To appropriately perform overload determination.

A drive controller comprises: a time count unit 60 for measuring lapse time Tt from an initial drive start time of a DC motor 101 after a power supply switch 71 becomes in an ON state; a power measurement unit 40 for measuring a change of motor power ΔW from the initial drive start time of the DC motor 101 after the power supply switch 71 becomes in the ON state; and an integration processing unit 50 for performing time integration on the measured motor power ΔW. A control unit 20 determines that an overload occurs and performs restriction by cancelling drive of the DC motor 101, when average power Wavg calculated by dividing a total sum Wad of integrated values Wts of motor power by the lapse time Tt counted by the energizing timer 60 exceeds reference power Wmax of the DC motor 101.