lapwinding

Lap winding is a method of connecting armature windings in electrical machines, most commonly described in the context of direct-current (DC) machines but also discussed in relation to stator windings in some discussions of AC machines. In a lap winding, the end connections of successive coils are made to adjacent slots around the armature periphery, so that the current path progresses in a “lapping” fashion from one coil to the next. The coils are arranged in series, and the conductors follow a path that tends to weave around the circumference of the armature.

A key characteristic of la p windings is the number of parallel paths. In a lap winding, the number of parallel paths typically equals the number of poles of the machine. This allows high-current, low-voltage applications to be served by distributing current across many parallel paths. In contrast, wave windings create a fixed small number of parallel paths (usually two), regardless of the number of poles, which suits high-voltage, lower-current designs better.

Lap windings are generally easier to construct for machines that operate at lower voltages with higher currents and many poles, because the multiple parallel paths help reduce current per path and improve current distribution. However, they can be less favorable for high-voltage operation due to the increased complexity of end connections across many parallel paths and the practical limits on pole count.

Historically, lap and wave windings have been foundational concepts in DC machine design and are often discussed as complementary winding schemes. In modern large-scale machines, other winding configurations and insulation practices have largely superseded these basic forms, but the concepts remain useful for educational purposes and for understanding early machine technology.