Re: Longitudinal Waves

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

Original poster: "Steve Greenfield by way of Terry Fritz <twftesla-at-qwest-dot-net>" <alienrelics-at-yahoo-dot-com>

> Original poster: "Mark Fergerson by way of Terry
> Fritz <twftesla-at-qwest-dot-net>" <mfergerson1-at-home-dot-com>

> > Original poster: "David Thomson by way of Terry
> Fritz
> <twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>

Steve said:

> > >Why would connecting the ground sides of each
> > >wire 1/3 of a turn, only a
> > >few percent of the total turns, magically change
> > >the current/voltage on each
> > >winding into 3 phase, when both ends of each
> > >winding are connected to the
> > >same points, and within the same exciting field?

Dave said:

> >I don't believe there is any three phase action in
> >the coil.  But it is
> >noteworthy that the three wire inductances are
> >slightly different from each
> >other.

Mark said"

>   It's probably a good idea to note that inductances
> add
> counterintuitively (like parallel resistances IIRC)
> so your
> trifilar coil likely has a different inductance from
> what you
> think it does. Have you tried measuring it? Do you
> attach all
> three outside coil ends together when running it in
> "single
> phase" mode? If not, do you just leave the other two
> hanging?

I added the "so and so said" to make that more clear.
That statement above was actually my question and then
Dave's "answer".

As for inductance: these three windings are really
just trifilar wound and connected to the same points
on each end. Center three wires connected to a ball or
output terminal, three outside all connected to
ground. So there should be no real increase or
decrease in inductance, this is really as if he'd used
3 wire Litz wire. Some coil parameters would be
slightly different compared to using one larger wire,
like self capacitance.

I can think of some fun possibilities for flat spiral
secondaries, both for center and edge grounded. How
about winding the secondary from say 8 inches center
to 20 inches outside, and the primary from 3 to 8
inches in the middle of that? Then ground the inner
lead of the secondary and the outer lead of the
primary?

Or wind the secondary as Dave has it (ignoring the
trifilar part) and making the primary just a few turns
around the outside? Seal both in layers of plexiglass
and wind the secondary so it has a hole in the middle
that is filled by a flat plate terminal. Now hand
people NE-2 bulbs and fluorescent tubes and let them
play around with it. The idea being to keep power low
enough so it won't spark through the plexiglass.

Steve Greenfield

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