Generators of Alternating Current
Generators used to produce an alternating current are
called AC generators or alternators.
The simple generator constitutes one method of generating
an alternating voltage.
[Figure 10-102] It consists
of a rotating loop, marked A and B, placed between
two magnetic poles, N and S. The ends of the loop are
connected to two metal slip rings (collector rings), C1
and C2. Current is taken from the collector rings by
brushes. If the loop is considered as separate wires A
and B, and the left-hand rule for generators is applied,
then it can be observed that as wire A moves up across
the field, a voltage is induced which causes the current
to flow inward. As wire B moves down across the
field, a voltage is induced which causes the current to
flow outward. When the wires are formed into a loop,
the voltages induced in the two sides of the loop are
combined. Therefore, for explanatory purposes, the
action of either conductor, A or B, while rotating in the
magnetic field is similar to the action of the loop.
Figure 10-103 illustrates the generation of alternating
current with a simple loop conductor rotating in a
magnetic field. As it is rotated in a counterclockwise
direction, varying values of voltages are induced in it.
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