Re: PC board primaries

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

Original poster: "R Heidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>

on 12/07/01 8:36 PM, Tesla list at tesla-at-pupman-dot-com wrote:

> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
> 
> Hi Jim,
> 
> I have never hear of this being done but it sounds like a great idea for a
> modest sized coil.  The board and etching will probably cost a little more
> than some things, but not bad.  Heat "might" be a concern but I think it
> will work fine.  You may consider a HV coating to discourage surface arcing
> between turns.
> 
> Cheers,
> 
> Terry
> 
> 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.
>> 
> 
> 
Printed-board flat primary coils are used, but in a TC you are working with
low frequency not 400 MHz+ and you dont want your equipment able to generate
unlimited high frequency TVI for FCC to find a reason to send the black-suit
boys to visit you.
   Robert  H