A motor drive device that drives motors with one inverter includes a step-out control unit that detects step-out in which the operating frequency of at least one of the motors does not match the inverter output frequency, or the operating frequency of at least one of the motors does not match the operating frequency of another one of the motors, and stops the motors by switching an energization state of the inverter when at least one of the motors is out of step.

An electronic timepiece, including: a motor having a rotor and at least two coils, the rotor being configured to rotate to a plurality of prescribed positions; and a driving processor for driving the motor, the driving processor being configured to: generate a detection pulse for detecting whether or not the rotor has rotated; cause the generated detection pulse to be applied to at least one of the at least two coils; receive a signal indicating a detected value of current flowing in the at least one of the at least two coils that is generated in response to the detection pulse outputted to the at least one of the at least two coils; and determine whether or not the rotor has rotated to one of the plurality of prescribed positions on the basis of the detected value of current.

An electronic timepiece, including: a motor having a rotor and at least two coils, the rotor being configured to rotate to a plurality of prescribed positions; and a driving processor for driving the motor, the driving processor being configured to: generate a detection pulse for detecting whether or not the rotor has rotated; cause the generated detection pulse to be applied to at least one of the at least two coils; receive a signal indicating a detected value of current flowing in the at least one of the at least two coils that is generated in response to the detection pulse outputted to the at least one of the at least two coils; and determine whether or not the rotor has rotated to one of the plurality of prescribed positions on the basis of the detected value of current.

A method for detecting stall of a multiphase motor operated in a sinusoidal micro-stepped mode. The method comprises: a) measuring at least one phase current and/or measuring the sum of all phase currents at regular time intervals synchronous with the micro-steps, b) calculating the difference between the measured phase current at a first moment and the measured phase current of the same phase at a previous moment and/or the difference between the measured sum of all phase currents at a first moment and the measured sum of all phase currents at a previous synchronous moment, c) analyzing the series of obtained current differences so as to generate a stall detection signal.

A method for detecting stall of a multiphase motor operated in a sinusoidal micro-stepped mode. The method comprises: a) measuring at least one phase current and/or measuring the sum of all phase currents at regular time intervals synchronous with the micro-steps, b) calculating the difference between the measured phase current at a first moment and the measured phase current of the same phase at a previous moment and/or the difference between the measured sum of all phase currents at a first moment and the measured sum of all phase currents at a previous synchronous moment, c) analyzing the series of obtained current differences so as to generate a stall detection signal.

Provided is a stepping motor abnormality detecting device capable of detecting an abnormality of a stepping motor. Stepping motor abnormality detecting device (100) includes power supply (1), stepping motor (4), stepping motor driver (3), determiner (5), and controller (6). Controller (6) causes stepping motor driver (3) to operate stepping motor (4), current level detector (2) to acquire a current level while stepping motor (4) is driven, and determiner (5) to detect the abnormality of stepping motor (4) by comparing the current level acquired with a predetermined threshold.

Provided is a stepping motor abnormality detecting device capable of detecting an abnormality of a stepping motor. Stepping motor abnormality detecting device (100) includes power supply (1), stepping motor (4), stepping motor driver (3), determiner (5), and controller (6). Controller (6) causes stepping motor driver (3) to operate stepping motor (4), current level detector (2) to acquire a current level while stepping motor (4) is driven, and determiner (5) to detect the abnormality of stepping motor (4) by comparing the current level acquired with a predetermined threshold.

A method for detecting a stall condition in a stepper motor includes measuring stepper motor current, computing load angle of the motor, and detecting a stall condition if the load angle is more than 90 degrees.

A method for detecting a stall condition in a stepper motor includes measuring stepper motor current, computing load angle of the motor, and detecting a stall condition if the load angle is more than 90 degrees.

Provided is an analysis device capable of reducing vibration and noise generated by a stepping motor due to countermeasure for step-out of the stepping motor. A drive unit is controlled such that a set value of driving torque of the stepping motor increases stepwise in a plurality of steps each time the step-out of the stepping motor is detected by the step-out detection unit.