Re: PC board primaries

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

You'd want to find a cheap source of copper clad.. maybe inspection rejects
from a mfr?  They make the stuff by rolling a copper film onto the
substrate, and they must have "roll ends", "mill defects", etc....  I've
bought raw panels everywhere from 3x4" on up to a monster 48x36" piece
(nitrogen laser project).  The problem is that the stuff is expensive..

Then there is the etching or machining.. but, I'll talk to some folks..
there might be way..

This brings to mind another approach... plasma or water jet cut a spiral out
of plate...

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, December 08, 2001 1:00 PM
Subject: Re: PC board primaries


> 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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