Frog-Leg Winding

A frog-leg winding consists of a lap winding and a wave winding. Assume the lap winding has m multiplex number. In order to connect the wave winding in parallel with the lap winding, the wave winding should have the same branch bake emf as the lap winding. Therefore, the number of branches in parallel of the wave winding has to be the same as that of the lap winding, or the multiplex number of the wave winding must be mp/2. The winding layout of a frog-leg-type winding with m=1 for dc machines is as shown below.

A frog-leg-type winding has the following relationships:

Coil pitch
Commutator pitch	yKa = ±m
Number of branch in parallel	a = pm

where