RE: Unexpected Shock From TC

To: tesla-at-pupman-dot-com
Subject: RE: Unexpected Shock From TC
From: "Basura, Brian" <brian.basura-at-unistudios-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Mon, 10 May 1999 19:04:08 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme
The worst one was when I leaned forward and took a static hit to my
forehead... Ouch..

Brian D. Basura


-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Friday, May 07, 1999 10:37 AM
To: tesla-at-pupman-dot-com
Subject: Re: Unexpected Shock From TC


Original Poster: "William R. Langston" <blangsto-at-iwvisp-dot-com> 

Hi,

Sufficient static discharge, it is imparting an amount of energy after all,
can do
one serious damage. But in the case of what we are talking about here, the
secondary is in more immediate danger of being dropped on the primary ;-).
The
danger to a human is what could happen when startled, at least from the
shock my
secondary holds. We have six or seven layers of poly varnish on the thing.
And it
does indeed hold a take-your-breath-away charge if you are not expecting it.

Bill L.

Tesla List wrote:

> Original Poster: Christopher Michaelis <cmichael-at-xmission-dot-com>
>
> Is it possible to be injured by static, or can I freely zap myself since
> I'm too lazy to touch a ground wire to my secondary?
>
> At 12:17 PM 5/5/99 -0600, you wrote:
> >Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
> >
> >At 01:27 AM 5/5/99 -0500, you wrote:
> >>
> >>
> >>
> >>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.
> >>      More likely, though, is that the secondary can hold a charge,
too.  I'm
> >>not sure if it has to do with the self capacitance of the coil, or the
> >>varnish on it, or what.  However, I know that most big coils I have seen
> >>could give quite a zap if you touched the secondary, even several
minutes
> >>after operation.  Usually, the operator would take a grounded wire and
> >>touching it to the secondary to remedy this.
> >>
> >>      Again, just thoughts of mine.
> >>
> >>
> >>
> >>                                                      Brent
> >
> >Coils that have thick coat of varnish can store pretty powerful static
> >charges on the varnish.  Coils can charge this dielectric layer to
> >extremely high voltage so that there can be an unexpectedly powerful
charge
> >stored on this seemingly benign dielectric surface.  One solution is not
to
> >coat the coil with a thick layer which keeps the windings near the
surface
> >where they will act to ground out the electrostatic charges.  Another
(used
> >by most) is just to realize the static charge is there and prepare one's
> >self before grabbing it :-))
> >
> >       Terry
> >
> >
> >
> >
>
> Christopher Michaelis
> cmichael-at-xmission-dot-com
>
> Pretium Corporation
> t:(435) 797-4100
> f:(815) 364-1274

--
II*