232 



ALTERNATORS. 



this case is assumed to be non-inductive, and the curve I. 

 in Fig. 109 shows the values thus obtained plotted in the form 

 of a characteristic. The resemblance to the curve obtained 

 experimentally (with a different exciting current) and 

 shown in Fig. 100, for the value cos0= 1-0 is apparent. 



Fig. 110 shows a similar series of diagrams tot hose on 

 Fig. 108 drawn for the same currents, but with an angle of 

 lag of 37 in the external circuit, corresponding to a power- 

 factor of -8. 



The lettering in diagrams 95, 108, and 110 has been made 

 to correspond, so that the various quantities may be followed 

 without difficulty. 



Fig. 110 has been drawn under the same assumptions as 



100 



90 

 80 

 7O 

 60 

 50 

 40 

 30 

 20 

 1O 



10 



40 



20 30 



Amperes. 



FIG. 109. CALCULATED CHARACTKKISTICS. 



1. Non-inductive load. 

 II. Inductive load. 



Power factor = '8. 

 Excitation, T64 amperes. 

 Speed, 1,200 revolutions per minute. 



the previous diagrams, viz., that the total voltage generated 

 in the armature remains constant at all loads, and that the 

 armature impedance also is constant. The first of these 



