# Lap and wave winding

Lap & wave winding

The armature winding is the most important part of the rotating machine. It is the place where energy conversion takes place, i.e., the mechanical energy is converted into electrical energy, and the electrical energy is converted into mechanical energy. The armature winding is mainly classified into types, i.e., the lap winding and the wave winding.

Lap Winding

The winding in which successive coils overlap each other is known as Lap winding. It is named “Lap” winding because it doubles or laps back with its succeeding coils.

In this winding (Lap Winding), the conductors are joined in such a way that their parallel paths and poles are equal in number. The end of each armature coil is connected to the adjacent segment on the commutator. in the lap winding, the number of brushes is equal to the number of parallel paths, and these brushes are equally divided into negative and positive polarity.

The lap winding is mainly used in low voltage, high current machine applications. The Lap winding is of three types.

Simplex Lap Winding

Duplex Lap Winding

Simplex Lap Winding: In this type of lap winding, the terminating end of one coil is joined to the commutator segment and the starting end of the next coil is placed under the same pole. Also, in the simplex lap winding, the number of parallel paths is similar to the number of poles of the windings.

Duplex Winding: The duplex winding is obtained by placing the two similar winding on the same armature and connecting the even number commutator bars to one winding and the odd number to the second winding.

In duplex winding the number of parallel paths between the poles is twice the number of poles.

Wave Winding

The wave winding forms a wave with its coil, so it is named as wave winding. It is also called series winding because its coils are connected in series.

In the wave winding, the conductors are connected to two parallel paths irrespective of the number of poles of the machine and parallel paths are provided between the positive and negative brushes. The end of the one armature coil is connected to the starting end of the other armature coil commutator segment of the same polarity as that of the first coil at some distance apart.

The wave winding is used in high voltage, low current machines.