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From: ken@rochester.UUCP
Newsgroups: sci.electronics
Subject: Re: Information on the implementation of "Spice"
Message-ID: <24996@rochester.ARPA>
Date: Thu, 19-Feb-87 14:04:58 EST
Article-I.D.: rocheste.24996
Posted: Thu Feb 19 14:04:58 1987
Date-Received: Fri, 20-Feb-87 21:19:04 EST
References: <1450@umd5>
Reply-To: ken@rochester.UUCP (SKY)
Organization: U of Rochester, CS Dept, Rochester, NY
Lines: 18
Keywords: mathematical models

I'm trying hard to remember what they taught me as an EE.

Any EE worth his salt can tell you that the analysis of circuits can
done by replacing the circuit components with the equivalent mesh of
resistances, impedances, generators, etc. For DC you must use the DC
equivalent. For AC you must use the appropriate model for the
frequencies you are working at. Then you formulate the mesh as a system
of linear equations, and solve. The linearity assumption is important.
If this doesn't hold well, you must use better models.

I'm not saying this is the way it is done in Spice, but it is one
general approach. I leave advanced comments for those who know better.

Check your local engineering library for books on Computer Analysis of
Circuits. I remember books on ECAP and other venerable programs.  I'm
sure the literature has been updated since then.

	Ken