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Re: Thyratron pair (was DC Drive)



---------- Forwarded message ----------
Date: Tue, 14 Oct 1997 09:32:35 +1200
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
To: tesla-at-pupman-dot-com
Subject: Re: Thyratron pair (was DC Drive)   

Hi Richard,

> From: richard hull <rhull-at-richmond.infi-dot-net>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: Thyratron pair (was DC Drive)  
> 
> At 09:58 PM 10/12/97 -0600, you wrote:
> >
> >
> >---------- Forwarded message ----------
> >Date: Mon, 13 Oct 1997 08:59:01 +1200
> >From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
> >To: tesla-at-pupman-dot-com
> >Subject: Re: Thyratron pair (was DC Drive) 
> >
> >Hi Richard,
> >
> >> From: Richard Wayne Wall <rwall-at-ix-dot-netcom-dot-com>
> >> To: Tesla List <tesla-at-pupman-dot-com>
> >> Subject: Re: Thyratron pair (was DC Drive)
> >> 
> >> 10/12/97
> >> 
> >> Bert wrote: 
> >> 
> >> snip
> ><SNIP>
> >> 
> >> So, why not determine the requirements of a particular resonator and 
> >> design our drivers to provide only these requirements?  We may be able 
> >> to exprimentally provide even better waveform content than that which 
> >> occurs naturally. 
> >
> >???
> > 
> >> Think about Dr. R's version of the extra coil where he has eliminated 
> >> the driver secondary altogether and drives the extra coil from the 
> >> primary alone.  The reason this works is that there is fast rise time 
> >> and the the required extra coil wave content is available.
> >> 
> >> As we become more familiar with these driving techniques, we will 
> >> eventually be able to elminate the primary/secondary driver altogether 
> >> and directly drive the resonator electronically.  
> >
> >I should point out that this is essentially CW drive and that this 
> >has all been done before. Duane Bylund published a CW fed mag 
> >some time ago using a 1/2 bridge driver. The real trick would be to 
> >get power disruptively into a single resonator. I don't think it can 
> >be done without using at least one other coil but I could be wrong.
> >I would regard a tap on the resonator as equivalent to using a second 
> >coil.
> >
> >Malcolm
> >
> >All,
> 
> I agree with the CW supposition and two coil bit.  The H2 Thyratron
> IS..,repeat IS,..a spark gap and IS disruptive in nature.  This is due
> solely to its on incredibly low resistance and absolute analog to a gas air
> gap.  No vacuum tube will ever be pressed into this kind of service!!!! (H2
> Thyratron is not a vacuum tube).
> 
> The biggest filament on the planet boiling off huge amounts of electrons
> will never equal the conducting power of the weakest of the H2 thyratrons!
> The strongest H2 thyratron will never equal the conducting power of a simple
> air gap!
> 
> H2 thyratrons just allow maggey work to go forward with tens of nanosecond
> on and off times under a modicum of control (something tough with a common
> air gap.)
> 
> Richard Hull

Very true, and of course there is the issue of supply voltage that 
the thyratrons can switch as well. I am wondering whether there is 
anything particularly special about that circuit apart from the fact 
that one can control conduction time fairly precisely without being 
influenced by the output discharge? Is there any benefit in applying 
an extremely narrow pulse to Lp/Cp? After what interval relative to 
half the ring period (PI.SQRT(LC)) did switching the thyratron off 
give the best output in experiments you've conducted? Did you use 
this configuration or did you dump a charged Cp into Lp? I'm sorry if 
I'm asking you to repeat yourself. So many topics have gone by with 
time.

Malcolm