Fourier and Laplace
437
Is = [2/s+2;8*s/(s^2-9)+1/s];
Vs =inv(Ys)*Is;
disp(‘*********************************’)
disp(‘********* RESULTS ************’)
disp(‘*********************************’)
disp(‘The node voltages V1(s) and V2(s) are: ‘)
disp(‘V1(s)=’),pretty(Vs(1))
disp(‘V2(s)=’),pretty(Vs(2))
disp(‘************************************’)
disp(‘The initial value voltages V1(t=0) and V2(t=0) (in volts)’)
disp(‘using the initial value theorem are verified returning:’)
V1 _ 0 = limit(s*Vs(1),s,inf)
V2 _ 0 = limit(s*Vs(2),s,inf)
disp(‘************************************’)
disp(‘The final value voltages V1(t=inf) and V2(t=inf) (in volts)’)
i 1 (t ) = 5 A
i 2 (t ) = 8 cos(3t ) A
R 1 = 3 Ω
R 2 = 4 Ω
R 3 = 9 Ω
C1 = 0.5 F
L1 = 3 h
sw closes at t = 0
L2 = 5 H
v 1 (t )
v 1 (t )
v 2 (t )
+
VC 1(0) = 4 V
−
IL1(0) = 3 A
IL 2(0) = 2 A
FIGURE 4.81
Circuit diagram of Example 12.20.
I 1 (s) = 5/s
I 2 (s) =
R1 = 3
ZC 1(S ) = 2/s
R 2 = 4
ZL1(s) = 3 s
sw Closes at t = 0
ZL 2(S ) = 5s
R 3 = 9
V 1 (s)
V 2 (s)
2 A
3/s
2/s
s 2 +9
8s
FIGURE 4.82
Equivalent s-domain circuit of Figure 4.81.
CRC_47760_CH004.indd 437
CRC_47760_CH004.indd 437
7/28/2008 12:26:20 PM
7/28/2008 12:26:20 PM