PROCEDURE IN DESIGN OF D.C. GENERATOR 215 



B g and B t at high densities, it will be found convenient to prepare 

 a table similar to the one below. 



Values of the actual tooth density, B t , from 21,000 to, say, 

 25,000 gausses are assumed, and the corresponding values of H 



25000 



24000 



23000 



22000 



1? 



| 21000 



20000 



19000 



100 200 300 400 500 600 700 800 900 1000 1200 1400 1600 1800 2000 

 Magnetizing Force (Gilberts per Centimeter) = H 



FIG. 80. B-H Curve for armature stampings high values of 

 magnetization. 



and fj. are then found by referring to the B-H curve, Fig. 80, 

 which is similar to Fig. 4 except that the quantities concerned 

 are expressed as B and H because this is more convenient for 

 obtaining /*. 



The quantity which is a function of n, in formula (62), can 

 now be determined, and the corresponding values of B g readily 

 calculated. 



In this example, we shall consider the tooth density in the 



