120
Practical MATLAB
® Applications for Engineers
The Norton’s short-circuit current I N is the current through terminals aa’, obtained
by replacing R L by a short-circuit while preserving all sources.
R.2.81 The equivalent circuits used to evaluate the values of V TH , I N , and R TH are shown
in Figure 2.12.
The Thevenin’s and Norton’s equivalent circuits are shown in Figure 2.13.
R.2.82 Note that the Thevenin’s and Norton’s equivalent circuits are related by a simple
source transformation as illustrated in Figure 2.14.
FIGURE 2.13
(a) Thevenin’s equivalent circuit, (b) Norton’s equivalent circuit.
a′
a
R TH
V TH
Arbitrary load R L
a ′
a
R TH
Arbitrary load R L
I N
(a)
(b)
FIGURE 2.12
(a) A network with a connected load, (b) Thevenin model for V TH , (c) Norton model for I N , (d) Thevenin–Norton
model for R TH .
Arbitrary
network
Arbitrary
load R L
a ′
a
a ′
a ′
a
a
Arbitrary
network
Vaa ′ = V TH
I N
Arbitrary
network
with all sources
set to a zero
Arbitrary
network
R TH
a ′
a
(a)
(b)
(c)
(d)
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