Mitsubishi Electric Corporation

Tomoyuki Kamiyama

Tsuyoshi Sekiguchi

Kazunori Hatakeyama

Kazuki Takahashi

Yuji Takayama

Megumi Takemoto

Haruka Matsuo

Katsutoshi Ikarashi

Kunihiro Satou

Takuya Furuyama

Masami Yorita

Kenichirou Suzuki

Takanobu Kondo

Sadaaki Baba

A motor drive device includes a single-phase inverter that converts a direct-current voltage into an alternating-current voltage applied to a motor. The motor drive device includes a control power supply outputting power having a voltage lower than the direct-current voltage. The motor drive device includes a drive signal generation unit driven by the power. The drive signal generation unit generates drive signals driving switching elements of the inverter. The motor drive device includes a power supply switch operating so as to allow supply of the power from the control power supply to the drive signal generation unit when a rotation speed of the motor is higher than a threshold. The power supply switch operates so as to stop the supply of the power from the control power supply to the drive signal generation unit when the rotation speed is lower than the threshold.

Motor drive device, electric blower, electric vacuum cleaner, and hand dryer

A coil drive device energizes an operation coil to close an electromagnetic contactor. A rectifier outputs, to a power supply line, an input voltage obtained by full-wave rectification of an AC voltage supplied from a main power source. A controller controls on and off of a switching element connected to a power supply line in series with the operation coil. The controller controls a duty ratio that is an on period ratio of the switching element in each switching period in accordance with a value of a parameter calculated from a detected value of the input voltage, in at least a partial period after start of energization of the operation coil in response to a close command for the electromagnetic contactor.

Electromagnetic contactor

A radiofrequency contactor includes a testing circuit board having a dielectric substrate, a lower ground conductor on a lower surface of the dielectric substrate, and a radiofrequency signal wiring conductor on an upper surface of the dielectric substrate, a radiofrequency signal pin contactor located on the upper surface of the dielectric substrate and connected to the radiofrequency signal wiring conductor, a ground block located on the upper surface of the dielectric substrate and spaced apart from the radiofrequency signal wiring conductor and the radiofrequency signal pin contactor, and a first side ground conductor and a second side ground conductor provided on the upper surface of the dielectric substrate and spaced apart from the radiofrequency signal wiring conductor and the radiofrequency signal pin contactor.

Radiofrequency contactor

A magnetic circuit includes a stationary iron core, a permanent magnet, and an armature, in a circular pattern. A contact mechanism spring separates the armature from the stationary iron core to open the magnetic circuit to switch a contact mechanism to a reset position. A coil on the magnetic circuit generates a magnetic flux in a direction same as that of the permanent magnet when an overload is detected and in an opposite direction when a predetermined time is elapsed after detecting the overload. A reset bar switches a movable stopper between an engaging position and a non-engaging position with the contact mechanism against a biasing force of the contact mechanism spring.

Electronic overload relay

A test jig is for testing electrical characteristics of a high frequency semiconductor device in a package having a ground electrode and a high frequency signal electrode. The test jig includes a test circuit substrate with a microstrip line structure, a grounding block and a high frequency signal contact pin. The test circuit substrate includes an insulating substrate, a ground conductor on a bottom surface of the insulating substrate and high frequency signal wiring on a top surface of the insulating substrate. The grounding block is disposed on the top surface of the insulating substrate and connected to the ground conductor. The high frequency signal contact pin is disposed on the top surface of the insulating substrate and connected to the high frequency signal wiring. The high frequency signal contact pin is spaced from the grounding block.

Test jig for testing a packaged high frequency semiconductor device

An overload relay, which trips a current flow between a power source and a load, includes a trip capacitor that stores therein an electric charge to excite a trip coil so as to trip the current flow, a reset capacitor that stores therein an electric charge to excite a reset coil so as to reset the tripped current flow, an energizing unit that energizes the coils, and a capacitor-diagnosing unit that diagnoses the capacitors. The energizing unit forcibly energizes the trip coil by using the trip charge when the capacitor-diagnosing unit diagnoses that there is a degradation of a property of the trip capacitor.

Growing community of inventors

Tokyo, Japan

Tomoyuki Kamiyama