Provided is a laundry treatment machine including a washing tub, a washing tub motor configured to rotate the washing tub, a drain pump configured to operate to drain the washing tub, a motor configured to operate the drain pump, a converter configured to output DC power, an inverter configured to convert the DC power, a dc terminal voltage detector configured to detect a dc terminal voltage output from the converter, and a controller configured to, when the dc terminal voltage continuously drops during a first period based on an operation of the inverter, perform control to turn off the inverter and operate the converter after the first period. Accordingly, it is possible to stably drive based on the dc terminal voltage during the operation of the drain pump.

The present disclosure relates to a laundry treatment machine. According to an embodiment of the present disclosure, a laundry treatment machine includes a controller controlling a motor, during dewatering, to be driven at a first speed when a lift is at a first level and to drive the motor at a second speed greater than the first speed when the lift is at a second level greater than the first level, wherein the lift is a difference between a water level of a water introduction part through which water flows into a drain pump and a water level of a water discharge part through which the water is discharged out of the drain pump. Accordingly, noise or vibration can be reduced even if the lift is changed during the dewatering.

A laundry treatment machine includes a washing tub, a washing tub motor, a water level sensor, a drain pump, a motor to operate the drain pump, a converter to output DC power, an inverter to convert the DC power into AC power, and a controller to, when power consumed by the motor during a drainage operation does not reach first power, perform control to increase a speed of the motor or the power consumed by the motor, and when the power consumed by the motor during the drainage operation reaches the first power and remains within a first range corresponding to the first power and then falls from the first range, output a drainage completion message. Accordingly, it is possible to quickly and accurately determine the completion of the operation of the drain pump. Therefore, it is possible to shorten the drainage time and reduce the waste of power.

A pump includes: a pump housing having an inflow port, a first discharge port, and a second discharge port; a pump motor for providing a rotational force; and an impeller disposed in the pump housing and configured to pump water introduced through the inflow port. A planetary gear train includes a carrier connected to a rotary shaft of the pump motor, a sun gear connected to the impeller, a pinion gear rotatably installed in the carrier and engaged with the sun gear, and a ring gear engaged with the pinion gear. A rotatable valve disc is couple with the ring gear in the pump housing, and configured to close the first discharge port and open the second discharge port in a first rotation position, and open the first discharge port and close the second discharge port in a second rotation position.

According to the present invention, a control method for a clothing treatment device comprises the steps of: transmitting a power-related order to a motor that provides electric power to a drain pump in order to perform a dehydration process; detecting a unit revolution count of the motor while the dehydration process is performed; determining whether the detected unit revolution count exceeds a preset limited revolution count; reducing the unit revolution count of the motor to a predetermined unit revolution count if the detected unit revolution count exceeds the limited revolution count; and repeatedly transmitting the power-related order to the motor.

The present invention provides a laundry treating apparatus including a drain pump having a motor, an inverter unit to transfer power to the motor, and a control unit to control the inverter unit to operate the drain pump, wherein the control unit sets an operation mode of the drain pump based on a current flowing in a part of the inverter unit, and controls the inverter unit based on the set operation mode.

A washing machine appliance includes a sump for collecting wash fluid, a drain pump for discharging the wash fluid from the sump, and a water level detection system fluidly coupled to the sump. A controller is configured for monitoring the electric current drawn by the drain pump during a drain cycle and determining that the sump is empty based on a drop in the electric current. The controller then measures the sump pressure and determines that a fault condition exists with the water level detection system when the sump is empty and the sump pressure exceeds a predetermined pressure threshold, e.g., zero pressure corresponding to an empty sump.

The present disclosure relates to a drain pump driving apparatus and a laundry treatment machine including the same. A drain pump driving apparatus according to an embodiment of the present disclosure and a laundry treatment machine including the same include: an inverter to convert an input direct current (DC) voltage into an alternating current (AC) voltage by a switching operation and to output the converted AC voltage to a drain motor; an output current detector to detect an output current flowing in the drain motor; and a controller to control the drain motor to rotate in a first direction during a first period, rotate in a second direction opposite to the first direction during a second period, and continuously rotate in the first direction when a level of the output current at rotation in the first direction is greater than a level of the output current at rotation in the second direction. Accordingly, it is possible to secure a pumping performance of the drain pump.

A laundry machine is disclosed. The disclosed laundry machine comprises: a detergent container for storing detergent; a detergent pump for discharging the stored detergent to the outside of the detergent container; a detergent detection sensor for detecting introduced detergent in the detergent pump; and a processor for determining whether there is detergent on the basis of a detection result of the detergent detection sensor, wherein, when a preset event occurs, the processor controls the detergent pump to operate for a preset time, and detects detergent after an operation of the detergent pump by using the detergent detection sensor.

The present disclosure relates to a drain pump driving apparatus and a laundry treatment machine including the same. A drain pump driving apparatus according to an embodiment of the present disclosure includes: a converter; a voltage dropper to drop the DC voltage from the converter; an inverter module to operate based on a first voltage from the voltage dropper and to output AC voltage converted by a switching operation to a drain pump motor; a controller to operate based on a second voltage from the voltage dropper and to control the inverter module; and a voltage adjuster to adjust the level of voltage information of the motor outputted from the inverter module and to output the adjusted voltage information to the controller. Accordingly, it is possible to stably drive the drain motor.