TSSP: List Archives

From: Paul
Date: Sun, 22 Apr 2001 10:49:35 +0100
Subject: Re: [TSSP] Remaining CW problems & next stage of the project

Boris,

Sorry for the delay with my reply,

I wrote:

> > I have an 'extended' version of tsim which
> > models the coil
> > plus the additional interactions of a realistic
> > external circuit,

Boris wrote (28/03/01):

> ---
> You mean walls,celling etc?
> ---

No, just the lumped and stray components associated with 
putting a signal into the base - the coupling box. I think
I'll take these bits out of tsim now - I just put them in
to satisfy myself that most of the observed complexity of
the coil's response near resonance, ie different frequencies
for max Ibase, max Vtop, Ibase phase zero, etc, are artifacts
of the coupling mechanism.

> > and
> > this model reproduces the observed features, eg
> > splitting of the
> > resonance into a more complicated response, eg for
> > Terry's probed
> > small coil, I get
> >
> > 311.850        Max Ibase        (Measured)
> > 312.920~       Ibase 90 deg to Vtop  (Predicted)
> ---
> 
> > 313.020        Max Vtop         (Measured)
> by mutual agreement this should be what we  call
> "resonance frequency " of the coil.

I'm settling on 'zeroes of the determinant of (A-1)' as 
a definition of the resonance. I hope to be able to say in
pn1401 just how this relates to the observed response
when driving into the base with CW.

> > 314.500~       Ibase in phase with Vbase (Predicted)
> >
> > which is an altogether more complicated picture. The
> > predicted
> > values above are based on guesses of various circuit
> > reactances,

> ----
> I see.This depends on what radious of loop filament
> one takes into account when calculates
> inductivity,cross section of wire and nonlinear flow
> of current thru it etc?
> ----

No, just things like shunt capacitance and leakage inductance
in the base drive coupling box.

> > ...[speaking of analysis of resonator in normal modes]
> > All falls apart of course when the load impedance is
> > a function of top
> > voltage.

> ----
> Will you be more specific here?
> ---

Just that the shape and position of each mode changes with
the load impedance, but I can see how to cope with that in
a piecewise linear kind of way, so not a show-stopper.
 
> ----
> arcs and nonlinearities don't have to bother us
> (yet).

Well I think it's about time we got to grips with this now,
enough time has been spent on a preliminary steady state 
understanding of the coil.

Cheers,
--
Paul Nicholson,
Manchester, UK.
--


Maintainer Paul Nicholson, paul@abelian.demon.co.uk.