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Re: Gap Dwell Times (formerly: Beating Solved)
Tesla List wrote:
>
> > Subject: Re: Gap Dwell Times (formerly: Beating Solved)
> > Subject: Re: Gap Dwell Times (formerly: Beating Solved)
>
> >From huffman-at-fnal.govThu Oct 10 22:47:17 1996
> Date: Thu, 10 Oct 1996 13:35:14 -0500
> From: huffman <huffman-at-fnal.gov>
> To: tesla-at-pupman-dot-com
> Subject: Re: Gap Dwell Times (formerly: Beating Solved)
>
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> ----------
> > From: Tesla List <tesla-at-poodle.pupman-dot-com>
> > To: Tesla-list-subscribers-at-poodle.pupman-dot-com
> > Subject: Re: Gap Dwell Times (formerly: Beating Solved)
> > Date: Wednesday, October 09, 1996 11:58 PM
> >
> > >From bert.hickman-at-aquila-dot-comWed Oct 9 22:50:21 1996
> > Date: Wed, 09 Oct 1996 20:58:31 -0700
> > From: Bert Hickman <bert.hickman-at-aquila-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: Re: Gap Dwell Times (formerly: Beating Solved)
> >
> Sorry Bert
> big snip here-
> > 10-15% of the optimal value. Dave could probably punch-in a slightly
> > different set of gap opening times on his model to simulate this effect
> > graphically as well (hint, hint...).
>
> I see some people have gotten the quench pictures from my FTP site.
> For me a picture helps to congeal the talk going on here about quench times
> and
> energy transfer between primary and secondary. I have some more
> pictures/simulations
> WRT different gap times.
> I have added pictures that show secondary levels at each zero voltage cross
> of the primary.
> These are only valid for the coupling of 0.1 I should have done this at
> 0.02 OOPS 8?( but
> it made the process faster.
> Of course, as Bert stated, if the secondary sparks to soon, quench time
> will not be as
> important an issue. If someone says the quench time should be 10us they are
> wrong. The time
> must be related to the frequency and coupling of the coil system.
> It has taken me a while to catch on, but I'm starting to see some of what's
> been said, by the gurus in
> this group, over the last year. Synergy certainly applies.
> Dave - boulders and flame throwers as needed.
>
<SNIP>
Dave,
Re: the Corum's study - for their specific case, 10 uSec _was_ the
optimal quench time. Their system had Fu=123.33kHz and Fl=74.18 kHz, and
k=.46(!). The predicted "best case" quenchtime was 1/(2*(Fu-Fl))=10.17
uS. Sorry if my previous post suggested that 10 uSec was the ideal
quench time for all cases - it clearly is not. My fault!
Thanks for the new simulations! For the parameters you used, the
theoretical optimum quench is about 25 uSec. Interestingly, the
predicted performance fall-off is not very great until you substantially
reduce the dwell (below 16.25 uSec).This fall-off is not nearly as
severe as with the Corum's chart. It would be interesting to extend the
dwell for a longer time to confirm the location of peak output, as well
as the rate of fall-off with dwelltimes above the optimum with a higher
("magic") coupling coefficient such as 0.22. It may turn out that
precise quenching is not as important as repeatable quenching at about
the right time bang after bang.
BTW, I have a suspician that the "magic" coupling coefficient numbers
may not be quite right, since the primary's coupled frequency will
normally NOT be at the "center" (uncoupled) frequency. Depending upon
the Q's, Fpri, and Fsec, the primary current will tend to be at either
the upper or lower peak. A "tweak" might be in order...
Safe coilin' (and fruitful simulatin') to ya, Dave!
-- Bert --