[Prev][Next][Index][Thread]

Re: Transistor Spark Gaps (fwd)



---------- Forwarded message ----------
Date: Tue, 19 May 1998 23:36:15 -0600
From: Jonathan Bazemore <jpbazemo-at-ouray.cudenver.edu>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Transistor Spark Gaps (fwd)

    Hello,

        Are you saying that instead of that loud, raucous spark gap, I
could use some kind of transistor or solid state relay?




Tesla List wrote:

> ---------- Forwarded message ----------
> Date: Fri, 24 Apr 1998 06:13:49 +0000
> From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: Spark Gaps (fwd)
>
> At 11:12 PM 4/22/98 -0600, you wrote:
> >
> >
> >---------- Forwarded message ----------
> >Date: Wed, 22 Apr 1998 09:48:52 +1200
> >From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
> >To: Tesla List <tesla-at-pupman-dot-com>
> >Subject: Re: Spark Gaps
> >
> >Hi John,
> >
> >> From:  John H. Couture [SMTP:couturejh-at-worldnet.att-dot-net]
> >> Sent:  Friday, April 17, 1998 7:09 PM
> >> To:  Tesla List
> >> Subject:  Re: Spark Gaps
> >
> ><snip>
> >> >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
> >> >
> >> -----------------------------------------------------
> >>
> >>   Malcolm -
> >>
> >>   I meant that because Tesla coils use dampened sine waves the quenching
> >> would be different compared to quenching pulsed waves such as square waves.
> >> Pulsed waves can have long off times where quenching would have no
> significance.
> >>
> >>   John Couture
> >
> >Just think of the transistors as a gap you can turn on and off any
> >time you like. The fact that waves are damped has no bearing on the
> >gap whatsoever. It reflects the fact that the coil operates on a
> >limited energy store. There was absolutely no difference between the
> >transistor setup and a standard disruptive setup save that the
> >primary ringdown was exponential due to the lack of the negative
> >resistance characteristic attributable to the airgap.
> >
> >Malcolm
> >
> --------------------------------------------------------
>
>   Malcolm -
>
>   It appears your tests were quenching pulsed or square waves and you
> assumed this was the same as quenching dampened waves. I would expect the
> quenching of the dampened waves would be different because of the
> differences between sine waves and pulsed or square waves.
>
>   However, does it matter when the quench occurs if there is a spark from
> the toroid? There would then be no energy left in the secondary to transfer
> back to the primary. Quenching could occur at any time before the next bang.
> There is a relatively long time between bangs. Your excellent waveform
> photos show this very well.
>
>   John Couture