440 



ELEMENTS OF ELECTRICAL ENGINEERING. 



another identically similar simplex winding. These two simplex 

 windings when sandwiched together on one armature core, as 

 shown in Fig. 58, form a duplex lap winding. This duplex wind- 

 ing is of course doubly reentrant according to Art. 47, inasmuch 



Six-pole drum duplex wave winding, doubly reentrant. Z= 64, front pitch = -(- 9, 

 back pitch =-j- n, average pitch 10, commutator pitch 10, number of paths = 4. 



Fig. 59. 



as each of the constituent simplex windings reenters itself. In 

 this winding the back pitch is -f 7, the front pitch is 1 1, and 



