Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Tsuyoshi Sekiguchi

Tomoyuki Kamiyama

Tetsuo Tanaka

Kyoichi Yamamoto

Tarou Andou

Sadaaki Baba

Kenichirou Suzuki

Fumihiro Takimura

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

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.

Overload relay and operating method thereof

In a direct-current voltage-driven magnetic contactor, a main contact is in an open circuit condition in an attraction period of an initial period of excitation by an operating coil, and in a closed circuit condition in a subsequent holding period, and a drive circuit includes a direct-current power supply voltage detecting circuit that gives a start signal when an applied voltage of a exciting direct-current power supply exceeds a predetermined value, a first drive circuit that makes a starting semiconductor switching element perform an ON operation on receiving the start signal, and a second drive circuit that makes a current limiting semiconductor switching element perform a switching operation when a terminal voltage of a charging capacitor reaches the predetermined value.

Drive circuit of direct-current voltage-driven magnetic contactor and power converter

A terminal cover for electrical equipment has two pieces of substantially U-shaped elastic engaging piece section each with an outer edge thereof integrally connected to the terminal cover and the other edge in the inner side thereof coupled to that of the other one with a bridging piece section provided therein, counter claw sections are formed on the two pieces of elastic engaging piece section respectively, and the terminal cover is fixed to a frame of equipment by engaging the counter claw sections in recesses for engagement formed on the frame of the equipment respectively.

Growing community of inventors

Tokyo, Japan

Tsuyoshi Sekiguchi