11-01-2012, 03:35 PM
Network Theorems
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Introduction
This chapter introduces important fundamental theorems of network analysis. They are the
Superposition theorem
Thévenin’s theorem
Norton’s theorem
Maximum power transfer theorem
Substitution Theorem
Millman’s theorem
Reciprocity theorem
Thévenin’s Theorem
Thévenin’s theorem can be used to:
Analyze networks with sources that are not in series or parallel.
Reduce the number of components required to establish the same characteristics at the output terminals.
Investigate the effect of changing a particular component on the behavior of a network without having to analyze the entire network after each change.
Norton’s Theorem
Norton’s theorem states the following:
Any two-terminal linear bilateral dc network can be replaced by an equivalent circuit consisting of a current and a parallel resistor.
The steps leading to the proper values of IN and RN.
Preliminary steps:
Remove that portion of the network across which the Norton equivalent circuit is found.
Mark the terminals of the remaining two-terminal network.
Reciprocity Theorem
The reciprocity theorem is applicable only to single-source networks and states the following:
The current I in any branch of a network, due to a single voltage source E anywhere in the network, will equal the current through the branch in which the source was originally located if the source is placed in the branch in which the current I was originally measured.
The location of the voltage source and the resulting current may be interchanged without a change in current
