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17
Methods of Analysis and
Selected Topics (ac)
17.1 INTRODUCTION
For networks with two or more sources that are not in series or parallel,
the methods described in the last two chapters cannot be applied.
Rather, methods such as mesh analysis or nodal analysis must be
employed. Since these methods were discussed in detail for dc circuits
in Chapter 8, this chapter will consider the variations required to apply
these methods to ac circuits. Dependent sources will also be introduced
for both mesh and nodal analysis.
The branch-current method will not be discussed again because it
falls within the framework of mesh analysis. In addition to the methods
mentioned above, the bridge network and �-Y, Y-� conversions will
also be discussed for ac circuits.
Before we examine these topics, however, we must consider the subject
of independent and controlled sources.
17.2 INDEPENDENT VERSUS DEPENDENT
(CONTROLLED) SOURCES
In the previous chapters, each source appearing in the analysis of dc or
ac networks was an independent source, such as E and I (or E and I)
in Fig. 17.1.
+
E
–
+
E
–
I I
FIG. 17.1
Independent sources.
N A