Re: Modeling and simulation

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

Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 

Tesla list wrote:
 >
 > Original poster: "S & J Young" <youngs-at-konnections-dot-net>
 >
 > To all those who trust in Spice and the like,
 >
 > The URL below is an interesting piece by Bob Pease (of National
 > Semiconductor fame) regarding how "helpful" modeling is ... or isn't.  I
 > would think his wisdom certainly applies to modeling of Tesla coils.

A simulator is useful, if you know what you are doing. If you don't
know quite well what a circuit is supposed to do, a simulator will
not tell you. Simulators are extremely useful for design verification,
confirming that a complex design does what it is supposed to do.
Some people try to optimize circuits using simulators, instead of
designing them correctly from the start. This may work, but will not
teach anything, and most probably will waste a lot of time.
The site mentioned says that it's frequent to see a Spice simulation
that works correctly, but an actual implementation that oscillates
furiously. This is indeed a common problem, because it's difficult
to include in the models (specially if the user has to do it) all
the parasitic elements, and something that Spice does not consider,
irradiation. Other than this, there is nothing wrong with the models
used in Spice, that model the physical reality quite well.

By the way, I recently found two Spice clones that are quite
interesting, and small:

This is free, unlimited, and very fast. Optimized for power electronics.
SwitcherCAD III: http://www.linear-dot-com
Another, with a small but powerful demo version:
TopSpice: http://www.penzar-dot-com

Antonio Carlos M. de Queiroz