Page 211 - Solutions Manual to accompany Electric Machinery Fundamentals

SOLUTION

(a) This winding is progressive, since the ends of each coil are connected to the commutator segments
ahead of the segments that the beginnings of the coils are connected to.

(b) There are two current paths in parallel through the armature of this machine (this is a simplex lap
winding).
(c) The voltage is positive at brush x with respect to brush y, since the voltage in the conductors is
positive out of the page under the North pole face and positive into the page under the South pole face.
The voltage produced by this machine can be found from Equations 7-32 and 7-33:


ZvBl Zr Bl
E  A 
a a
where Z is the number of conductors under the pole faces, since the ones between the poles have no
voltage in them. There are 16 conductors in this machine, and about 12 of them are under the pole faces
at any given time.

   1800 r/min   2 rad      1 min    188.5 rad/s
 1 r   60 s 

  Zr Bl 12 cond 0.10 m  188.5 rad/s 1.0 T 0.3 m 
E    33.9 V
A
a 2 current paths
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