To exactly detect a rotational speed of every rotational direction and the number of the revolutions of a brush-type DC motor with a simple and spaceless configuration, and to effectively control the rotation.
A DC motor 13 comprises electrode brushes B21 and B22, and rotation-detection brushes BD2a and BD2b. A pulse-count means 151 of a motor- control circuit 15 counts the number of output pulses of a comparator 14 that selectively compares the rotation-detection brush BD2a and BD2b with a reference voltage, gives the number to an accumulated revolution-number calculation means 152 and calculates the accumulated number of revolutions of a rotor, i.e., a motor, based on the number of pulses. A remaining revolution-number calculation means 153 calculates the remaining number of revolutions that is before reaching a target accumulated number of revolutions based on the accumulated numbers of revolutions calculated by the accumulated revolution- number calculation means 152 and based on the target number of revolutions, and feeds a motor-control signal that corresponds to the remaining number of the revolutions to a motor-driving circuit 12.
KOYAMA KENJI
TSURUKAWA IKUYA
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