Re: Secondary Coil design

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

Original poster: "James by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mustang3-at-home-dot-com>

Hi Gregory,
    All of my secondary failures have occured in the same place. Within an
inch or two of the bottom. I presume that it's a function of the current in
the secondary. I'm now winding a larger secondary using larger wire for the
first 6 in. I don't think that the coilform is the prob. The last time I
fired it, a puff of smoke came out first, and then the flames. I have seen
pics on the list of a fire low on a secondary. I can't remember where
however.

Later,

James
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, November 15, 2001 12:54 PM
Subject: Secondary Coil design


> Original poster: "G by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<bog-at-cinci.rr-dot-com>
>
> Hello List,
>
> I have noticed a failure pattern in all of my secondary coils and am
> searching for a solution. Each one has had a failure within the
> bottom 25 turns (shorts between turns).During the most recent
> failure, I was watching the operation very carefully in a dark room
> and I am sure there wasn't any arc struck between the secondary and
> the primary, or even corona.
>
> I have not noticed any other report of this problem. Has anyone had a
> similar occurrence?
> I may try using a larger gauge wire toward the bottom to help deal
> with the higher current in this region. Is current even the problem?
> Would using a larger gauge wire cause a damaging voltage gradient?
> Is space winding the bottom turns a possible solution? (also-
> negative effect on coupling?)
>
>
> Thanks!
> Gregory
>
> PS- I came across some construction trash dwv pipe labeled 'triple
> wall hdpe'. It is lighter than a thinwall pvc pipe and is a
> lower-loss plastic. Would the air pockets that exist between the
> layers cause a secondary coil to burn through, or last longer?
>
>
>