Re: Marx spark gaps (fwd)

["High Voltage list" <hvlist@xxxxxxxxxx>]

Original poster: <sroys@xxxxxxxxxxxxxxxxx>



---------- Forwarded message ----------
Date: Mon, 6 Jun 2005 07:37:45 -0600
From: Gomez Addams <gomez@xxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Marx spark gaps (fwd)


On Jun 5, 2005, at 2:09 PM, High Voltage list wrote:

> Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Fri, 03 Jun 2005 12:02:24 +0200
> From: Herwig Roscher <herwig.roscher@xxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Re: Marx spark gaps (fwd)
>
>
> Jim, Gomez, list.
>
>>> Consequently the gap distance of the first gap should be about .27",
>>> that of the second gap about .54", that of the third gap about .81"
>>> and so on.
>
>> That is simply not true, and I have never heard of that practice
>> before now.
>
> "The Firing Probability of Coupling Spark Gaps of the Multiplying
> Circuit according to Marx" by A. Rodewald, Basel clearly proofes that
> Marx generators with *capacitive and resistive loads" behave like
> mentioned above. However the generators without load, as we usually
> build, behave different and have to have nearly equal spark gap
> distances. Or did I interpret this article wrong?

  All I was saying is that I have not heard of professional Marx banks 
being
set up in that fashion, regardless of what the Haefely paper suggests.

  It's not my intention to argue with the authors over whether it is a 
good
idea - clearly anyone who works at Haefely knows far more than I ever 
will
about the design and operation of Marx type impulse generators!

  Further, I have not examined one of Haefely's Marx banks.  (wouldn't 
any
of us just love to!)

  Interestingly, Hipotronics (one of Haefely's main competitors in the
impulse generator business) use a design which triggers every switch in 
the
stack simultaneously, but many of their machines use something they 
call the
Polytron gap, which is a fully enclosed, pressurized multi-gap switch 
with
capacitively coupled triggering, and stage firing voltage is determined 
by
gap pressure.

  I've looked around the net and Haefely's web site for documentation on 
how
they suggest operators set their gap spacing, but haven't found anything
yet.