Patent attributes
This rotation driving apparatus includes a torque generating circuit 72 for generating a torque of a servo motor 30 with voltage supply from a power source 71 and a motor control circuit 73 for controlling rotation of the motor. In the torque generating circuit 72, a condenser 76 is arranged to detect a level of the supplied voltage and a period of voltage drop. A voltage-drop information detected by the condenser 76 can be transmitted to a host controller 70. The host controller 70 previously memorizes a power-recovery information having a voltage drop and a time under an instantaneous blackout capable of recovering within a predetermined period and a rotation control pattern information of the motor corresponding to the power-recovery information and further compares the voltage-drop information, the power-recovery information and the rotation control pattern information of the motor with each other. Based on a control signal, the controller 70 controls the rotation of the servo motor 30. Then, by controlling the rotation in correspondence with the voltage drop during the driving of the motor, it is carried out to suppress increasing of a driving period, improving the throughput and restricting vibration due to a rotational standstill of the motor by the voltage drop.
