ALTERNATING GENERATORS AND SYNCHRONOUS MOTORS. 109 
losses, as practically all these losses are located in the 
armature core, where the magnetization is always varying. 
AmPERE TURNS FoR ENTIRE PoLe System: The values of 
ampere turns previously found are for one pole only; 
therefore, for the entire pole system the total value will 
be equal to 64 x 4,310 = 275,840 ampere turns for a 
voltage of 3,000 at the terminals. 
179. Calculation of Short Circuit Characteristic.—In 
Par. 121, it has been shown that the short circuit char- 
acteristic is represented by the equation: | 
~ Aye = Ay X ks 
where, 
a 4 r. RR 3 
ks = 1 + 7 ‘2 poe pe 
This factor for a wide range of excitation remains constant; 
therefore the characteristic is a straight line and its deter- 
mination is identical with the calculation of the factor ks. 
180. Example 24.—For a practical example, the data of Par. 
178 may be used, from which it is necessary to calculate 
the values of r,, r,, r'. and r', by means of Equations 
(19), (20), (23) and (24). 
SATURATION OF MAGNETIC CrrcutT: As already pointed out, 
the saturation of the magnet circuit with a short circuited 
armature, is very low and corresponds only to the leakage 
flux. In eonsequence of this low saturation, the values of 
the permeability in the pole core as well as in the wheel 
rim, will have comparatively high values, as proved by a 
glance at the permeability curves of Fig. 46. With these 
large permeability values, the items = and - in the ex- 
pression of k, are entirely negligible; therefore k, may 
equal 1 + —: 
