A carriage apparatus characterized by comprising a carriage configured to reciprocally move in a predetermined direction, a first motor arranged on a side of one end of a range of movement of the carriage and configured to drive the carriage, a second motor arranged on a side of the other end of the range of movement of the carriage, configured to drive the carriage, and has the same kind of driving characteristics as driving characteristics of the first motor, detection means for detecting a position of the carriage related to the predetermined direction, and control means for controlling driving of the first motor and the second motor by feeding back a detection result detected by the detection means.

An electronic expansion valve (EEV) controller allows a user to drive the stepper motor of EEVs. Thus, the EEVs toggle between an open position or a closed position. The EEV controller includes a housing, a portable power supply, a motor driver printed circuit board (PCB), a power switch, a directional switch, and a motor connector. The housing is used to protect and hold in place the motor driver PCB, the portable power supply, the power switch, the directional switch, and the motor connector. The portable power supply is used to provide electrical energy to the motor driver PCB and to the stepper motor of EEVs through the motor connector. The power switch allows a user to manually turn on or off the EEV controller and the stepper motor. The directional switch is used to toggle the stepper motor between a clockwise rotation or a counter-clockwise rotation.

Provided are a method and system for controlling an electric motor, and a controller. The method comprises: controlling an electric motor to operate in an open-loop manner; determining whether a rotational speed of the electric motor reaches a preset rotational speed; if so, determining whether the absolute value of an angle difference between an open-loop angle and a calculated position angle of the electric motor is greater than a preset angle; and if the absolute value of the angle difference is less than or equal to the preset angle, controlling the electric motor to operate in a closed-loop manner so as to avoid the situation where the electric motor cannot operate stably due to problems such as electric motor speed vibration caused by too large an angle difference between the open-loop angle and the position angle.

Provided are a method and system for controlling an electric motor, and a controller. The method comprises: controlling an electric motor to operate in an open-loop manner; determining whether a rotational speed of the electric motor reaches a preset rotational speed; if so, determining whether the absolute value of an angle difference between an open-loop angle and a calculated position angle of the electric motor is greater than a preset angle; and if the absolute value of the angle difference is less than or equal to the preset angle, controlling the electric motor to operate in a closed-loop manner so as to avoid the situation where the electric motor cannot operate stably due to problems such as electric motor speed vibration caused by too large an angle difference between the open-loop angle and the position angle.

A motor drive control device has a controller and a driver. The controller generates a control signal for controlling driving of a two-phase stepping motor so as to alternately repeat one-phase excitation in which a coil of one phase in coils of two phases of the two-phase stepping motor is excited and two-phase excitation in which the coils of two phases in the coils of the two phases are excited. The driver drives the coils of the two phases, based on the control signal. The controller determines, based on a back electromotive force generated in the coil that was not excited during the one-phase excitation, a period of performing the one-phase excitation, and determines, based on the period of the one-phase excitation performed before the two-phase excitation, a period of performing the two-phase excitation.

A novel technology for detecting an absolute position of a target object by using Hall elements is provided.

A magnetic detection unit (2) includes two Hall elements (a first Hall element H1 and a second Hall element H2). The Hall elements are connected in series to each other on an input side of each of the Hall elements.

A motor drive control device has a controller and a driver. The controller generates a control signal for controlling driving of a two-phase stepping motor so as to alternately repeat one-phase excitation in which a coil of one phase in coils of two phases of the two-phase stepping motor is excited and two-phase excitation in which the coils of two phases in the coils of the two phases are excited. The driver drives the coils of the two phases, based on the control signal. The controller determines, based on a back electromotive force generated in the coil that was not excited during the one-phase excitation, a period of performing the one-phase excitation, and determines, based on the period of the one-phase excitation performed before the two-phase excitation, a period of performing the two-phase excitation.

An image forming apparatus is provided. The image forming apparatus includes an engine unit to be used for performing an image forming job, a motor to start the engine unit, a driver circuit to sense a current flowing in the motor and supply the motor with a power source, and a processor to determine a load size of the motor based on the sensed current and control a driving speed of the motor based on the determined load size.

A rotation speed of a motor is estimated based on a current value of the motor, and rotation control on the motor is performed at a first cycle. Processing for detecting a loss of synchronism in the motor based on the current value is performed at a second cycle that is shorter than the first cycle.

A rotation speed of a motor is estimated based on a current value of the motor, and rotation control on the motor is performed at a first cycle. Processing for detecting a loss of synchronism in the motor based on the current value is performed at a second cycle that is shorter than the first cycle.