Page 219 - Solutions Manual to accompany Electric Machinery Fundamentals

segments b-c-d and j-k-l at the instant shown in the figure. Each brush should be two commutator
segments wide, since this is a duplex winding.
(c) Duplex (see above)
(d) There are 16 coils on the armature of this machine. Of that number, an average of 14 of them would
be under the pole faces at any one time. Therefore, there are 28 conductors divided among 4 parallel
paths, which produces 7 conductors per path. Therefore, E  7 e  V for no-load conditions.
A
T
7-10. Describe in detail the winding of the machine shown in Figure P7-4. If a positive voltage is applied to the
brush under the north pole face, which way will this motor rotate?

SOLUTION This is a 2-pole, retrogressive, lap winding. If a positive voltage is applied to the brush under
the North pole face, the rotor will rotate in a counterclockwise direction.

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