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Re: new secondary problems
From: Thomas McGahee[SMTP:tom_mcgahee-at-sigmais-dot-com]
Sent: Sunday, November 23, 1997 12:06 PM
To: Tesla List
Subject: Re: new secondary problems
>
> From: D.C. Cox[SMTP:DR.RESONANCE-at-next-wave-dot-net]
> Sent: Saturday, November 22, 1997 2:21 PM
> To: Tesla List
> Subject: Re: new secondary problems
>
> to: Tesla List
>
> The static shock is quite common especially with enamel magnet wound
> secondaries. Before removing the sec just hold a small finishing nail in
> your hand and run it down the coil about 1 inch away from the sec. That
> will bleed off all the electrostatic charge. A car key also works -- just
> don't drag it on the sec coil and mar your insulation.
>
> The definition of a capacitor is a plate -- dielectric -- plate. In this
> case the wire is the plate, the insulation is the dielectric, and the next
> turn of wire is the other plate. A considerable amount of charge is stored
> in the insulation of these hundreds of small capacitors which can zap you
> if you are not ready for it. As John points out your hand is also a
> conductor (70% water) which forms another plate in the equation.
>
> DR.RESONANCE-at-next-wave-dot-net
>
Dr. Resonance,
I do not want to be nit picky here, but just want to make sure no one out
there gets the wrong idea. You said:
> In this case the wire is the plate, the insulation is the dielectric,
> and the next turn of wire is the other plate.
The inter-turn capacitance you talk about is indeed
very real, but it is not the operative thing in this particular case.
The entire secondary *winding* forms a conductive zone that is surrounded
turn by turn with dielectric. The "static" charge that we find on the
outside of our Tesla coils is due to the capacitor that is originally
formed from the "plate" that is the entire secondary winding, the
dielectric that is the wire insulation (and other secondary coatings
we may have applied), and the other "plate" that is really, well,
everything else "out there" that surrounds the coil. As in isotropic.
More or less.
You can first place one hand near the base of the coil and slowly move
the other over the surface to neutralize the charge. You will only get
a shock if you initially grab the thing at points that are separated
by more than a few inches. After a while you get used to "running your
hands" over the coil to neutralize it before moving it.
Hope this helps,
Fr. Tom McGahee