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 is performed by a drive circuit that controls a brushless motor. The brushless motor includes a rotor and a coil structure. The coil structure includes at least one coil. The circuit receives an instruction to drive the rotor in a forward direction. The circuit senses a residual direction of the rotor and a residual speed of the rotor. At least partially in response to the sensed residual direction being reverse direction which is opposite the forward direction, the circuit determines a time period as a function of the sensed residual speed, for applying a brake to the motor to slow the rotor. The brake is applied for the determined time period. After lapse of the determined time period, the circuit initiates driving the rotor to rotate in the forward direction.

A method is performed by a drive circuit that controls a brushless motor. The brushless motor includes a rotor and a coil structure. The coil structure includes at least one coil. The circuit receives an instruction to drive the rotor in a forward direction. The circuit senses a residual direction of the rotor and a residual speed of the rotor. At least partially in response to the sensed residual direction being reverse direction which is opposite the forward direction, the circuit determines a time period as a function of the sensed residual speed, for applying a brake to the motor to slow the rotor. The brake is applied for the determined time period. After lapse of the determined time period, the circuit initiates driving the rotor to rotate in the forward direction.

A handheld work apparatus having an electric motor and a drive circuit for the electric motor. The rotation movement of the motor is converted into an oscillating movement of the work tool via a gear mechanism. The motor is situated in a circuit including at least the motor and a switch for operating the motor. To reduce wear of the gear mechanism, a control unit for operating the motor in one of two directions of rotation is provided. The control unit independently determines a selected direction of rotation for a next operating cycle as a function of a control variable. When the motor is started, the motor is started by the control unit in the direction of rotation which is associated with a value of the control variable. The control variable changes before the motor is restarted for a following operating cycle.

An electric motor (10) has a stator (20) having a number S of stator poles (21, 22, 23, 24, 25, 26); a rotor (40) having a rotor magnet (40′), which rotor magnet (40′) has a number R of rotor poles (41, 42, 43, 44, 45, 46), R being equal to S, and the rotor (40) or the stator (20), or both, exhibiting a magnetic asymmetry. The asymmetry facilitates startup. The electric motor has a single-phase winding arrangement (30) with first (11), second (12) and third (13) terminals. Current can be made to flow, selectively, from either the first or the second terminal, through certain coils, to the third terminal (13). There is an output stage (50), preferably an H-bridge. The W total coils comprise a plurality of subgroups (TG1, TG2) of coils. A method for current flow through an electric motor utilizes these sub-groups (TG1, TG2) for current flow.

An electric motor (10) has a stator (20) having a number S of stator poles (21, 22, 23, 24, 25, 26); a rotor (40) having a rotor magnet (40′), which rotor magnet (40′) has a number R of rotor poles (41, 42, 43, 44, 45, 46), R being equal to S, and the rotor (40) or the stator (20), or both, exhibiting a magnetic asymmetry. The asymmetry facilitates startup. The electric motor has a single-phase winding arrangement (30) with first (11), second (12) and third (13) terminals. Current can be made to flow, selectively, from either the first or the second terminal, through certain coils, to the third terminal (13). There is an output stage (50), preferably an H-bridge. The W total coils comprise a plurality of subgroups (TG1, TG2) of coils. A method for current flow through an electric motor utilizes these sub-groups (TG1, TG2) for current flow.

A motor drive utilizes redundant current feedback to monitor force being produced by a motor and to provide safe limited force producing operation of the motor. A first set of current sensors provides a first current measurement, and a second set of current sensors provides a second current measurement. The two current measurements are provided to two diverse force producing calculations, where each force producing calculation provides a value of the force produced by the motor. The motor drive compares the output of the two algorithms to each other. If the output of the two force producing calculations is the same, within an acceptable band, the controller continues operating as commanded. If the output of the two force producing calculations differs beyond the acceptable band, then the controller may generate a fault message provided back to a central controller, stop operation of the motor, or a combination thereof.

A motor drive utilizes redundant current feedback to monitor force being produced by a motor and to provide safe limited force producing operation of the motor. A first set of current sensors provides a first current measurement, and a second set of current sensors provides a second current measurement. The two current measurements are provided to two diverse force producing calculations, where each force producing calculation provides a value of the force produced by the motor. The motor drive compares the output of the two algorithms to each other. If the output of the two force producing calculations is the same, within an acceptable band, the controller continues operating as commanded. If the output of the two force producing calculations differs beyond the acceptable band, then the controller may generate a fault message provided back to a central controller, stop operation of the motor, or a combination thereof.

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 unit comprises a motor controller, a motor, and a Hall sensor, where the motor controller is used for driving the motor. The motor controller comprises a switch circuit, a control unit, a phase signal generating unit, and an operational amplifier. The control unit generates a plurality of control signals to control the switch circuit. The motor comprises a rotor, a silicon steel plate, and a coil. To increase a success rate of starting a forward rotation, the silicon steel plate may have an asymmetrical structure, such that a fan blade is inclined to a forward rotation direction in a still state. When a Hall voltage is zero, the motor controller may start the motor and switch phases.