Kabushiki Kaisha Toyota Jidoshokki

Nissan Motor Company Limited

Yoshiaki Ishihara

Seiki Sakata

Yasuharu Odachi

Kazuki Najima

Yasuhiro Koike

Tomotaka Kurozu

Hajime Satoh

Kazuji Yamazaki

Naoto Kikuchi

Masayuki Fukuda

Yoshitoshi Watanabe

Yuichi Noge

Shuhei Aoyama

A power conversion device includes two lower arm switching elements connected in parallel to each other and a lower arm driver circuit that drives the two lower arm switching elements. The two lower arm switching elements respectively include gate terminals and detection terminals used to detect counter-electromotive forces. The power conversion device includes a common connection line that connects the two detection terminals to each other and connects the two detection terminals to an addition circuit of the lower arm driver circuit. A combined electromotive force is transmitted via the common connection line.

Power conversion device

A noise filter disclosed herein is configured to suppress a common mode voltage that is generated in cables connected to an electric power converter. The noise filter includes: detecting capacitors connected to the cables, respectively, and configured to detect the common mode voltage; an operational amplifier having a positive input terminal via which the common mode voltage detected by the detecting capacitors is inputted; an emitter follower circuit having an input terminal connected to an output terminal of the operational amplifier and having an output terminal connected to a negative input terminal of the operational amplifier; and a transformer configured to apply a compensating voltage to each of the cables by applying a voltage at the output terminal of the emitter follower circuit to each of the cables in opposite phase.

Noise filter

An inverter includes a plurality of transistors, generates a 3-phase AC voltage, and supplies it to a 3-phase AC motor. The voltage on the primary side of a transformer connected to the neutral point of the 3-phase AC motor is controlled by changing the phase difference of a drive signal of each phase supplied to the inverter through a phase difference circuit. Thus, the output voltage of the transformer can be set to a desired value by a power supply circuit with a simple configuration.

Power supply apparatus

A charging apparatus for charging batteries of automobiles includes an inverter for converting the direct current from a direct current power source into an alternating current and a transformer having a first coil and a second coil. When an alternating current from the inverter is applied to the first coil, the second coil produces an alternating voltage. A capacitor is connected between the terminals of the second coil to increase the alternating voltage produced in the second coil. A rectifier circuit rectifies the alternating voltage increased in the booster circuit into a direct current voltage and the direct current voltage is applied to the battery. Two transistors, which function as a short circuit, are provided in the rectifier circuit. When the direct current voltage from the rectifier circuit is equal to or higher than a predetermined permissible value, a drive signal from a drive circuit turns on the two transistors. Then, the terminals of the second coil are short-circuited and the voltage applied to the terminals instantaneously turns null. This protects the elements forming the charging apparatus from high voltage.

Battery charger with monitor and protection circuits

Growing community of inventors

Kariya, Japan

Yoshiaki Ishihara