THE INDUCTION MOTOR. 

 For the e. m. f. we have : 



e = . 2.22 . 

 3 



. 10-8 

 . 10-8 



(21) e = 1.48 . ~ . z . 



109. It will readily be seen from these formulae that it is not advan- 

 tageous to use a coil spread over the whole pole-pitch. 



' ' i i; I i I ' "i 'iff 



N=i B.b.t. 



1.48 



\ 



FIG. 31. 



110. We can now proceed to study in detail the qualities of the 

 single-phase motor ; to this purpose we shall devote the next chapter, 

 taking the iron frame of the three-phase motor designed in chapter 

 V, and winding it as a single-phase current motor. 



62 



