Re: Capping secondary coil forms

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

Original poster: "Steven Ward by way of Terry Fritz <twftesla-at-qwest-dot-net>" <srward16-at-hotmail-dot-com>

I have 2 experiences with this.  My large coil has a 25" tall 6.3" diameter 
with 24awg.  Its makes sparks about 2.5X that length (about 60"is common 
70" max).  It has no caps to protect it.  I had a small coild once with a 
10" tall 2.3" form of 28awg.  It had not caps and made about 18" sparks, 
but eventually arced over constantly.  IT would arc over once in awhile, 
but eventually, thats all it would do.  So i had to make another coil 14" 
tall. This easily handles 20" at least.  So maybe it depends on the size of 
the coil and other factors.  Maybe also the quality of the pipe 
surface?  But, i guess to play it safe, use the caps, but i usually dont 
unless there is a problem.

Steve Ward.






>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Capping secondary coil forms
>Date: Tue, 17 Dec 2002 13:00:22 -0700
>
>Original poster: "Gregory Peters by way of Terry Fritz 
><twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>
>
>Hello all,
>
>All these years I have been capping my secondary forms with
>plexiglas/acyrlic or lexan/polycarbonate discs. This apparently
>prevents arcs down the centre of the secondary. I have never
>questioned this theory until now. I just made a new secondary and
>really couldn't be bothered capping it, though I eventually did
>anyway. But I really think that if the toroid is large enough, arcing
>inside the form wouldn't happen anyway. I've noticed that arcs never
>seem to leave the centre of the toroid, supporting my theory. Is this
>just another theory that stems from the days of doorknob discharge
>terminals? Anyone out there running uncapped coils with outputs that
>vastly exceed the winding length?
>
>Cheers,
>
>Greg.