Fig. 266.—Developed view of a typical wave winding. This winding, instead of lapping back toward the commutator segment from whence it came, as in lap winding, turns the other way. For instance, d-7-12 does not return directly to e, but goes on to i, whence another element i-17-4-e continues in a sort of zigzag wave.
Ques. Are coils such as shown in [figs. 263] and [265] used in practice?
Ans. No, for practical use each coil would consist of several turns, the diagram then merely indicates the end connections and slots for the several turns of each coil.
Series or Wave Drum Winding.—In this mode of winding, the inductors are arranged around the armature so that they do not turn back, thus describing a zigzag or wave-like path; that is, the coil ends instead of connecting with adjacent segments of the commutator, are attached to segments more or less remote.
Ques. Describe the circuits of a simple or simplex wave winding.
Ans. Only two sets of brushes are required for such a winding, but as many brushes as there are poles can be used.
Fig. 267.—Five coil wave winding for a four pole machine. In this winding only two brushes are used, there being only two paths through the armature.
Ques. For what service are wave windings adapted?
Ans. They are generally used on armatures designed to furnish a current of high voltage and low amperage.