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Re: Arc length vs pwr
Tesla List wrote:
>
> >From rwstephens-at-ptbo.igs-dot-netFri Oct 18 22:54:40 1996
> Date: Sat, 19 Oct 1996 00:27:26 -0500
> From: "Robert W. Stephens" <rwstephens-at-ptbo.igs-dot-net>
> To: tesla-at-pupman-dot-com
> Subject: Re: Arc length vs pwr
>
> >Date: Wed, 16 Oct 1996 22:25:25 -0600
> >From: Tesla List <tesla-at-poodle.pupman-dot-com>
> >To: Tesla-list-subscribers-at-poodle.pupman-dot-com
> >Subject: Re: Arc length vs pwr
> >Reply-to: tesla-at-pupman-dot-com
>
> >>From MALCOLM-at-directorate.wnp.ac.nzWed Oct 16 22:23:39 1996
> >Date: Wed, 16 Oct 1996 09:37:39 +1200
> >From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
> >To: tesla-at-pupman-dot-com
> >Subject: Re: Arc length vs pwr
>
> >A quick comment on this:
> > I think arc length would have to obey a square law at least as
> >far as upping power is concerned. The longer the spark, the more
> >power dissipated along it both in maintaining ionization (width) and
> >length (series resistance). I think one further order of power loss
> >occurs in the gap when upping power levels. I do think though that
> >primary things can be tailored to reduce this loss - it will be
> >different for different gap systems in my opinion.
> >
> > On the lumped vs distributed thing for the secondary: the more
> >top-C you have, the more lumped it gets as the secondary current
> >becomes uniform and hence 0.5LI^2 applies. That measure of magnetic
> >energy cannot apply in a distributed circuit as the current is not
> >uniform along the length of the coil. There would be (in my opinion)
> >an optimum top-C for a given secondary and bang size because several
> >things happen while increasing terminal capacitance: (1) the
> >secondary inductance is becoming more effective (Q increases), (2)
> >voltage holdoff is increasing (assuming more C = greater radius of
> >curvature (ain't necessarily so), and (3) output will eventually
> >decrease due to energy limitation. It would be jolly nice to quantify
> >this optimum R.O.C. and size.
> >
> > On tuning: there is one subtlety I have used where Lp and Cp are
> >more-or-less fixed: raising and lowering the top terminal can
> >dramatically alter secondary fr.
> >
> >fwiw,
> >Malcolm
>
> Malcolm, Richard Hull, All,
> by varying the height above the secondary we are not only
> changing the voltage developed by the change in Q, but we are
> changing the breakaway voltage of the toroid by the change in
> electrostatic field control around it. Isn't it nice trying to
> analyze several interwoven variants changing at the same time?
>
> One thing is certain to me at this point at least. I have ample experimental
> evidence of how certain topload shapes can be made which do a much better
> job than a simple toroid to deliberately throw streamers upwards
> through modified electrostatic field control. Trouble is, I
> rather enjoy those white hot lightning strikes to earth! : ) My goal
> with using what I am learning about the e-field topload control then is to be able
> to input more power with this strategy so that the innevitable strikes to earth
> will occur farther out from the coil tower, and hopefully avoiding self strikes
> which are such a nuisance and potential source of system damage as
> powers are increased to more and more exciting levels.
>
> fwiw,
> rwstephens
Robert,
If we focus in on a specific item in the Tesla coil system i.e., the gap,
the toroid, the secondary, the coupling, yada, yada, yada..., we often
think we are narrowing it down a bit, but NOOOO! We see a multitude of
subtle hidden variable working yet again.
The dog with fleas who themselves have fleas seems to be a never ending
quest for something simple and "pin-downable". We will ultimately get
there, of course, but the silly little spark excited tesla coil which is
so spurned by the "wheels of science" is a real interesting and complex
bear that consistently obeys all of natures laws of physics. All 142,789
of 'em, seemingly at one time with almost as many shifting parameters.
This is what keep me dinkin' around with 'em. If it was a case of F=ma,
I woulda' jumped ship years ago!
I see you have noted all the things that we have noted about the simple
positioning of a toroid.
Richard Hull, TCBOR