Re: Stroke of brilliance?

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

Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>

Tesla list wrote:
 
> Original poster: "Loudner, Godfrey by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <gloudner-at-SINTE.EDU>
 
> Hi Sean
 
> It seems like the mechanical interruption of the transformer's primary would
> induce a cascade of transients into the transformer.

	It would preferentially be done with a synchronous motor.
	Once set, should work.

> You would have to disconnect at the right part of a cycle to avoid
> current surges. It sounds like a timing problem that would be too
> difficult to handle by mechanical means.

	A synchronous commutator, strictly analagous to a sync gap.

	On Balance, I think adequate static filtering is a better
	approach.

	Someone proposed SCRs or whatever.  Recall, please:
	This is proposed to avoid HV spikes damaging the the
	tranny.  WHAT are the spikes gonna do to the solid state
	switches????

	(Yes: HV SCRs (or whatever) can be had.  I suspect a
	filter is a better solution....)

> > -----Original Message-----
> > From: Tesla list [SMTP:tesla-at-pupman-dot-com]
> > Sent: Tuesday, January 29, 2002 1:00 AM
> > To:   tesla-at-pupman-dot-com
> > Subject:      Stroke of brilliance?
> >
> > Original poster: "Sean Taylor by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> > <taylorss-at-rose-hulman.edu>
> >
> > I just had an idea . . . it might be able to go somewhere, but is probably
> > just
> > a lot of extra work to accomplish not a whole lot.  Anyway . . .
> >
> > In TC operation, there are huge voltage peaks that can go back into the
> > transformer from the primary tank oscillations.  Filters do reasonably
> > well at
> > protecting the transformer, but don't entirely.  So - I was thinking about
> > disconnecting the transformer while the spark gap was firing - yes, 120
> > times a
> > second.   I was thinking about a rotary spark gap, and thought about
> > changing
> > the conducting areas and "blank" areas, such that when the spark gap is
> > firing,
> > the transformer would be disconnected from the circuit.  I.E. there are
> > two
> > spinning disks on one shaft, one with bolts going through it on 2 or 4
> > locations, the other with metal all the way around, except in those 2 or 4
> > corresponding locations.  So most of the time, the transformer would be
> > charging the tank capacitor, then it would be disconnected just before the
> > electrodes lined up to fire the spark gap, then a few microseconds (~400
> > or
> > 500) later (to allow for ringing to die out), the metal would come back
> > for the
> > transformer to start charging the tank capacitor again.  I know it's
> > pretty
> > complicated, but it would allow for isolation of the transformer and the
> > tank
> > circuit, and probably allow a more efficient energy transfer to the
> > primary,
> > with less damping.  Any thoughts/comments/ideas?  I'm working on building
> > a
> > SRSG right now, with a fairly small motor (1/8 HP), but maybe i'll get a
> > bigger
> > motor soon, and try it out.  This would all be easiest on a 3600 RPM
> > moter, at
> > 120 bps, so there would be many less transitions to worry about - only 2
> > per
> > revolution.  BTW - if this ends up working well, I've got rights to it :-)
> >
> > Also, in case of incomplete discharge, would it be better to put a full
> > wave
> > rectifier on the output of the transformer so that any leftover charge
> > wouldn't
> > fight the transformer, but aid it instead?
> >
> > Also, thanks to everyone who helped with the instructions for converting a
> > motor to sychronous - it worked wonderfully.


	best
	dwp