Chapter Contents |
Previous |
Next |
The MODEL Procedure |
Figure 14.81: Nonlinear Resistor Capacitor Circuit
The theory of electric circuits is governed by Kirchhoff's laws: the sum of the currents flowing to a node is zero, and the net voltage drop around a closed loop is zero. In addition to Kirchhoff's laws, there are relationships between the current I through each element and the voltage drop V across the elements. For the circuit in Figure 14.81, the relationships are
label dvdt
Consider the following data.
data circ; input v2 v1 time@@; datalines; -0.00007 0.0 0.0000000001 0.00912 0.5 0.0000000002 0.03091 1.0 0.0000000003 0.06419 1.5 0.0000000004 0.11019 2.0 0.0000000005 0.16398 2.5 0.0000000006 0.23048 3.0 0.0000000007 0.30529 3.5 0.0000000008 0.39394 4.0 0.0000000009 0.49121 4.5 0.0000000010 0.59476 5.0 0.0000000011 0.70285 5.0 0.0000000012 0.81315 5.0 0.0000000013 0.90929 5.0 0.0000000014 1.01412 5.0 0.0000000015 1.11386 5.0 0.0000000016 1.21106 5.0 0.0000000017 1.30237 5.0 0.0000000018 1.40461 5.0 0.0000000019 1.48624 5.0 0.0000000020 1.57894 5.0 0.0000000021 1.66471 5.0 0.0000000022 ;
You can estimate the parameters in the previous equation by using the following SAS statements:
proc model data=circ mintimestep=1.0e-23; parm R2 2000 R1 4000 C 5.0e-13; dert.v2 = (v1-v2)/((r1 + r2*(1-exp( -(v1-v2)))) * C); fit v2; run;
The results of the estimation are shown in Output 14.9.1.
Output 14.9.1: Circuit Estimation
Chapter Contents |
Previous |
Next |
Top |
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.