Panasonic Intellectual Property Management Co., Ltd.

Takashi Shirakawa

Kenji Hanamura

Shogo Hirota

Takeshi Saeki

Takanori Yamamoto

For power transfer from a first DC part to a second DC part in a dual active bridge (DAB) converter by stepping down a voltage, a first bridge circuit includes a period in which the first DC part and a primary winding of an insulated transformer conduct and a period in which ends of a primary winding of the insulated transformer are short-circuited in the first bridge circuit. A second bridge circuit includes a rectification period. A control circuit variably controls a phase difference between a first leg a the second leg, variably controls a simultaneous off period of a fifth switching element and a sixth switching element, and variably controls a simultaneous off period of a seventh switching element and an eighth switching element.

Power conversion device

For power transfer from a first DC part to a second DC part in a dual active bridge (DAB) converter by stepping up a voltage, the second bridge circuit includes a period in which a secondary winding of an insulated transformer and the second DC part conduct and a period in which ends of the secondary winding of the insulated transformer are short-circuited in the second bridge circuit. A control circuit fixes a phase difference between a first leg a the second leg, variably controls a simultaneous off period of a fifth switching element and a sixth switching element, and variably controls a simultaneous off period of a seventh switching element and an eighth switching element.

The present invention provides an electronic device that can operate as long as possible even if the battery level is low and that can avoid an unexpected shutdown as much of the time as possible while data is being transmitted to, or received from, an external device. The electronic device has a particular mode of operation in which the electronic device is connected to an external device and can accept a request to read and/or write information sent by the external device. The electronic device includes: a battery; an interface, which is connected to the external device so as to get power from the external device and which accepts the request sent by the external device; and a control section for changing conditions for enabling that particular mode of operation according to a supply value, which is at least one of the values of current and voltage supplied by the external device, and a value representing a level of the battery.

Growing community of inventors

Ehime, Japan

Takashi Shirakawa