RE: Tesla Coil Blunders

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-uswest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi John,

On 29 Mar 01, at 16:54, Tesla list wrote:

> Original poster: "John H. Couture by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>
> 
> 
> Matt -
> 
> The resistance R can be very large. For example the default coil shown
> at
> 
>     http://home.att-dot-net/~couturejh/
> 
> The resonant frequency is 169.8 Khz (click calculate) using the
> Wheeler/Medhurst equations. Assume a frequency reduction of 11.5%
> (150.34 Khz) the R would be 35000 ohms. Test data I have collected
> indicates 11.5% is realistic. I haven't figured out how to find this
> resistance at the design stage so have "blundered" along like other
> coilers with the calcs. You might want to test your coils for resonant
> frequency at low voltage with a generator and meter and also at
> operating high voltage with a scope and antenna probe to determine the
> reduction in resonant frequency.

Wow! 35k Ohms. Is that effective series resistance or equivalent 
shunt resistance? That can't be an unloaded measurement can it?
Does that figure include spark loading? I guess it must.

Regards,
malcolm