zeroes, poles and circuits

[Magnus Danielson]

From: Rene Schmitz <uzs159 at uni-bonn.de>
Subject: zeroes, poles and circuits
Date: Mon, 27 Sep 1999 17:21:56 +0200

> Hello all,
> 
> Perhaps someone can enlighten me. 
> How does one translate between a circuit topology and the s-plane ?

It is quite simple really, but it takes some work. You recall the old
jw-method? Here is the real one:

Resistor:

Z  = R
 R

Capacitor:

     1
Z  = --
 C   sC

Inductor:

Z  = sL
 L

Then you just transform your curcuit into some equation with an input
voltage (or current) and some output voltage (or current) and then you
get your transfer function by applying:

       Vout(s)
H(s) = -------
       Vin(s)

Amplifiers just transform into amplification factors.

There is even a program (I have the Fortran sources on paper somewhere here)
which will take a Spice like netlist and generate this form of equation.
I must dig that book up, it was soo good!

Got it?

Cheers,
Magnus