Re: Capacitive transformer Tesla coil

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

Original poster: "Jolyon Vater Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>

Antonio,
I have been thinking about those primary coils myself re. how much
capacitance from the topload do they intercept -especially the wider flat
"pancake" and "conical" types of primary.

Since with the CCTC the primary is replaced by the influence plane the
coupling will be greater as the plane is made wider or more enclosing
because it will intercept more of the topload capacitance increasing C2 and
decreasing C3. Is this not also true with inductively-coupled TCs which use
flat or conical primaries?

Also with regard inductively-coupled TCs where if I am correct tuning and
coupling are traditionally considered independent, is this really true, for
instance, when tapped primaries are used with different capacitors to
"match" the same secondary. Surely, as the number of primary turns changes
so does the coupling ie. more turns= more coupling, fewer turns = less
coupling, unless I am mistaken.

Would it not be possible to use a variable capacitor between C1-L1 and the
influence plane to vary the coupling without affecting the frequency unduly?

Finally, as the topology of the influence plane is developed to minimise
C3 -from a flat plane through a cone and finally a cylinder or sphere
doesn't the plane become nore like a waveguide to some extent?
Jolyon




----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, August 16, 2002 2:43 AM
Subject: Capacitive transformer Tesla coil


> Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>
>
> Hi:
>
> I have set up a page describing the capacitive transformer Tesla
> coil, at:
> http://www.coe.ufrj.br/~acmq/tesla/mres4ct.html
> Not much material is there yet. Just the pictures that I already
> put in previous posts and a few more. No theory yet. I will add
> more after I complete a more powerful version.
>
> Looking at that device I wonder if a significant part of the
> energy transfer in conventional transformer Tesla coils is not
> due to the same effect, specially in those coils with large
> conical primaries.
>
> I made some experiments with it:
> Different spark gaps: A Jacob's ladder results in the system
> working only when the arc is at the end of its path, about to
> be interrupted. A single gap between points results in practically
> no output.
> Heat from the arcs: They burn wood, and cut through styrofoam
> as it were not there. A block of this material placed over the
> tip of the antenna first glows, then corona emerges from it,
> then it melts and catches fire.
>
> Antonio Carlos M. de Queiroz
>
>
>
>
>