AC GENERATOR COMPONENTS
Slip rings are electrical connections that are used to transfer power to and from the rotor of an
AC generator (refer to Figure 1). The slip ring consists of a circular conducting material that is
connected to the rotor windings and insulated from the shaft. Brushes ride on the slip ring as
the rotor rotates. The electrical connection to the rotor is made by connections to the brushes.
Slip rings are used in AC generators because the desired output of the generator is a sine wave.
In a DC generator, a commutator was used to provide an output whose current always flowed
in the positive direction, as shown in Figure 2. This is not necessary for an AC generator.
Therefore, an AC generator may use slip rings, which will allow the output current and voltage
to oscillate through positive and negative values. This oscillation of voltage and current takes
the shape of a sine wave.
Figure 2 - Comparison of DC and AC Generator Outputs