26 



ELEMENTS OF ELECTRICAL ENGINEERING. 



of the electromotive force curve, and to show how the positive 

 and negative sets of electromotive force values are unlike when 

 the north poles of the field magnet are not similar to the south 

 poles. 



The electromotive force curves in Fig. 23 are of the shape that 



Fig. 23<*. 



If 



8 



Y////////////////////////////////////////////////W 



Armature core 



\ 



Y/////A 



Axis of time 



one cycle 



Fig. 23*. 



is generally given by alternators with concentrated armature wind- 

 ings, and the curves in Fig. 24 are of the shape that is generally 

 given by alternators with distributed armature windings. When, 

 however, a concentrated armature winding is placed in very large 

 slots, a very considerable reduction of total field flux occurs 



