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Re: R.I.P. Neon!

In a message dated 97-02-13 03:20:03 EST, you write:

<< Hey everyone from both lists, before I do something stupid, let me get
 some facts straight. Here are some quotes from various text about the
 stability of neons:
 
 "Neon sign transformers have a built-in series inductance,
 which limits the current when they are shorted so there is no problem in
 using them for Jacob's Ladders." -William Beaty
 (http://www.eskimo-dot-com/~billb/tesla/jl1.txt)
 
 Ok, well, thats the only quote now, I dont feel like scrolling through
 500+ messages from just this month from all the mailing lists I'm on,
 AND its late. (This is where that little red flag in Netscape comes in
 REAL handy ;)
 
 What I am asking is if Bill is stating this (which we know Bill is
 allways right), then why do neons die? Is it from a backflow from the
 caps or the primary that causes this? Or CAN you actually burn out a
 neon by overloading it?
 
 And if it is because of backflow from the caps/primary, how is this
 prevented? Safety gaps?
 
 See ya guys l8r. I am hopeing I can get out to the Hamfest in Orlando.
 
 PS: Anyone know the admission cost?
 
 Jeremy Bair
  >>

Jeremy,

Neon sign transformers have shunt plates built in to limit the current to the
faceplate rating.  They are made for continuous duty at their rated voltage
and current.  You can directly short the high voltage outputs and not bother
it a bit.  Most of these transformers die in Tesla primary circuits because
the voltages impressed back across the high voltage windings (from the
resonant primary circuit) far exceed the breakdown voltage of the windings.
 This is why it is important to place the spark gap across the output of the
transformer and use safety gaps and series chokes and limiting resistors to
protect the transformer.  Also, you must be careful not to open up the main
spark gap too far - this will kill them quickly.  I can't tell you how much
is too much but you will find out sometime.  I use 5 series .030 gaps for the
main gap and have the safety gaps set at about .40" for my small coil using
one 12 kv 30 ma transformer.

Ed Sonderman