338 



PRINCIPLES OF ELECTRICAL DESIGN 



sary to take account of the effects of saturation in the stator 

 teeth of alternators, because with the comparatively low flux 

 densities especially in 60-cycle machines no serious error will 



24000 



23000 



22000 



21000 



20000 



19000 



< 18000 



| 17000 



X 16000 



& 15000 



P 14000 



J 13000 



12000 



11000 



10000 



9000 



8000 



7000 



6000 





I 10000 12000 14000 

 Air Gap Density B g CGausses) 



18000 



Fia. 138. Tooth densities in terms of air-gap density 8000 k.v.a. 



turbo-alternator. 



be introduced by using the "apparent" tooth density in the 

 calculations. 



The depth of slot in rotor can be approximately determined as 

 follows: 



