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Re: three phase coiling
Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net>
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
Sent: Sunday, January 18, 2004 5:04 PM
Subject: Re: three phase coiling
> Original poster: Greg Leyh <lod-at-pacbell-dot-net>
> Solid-state primary switching might be the best way to get the timing
> resolution you require for accurate 3-phase RF control. I'll have a
> idea within a few weeks what degree of control such a 'phasing' knob has
> the output arcs of a twin coil. The phasing control for the ALF prototype
> will have a resolution of about 200nS, on a 16uS period Fo.
But... I haven't seen many (inexpensive) solid state primary switches that
can take the kilovolts at kiloamps kind of thing that a spark gap does so
nicely. However, maybe triggered spark gaps might be the ticket.
> >Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net>
> >I've been running some interesting simulations, in respect of having 3
> >basically identical (but slightly different) coils running
> >near each other, to see if you could get triangular or Wye sparks.
> >The first cut is to try and force the coils to run 120 deg out of phase
> >each other (RF phase, not AC charging). I worked out some LC networks
> >such that can do this (you basically create something that looks like a
> >phase shift oscillator network), but I suspect that as the sparks grow,
> >loading will change the frequency enough to perturb the situation.
> >I suspect that any sort of spark gap system will have enough jitter in it
> >that precisely synchronized firing (we're talking tenths of microseconds,
> >here) is unlikely to occur. In fact, one can help things along a bit by
> >providing some loose coupling with a phase shift between the primaries,
> >running a triggered/rotary gap on one primary and static gaps on the
> >others. As the first coil fires, the voltage change in it will raise or
> >lower the voltage on the other coil (depending on if it's leading or
> >coupling), and cause it to fire a bit early or late, making the RF out of