Patent ID: 7109628

Claim:
A motor comprising: a plurality of excitation coils; a commutator having a plurality of segments, wherein each coil is connected to corresponding ones of the segments; a plurality of supply brushes slidable on the segments, wherein the supply brushes include a plurality of supply brushes each having one of an anode and a cathode, and at least one supply brush having the other one of an anode and a cathode, and wherein the supply brushes each simultaneously contact different one of the segments; and a short-circuit line for short-circuiting segments that simultaneously contact the supply brushes of the same pole, wherein the supply brushes of the same pole separate from the short-circuited segments at different times, and wherein, among the supply brushes of the same pole, the supply brush that lastly separates from the short-circuited segment has a higher electrical resistance than the other supply brushes of the same pole.