78 ALTERNATING GENERATORS AND SYNCHRONOUS MOTORS. 
That is to say: For a power factor cos P= O the angle 
is equal to 90-+90—180 degrees; for cos P=1 it is 
90 + 0 = 90 degrees, ete. 
The above rule is also illustrated in the simple diagram Fig. 
38. The triangle consists of the field turns O A and the 
reactive turns A B' as. two sides; 90+ Pas one of the 
angles; and the third side is represented by the field 
ampere turns, which correspond to the load voltage on the 
saturation curve. In this manner O B', Fig. 38, repre- 
sents the resultant ampere turns with cos P =1, and 
0: B* the resultant ampere turns with cos p = .8. 
134. Determination of Non-Inductive Regulation.— 
Fig. 39 shows the determination of the non-inductive regu- 
SXUTIATIUN CURRENTLY AMPS. 
0 SF © Y§ 20 25 30 35 4 
Coa 
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nS 
LW AMPS. 
: 
6 a 
’ ‘7. 
; 
= 8 
CIROU 
, 
os” 
- 
ale 
V7 be 
TERMINAL PRESSURE IN VOLTS: 
Vee ee Be 
~ 
BX 
we 
K 
sy 
CURRENT. 
, N, S 
— ar a S 
‘ ~A Ff \ 
, \ i. — aH! 
| ene 
mle Wh ie 
Fie. 39.—DETERMINATION OF THE Non-INDUCTIVE Cos p = 1 
REGULATION OF ALTERNATORS FROM THE No-LOAD AND “* 
SHORT CIRCUIT CHARACTERISTICS. 
ation of the 235 KVA. three-phase generator, the char- 
acteristics of which are shown in Fig. 34. 
