The various armature coils in a d.c. armature winding should be joined nonparallel (series) with one another means that of end connection in a very manner in order that the generated voltages of the individual coils can aid one another within the production of the terminal e.m.f. of the winding.
The two simple ways of creating these end connections are as follows:
- Lap winding
- Wave winding
In simple lap winding, the commutator pitch yc=1 and coil span ys=pole pitch. Therefore the ends of any coil are brought out on adjacent commutator segments and therefore the results of this technique of connection is that all the coils of the armature are in sequence with the last coil connected to the primary coil. Subsequently, loop winding results (closed circuit) this is often shown in the in the fig below. Wherever a part of the lap winding is shown. Solely 2 coils are shown for easiness. The name lap originates from the manner within which succeeding coils overlap the preceding one.
In a simple wave winding, the commutator pitch yc=2 pole pitches and coil span = pole pitch. The result's that the coils beneath consecutive pole pairs are joined along nonparallel (series) thereby adding along their e.m.f.s, shown fig below. When passing once around the armature, the winding falls in a very slot to the left or right of the start line and therefore linking up another circuit. Continued during this manner, all the conductors are connected in a single closed winding. This winding is termed wave winding from the looks (wavy) of the tip connections.