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Re: Wire Guage Sizes (for Q)



Subject:     Re: Wire Guage Sizes
      Date:  Mon, 26 May 1997 09:21:56 -0800
      From:  Greg Leyh <lod-at-pacbell-dot-net>
        To:  Tesla List <tesla-at-pupman-dot-com>
References:  1


Rodney Davies wrote:


> I'm wondering if there is a wire guage to secondary size
> proportionality.


Rodney,

There is one bottom-line relationship between wire guage 
and secondary size, and that is Q.

The secondary coil will transfer most of its energy to the 
arc in less than 10 cycles, when properly designed and
loaded.  Therefore, as a rule of thumb, the unloaded Q of 
the secondary should be about 100, since any increase 
in Q beyond this point can yield only single-digit percent
improvements in the efficiency, and cost seems to go up
as the square of Q.

Given that Q = 2*pi*F*Lsec/Rsec,   and Q = 100,

Then Rsec = 2*pi*F*Lsec/100.

At this point, plug in your favorite equations that relate
coil size vs. frequency and inductance, and
wire resistance vs. winding length and skin depth.

-GL