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Re: Vf,Zo,R,G,L,C.....



Tesla List wrote:
> 
> Original Poster: Terry Fritz <twf-at-verinet-dot-com>
> 
> Hi All,
> 
>         I was doing a little modeling of Tesla coils today and I tried to
use the
> formula for the parameters of a transmission line from the Corum's papers.

What sort of transmission line is this: balanced pair in free space,
balanced pair above a ground, single wire above ground? etc....

Here are some equations (exact (assuming lossless conductors (!) (you
are using lots of liquid He, right?)):

For parallel conductors in air, well away from ground (many wavelengths,
unlikely for coiling, but here for reference):

Z0 = 120 inv cosh( D/d) where D is center to center spacing, d is
diameter of conductor
   = approx 120 ln (2D/d)

For balanced pair near ground

Z0 = (276/sqrt(epsilon))*log10((2D/d)*(1+(D/2h)^2)^-.5)

h is height of centers above ground, assumes wire diameter very much
smaller than D or h.

For parallel strip line:

Z0 = approx 377 * w/l
where w = spacing between strips (not center to center)
      l = width of strips
valid for w/l < 0.1


Velocity factor is, in general, proportional to 1/sqrt(epsilon), so, for
air insulated velocity factor is typically > .99



-- 
Jim Lux                               Jet Propulsion Laboratory
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