152 



ELECTRICAL ENGINEERING 



Generator 



I I.I.I I I.I.I LJ_ 



LrJ-H 



FIG. 116. Six-pole series drum winding, retrogressive. 



where 



N = number of armature coils, 

 p/2 = numbers of pairs of poles, 

 and C = a constant whole number. 



Each coil may have any number of turns. 



