THE DESIGN OF ALTERNATING 
GENERATORS AND SYNCHRONOUS 
MOTORS. 
SUMMARY OF PROBLEMS IN DESIGN, 
181. Problems in Design.—The principal problems in 
| design are: 
1, regulation ; 
2, losses or efficiencies ; 
3, temperature rise; 
4, economical use of the different materials; and 
5, the method of arranging suitable space for the wind- 
ings with regard to mechanical safety. 
All these problems are more or less connected with each 
other and their best combination is specified in Pars. 12 
to 19. 
Practice has approved certain compromises in the determin- 
ation of the different items, in order to obtain successful 
designs. 
182. Regulation and Efficiency.—The compromise between 
the items 1 and 4 may be characterized principally by 
the proper choice of the armature ampere turns, or of 
the total magnetie flux 2p X F, corresponding to the 
normal open cireuit pressure. The former, as the copper 
source of the alternator, affects the amount of copper 
required; and the latter, the iron source of the alternator, 
directly influences the amount of iron material. 
It is obvious, that a certain size of alternator with certain 
