Re: [TCML] Safely Grounding a Tesla Coil

["Tim Wenzel" <cuba_pete@xxxxxxx>]

I would take all of the counterpoise info with a grain of salt, however. 
Designing a Tesla coil as one would design an antenna might not be the 
correct method.  We do not want our coil to radiate (transmit), we want to 
shunt the RF energy to ground.  Making a solid connection to mother Earth is 
what we are after, providing a current path back to the source.  Right?
----- Original Message ----- 
From: "Brandon Hendershot" <brandonhendershot@xxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Saturday, February 06, 2010 10:48 PM
Subject: Re: [TCML] Safely Grounding a Tesla Coil


> Ok, so if I get a big piece of cardboard, glue some alluminum foil to  it, 
> throw it in the front yard and connect it to my secondary, I  should be 
> good?
>
> On Feb 6, 2010, at 8:12 PM, mddeming@xxxxxxx wrote:
>
> > Hi Brandon,
> >
> > In a nutshell, a counterpoise is a large radial array or screen, 
> > insulated from the ground but close* to it, to serve as a  capacitively 
> > coupled ground. It was developed for use where soil was  too poor for a 
> > good ground connection. This was the term as used in  antenna theory 
> > texts between ~1920 and ~1950 and is still the way  coilers use it. In 
> > recent years, the term has been bastardized in  antenna books to include 
> > any and all elevated radials on a monopole  antenna.[1] Of course, for an 
> > antenna whose function it is to  radiate energy, a much larger 
> > counterpoise is necessary. For a TC it  is adequate for the diameter of 
> > the counterpoise to equal the  overall height of the coil.
> > There are several ways to make one for a TC: The quick and dirty  Type 1 
> > is just a large disk of aluminum foil glued to a board or  sheet of 
> > cardboard. Type 2 is copper window screen. Type 3 chicken  wire. Type 4 
> > radial wires laid out like a "daisywheel" print head [3]. Type 1 is the 
> > easiest to make, type 2 & 3 more expensive and  harder, but lower eddy 
> > currents, type 4 the hardest, but has the  least eddy current losses.[2]
> >
> > Matt D.
> >
> > [1] http://www.antennex.com/shack/Dec06/cps.html
> > [2] Bylund, Duane - "Modern Tesla Coil Design Theory"
> > [3] http://en.wikipedia.org/wiki/Daisy_wheel_printer
> >
> > * close in terms of a tiny fraction of wavelength
> >
> >
> >
> >
> > -----Original Message-----
> > From: Brandon Hendershot <brandonhendershot@xxxxxxxxx>
> > To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> > Sent: Sat, Feb 6, 2010 12:10 pm
> > Subject: Re: [TCML] Safely Grounding a Tesla Coil
> >
> >
> > Hi Jim,
> >
> > Could you explain the concept of "counterpoise" for me or provide a  link 
> > to some documentation? I've never heard of anything like it...
> >
> > Thanks btw,
> > Brandon
> >
> >
> >
> >
> >
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla

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