To provide a DC motor drive device which can perform overcurrent protective operation, to both a drive current to be supplied to an armature coil from a DC current through a switching circuit and a current flowing through the switching circuit by the induced voltage of the armature coil.
In the DC motor drive vice, current detecting resistors Ri1, Ri2 are respectively inserted between the grounding side switching elements F21, F22 of the switching circuit 1A, which switch the polarity of the drive current to be supplied from the DC power supply 5 to a DC motor 2, and grounding. A current detecting means, which detects both the drive current flowing from the DC power supply 5 to the motor 2 through the switching circuit and the current flowing through the switching circuit by the induced voltage of the armature coil of the motor, is constituted of the resistors. When the current detecting means detects current exceeding the limiting value, the switching circuit 1A is controlled so that the switching element in the switching circuit becomes an off-state to perform overcurrent protection operation.
HATANO YASUKAZU
UCHIUMI JUN
