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RE: Bart's Coil
Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
But do the artifacts give you the true coupling?
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, November 29, 2001 3:00 PM
Subject: RE: Bart's Coil
Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>"
On 29 Nov 2001, at 11:16, Tesla list wrote:
> Original poster: "John H. Couture by way of Terry Fritz
> Malcolm -
> Isn't the two side frequencies test only for critical coupling when the Qs
> are related to coupling? My handbooks are not available at present so I
> cannot look this up.
Actually, no. The artifacts appear any time coupling is set beyond
> Kc = 1/sqrt(QpQs)
> John Couture
> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Wednesday, November 28, 2001 8:44 PM
> To: tesla-at-pupman-dot-com
> Subject: RE: Bart's Coil
> Original poster: "Malcolm Watts by way of Terry Fritz
> Hi John,
> Now I'm a little surprised:
> On 28 Nov 2001, at 19:47, 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 test frequency is not arbitrarily chosen. The bare secondary of
> > coil has three "resonant" frequencies. One is the natural resonant
> > (114.56) with the coil self capacity that you can calculate or obtain
> > 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
> > primary is changed. There is much more to this unsolved TC problem that
> > not mentioned in any textbooks.
> I would have expected the side-frequencies to be sitting either side
> of the 114.56kHz. They have been every time I've measured coupling
> that way. I'm not surprised there appears to be no relation between
> the side-frequencies and the 114.56kHz. I will have to revisit the
> posts on this topic to see how the tests were done. My fault for
> being lazy.
> > 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,
> > and 68.493, no toroids or shorts!
> I believe you already gave the formula relating k and Fo to Fhi and
> Flo. That is the only relationship I'm aware of it. It's been known
> for decades.
> > If you are going to make these tests use smaller coils and tighter
> > couplings. The frequencies will be farther apart and easier to read.
> > to the graph mentioned in a previous post.
> Will do.