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Re: Optimal Quenching Tests
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>Subscriber: Benson_Barry%PAX5-at-mr.nawcad.navy.mil Mon Feb 3 21:28:27 1997
>Date: Mon, 03 Feb 1997 07:05:00 -0500 (EST)
>From: Benson_Barry%PAX5-at-mr.nawcad.navy.mil
>To: tesla-at-poodle.pupman-dot-com
>Subject: Re: Optimal Quenching Tests
>
>
>The resistor switch model is
>the best that I can do at the
>moment as the spark gap
>model is not accurate. I
>haven't tried Jim's signal
>generator model yet. I
>think that it will be the best
>until someone can generate
>a better one. The version
>of spice that I have doesn't
>allow me to dig into the device
>model equations.
>Barry
>
Barry,
If you are referring to the schematic on my ftp site with a
signal source driving a voltage controlled switch, that was used to
model ballasting of the system and not the spark gap. The signal
generator was to simulate my rotary gap with a simple switch and
resistance.
I think that the next type of model to use would be a voltage
controlled switch (with hysteresis) and a non linear series resistor
using a model something like this:
> The conductivity in ohm-m of a fully ionized plasma (which a flame is
> not) is
>
> 5.2e-5 * Z * ln lambda / T_e^(3/2)
>
> where Z is the charge of the ions, ln lambda, known as the Coulomb
> logarithm, is a weak function of density and temperature usually equal
> to 10 or 15, and T_e is the electron temperature expressed in electron
> volts (eV). Thus a plasma is a poorer conductor than copper unless it
>Ø is hotter than about 1 keV (10 000 000 deg).
>Another rule of thumb for radiating plasmas, is that its conductivity
>varies with the current to the 3/2 power I^(3/2a).
With an appropriate set of constants applied to the I^(3/2) term
instead of the T_e equation. (more digging is needed here to get a
model, or some curve fitting from some of the better instrumented
coilers out there)
I plan to continue my spice modeling after I've gotten enough ozone to
cure my withdrawal symptoms;)
Regards,
jim