SYNCHRONOUS MACHINERY 



255 



angle (f>. At the instant represented the current is maximum and 

 the m.m.f. of the coil is maximum and acts in direction OF. The 

 current in phase 2 is now zero. The m.m.f. 's acting are shown in 

 Fig. 231. 



jMa 

 Alternator 



FIG. 230. 



FIG. 231. 



In Fig. 232 the coil AB has moved through angle and its current 

 has decreased to IQ cos and its m.m.f. to n/ cos 6. The current 

 in coil CD has a value 7 sin 6 and its m.m.f. is n! sin 9. 



FIG. 232. 



FIG. 233. 



The component of the m.m.f. of phase 1 in direction OF is 

 ?i/o cos cos 6 = nlo cos 2 6 and the component in direction OX is 

 n/ cos 6 sin 8. 



The component of the m.m.f. of phase 2 in direction OF is 

 n/o sin 6 sin 6 = nI Q sin 2 6 and the component in direction OX is 

 +n/o sin 6 cos 6. The resultant m.m.f. of the two phases in direc- 



