Abstract :
IN COMMUTATOR-type motors, the current is reversed in the armature coils as the commutator bars, to which they are connected, pass under the brushes. During the period of reversal the coils are short-circuited due to the brush making contact with two bars to which the ends of the coils are connected. The current in the short-circuited coil is determined by the voltage which is generated in that coil and the resistance of the coil, brush, and brush contact.
