Lap Winding

Lap Winding Points : Lap Winding A developed view of lap. The coil span equals 12/4 i.e., 1, 2, 3, 4.. ...denote the upper sides of the coils while 1’, 2’, 3’, 4’..... ..denote lower sides of the coils. The coil side 1 lies in the upper half of the first slot while the lower side of the coil i.e. 1’ lies in the bottom half of the fourth slot and so on. The number of commutator segments is 12 i.e. equal to the number of slots. The winding is progressive. Thus if the emfs in the conductors under N pole are assumed downward, the emfs in the conductors under S pole would be upward. The conductor lying in the interpolar region would flat have any induced emf (e.g. conductors 1, 4, 1 etc). At the positions of meeting points of two emfs, positive brushes are placed. At the position of separating points of two emf, negative brushes are placed. The positive bushes are connected together and connected to the positive terminal of the output. The negative brushes are connected together and connected to the negative terminal of the output. It is evident from that there are four parallel paths in the winding. In general the number of parallel paths is equal to the number of’ poles in a lap winding. The total induced emf is the emf induced in one path and the current delivered to the external circuit is equal to the current in each armature coil multiplied by the number of parallel paths.