Re: In vs. Out

From: 	Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent: 	Monday, July 28, 1997 5:42 PM
To: 	tesla-at-pupman-dot-com
Subject: 	Re: In vs. Out

Some nice thoughts in here....

> From:   FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
> Sent:   Sunday, July 27, 1997 8:55 AM
> To:     tesla-at-pupman-dot-com
> Subject:    Re: In vs. Out
> In a message dated 97-07-27 10:28:20 EDT, you write:
> << at the risk of being somewhat of a radical here, why not try a totally 
> > different tact - let us imagine that input power is at least well defined
> and 
> > in theory measurable (a hot wire and a photo cell being one way).
> > Imagine a "quality" metric which is a function of 2 variables - spark
> length 
> > and overall intensity.  Max spark length can be measured,it's a number of 
> > meters (feet, centimeters, Ells, whatever unit you choose)
> > Intensity can also be objectively measured - a convenient unit is total 
> > brightness, measured using a "standard" photo cell with a "standard" lens.
> >This could be cheap stuff, like a silicon solar cell from Radio shack with
> no 
> > lens, at a specified distance, or a cadmium sulfide photo resistor mounted
> in 
> > a disposable camera body.
> > The quality metric should give a bigger number for more brightness,and for 
> > more spark length.  So, I would recommend something of the form:
> >   (brighness/K)*spark length
> > Select K so that given agreed units of brighness (ohms mesured on the
> standard 
> > cell, candellas, lumens per steradian, again, whatever you agree on) the 
> > result of a bright spark divided by K will be close to 1, that way a "weak 
> > spark" will be penalized in a standard maner, and a nice thick spark will
> be 
> > suitably rewarded.
> > Note that you would also want to average the reading over several seconds.
>   >>
> William,
> Nothing radical there, I was thinking of something similar.  In theory this
> should work.  It solves the brightness variable.  Somehow though, if 
> someone built a coil that gave a monstrously bright, but very short 
> spark, and we had to give it the same efficiency rating as a coil with
> a much longer but dimmer spark...it just wouldn't seem "right" 
> somehow even though it is technically correct...hmmm.
> John Freau

I would like to suggest that rather than being held of a measure of 
resistance (which as we all know is continuously changing), spark 
brightness is a pretty good measure of current to a first order 
approximation. Length might be seen as the "sustaining" voltage for 
an arc. The product of the two would give a first order power 
approximation. This is only going to work for optimal loading however.
Long air streamers are quite dim by comparison and a lot of energy is 
wasted in the gap under this condition. However, a summation of these
spark parameters at _both_ ends of the system could be useful as a 
total in-system power approximation.