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Spark Gaps
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From: Malcolm Watts [SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent: Wednesday, April 15, 1998 11:21 PM
To: Tesla List
Subject: Re: Spark Gaps
Hi John,
> From: John H. Couture [SMTP:couturejh-at-worldnet.att-dot-net]
> Sent: Wednesday, April 15, 1998 12:54 AM
> To: Tesla List
> Subject: Re: Spark Gaps
>
>
> At 03:50 AM 4/13/98 -0500, you wrote:
> >
> >----------
> >From: richard hull [SMTP:rhull-at-richmond.infi-dot-net]
> >Sent: Sunday, April 12, 1998 5:05 AM
> >To: Tesla List
> >Subject: Re: Spark Gaps
> >
> >At 08:33 PM 4/11/98 -0500, you wrote:
> >>
> >>----------
> >>From: Bert Hickman [SMTP:bert.hickman-at-aquila-dot-com]
> >>Sent: Friday, April 10, 1998 10:25 PM
> >>To: Tesla List
> >>Subject: Re: Spark Gaps
> >
> >>Thratron or transistor switches were used by Richard Hull and Malcolm
> >>Watts respectively to switch off primary current at earlier current
> >>"zeros" (of the coil's fundamental operating frequency) during a number
> >>of very interesting quenching experiments last year. Malcolm's attempts
> >>to turn off a low-power transistor-switched primary circuit at points
> >>other than primary current zeros did result in the expected high voltage
> >>spikes stemming from rapid di/dt, but it's not clear that the an arc's
> >>characteristics will permit this to actually occur under any reasonable
> >>circumstance in higher power air-gap systems.
>
> ------------------------------------------------
>
> Did these tests quench dampened waves or pulsed waves?
>
> John Couture
Not exactly sure what you mean. You can turn a transistor off any
time you like. I tried turning off at first primary energy notch,
first primary quarter cycle (thank heavens for parasitic zeners in
the FETs), etc. It behaved just like a gap except it was a gap I
could effect ideal quench/dwell times with. The test setup was a
standard disruptive two coil system with k set to about 0.1
Malcolm