Re: spark gap/arc resistance (fwd)

---------- Forwarded message ----------
Date: Mon, 20 Jul 1998 20:20:17 -0600
From: terryf-at-verinet-dot-com
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: spark gap/arc resistance  (fwd)

At 10:02 PM 7/19/98 -0600, you wrote:
>---------- Forwarded message ----------
>Date: Sun, 19 Jul 1998 21:36:49 -0600 (MDT)
>From: Chip Atkinson <chip-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: spark gap/arc resistance 
>Is there a rule of thumb type calculation for the resistance of a spark
>gap (that's firing :-)) such as 1 ohm /inch for example?  I checked my web
>site and list archives and didn't find anything such as this and don't
>remember any actual values, despite the fact that the topic is often
>Thanks in advance.
> Chip Atkinson 
> http://www.pupman-dot-com 
> --- If I can't fix it, I can fix it so it can't be fixed --

Hi Chip,

No known rule of thumb.  I think the gap acts much like back to back zener
diodes with some resistance.  I suspect the energy dissipated in the dead
window of the zeners is very significant.  The gap fires when the voltage
reaches a certain level and stops when the current reaches zero.  The firing
voltage decreases somewhat on subsequent firings.  There are all kinds of
messy rings going on near the zero current crossings.  I have been just
assuming a series resistance based on the ring down time for just the
primary system.  In my case it is 3 ohms.

	Terry Fritz