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Re: Results of new single static gap
to: Terry
No, have not tried that experiment. We primarily use the 1800 RPM motors
because of their very low cost -- we purchased approx 24 pcs surplus a few
years back for $30 per unit -- a real steal, so we keep using these at
present. It would be a nice experiment -- wonder if the NST could really
keep up on the charging curve? A primary turns increase would also mandate
your oscillator base be a lot larger -- something we try to avoid in our
designs. I prefer more compact designs with 12 turns or less. We use
copper strap on edge for all of our NST or potential xmfr powered units
which keeps the oscillator base size reasonable as the strap can be wound
in a rather dense fashion with only 3/8 inch turn to turn spacing and, do
to the thickness of the strap, it results in high density as opposed to
copper tubing with it's larger cross sectional area. If you should happen
to do this experiment please advise me as the the results. If you have a
3600 rpm motor I could furnish you with an 1800 rpm motor so you could make
the comparison test.
DR.RESONANCE-at-next-wave-dot-net
----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Results of new single static gap
> Date: Saturday, August 29, 1998 4:11 PM
>
> Original Poster: Terry Fritz <terryf-at-verinet-dot-com>
>
> Hi Dr. Resonance,
>
> So, your 1800 RPM sync gap fires 120 time per sec. For a 60 mA neon I
> assume you used about a 19nF primary cap. Have you ever tried the same
> setup but with say 8 gaps and a 8.5 nF cap? This would give about 240
BPS
> with roughly the same setup and energy (half the C but twice the firing
> rate). I was just wondering if you doubled the firing rate and cut the
> primary cap size in half (so the neon can charge it twice as fast) what
the
> effect would be. Of course, the primary turns increases to keep the
> frequency in tune which increases the coupling......
>
> I have been experimenting with this, but so far I have gotten many more
> questions than answers :-))
>
> Thanks,
>
> Terry Fritz
>
>
> >FROM: "D.C. Cox" <DR.RESONANCE-at-next-wave-dot-net>
> >
> >to: Russ
> >
> >I wanted to know the answer to that same question in the early 70's, so
I
> >built a subdivided gap system with 24 electrodes each adjustable and
> >arranged in rows of 4 so I could jumper them to come up with a wide
range
> >of combinations. It seems most NST systems running 30 ma seemed to
favor
> >either 2 or 3 max for good performance. With 60 and 120 ma driving
current
> >the favorite was 5-6 gaps (60 ma) and 7-9 gaps (120 ma). This system
was
> >tried with 5 different NST powered coils and produced similar results.
> >Coil sizes varied with diameters from 3 in thru 18 inch in a 4:5 to 1
> >aspect ratio for most (one was 6:1). Multibladed rotors are not
necessary
> >and usually overquench as someone in the List recently posted. The very
> >best system for small coils is still the synchro RSG running at 1800 RPM
> >with a 4 electrode rotor. We use 2 stationary gaps on each side of the
> >wheel for a series of 4 total gaps usually set to 1/16th inch each gap.
> >This produces a very smooth output which fires early on the variac and
> >delivers consistently good quenching for NST powered systems. The
synchro
> >RSG works good with both 60 and 120 ma drives at either 12 kV or 15kV.
The
> >subdivided stationary gaps I described above usually work best with a
> >150-200 CFM blower fan arranged at 1 1/2-2 inches away from the active
> >sparking area. The vacuum cleaner suction system also works very well
to
> >promote good gap quench but it's usually not necessary unless you drive
> >above 120 ma.
> >
> >----------
> SNIP........
>