Biomedical Engineering Reference
In-Depth Information
the sources except one and assuming the other sources are dead. After the circuit is ana-
lyzed with the first source, it is set equal to a dead source, and the next source is applied
with the remaining sources dead. When each of the sources has been analyzed, the total
response is obtained by summing the individual responses. Note carefully that this princi-
ple holds true solely for independent sources. Dependent sources must remain in the circuit
when applying this technique, and they must be analyzed based on the current or voltage
for which it is defined. It should be apparent that voltages and currents in one circuit differ
among circuits and that we cannot mix and match voltages and currents from one circuit
with another.
Generally, superposition provides a simpler solution than is obtained by evaluating the
total response with all of the applied sources. This property is especially valuable when
dealing with an input consisting of a pulse or delays. These are considered in future
sections.
EXAMPLE PROBLEM 9.8
Using superposition, find
V
0
as shown in the following figure.
2
Ω
3
Ω
+
+
−
10 V
V
0
2 A
5
Ω
3 A
-
Solution
Start by analyzing the circuit with just the 10 V source active and the two current sources dead,
as shown in the following figure.
2
Ω
3
Ω
+
+
−
10 V
V
0
10
5
Ω
-
