Re: Spark Gaps (fwd)

---------- Forwarded message ----------
Date: Mon, 27 Apr 1998 08:46:07 +1200
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Spark Gaps (fwd)

Hi John,

> 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)

> >>   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. 

I still don't understand what you mean. I turned on a gap that 
discharged a capacitor into the primary coil and turned it off again 
at various times. I didn't switch a DC supply into the primary coil.
I assume *nothing*. The scope photos show the story in graphic detail.
I really don't grasp the significance of your emphasis on dampened 
waves. One could either do things as per usual (switch a cap to the 
primary) or switch a CW source to the primary. I did the former of 
the two. The oscillations die down because of a finite energy source 
(the capacitor) and the losses in the system.

>   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.

It is axiomatic that a quench *does* occur if the secondary loses its 
energy and the power supply isn't keeping an arc going in the gap. In 
fact it is that huge energy loss which effects the quench.

> Quenching could occur at any time before the next bang.

Quench is effected when the energy has pretty much left the system.


> There is a relatively long time between bangs. Your excellent waveform
> photos show this very well.
>   John Couture