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From: Malcolm Watts [SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent: Tuesday, August 11, 1998 10:12 PM
To: Tesla List
Subject: Re: Quench, Coherence etc.
Hi Gary,
> From: Gary Lau 11-Aug-1998 1508 [SMTP:lau-at-hdecad.ENET.dec-dot-com]
> Sent: Tuesday, August 11, 1998 2:26 PM
> To: tesla-at-pupman-dot-com
> Subject: Re. Quench, Coherence etc.
<snip>
> > A most interesting thing was noted that suggests that optimum
> >quench <> optimum sparks (also suggested in the spark lengths above).
> >For the same breakout conditions, the amplitude of the waveform was
> >significantly higher in the second ringup than if the system
> >optimally quenched and decayed. In effect, the coil had two hits at
> >the air some time apart and with still high amplitude on the second
> >hit. Arc dynamic theorists might have something to say about that one.
> >
> > I made a note elsewhere about the streamers observed and how
> >their number related to breakout voltage and ROC.
> >
> >Sorry about the unintended snippage.
> >Malcolm
>
>
> What I read from this experiment was that as the number of gaps increased,
> the quenching improved, but that spark output diminished as gaps increased
> above a certain point.
>
> Terry Fritz's experiments comparing multi and single gaps at various coupling
> coefficients also showed that with single gaps, higher secondary currents
> resulted, but at the expense of inferior quenching.
>
> This appears to suggest higher gap losses in multi-gap designs. That Terry's
> multi-gaps quenched better than his single gap is not surprising since
> neither of his gaps had any sort of forced air flow. Could a "full
> blown" single gap with optimally adjusted airflow offer better performance
> (not necessarilly better quenching) than a multi-gap arrangement? I'm nearing
> completion of such a gap and will report on it's comparative performance soon.
On reflection I agree about the gap loss. The double hit could
explain air streamer phenomenon which I didn't quantify but couldn't
explain attached sparks.
I have tried a single gap with varying degrees of airflow. While
never being able to make it quench (except with a real blast of air
and with terrible losses as a result), a moderate flow not only
raised the firing voltage but did boost output somewhat. Not properly
quantified sorry.
Based on my results, my future policy will be to use only as many
gaps as needed to effect consistent second notch quench with air
streamers or no breakout with total spacing set for the desired
primary voltage.
Regards,
Malcolm