Page 67 - NETWORK ANALYSIS

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Norton Theorem

Norton’s theorem states that any linear circuit can be simplified to an equivalent

circuit consisting of a single current source and parallel resistance that is connected to
a load. This circuit is known as Norton equivalent circuit. Applying Norton’s theorem

to simplify a circuit that is easier to determine variable loads.

Comparison between Thevenin’s and Norton’s theorem

Thevenin’s theorem and Norton’s theorem are used to simplify complex circuit into a

simple circuit.

No Thevenin’s theorem Norton’s theorem

1 First, find the Thevenin resistance, Rth Find Norton resistance, RN by
by removing the load and replaced the removing the load and replaced the

voltage source with a short circuit and voltage source with a short circuit and

the current source with an open the current source with an open
circuit. circuit.

Rth = RN

2 Second, calculate the Thevenin Calculate the Norton current source,
voltage, Vth by removing the load. IN by removing the load and replacing

a short circuit.

3 Third, draw the Thevenin equivalent Draw the Norton equivalent circuit.
circuit.

4 Fourth, find the load current, iL Find the load current, iL flowing

flowing through the load resistor by through the load resistor by using:
using: R
iL= N x IN
V R +R L
N
iL = th
R +R L
th

= 3 + 0.67