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Re: Coiling Waveforms.
From: Bert Hickman[SMTP:bert.hickman-at-aquila-dot-com]
Reply To: bert.hickman-at-aquila-dot-com
Sent: Thursday, August 07, 1997 2:12 AM
To: Tesla List
Subject: Re: Coiling Waveforms.
Tesla List wrote:
>
> From: John H. Couture[SMTP:couturejh-at-worldnet.att-dot-net]
> Sent: Wednesday, August 06, 1997 7:05 PM
> To: Tesla List
> Subject: Re: Coiling Waveforms.
>
> At 11:14 AM 8/6/97 +0000, you wrote:
> >
> >From: Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
> >Sent: Tuesday, August 05, 1997 6:45 PM
> >To: tesla-at-pupman-dot-com
> >Subject: Re: Coiling Waveforms.
> >
> >Hello John,
> > Perhaps I should elaborate a little on my original
> >answer to this question:
> >
> >> From: John H. Couture[SMTP:couturejh-at-worldnet.att-dot-net]
> >> Sent: Tuesday, August 05, 1997 2:48 AM
> >> To: Tesla List
> >> Subject: Re: Coiling Waveforms.
> >>
> >> At 04:03 AM 8/4/97 +0000, you wrote:
> >> >
> >> >From: Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
> >> >Sent: Sunday, August 03, 1997 4:54 PM
> >> >To: tesla-at-pupman-dot-com
> >> >Subject: Coiling Waveforms.
> >> >
> >>
> >> >- To see the rings etc required high speed timebase settings (e.g. 5
> >> >and 10 uS.div). I would like to say right here: if you believe that
> >> >the secondary gets rung up and up with successive primary shots at
> >> >300 BPS, you are wrong! The gap fires showed up as mere blips on a
> >> >straight line. Still the sparks wax and wane and grow and die. This
> >> >is undoubtably an ionic storage/persistence effect.
> >> >
> >>
> >> >Malcolm
> >>
> >> -----------------------------------------------------------------------------
> >>
> >> Malcolm -
> >>
> >> Are you saying that it was possible to count the number of charges (BPS)
> >> for that special long spark? How did you isolate the long spark?
> >>
> >> John Couture
> >
> >I am looking at the stored ringdown/beat envelope of a *non-breakout*
> >waveform I captured and stored in the scope *right now*. The waveform
> >was captured at 300BPS.
> > Time to quench: <25uS 7 complete beat envelopes, Amplitude <25%
> >of first transfer at quench.
> > Time between breaks: 3.33333333333 mS
> >
> >Does that answer your question?
> >
> >Malcolm
> >
> >---------------------------------------------------------------------
>
> Malcolm -
>
> As far as I can determine you are the only one doing this type of
> research so we coilers will have to depend on what you find. I do not know
> whether or not the secondary rings up with successive primary shots. This is
> a possibility but may not occur.
>
> By seven complete beat envelopes are you referring to the primary circuit
> or secondary circuit? Is it votage or current? Is it a dampened wave? What
> does non breakout waveform mean? Is this from an operating Tesla coil? What
> is the input wattage, operating frequency, spark length. I have lost track
> of what you are testing.
>
> John Couture
> >
> >
John,
I can back up Malcolm's measurements. I've done numerous measurements on
my 10" coil under various operating conditions in order to characterize
its operational behavior. The longest ring-down time on the secondary
only occured when the secondary did not break out, and after the primary
gap quenches, since under these conditions the resonator is losing
energy at the slowest rate. These measurements were performed in order
to estimate effective secondary "Q" during various output streamer
loading conditions.
The bottom line:
Even under the "best-case", no-breakout, condition, the resonator fully
"rings down" prior to the NEXT gap firing. Each secondary energy "event"
is essentially independent of the previous one. On my system, full
ringdown occurred in about 1000 uSec when breakout was inhibited.
Secondary ring-down dropped to about 100 uSec when streamers were
present. [This translated to a non-breakout Q of about 188 going down to
about 19 under breakout conditions].
The time between successive gap firings (about 320 BPS) was of the order
of 3X the longest ring-down period with no breakout, and about 30X the
ring-down period when streamers were present. Since the rate of
secondary energy loss significantly worsens when streamers are present,
any proposal that secondary energy could somehow be building up on
sucessive "bangs" is inconsistent with empirical measurements on
operating 2-coil systems.
-- Bert H --