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Glass Caps




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From:  Esondrmn [SMTP:Esondrmn-at-aol-dot-com]
Sent:  Tuesday, January 27, 1998 10:18 AM
To:  tesla-at-pupman-dot-com
Subject:  Re: Glass Caps

In a message dated 98-01-25 11:45:25 EST, you write:

<< Dear Readers,
 
 Anyone ever run a medium or large coil with a glass cap?  I'm trying 
 to figure out how bad the heating problem is at 1KVA and up.  I've 
 only built 3 small coils, all under 500VA.  All I've ever used is 
 glass caps, and I've only experienced one unexplained failure in a 
 foil & window glass cap on a 380VA coil.  A hasty autopsy revealed 
 glass panes laced with very fine, spider web-like cracks.  Might've 
 been due to thermal effects.  My current 450VA coil runs with salt 
 water bottle caps.  I think the water sinks so much heat, I'll never 
 be able to detect RF heating at such low power input levels.
 
 Greg
  >>
Greg,

My very first Tesla coil, built many years ago, used a flat glass plate cap
made from window glass with copper foil bonded to each side.  It did get hot
and two of them failed.  These were operated dry - no oil.  I was using a 12
kv 30 ma transformer.

Ed Sonderman