Mitsubishi Electric Corporation

Toshiki Asai

Kohei Sato

Shunsuke Sasaki

Akihiro Tsumura

Yusuke Morimoto

Yoshiko Fujima

Shigeo Takata

Yasuhiko Wada

Junji Morimoto

A power supply control device includes: a power conversion device; a controller; a current detection device; a comparison device configured to output a shut-off start signal when a value of current detected by the current detection device is larger than a preset current threshold value; a shut-off device configured to shut off, based on a shut-off control signal, a conversion operation signal; a latch device configured to output the shut-off control signal based on the shut-off start signal output by the comparison device and to perform, until a latch release signal is input, a latch operation, in which the shut-off device is caused to maintain a state in which a conversion operation signal is shut off; and a delay device configured to output a latch release signal after a delay time elapses, the delay time being determined by components of the delay device.

Power supply shut-off control device

A motor control device includes a power converter that supplies a three-phase voltage to two motors being connected in parallel, a three-phase power line that connects between one of the two motors and the power converter, a branch three-phase power line that connects between the other of the two motors and the power converter, a switching device having two switches that are provided on the branch three-phase power line, a current detection device that detects three-phase currents flowing in the two motors, and a controller. The controller performs a failure determination of the switching device by identifying a phase of a power line in which no current flows in the three-phase power line and the branch three-phase power line, and, when a failure is detected in one of the two switches in the failure determination, controls to change a state of the other switch, which operates normally, to coincide with a state of the failed switch.

Motor control device and air-conditioning apparatus having the same

There is provided a printed circuit board in which an amount of molten solder adhering over electrodes adjacent to each other is increased in flow soldering. The printed circuit board according to the present invention includes: a first insulating substrate () having a mounting hole () that penetrates through the first insulating substrate () from a first surface () to a second surface (); a second insulating substrate () including a connection portion () that penetrates through the mounting hole () from the first surface () side and protrudes from the second surface (); first electrodes (and) that are provided on the second surface () and are arranged at an edge of the mounting hole (); and second electrodes (and) provided on the connection portion (). The first electrodes (and) and the second electrodes (and) are joined by solder. The printed circuit board further includes a coating film () that is disposed at least on a front end side of the connection portion () than a portion where the second electrodes (and) are joined to the first electrodes (and) by the solder.

Printed circuit board

A printed circuit board includes: a first insulating substrate having a mounting hole that penetrates through the first insulating substrate from a first surface to a second surface; a second insulating substrate including a connection portion; a first electrode provided on the second surface and disposed at an edge of the mounting hole; a second electrode provided on the connection portion and joined to the first electrode; and an electronic component provided on the second surface. A center of mass of the second insulating substrate is disposed on the first surface of the first insulating substrate. A center of mass of the electronic component is disposed on the second surface of the first insulating substrate. The electronic component has a weight equivalent to a weight of the second insulating substrate.

A heat exchanger unit connected to a refrigerant pipe in which refrigerant is sealed includes plural heat sources, each of the heat sources having a different amount of heat generation, and plural cooling units. Each of the cooling units cools an associated one of the heat sources. Cooling provided by each of the cooling units is different depending on amounts of heat generation of the associated heat source.

Growing community of inventors

Tokyo, Japan

Toshiki Asai