120 Practical MATLAB® Applications for Engineers
The Norton’s short-circuit current IN is the current through terminals aa’, o b t a i n e d
by replacing RL by a short-circuit while preserving all sources.
R.2.81 The equivalent circuits used to evaluate the values of VTH, IN, and RTH 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
RTH
VTH Arbitrary load R
L
a′
a
RTH Arbitrary load RL
IN
(a) (b)
FIGURE 2.12
(a) A network with a connected load, (b) Thevenin model for VTH, (c) Norton model for IN, (d) Thevenin–Norton
model for RTH.
Arbitrary
network
Arbitrary
a′ load RL
a
a′
a′
a
a
Arbitrary
network Vaa′ = VTH
IN
Arbitrary
network
with all sources
set to a zero
Arbitrary
network
RTH
a′
a
(a)
(b)
(c)
(d)