
1. The difficulty of cutting the disks
2. The difficulty of ensuring an absolutely spark-proof seal where the disk
meets the secondary
3. The secondary becomes MUCH larger and more fragile and difficult to
store when not in use

I had an idea which does not suffer from these problems.  Rather than
having just a few creepage disks, the secondary surface is made to be
corrugated, just like beehive insulators.  What I propose is, after a
secondary is wound, apply a space-wound layer of nylon rope along the
length of the secondary.  Then apply the usual several coats of
polyurethane to the rope and secondary.  It would probably be necessary to
have a motorized jig turning the works until the polyurethane dries to
avoid drips and runs.

I have not tried this and odds are I probably won't, but I thought I'd
throw out the idea should anyone else be so inclined.

Gary Lau
MA, USA





From:  "Tesla list" <tesla@xxxxxxxxxx>
To:  tesla@xxxxxxxxxx
Subject:  Re: Racing Sparks
Date:  Wed, 03 May 2006 07:11:05 -0600
>Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
>
>Hi Jared,
>
>Oops, I just thought of one more cause:
>
>1. Too much power for the coil size.  Topload voltage is too high
>for the coil height.  Probably requires a topload that is too large
>and breakout doesnt happen soon enough.
>
>2. Too much coupling. The energy coupled into the coil is more
>concentrated
>in the lower turns and less spread out resulting in an energy wave
>propagating up the coil that causes too much stress between
>windings.
>
>3. Out of tune.  This can result in exitation of the higher resonant
>modes
>that can cause a voltage node at an intermediate position up the
>coil.
>
>4.  Topload is too small allowing for greater exitation of the
>higher
>resonant modes.
>
>5.  Bang energy is too large for the coil size.  This results in an
>energy wave that is too large.  Sorta related to #1 and the same
>mechanism as #2
>
>Gerry R..
>
>