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 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 motor, a driving circuit thereof and a driving method thereof are provided. The motor driving method includes: during a motor starting stage, when a detected rotor magnetic field is a first polarity and a polarity of an AC power source is positive, or the detected rotor magnetic field is a second polarity and the polarity of the AC power source is negative after a zero voltage crossing point of the AC power source, instantly sending a trigger pulse to a controllable bidirectional AC switch connected in series with a motor winding at both ends of the AC power source; during a motor operating stage, after the zero voltage crossing point of the AC power source, sending a trigger pulse to the controllable bidirectional AC switch after a delay time after the zero voltage crossing point. This method can provide a large torque during the motor starting stage.

Utilizing an asymmetric magnetic field caused by a mechanism design between a motor rotor and a stator to induce a BEMF, a method for starting a fixed rotation direction of single-phase sensorless DC brushless motor, includes: power-on starting a motor control circuit; if the motor is not in a rotating state before starting the excitation, executing a static starting procedure; then, if the motor rotation direction conforms to a predetermined direction, executing a normal driving procedure; otherwise, executing a static starting procedure. The static starting procedure, by discharging remnant energy of the motor, achieves the purpose of star-up by performing the steps of first phase excitation, stop excitation, and strong second phase excitation. In the normal driving procedure, the slope of BEMF signal of the first phase or the second phase is taken out periodically to detect the motor rotation direction.

A drive circuit for an electric motor includes a first filter, a rectifier, an inverter, and a line contactor. The first filter is configured to be coupled to an AC source and produces a filtered line frequency AC signal. The rectifier is coupled to the filter and produces a DC signal from the filtered line frequency AC signal. The inverter is coupled to the rectifier and produces an AC signal on an output node of the inverter. The AC signal is supplied to the electric motor to energize its stator windings. The line contactor is coupled between an output node of the first filter and the output node of the inverter. The line contactor supplies the output node of the inverter directly with the filtered line frequency AC signal to energize the stator windings when the inverter is disabled.

A motor device includes a motor, a motor driving control device and a position detector for outputting a position detection signal. The motor includes magnetic poles (n*6) and coils wound around teeth (n*4) where n is a positive integer. The coils are arranged in a peripheral direction such that the first-system coils and the second-system coils are alternately arranged. The motor driving control device includes a first drive circuit and a second drive circuit, each including an inverter circuit and a control circuit portion. The first drive circuit energizes the first-system coils and the second drive circuit energizes the second-system coils at an energization timing different from that of the first-system coils.

The invention utilizes an asymmetric magnetic field caused by a mechanism design between a motor rotor and a stator to induce a BEMF, and discloses a method for starting a fixed rotation direction of single-phase sensorless DC brushless motor, including: power-on starting a motor control circuit; if the motor not in the rotating state before starting the excitation, executing a static starting procedure; then, if the motor rotation direction conforming to the predetermined direction, executing a normal driving procedure; otherwise, executing a static starting procedure. The static starting procedure, after of static starting by discharging remnant energy of the motor, achieves the purpose of star-up by performing the steps of first phase excitation, stop excitation, and strong second phase excitation. In the normal driving procedure, the slopes of BEMF signal of the first phase or the second phase is taken out periodically to detect the motor rotation direction.

A method is for a machine having an alternating current (AC) power source with a first side (L1) and a second side (L2), two or more pairs of power switches, and one or more windings. The method comprises closing one pair of power switches by a control circuit to cause current to flow from a first side of the AC power source, through the one or more windings, and to the second side of the AC power source and closing another pair of power switches by the control circuit to cause current to flow from the second side of the AC power source, through the one or more windings, and to the first side of the AC power source.

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 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.