10/17/10
Dr. Bruce McCamm
1
Superposition
Superposition
In this lecture, you will:
Learn the principle of superposition
Learn how to apply the principle of
superposition to solve DC circuits
Understand the tradeoffs in applying
superposition versus other circuit analysis
approaches
Linearity
Linear operators:
Add and subtract
Multiply and divide by constants
Differentiate and integrate
Nonlinear operators:
Exponents other than 1
• For example, squares and square roots
Logarithms and many other functions.
Linear Circuit Elements
Resistors are linear circuit elements:
V = IR
is clearly a straight line.
Ideal capacitors and inductors are linear.
Independent sources are linear.
Dependent sources are linear provided that the
output voltage or current is proportional to the
first power of a specified voltage or current
(or a sum of these).
Nonlinear Circuit Elements
Semiconductor devices are nonlinear.
Diodes
Transistors
Devices using ferromagnetic materials
are nonlinear.
Iron core inductors.
Many other real world devices are
nonlinear although their response may
be approximately linear over a limited
range.
Linear Circuits
A
linear circuit
is a circuit composed
exclusively of linear circuit elements.
3 A
5
Ω
10
Ω
40
Ω
+
50 V

This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document10/17/10
Dr. Bruce McCamm
2
Superposition
Superposition is a property of all
linear
systems:
Superposition
Definition
:
Any linear system obeys the
principle of
superposition
, which states
that whenever a linear system is excited
or driven by more than one independent
source of energy, the total response is
the sum of the individual responses that
result from each independent source
acting alone.
What does this mean?
This is the end of the preview. Sign up
to
access the rest of the document.
 Fall '06
 MCCANN
 Superposition, Thévenin's theorem, linear circuit, Dr. Bruce McCamm

Click to edit the document details