Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Sadayuki Tamae

Mitsuyuki Kiuchi

Hisashi Hagiwara

Shoichi Matsui

Hisayuki Imahashi

Takeru Nakamura

Masahiro Suzuki

Norimasa Kondo

Yoshiaki Sakita

Shuichi Kojima

Akihito Ohtani

A motor drive unit comprises a DC power source, a plurality of inverter circuits for converting the a power of this DC power source to an AC power, current detectors for detecting an output current of at least one of those plurality of inverter circuits and a controller for performing PWM control of those plurality of inverter circuits. This controller is constructed in a way to synchronize a PWM period of the plurality of inverter circuits, so as to drive a plurality of motors at once by means of those plurality of inverter circuits respectively.

Motor drive unit

A washing machine motor drive device drives a motor using an inverter circuit, which implements a constant torque control through a change in the torque-revolution speed characteristic of the motor. This facilitates an easy control of braking torque (negative torque), thereby providing a maximized braking torque. An easy control of regenerative energy is also provided, and back electromotive force is consumed by the internal resistance of the motor. Practically described, DC power of a rectifier circuit connected to an alternating current source is converted by an inverter circuit into AC power for driving the motor for operating an agitator or a washing/spinning tub. Motor rotor position is detected by rotor position detector, motor current is detected by current detector, and a control device controls the inverter circuit for resolving the motor current into a current component corresponding to magnetic flux and a current component corresponding to torque. At a motor braking operation, the current component corresponding to magnetic flux and the current component corresponding to torque are controlled independently. As a result, the torque at high speed revolution can be increased, or the efficiency at low speed revolution can be improved. This leads to the use a downsized and energy-conscious motor, and contributes to the prevention of an abnormal rise of DC voltage in the inverter circuit.

Washing machine motor drive device

A cloth amount detecting device in a washing machine including a process controller for controlling a process of washing, rinsing and spin-drying cloths put into the washing machine is designed to detect the amount of the cloths. If the user of the washing machine changes the level of water within the washing machine to a different water level after the amount of cloths has been detected, a reference value used to determine the amount of cloths is updated by learning in dependence on the water level so changed by the user and the number of waveforms of a drive motor, to thereby accomplish a determination faithful to the amount of cloths.

Cloth amount detector in washing machine

A control device for a washing machine, comprising: a state detecting device for detecting a state of the washing machine, which includes a soil detecting member for detecting degree of soil of liquid in a tub of the washing machine, a quantity detecting member for detecting quantity of items to be washed and a liquid level detecting member for detecting liquid level in the tub; a control unit which receives a signal from the state detecting device so as to control washing, rinsing and hydro-extracting operations of the washing machine; and an operational condition changing device for changing an operational condition of the washing machine, which can be operated by a user; the control unit including control rule data for determining periods allocated to the washing, rinsing and hydro-extracting operations, respectively such that the control rule data is changed by operating the operational condition changing device.

Control device for washing machine

Control apparatus for washing machine

The control device for a washing machine is provided to have a function of testing the working characteristic of the transmission sensing device for sensing light transmission of water filled while the water supplied in a washing bath is fresh before putting detergent therein or stirring the cloth for rinsing. The control device makes it possible to automatically test the working characteristic of the transmission sensing device and judge if abnormality takes place if the washing or rinsing operation is executed while the washing machine is in operation.

Growing community of inventors

Osaka, Japan

Sadayuki Tamae