PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

Direct Current and Transient Analysis 195

with the boundary conditions given by

Ldi t

dt

()tC
 0 

v()010V

or

di t

dt

()t
 0 

 40 Vandi() 0 0 A

Note thatLdi t

dt C

()
 (^1) ∫it() 00 for satisfying KVLt
MATLAB Solution

current it = dsolve(‘D2y+144*y=0’,’y(0)=0,Dy(0)=40’,’t’)
current it =
10/3sin(12t)
ezplot(it,[0 1]) % the plot is shown in Figure 2.96
xlabel(‘time t in sec’)
ylabel(‘i(t) in amps’)
title(‘i(t) vs t’)
FIGURE 2.95
Network of Example 2.28.
FIGURE 2.96
Plot of i(t) of Example 2.28.
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
− 4
− 3
− 2
− 1
0
1
2
3
4
time t in sec
i(t) versus t
i(t) in amps
V 0 = 10 V
Switch moves down at t = 0

• 
  
  
  
  • −
    −
    C 1 = 1/36 F
    R = 2 Ω
    i(t)
    L = 1/4 H