ALTERNATING GENERATORS AND SYNCHRONOUS MOTORS. 19 
168. 
169. 
170. 
171. 
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1 ahs 
174. 
175. 
of conductors per slot. It is to be noted that with regard 
to a convenient winding arrangement the higher, even 
number of conductors per slot above that obtained by 
calculation is to be taken. | 
With the number of conductors per slot ascertained in the 
preceding question, calculate the corrected number of 
total armature conductors. 
With the above stated form factor value, k = 2.0, and the 
corrected number of total armature conductors, calculate, 
by means of Equation 33 of the Instruction Book, the’ 
corrected useful flux per pole. 
By means of Fig. 63 and Equation 3% of.the Instruction 
Book, calculate the approximate armature bore of this 
alternator. It is to be noted that the peripheral density 
of this single phase alternator will be about 20 per cent. - 
lower than that of a polyphase alternator of equal size. 
The armature bore of this machine being definitely fixed 
at D = 36 inches, calculate by means of Equation 38 of 
the Instruction Book the approximate peripheral speed 
of the magnet wheel, neglecting the small difference ex- 
isting between the armature bore and the external 
diameter of the magnet wheel, that is, the air gap. 
Allowing a current density of 2,200 amperes per square inch 
for the armature conductors, determine the most suitable 
size for same, but do not employ thicker wire than .16 
inch diameter. Calculate also the number of wires per 
slot. 
Determine the most suitable slot-shape, considering the best 
ratio of slot width to slot height. Make a sketch showing 
the different slot dimensions and the arrangement of the 
wires. Micanite insulation of .05 inch thickness and a 
fixing wedge of .2 inch thickness are to be applied. 
Caleulate the mean thickness of a tooth. 
By means of Fig. 27 of the Instruction Book, calculate the 
approximate effective teeth section belonging to a pole. 
