Hitachi, Ltd.

Minoru Kobayashi

Kenichi Iizuka

Hideo Uzuhashi

Yoshihisa Uneyama

Ryoichi Fujimoto

Morio Kobayashi

Michiya Matuda

A refrigerator temperature control system is disclosed in which the compressor for compressing a refrigerant is driven selectively at either a normal lower rotation speed or a higher rotational speed and the higher rotational speed is applied only when any of the freezer compartment temperature and the fresh food compartment temperature is not reduced below a predetermined temperature level for at least a predetermined time interval.

Refrigerator temperature control system

The present invention continuously speed-controls an electric motor for driving a compressor for refrigerant compression such that the compressor is driven in its maximum rpm if the difference (temperature deviation) between a target cooling temperature and an actual temperature is greater than a first predetermined value, the compressor is stopped if the temperature deviation is less than a second predetermined value, and the compressor is speed-controlled by a digital control signal if the temperature deviation is between said first and second predetermined values.

System of controlling refrigerator temperature

A novel refrigerator control system is disclosed which comprises an inverter for driving a motor for a compressor, and a change-over device for driving the compressor directly with a commercial power supply when the compressor motor is not driven by the inverter.

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Tochigi, Japan

Minoru Kobayashi