Page 218 - Solutions Manual to accompany Electric Machinery Fundamentals

(a) How many parallel current paths are there through this armature winding?

(b) Where should the brushes be located on this machine for proper commutation? How wide should
they be?
(c) What is the plex of this machine?

(d) If the voltage on any single conductor under the pole faces in this machine is e, what is the
voltage at the terminals of this machine?

SOLUTION

(a) This is a duplex, two-pole, lap winding, so there are 4 parallel current paths through the rotor.
(b) The brushes should be shorting out those windings lying between the two poles. At the time shown,
those windings are 1, 2, 9, and 10. Therefore, the brushes should be connected to short out commutator

212