Re: cap specifications

To: tesla-at-pupman-dot-com
Subject: Re: cap specifications
From: misc3312-at-cantva.canterbury.ac.nz
Date: Wed, 19 Jun 1996 22:46:42 +0000

Tesla list Wrote

> I am curious about the capacitor specifications that people are using 
> for resonating Tesla coil primaries.  I have seen several posts where 
> it appears that a cap working voltage equal to the transformer 
> secondary voltage is used.  <snip>

>Thus you can easily get a 10x  or more increase in voltage by switching a tuned circuit across a 
> voltage source.  Something similar may happen when the gap fires in 
> the Tesla coil.

I've observed the voltage across the capacitors on my Tesla coil with 
a 60Mhz storage scope.  My spark gap fires at 12 kV.  The capacitor 
voltage peaks at 20kV and appears to oscillate at about 10Mhz for 2us 
then settles down to oscillations at the primary resonant frequency 
with peak voltages of about 5kV getting smaller with time.  Keep in 
mind though, I am unsure of the bandwidth of the Fluke 80K-40 probe I 
was using so perhaps what I was seeing on the scope wasn't exactly what was 
really there.  I hope to look at this with a 500Mhz scope that 
samples at a higher rate sometime.

Regards

Richard