Re: PC board primaries

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Justin Hays by way of Terry Fritz <twftesla-at-qwest-dot-net>" <pyrotrons2000-at-yahoo-dot-com>

Hi.

Great idea...I lick it.

I don't think you'd have to worry about heating, skin
effect, or arcing at all if it was reasonably
designed.

Skin effect is basically not there at 300kHz, but I'm
not sure if that's the right thing to think about. The
current risetime (nanoseconds...a spark...) would be
more of a consideration than the operating frequency I
think. The question is, is skin effect more pronounced
during the first few microseconds of the current pulse
when the gap fires? I imagine so.

Either way, I don't think it matters much at all. Even
if the primary DID heat up bad, I don't think you'd
ever notice it in the output. I mean, even the
smallest of TC's gets hundreds of amps poured into the
system. So what if you lose 10 or 20 due to heat.
Spark gaps are different, you lose all KINDS of power
with them. The effect is noticeable.

Again, cool idea. I'd like to try this, wouldn't it
make a gorgeous primary? A nice, shiny perfect copper
spiral, flat on a great insulator. Why not?!

Justin Hays
KC5PNP
Email: pyrotrons2000-at-yahoo-dot-com
Website: www.hvguy-dot-com






> At 01:43 PM 12/7/2001 -0800, you wrote:
> >Has anyone ever tried making a flat primary by
> etching a piece of copper 
> >clad board?  With suitable copper thickness, the AC
> resistance might not be 
> >all that bad (skin effect, and all).  Say you
> etched  a 1/2" wide spiral 
> >trace... 2 oz copper is 0.007112 cm  Skin depth at
> 300 kHz in copper is 
> >around 0.01 cm..  Double sided board, with the
> spiral on both sides, might 
> >have a decent cross sectional area.
> >
> 
> 


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