Hitachi, Ltd.

Toru Inoue

Yukio Kawabata

Yuhachi Takakura

Makoto Ishii

Tsunehiro Endo

Toru Watanabe

Yasuo Notohara

Yoshiharu Yamashita

Yuzo Nishinaka

Kiyoshi Nagasawa

Hiroo Nakamura

Susumu Kashiwazaki

Hiroshi Shinozaki

Kouji Katou

Shinji Nishi

Motoo Morimoto

Jun Nishikawa

Shoji Takaku

There is provided a digital broadcasting receiver apparatus in which a temperature in the area surrounding a removable HDD does not become a high temperature during an operation regardless of whether it is disposed horizontally or vertically. A component with a large heat generating quantity and a component with a small heat generating quantity are installed in respective spaces inside a case. An adapter of the removable HDD is mounted to dispose the removable HDD in a space in which a component with a small heat generating quantity is mounted, thereby preventing the temperature in the area surrounding the removable HDD from becoming a high temperature.

Receiver apparatus

After the rotor position has been fixed prior to the start of a motor, the driving mode can be rapidly switched to sensorless driving and the motor can be started and controlled, by conducting current conversions in such a power supply pattern that increases the starting output torque of the motor, and controlling the inverter output voltage.

Starting control method of and control apparatus for synchronous motor, and air conditioner, refrigerator, washing machine and vacuum cleaner each provided with the control apparatus

For achieving an air conditioner being applicable to various a-c source voltages in common and operative with high power factor by suppressing generation of high harmonics, an a-c source voltage from an a-c electric power source 1 is rectified in full-wave by a rectifier 2, and a d-c source voltage Ed of an inverter 13 is obtained by being charged in a condenser 5. Here, there are a-c source voltages of 100 V and 200 V, and a divided voltage Ed1 of the d-c voltage of the condenser 5 is selected when the a-c source voltage is 100 V, a divided voltage Ed2 (here, Ed1&gt;Ed1) of the d-c voltage of the condenser 5 is selected when the a-c source voltage is 200 V, respectively by an exchange switch 18, and is used as a d-c voltage Ed' for controlling on and off of a switch element 6. Though the d-c source voltage Ed differs depending on the a-c source voltage of 100 V or 200 V, it is possible to set the d-c source voltage Ed at a voltage value for operating the inverter 13 with low loss and high efficiency, for each one of the a-c source voltages, by setting a ratio of the voltage division appropriately.

Air conditioner

A control system for brushless DC motors detects counter electromotive force voltages induced in motor windings and produces rotor position detection signals from the counter electromotive force voltages. The maximum value of an input DC current to a motor drive circuit is held and the phase of the rotor position detection signals is changed in accordance with the held value of the input DC current to prevent the phase of the position detection signals from varying with the load on the brushless DC motor.

Control system for brushless DC motor

Growing community of inventors

Yokohama, Japan

Toru Inoue