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Re: s-s testing of Mag (was RESEARCH ON WHAT?)



Hi Richard (Craven),

> Original Poster: "R M Craven" <craven-at-globalnet.co.uk> 
> 
> <SNIP>
<more snip>

> >I agree that static conditions don't scale in terms of spark lengths
> >under repetitive conditions. However, I see no reason why voltages
> >wouldn't. Again, I am interested to know what proportion of total
> >output voltage is produced by the resonator. I think it could be done
> >and should be done. It would certainly be a reasonable test of Dr de
> >Queiroz's modelling of the sec+extra system in my opinion. Anybody
> >see any reason why not?
> 
> 
> The voltage induced in the secondary of a mag will be -M (dI/dt) which is
> not dependent on whether the system is single shot (s-s) or repetitively
> pumped.
> 
> I wonder, though, if the Z which the extra-coil or resonator represents
> might change under rep-rate conditions. The resonator voltage distribution
> will change when repetitively driven and thus the complex feed point
> impedance will change in phase/magnitude.

Why should it change?
 
> Thus I think the voltage seen at the output end of the resonator  will
> change when it is repetitively driven, but the voltage at the input to the
> resonator will not vary (assuming that the source Z of the pri-sec
> combination is low such that it looks like an ideal "stiff" voltage source
> and is not significantly loaded by the resonator).

Does the primary really look like a voltage source? It is ringing 
down as the transfer proceeds. 

> As a corollary to this: when the feedpoint impedance of the resonator
> changes under rep-rate conditions (assuming no breakout which would end up
> with the 220k/1pF per foot Z being transformed to its conjugate at the
> feedpoint), and the pri-sec combination is not low enough Z (I'd assume a
> 5:1 or preferably 10:1 ratio would be needed), then the feedpoint voltage at
> the resonator input may droop.

Given the figure Richard Hull gave for the transmission line 
discharge under repetitive running, I would be interesting to see the 
sshot length and compare the two. Would I be right in thinking that 
you are suggesting it might be longer under sshot conditions? 

Cheers,
Malcolm