Re: Puncture voltage

In a message dated 96-08-24 01:00:07 EDT, you write:

<< Hi,
 	Im fairly new on building Tesla Coils, i recently built a small 
 	one, it uses a 9000, 30ma neon sign transformer. My problem is 
 	with the cap, i live in a small town and theres no where i can 
 	get the poly to build the caps, so instead i used 1/8" window 
 	glass, i sumerged the cap in oil and i also spreaded some in 
 	between the plates, my question is ? Can the cap hold and for 
 	how long ?.
 	Could some one please answer, i know this must be an easy 
 	question for some of you, but im new at this some and im a 
 	little nervous turning on the coil and have the cap blow up. 
 	Jorge Fuentes				 >>


Most of us who built Tesla coil caps with window glass have eventually had
them fail.  Placing it in oil will help.  Window glass isn't really a good
dielectric for this type of cap.  Start with a relatively small spacing on
your gaps.  This will limit the voltage rise in the primary (and the output
of the coil of course) and lower the stress on the glass.  Gradually increase
the gap width and the output power will increase.  You will probably find a
gap width that will rupture the glass.  Then either build more of them and
try a series parallel combination or maybe order some poly from a plastics
dealer in the nearest large city and drive over to pick it up some day.

Ed Sonderman