A motor drive control device capable of determining a drive state of a motor is provided. The motor drive control device includes a plurality of motor drive circuits performing, based on drive control signals (Sca1 and Sca2) for controlling the number of rotations of a motor, control of energization of the motor and outputting FG signals (fg1 and fg2) having a cycle corresponding to the actual number of rotations of the motor, a composite signal generation circuit receiving an input of each of the FG signals output from the motor drive circuits and generating a composite signal by combining input signals, and a drive control circuit generating, based on a speed command signal indicating a target number of rotations of the motor, the drive control signals and outputting the drive control signals to each of the motor drive circuits. The FG signals output from the motor drive circuits have a phase difference from each other.

A method for driving a single-phase electric motor includes switching drive electronics to a first on-state during a first on-time interval of a pulse width modulation period, switching the drive electronics to a second on-state during a second on-time interval of the pulse width modulation period, switching the drive electronics to an off-state between the first and second on-time intervals, and measuring the phase current with a current sensor. The first and the second on-time interval of one pulse width modulation period are provided with different interval lengths if a defined effective duty cycle is lower than a first duty cycle threshold value so that one of the first and the second on-time interval has an interval length which is equal to or larger than a defined minimum on-time interval length. The phase current is measured during the first and/or second on-time interval with the defined minimum on-time interval length.

A system is for a machine having an alternating current (AC) power source with a first side and a second side, one or more windings, an AC polarity detector, a Hall effect device, two or more pairs of power switches, and a motor controller. The motor controller determines which of the power switches to open or close to obtain a direction of current flow through the one or more windings based on signals from the AC polarity detector and the Hall effect device.

A drain pump for an appliance includes a single, self-starting, single-phase synchronous motor and a pump chamber having an inlet and first and second outlets. The first outlet is a drain outlet and the second outlet is a recirculation outlet. An impeller is disposed within the pump chamber and is selectively and bi-directionally driven by the single-phase synchronous motor. Rotation of the impeller in a first direction directs fluid from the inlet toward the drain outlet and away from the recirculation outlet. Rotation of the impeller in the second direction directs the fluid from the inlet toward the recirculation outlet and away from the drain outlet.

A method for starting a drive motor. The drive motor includes a motor stator with stator coils and a motor rotor, and a control electronics system and a power electronics system which supply power to the stator coils with a predefined coil voltage and a predefined constant start-up rotation frequency to generate a rotating field to drive the motor rotor. The method includes supplying power to at least one stator coil with a coil voltage corresponding to a start value, increasing the coil voltage in steps, monitoring an electric current flowing through the power electronics system, and, when a specific minimum voltage drop is detected, terminating the increasing of the coil voltage in steps, and performing a safety increase of the coil voltage by increasing a start-up voltage value by a predefined safety value to a first operating voltage value where the motor rotor is drivable in an unregulated mode.

A method and circuit for controlling or starting a U-shape single phase synchronous permanent magnetic motor (U-SPSPM motor) having a rotor and a stator and coupled to a single phase alternating current (AC) power source through a switch, including estimating back electromotive force (back-EMF) of the motor based on an observer model with inputs indicative of the measured signals, and triggering the switch to supply power to the motor based on the estimates of the back-EMF.

A method for controlling a single coil BLDC motor having an electrical time constant, the method includes EHP sequences having a pulse train with at least two driving pulses of a same polarity, each driving pulse comprises: applying a driving signal during a torque generating period (TGP), followed by a non-torque generating period (NTGP); monitoring the phase current, wherein the sensing window lasts at least during a time constant, which is the electrical time constant or an approximation thereof, if the sensing window is during the TGP, and wherein the sensing window minimally lasts until the phase current has reduced to less than half the maximum phase current which was generated during the TGP if the sensing window is during the NTGP; determining parameters for the ongoing EHP, and/or for at least one next EHP sequence based on the obtained phase current information.

A single-strand EC motor with a winding strand with two winding connections, has a current regulating device in the winding strands between the winding connections. The current regulating device regulates the winding current of the single-strand EC motor during a first commutation phase with a positive current flow and a second commutation phase with a negative current flow. In each case, at a constant value. The value of the average output voltage uw(t) of the current regulator is used to ascertain the commutation time.

A method for starting a sensorless single-phase electric motor. The electric motor includes a permanent magnetic motor rotor, an electromagnetic motor stator having a stator coil, a power electronics which energizes the stator coil, a current sensor which measures a current flowing in the stator coil, and a control electronics which controls the power electronics. The control electronics is connected with the current sensor. The method includes energizing the stator coil with an alternating drive voltage, monitoring a drive current which is generated in the stator coil by the alternating drive voltage, and commutating the alternating drive voltage whenever the drive current reaches a predefined positive current threshold value or a predefined negative current threshold value.

The present disclosure provides a single phase motor driving circuit which includes a stator winding, a control unit, a controllable bidirectional AC switch, and two power input terminals configured to connect an AC power source. The stator winding includes a first winding and a second winding. The parallel-connected first winding and second winding and the controllable bidirectional AC switch are connected in series between the two power input terminals. The control unit is connected to a control electrode of the controllable bidirectional AC switch, to control the controllable bidirectional AC switch to be switched on and off. The present disclosure further provides a driving method for the single phase motor driving circuit. The single phase motor driving circuit and the driving method thereof has better reliability while ensuring sufficient starting torque.