[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: PSPICE model for Static Spark Gap
Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-hp-dot-com>
I made a first order model of a static gap with Pspice. This model has
fixed (but adjustable) static breakdown voltage, ON resistance, and quench
time. See http://www.laushaus-dot-com/tesla/gapsim.htm. Now if you really
want to get into it, the on-resistance of a gap is dynamic, varying with
current. Marco Denicolai made a Pspice model that accurately shows the
linear decrement, but the functions he used are not included with the demo
version of Pspice. The URL that I have for his web site doesn't seem to be
working, but his simulation page was at
Simulating the quench time will certainly be challenging! I'm not sure the
fundamentals are presently understood well enough to predict exactly when a
gap will quench. I think for now, we'll just have to make assumptions
about first, second or third notch quenching and set the gap conduction
time to these time intervals.
You may also wish to look at
http://www.spectrum-soft-dot-com/down/winter99.pdf, which shows how to model a
spark gap (but not with Pspice).
Lastly, if you're serious about generating a very accurate model, I think
the present models we have for NST's are deficient in accounting for
non-linearities in the current limiting shunts. I think this has a larger
impact on the final outcome than the error introduced by gap non-linearities.
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Tuesday, December 10, 2002 10:29 AM
Subject: PSPICE model for Static Spark Gap
Original poster: "Mccauley, Daniel H by way of Terry Fritz
I'm interested creating a simple static spark gap using PSPICE. Anyone have
a model they are already
using. Right now I'm thinking its just going to be a voltage-controlled
switch. Basically, when the
voltage exceeds some voltage X, it will close the switch.
However, the tough part of the model would be the following:
A. Impedance of the arc
B. Quenching of the arc
C. The duration of the arc (at which voltage / current limit) will it
extinguish (B. probably also part of this)
Any help appreciated. I'm planning on creating a simulation for my minicoil
running on a 4kV, 20mA NST and want an
accurate enough model so I can explore the use of PSPICE design to create a
tesla coil with longer streamers etc...