Re: How should we measure coil efficiency

From: 	FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
Sent: 	Sunday, July 27, 1997 1:58 AM
To: 	tesla-at-pupman-dot-com
Subject: 	Re: How should we measure coil efficiency

In a message dated 97-07-26 22:07:21 EDT, you write:

<< snip>
>  Was it possible to measure the cap voltage for one long free air spark? 

John C, All,

How can there even be a cap voltage for one free air spark?  Sparks build
up over multiple gap firings.
> How did it compare with the cap voltages for the shorter sparks?

I have a feeling that if the cap had the exact same voltage and energy
at every gap firing, we would still see the same long and short sparks
that we now see.  This spark length variation seems to have a lot to do
with ionization effects.  But I have not yet verified this theory so it's
speculation so far on my part. 
>  Note that the length of the spark depends upon the voltage and energy in
> the cap. 

I don't think the spark length depends on the voltage and energy in the
cap, because the spark builds up over many firings as mentioned above.
It's the average cap energy that is important towards spark length.
 >  If there were no changes in the cap voltages do you think the ionization
> of the air is being averaged out over time? I have never heard of anyone
> has checked this possibility.

I wouldn't say that the ionization is averaged over time, rather I think it
non-averaged over time.  I.e., the ionization or its effect on spark length
fluctuates over time due to the bizzarre way the sparks grow, even if
cap energy remains constant from firing to firing.  All speculation on my
part here.

John Freau
 > JHC