THE ALTERNATOR. 9 



winding being arranged to deliver current to a separate receiving 

 circuit. Thus the armature winding shown in Fig. 1 1 is a two- 

 phase winding. The coils which are square on the ends to the 

 right constitute one winding and the coils which bend backwards 

 and pass behind the square ends constitute the other winding. 

 Polyphase alternators are discussed in Chapter VII. 



Fig. 11. 



Concentrated and distributed armature windings. - The type 

 of armature winding in which all of the wires on the armature are 

 grouped in / slots, where p is the number of field magnet poles, 

 is called a concentrated armature winding. The slots for a con- 

 centrated armature winding are usually rather large and each 

 slot contains a bundle of wires. Figure 2 shows a concentrated 

 armature winding with one wire per slot. 



The type of armature winding shown in Figs. 3 and 4, in 

 which the wires on the armature are spread out in / similar 

 groups of slots, where / is the number of field magnet poles, is 



