Figure 1 Sketch of four-pole dc matchine
The four excitation or field poles are usually joined in series and their ends brought out to
terminals marked F1 and F2. They are connected such that they produce north and south poles
alternately.
The type of dc generator is characterized by the manner in which the field excitation is
provided. In general, the method employed to connect the field and armature windings falls
into the following groups (see Fig.2):
2