A stepping motor control device is configured to drive a stepping motor by applying a normal drive pulse or a fixed pulse having an energy larger than that of the normal drive pulse. The stepping motor control device includes a determination unit configured to, based on whether or not a pulse applied to the stepping motor before the normal drive pulse is the fixed pulse, determine whether or not to add a degaussing pulse is applied to the normal drive pulse, the degaussing pulse being a pulse for canceling a residual magnetic flux generated in a stator of the stepping motor when the fixed pulse; and a drive control unit configured to, based on a determination result of the determination unit, drive the stepping motor with the normal drive pulse to which the degaussing pulse is added.

A motor drive control device includes a control unit generating a control signal Sd such that one-phase excitation of exciting, of coils and of two phases of a two-phase stepping motor, a coil for one phase and two-phase excitation of exciting the coils for two phases are alternately repeated, and a drive unit driving the coils of two phases based on the control signal Sd. An energization angle θ representing a magnitude of an electric angle for continuously energizing the coil of one phase in one direction is capable of being set in the control unit. Specifically, the control unit determines a period T1n for performing the one-phase excitation based on a back electromotive voltage generated in the coil non-excited in the one-phase excitation, and determines a period T2n for performing the two-phase excitation based on an elapsed time per unit angle while the two-phase stepping motor is being excited and the energization angle θ.

The present invention relates to a method of operating a stepper motor for use in a dental tool machine (1) for removing material from a dental blank (2), the method comprising: a step of adapting torque reserves of the stepper motor at operating points to net load moments (M_net) respectively, characterized by further comprising: a first step (S1) of predicting, through simulation, the net load moments (M_net) beforehand; a second step (S2) of predicting, through simulation, the supply current (I_tr) to be supplied to the stepper motor for setting up the torque reserves that correspond to the predicted net load moments (M_net) respectively; and a step (S3) of driving the stepper motor based on the predicted supply current (I_tr).

The present invention relates to a method of operating a stepper motor for use in a dental tool machine (1) for removing material from a dental blank (2), the method comprising: a step of adapting torque reserves of the stepper motor at operating points to net load moments (M_net) respectively, characterized by further comprising: a first step (S1) of predicting, through simulation, the net load moments (M_net) beforehand; a second step (S2) of predicting, through simulation, the supply current (I_tr) to be supplied to the stepper motor for setting up the torque reserves that correspond to the predicted net load moments (M_net) respectively; and a step (S3) of driving the stepper motor based on the predicted supply current (I_tr).

A motor driving apparatus including a driving circuit for supplying a first pulse with which a first coil included in a two-phase stepping motor generates a first magnetic flux, a second pulse with which a second coil included in the stepping motor generates a second magnetic flux opposite to the first magnetic flux, a third pulse with which the first coil generates the second magnetic flux, and a fourth pulse with which the second coil generates the first magnetic flux, to the stepping motor. The driving circuit supplies the second pulse, the third pulse, and the fourth pulse in this order to the stepping motor in a state of being stopped to start the stepping motor, and supplies the first pulse, the second pulse, the third pulse, and the fourth pulse in this order to the stepping motor after starting to continuously drive the stepping motor.

A motor driving apparatus including a driving circuit for supplying a first pulse with which a first coil included in a two-phase stepping motor generates a first magnetic flux, a second pulse with which a second coil included in the stepping motor generates a second magnetic flux opposite to the first magnetic flux, a third pulse with which the first coil generates the second magnetic flux, and a fourth pulse with which the second coil generates the first magnetic flux, to the stepping motor. The driving circuit supplies the second pulse, the third pulse, and the fourth pulse in this order to the stepping motor in a state of being stopped to start the stepping motor, and supplies the first pulse, the second pulse, the third pulse, and the fourth pulse in this order to the stepping motor after starting to continuously drive the stepping motor.

The task of the present invention is to provide a driving circuit capable of outputting information useful to design or control of a system to outside. The present invention relates to a driving circuit and a driving method of a stepping motor, and an electronic machine using the driving circuit of a stepping motor. A counter electromotive force detection circuit detects a counter EMF generated in a coil. A revolution count detection circuit acquires the revolution count of the stepping motor. A load angle estimating portion calculates a load angle according to the counter EMF and the revolution count. An interface circuit is configured to be capable of outputting angle information associated with the load angle to outside, or accessing the angle information from the outside.

The task of the present invention is to provide a driving circuit capable of outputting information useful to design or control of a system to outside. The present invention relates to a driving circuit and a driving method of a stepping motor, and an electronic machine using the driving circuit of a stepping motor. A counter electromotive force detection circuit detects a counter EMF generated in a coil. A revolution count detection circuit acquires the revolution count of the stepping motor. A load angle estimating portion calculates a load angle according to the counter EMF and the revolution count. An interface circuit is configured to be capable of outputting angle information associated with the load angle to outside, or accessing the angle information from the outside.

In a motor control device, a rotational phase detection unit detects a rotational phase of a rotor of a stepping motor, and a driving waveform generation unit generates a driving waveform for driving the stepping motor. An advance angle control unit detects a phase difference (advance angle) between a rotational phase of the rotor and a phase of the driving waveform and controls an amplitude or a period of the driving waveform generated by the driving waveform generation unit to perform advance angle control. The advance angle control unit controls an amplitude of the driving waveform by determining a target advance angle based on a variation (advance angle change rate) of an advance angle with respect to a variation of an amplitude in accordance with a change in the advance angle when the amplitude of the driving waveform is changed.

In a motor control device, a rotational phase detection unit detects a rotational phase of a rotor of a stepping motor, and a driving waveform generation unit generates a driving waveform for driving the stepping motor. An advance angle control unit detects a phase difference (advance angle) between a rotational phase of the rotor and a phase of the driving waveform and controls an amplitude or a period of the driving waveform generated by the driving waveform generation unit to perform advance angle control. The advance angle control unit controls an amplitude of the driving waveform by determining a target advance angle based on a variation (advance angle change rate) of an advance angle with respect to a variation of an amplitude in accordance with a change in the advance angle when the amplitude of the driving waveform is changed.