Re: TC Electrostatics


I've noticed that my secondary acts just like an electrostatic
precipitator, pulling microscopic sized dust out of the air and
redepositing it as a dusty film on the outside surface of the coil
(coated with Behr Build 50 epoxy). I've also taken some pretty good
static electricity "hits" off mine, even after its been powered down for
a day or two. As near as I can tell, the outside surface of the coil is
a superb, very low leakage insulator. During operation, it picks up a
very high surface charge. The wire underneath the coating is normally
grounded through the base of the coil. If I attempt to wipe the outer
surface clean, some of this charge transfers to me, and if I don't make
sure that I was grounded, my entire body picks up a significant charge.
Once I make contact with the toroid, baselead ground, or the grounded
strikerail... big ZAP! 

I've gotten to the point where I normally hold one hand on the
strikerail, and do all my cleaning with a rag held in the other hand.
This still causes snaps and crackles as I clean the coil, but at least I
don't get the big jolts to ground anymore. However, moving the coil
usually results in getting zapped a little bit no matter how I do it. A
deionizer (like those used for discharging non-conductive surfaces for
Electrostatic Discharge protection) would probably be fairly effective
at dissipating the trapped charges on the outer surface of the coil but,
_unfortunately_, I don't have one!

Anyways... Safe, and sometimes zapped, coilin' to ya!

-- Bert --
Tesla List wrote:
> >From cfbrush-at-interport-dot-net Fri Dec  6 23:46:58 1996
> Date: Fri, 6 Dec 1996 10:07:30 -0500 (EST)
> From: Charles Brush <cfbrush-at-interport-dot-net>
> To: tesla-at-pupman-dot-com
> Subject: Re: TC Electrostatics
> > >I saw an interesting thing while firing my coil on the work bench. An
> > >article from a magazine was hanging from a hook about 20" from the
> > >discharge electrode. When the coil was operated the paper pulled itself to
> > >the pegboard clearly do to electrostatic charge. It's amazing how much
> > >static these things put out.
> > >Dave
> Last weekend I had my first chance in months to play with my big coil.  On
> saturday it was quite dry, and I found myself getting zapped by practically
> everything in the room.  I received a particularly good one right through
> the chest while lifting the coil by its top edge with one hand, while
> placing a tuperware container under it with the other (to reduce coupling).
> I've gotten zapped by the residual charge on a coil form several times (who
> hasn't), but hadn't expected the jolt to go right through  to the hand
> touching only the container.  Even a highly charged dielectric shouldn't
> have done this(??).  Anyway I'll definitely stick to one hand technique
> next time!  Also noticed the cobwebs hanging from the rafters all swinging
> in towards the coil whenever power was applied.  Needless to say, this
> ongoing discussion of TC electrostatics was in my thoughts.   Very
> interesting stuff indeed!  The damp low pressure system that came into the
> area on sunday was quite welcome.
> Charles Brush