240 



ALTERNATING CURRENTS 



reversed field and so exert a torque opposite to that of the other 

 conductors in that belt. Also, conductor a' in an adjacent cur- 

 rent belt exerts a torque opposite to that of the other conductors 

 in its belt. The torques exerted by conductors a and a' produce 



(a) Current belt a space-degrees out of phase with flux wave, when rotor react- 

 ance is high. 



(6) Space distribution of current and flux, differing in space-phase by angle a. 

 FIG. 228. Relation among flux, current and torque when current belt is not 

 in space-phase with flux wave. 



the negative loops of the torque curve, Fig. 228 (6) . The torque 

 under these conditions is less than it is in Fig. 227 (6), even with 

 the same values of current and flux. This is due to the negative 

 values of torque, shown in Fig. 228 (6). 



