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Re: grounding - this doesn't make sense - wire size
Subject: Re: grounding - this doesn't make sense - wire size
Date: Tue, 06 May 1997 06:51:15 -0400
From: "Daryl P. Dacko" <mycrump-at-cris-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
At 11:14 PM 5/3/97 -0500, you wrote:
>
>I read about the importance of a high current ground, and the use of
>heavy
>wire to connect to it. Yet the secondary wire isn't all that big. I'm
>using
>24 gague on a 4 inch secondary - if I remember right the largest wire
>size on
>a secondary I've read about on the list is 18 gague??? What I don't
>understand is why the wire from the secondary to the ground rod (or
>whatever)
>needs to be more than one wire size (or 2) larger than the wire that the
>secondary is wound with. IT would seem to me that current is limited by
>melting the secondary wire. Can someone explain.
One of the ways of looking at a Tesla coil is to think of it as a
quarter wave transmision line.
A PERFECT quarter wave line can be thought of as a current to voltage
converter (or vice versa) where the voltage at the top is proportional
to the current at the bottom.
So, to over simpilify a whole lot, the voltage rise at the top also
gives
a proportional current rise at the base. If you use too small a wire
at the base of the coil, the heavy base current can't excape, and you
limit the voltage rise at your secondary...
There have been some heavy discussion on the list about quarter wave
line vs. lumped constant models of Tesla coils, that you might want
to search the archives for and study to help yourself visualise what's
going on in a conventional Tesla coil.
Daryl