Re: Impedance of Corona or Arcs vs Voltage (fwd)

---------- Forwarded message ----------
Date: Mon, 13 Jul 1998 09:02:24 +1200
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Impedance of Corona or Arcs vs Voltage (fwd)

Hi Terry,
           This might be rather difficult to measure except with 
strictly controlled arc currents:

> Date: Sat, 11 Jul 1998 06:29:06 -0600
> From: terryf-at-verinet-dot-com
> To: tesla-at-pupman-dot-com
> Subject: Impedance of Corona or Arcs vs Voltage
> Hi All,
>         Does anybody know how the resistance (impedance) of either corona or
> TC arcs to space increase with voltage?  Ie what function defines the drop
> in impedance as voltage increases?
>         Also, does anybody care to guess what those impdeance might be?  I
> get from the low hundreds of Kohms out to the low mega ohm region.
>         I just thought I would ask.  There should be some information on
> corona loss at least.

The loss is not very high with corona only. One coiler said he 
measured Qs dropping by about 50% under this condition. It drops far 
more with an attached arc loss. Way back in the archives is some 
information on this posted by Ed Harris when we were discussing gap 
characteristics. Given the transient nature of TC discharges, the use 
of a storage scope to capture simultaneous Vs and Is at the top might 
yield useful answers which could be plotted. It could possibly be 
useful to conduct such tests without a top terminal so the surge 
impedance of the secondary was totally in play (capacitive end effect 
excepted but that would be relatively small I think). I believe you 
might have the probes to do the job.