RE: Bart's Coil

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

Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>


Malcolm -

The test frequency is not arbitrarily chosen. The bare secondary of Bart's
coil has three "resonant" frequencies. One is the natural resonant frequency
(114.56) with the coil self capacity that you can calculate or obtain using
one of those famous TC Design programs. There are two other frequencies
(68.493 and 69.444) that vary when the coupling between the secondary and
primary is changed. There is much more to this unsolved TC problem that is
not mentioned in any textbooks.

My question - At the design stage the natural resonant frequency can be
determined. How do you determine the other two frequencies at the design
stage? What is the "theoretical"? relationship between these three
frequencies? The secondary is unchanged for two of the frequencies, 114.56
and 68.493, no toroids or shorts!

If you are going to make these tests use smaller coils and tighter
couplings. The frequencies will be farther apart and easier to read. Refer
to the graph mentioned in a previous post.

John Couture

----------------------------------


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, November 28, 2001 3:40 PM
To: tesla-at-pupman-dot-com
Subject: RE: Bart's Coil


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

Hi John,

On 28 Nov 2001, at 10:49, Tesla list wrote:

> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
>
>
> Malcolm -
>
> The 68.493 KHz (Fo) is with the secondary without a toroid and not
shorted.
> The 114.56 KHz (Fr) is also with the secondary without the toroid. In
other
> words the secondary coil is the same for both frequencies but the
> frequencies are different.

Am I right in understanding that one frequency is the test frequency
and the other is the natural resonant frequency of the coil? If so,
isn't the test frequency arbitrarily chosen? If that is true, why
should there be a relationship between them? Sorry for *my*
confusion. I obviously haven't been following this closely enough.

Regards,
malcolm