Re: Modeling the SG linear decay

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "R.E.Burnett by way of Terry Fritz <twftesla-at-uswest-dot-net>" <R.E.Burnett-at-newcastle.ac.uk>


Hi Marco, all,

I have found that a pair of back to back zener diodes can be quite
effective at modeling the primary gap during conduction.  This approach
models the gap as a constant voltage drop for current in either direction.
It gives a linear decrement of the primary waveforms and glitches at the
zero current instants.  It even kind of "quenches" when the primary
voltage becomes insufficient to forward bias the zeners.

I guess this is kind of primitive,  but is the best I came up with. I know
others have mentioned using zeners some time ago for gap modelling.  I can
dig out the Microsim file if nothing better turns up.

						Cheers,

						-Richie,

On Fri, 30 Mar 2001, Tesla list wrote:

> Original poster: "Marco Denicolai by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <marco.denicolai-at-tellabs-dot-com>
> 
> Hello all,
> 
> I would like to include a SIMPLE model of the SG in my model of Thor in
> order to linearize the decay profile. That way, I would get a quite
> similar waveshape from the model and from my measurements.
> 
> Playing with Mathcad I understood I need a negative resistance (for the
> SG); I simulated that with Microsim using a voltage-controlled resistor,
> an equation block and a current-to-voltage block. I got the waveshape
> quite much better and linearized but...
> 
> I would like to know if some of you is aware of the equation(s)
> regulating the SG V-I profile, or some approximation of them. That would
> be easier than to start digging in the library :)
> 
> Regards
> 
> 
> -- 
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