Re: potential gain vs. power in TC systems

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Paul Nicholson <paul@xxxxxxxxxxxxxxxxxxx>

Steve Conner wrote:

> I would go one step further and say that anyone tuning
> a magnifier empirically would end up avoiding that condition
> by a country mile.

Agreed.  The idealised 3-coil tuning for multi-mode coherence
is potentially the most stressful tuning for the coils involved.
Apart from Antonio, I don't think anyone has attempted it.

D.C. wrote:
> first secondary inductor has a very high Q factor
> ... Example: 150 to 200 turns of #10 or #12 AWG.

> The resonator coil does not have to have a high Q ...
> best served with many turns of fine guage wire, ie, #28 or
> #30 AWG

> I disagree with equal size wire guages on both driver and
> resonator coils.

I'll go with D.C. on the above comments.

With a single continuous uniform secondary, much of the voltage
rise occurs in the lower half of the coil - that's where most
of the current is, so that's where most of the LdI/dt is racked
up.

Splitting that single secondary into a 2nd and 3rd coil, and
introducing some transmission line capacitance, increases that
effect, ie even greater percentage of the voltage rise is in
the lower secondary coil.  Unless you adjust the relative
inductive reactances of the two secondary coils in the manner
described by D.C., your 3rd coil is going to be little more than
a pedestal supporting the topload and Steve's comments would
apply very strongly.

The tricky bit is to figure out in advance how to divvy up
the total secondary inductive reactance, so as to establish
the t-line voltage at some desired fraction of the topload
voltage.   It's a pretty committing decision when you choose
a set of coil and wire sizes.  Once you've also committed to
a particular topload, your only remaining secondary tuning
variable is the t-line capacitance.   Others (eg Bert Pool)
have reported using quite high capacitance here, eg wide
strip conductors - surely not with I^2R loss in mind, but to
hang some extra C onto the system.

> With the incredible efficiency of solid state switching it
> would be cool to see a DRSSTC magnifier type system run.

Definitely.  And it would be great to set up a computer model
of a well-instrumented solid state 3-coil system.

Perhaps an important advantage of the 3-coil system is the
ability, by varying the t-line C, to fiddle with the resonator
characteristic impedance in search of an optimum impedance
(and therefore loaded Q) to maximise the streamer development
in the E-field environment set by a given topload, within the
constraint of a given primary and bang size.

I've some thoughts to submit on the topic of resonator Zo and
streamer load resistance, but I'll leave those for another post.
--
Paul Nicholson
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