PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

180 Practical MATLAB® Applications for Engineers

The script fi le RL is executed and the results and plots (Figure 2.82) are shown as

follows:

>> RL

******************************************************

The solutions i(t) for R=1, 2 and 5 (in Ohms) are :

******************************************************

******************************************************

itR _ 1 =

10-10*exp(-t)

******************************************************

itR _ 2 =

5-5*exp(-2*t)

*******************************************************

itR _ 5 =

2-2*exp(-5*t)

******************************************************

******************************************************

0 0.5 1 1.5 2 2.5 3

0

1

2

3

4

5

6

7

8

9

10

11

time t

i(t) versus t for L=1 & R=1, 2, and 5

i(t)

time const = 1 sec

time const = 0.5 sec

time const = 0.2 sec

FIGURE 2.82

Transient current plots of Example 2.23.

Example 2.24

Create the script fi le RL_vol_plots that returns

1. The expression of vL(t) and plot vL(t) versus t, for t ≥ 0


2. The expression of vR(t) and plot vR(t) versus t, for t ≥ 0
   for the circuit shown in Figure 2.81, for the same three resistors: R = 1, 2, and 5 Ω,
   assuming that the initial current is iL(0) = 0 A.