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heavy copper bars connected together at each end by a metal ring made of copper or brass. No insulation
is required between the core and the bars. This is because of the very low voltages generated in the rotor
bars. The other type of winding contains actual coils placed in the rotor slots. The rotor is then called a
wound rotor.
Figure 4-8.—Induction motor.
Figure 4-9.—Types of ac induction motor rotors.
Regardless of the type of rotor used, the basic principle is the same. The rotating magnetic field
generated in the stator induces a magnetic field in the rotor. The two fields interact and cause the rotor to
