Re: Unexpected Shock From TC

To: tesla-at-pupman-dot-com
Subject: Re: Unexpected Shock From TC
From: Hollmike-at-aol-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Thu, 06 May 1999 17:30:41 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

In a message dated 5/6/99 5:00:58 AM Mountain Daylight Time, tesla-at-pupman-dot-com 
writes:

> >
>  >To Bill Langston, and all coilers:
>  >
>  >	I noticed in your post that you (Bill) wrote that you got a shock by
>  >touching the TC long after it was turned off.  I know of two reasons why
>  >this might happens, and how to fix each of them.
>  >	One cause is that the tank capacitor can hold quite a charge after the
>  >coil is shut off.  It usually bleeds off through the circuit after a few
>  >seconds, maximum.  However, according to Terry Fritz, if some connection
>  >in the circuit is disconnected, this bleeding off may not happen.  Ask
>  >around for ideas about bleeder resistors across the tank capacitor, and
>  >other ways to fix this.  


    I cannot see how one would get a shock from touching the secondary with 
the primary cap having a residual charge.  Unless the spark gap is firing, 
there is no energy transfer to the secondary.  You could get a fairly nasty 
shock touching anything in the primary system if the cap has a charge on it.
    The likely cause is that the secondary(self capacitance) retains a 
charge.  My 8 inch coil has a very thin coating of insulating varnish(applied 
with a spray can) and still retains a charge after shutting down.  This 
varnish has a dielectric strength of 2100v/mil so even a thin coating can can 
hold a fairly good charge.
Mike