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Re: 3 Pahse Rotary Gap

Tesla List wrote:
> 
> Original Poster: Greg Leyh <lod-at-pacbell-dot-net>
> 
> > Original Poster: "Robert W. Stephens" <rwstephens-at-headwaters-dot-com>
> 
> > Greg,
> >
> > I considered this system and in fact had detailed discussions with
> > Malcolm Watts about it (at the time being my idea I thought) about 2-1/2
> > years ago.  The "big problem' is that you cannot capture the full power
> > capability of your power source and place it in every single repeating
> > 'Bang'.  At best you go to a lot more costruction trouble to make a
> > 3-banger system that should perform no better than a much simpler system
> > on single phase power at 1.732X the ampacity of this 3-banger.
> 
> But if the '3-banger' is designed such that each capacitor
> has a forced charging curve covering most of a half-cycle
> (say about 5mS), then the ampacity of the transformers is
> utilized far more efficiently than in a single-phase setup,
> which has to 'spike-charge' the cap in order to get more
> than 120BPS. And, as we have seen, coils require BPS rates
> in excess of 200 or so to be efficient spark producers.

Greg,

Any TC system driven at the mains frequency and pushed to multiples of
120 BPS either due to adequately undersizing the tank capacitor for
static gap systems, or forced by use of an asynchronous rotary (or
multi-presentation synchronous) is going to operate in 'spike charged'
mode as you put it.  This method is much more the norm than the
exception and certainly works adequately. 90% of all practising coilers
can't all be wrong.  At the same time I cannot dismiss the valid point
you make about the more efficient charging gained from using more of the
sine curve. Would it alone make enough of a difference however to
overcome the smaller bang size where only one third of the system's tank
capacitor bank, and hence total energy in Joules is available per pop? I
think I'd need to see two coils side by side with the same 'toaster
watts' input from the wall socket, one 3-banger and one standard model,
to be convinced on the merits of the 3-banger scheme. 

Let's face it though, one is a 3-phase power driven load, the other is
single phase, here alone there is no contest in efficiency!  To be fair,
both coils in such a contest would have to be run off 3-phase DC
supplies. Alternately, one could run them both from single phase mains
and employ a rotary or solid state converter to provide the 3 phase for
the 3-banger, but allowing for the conversion inefficiency complicates
the issue.

I totally agree in your statement that more than 200 BPS is required to
support good streamer growth based on plasma channel ion lifetimes.  I
think this becomes even more important in show coils operated outdoors
where there is nearly always some unwanted wind.
> 
> > Do you know anyone with a large Tesla 'show only'
> > (as opposed to reseach) coil that *ever* demonstrates it at 1/3rd or
> > 2/3rd's power of what it can achieve at full horsepressure?
> 
> Yes!  I do all the time!  I will always start the coil at
> the _lowest_ safe power setting, about 70BPS for my coil,
> which is 1/5 full power.  Ramping the coil up to full power
> from there thru the entire power range is far more dramatic
> than just turning it on at a full, but monotonous, power level.

I guess I misworded my question. "Would you or anyone you know who
operates a show coil be happy if full power operation were not available
to you/them?"  

> --
> 
> -GL
> www.lod-dot-org

Robert W. Stephens