PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

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)