Mitsubishi Denki Kabushiki Kaisha

Ichiro Arinobu

Kazuhiro Ishii

Kouji Hirotsune

Kazushi Sato

Masakatsu Suzuki

Kazuyoshi Sugihara

Hiromitsu Takahashi

Hirohisa Mizuhara

Katsuya Sakai

Koji Hirotsune

Shingo Akita

Yasuhiro Ishii

An electronic circuit breaker is provided with a plurality of air coils, each of which is coupled to a main circuit and an overcurrent signal integrating circuit which receives the output of the air coil to output an overcurrent signal when the current through the main circuit exceeds a predetermined value. A current signal simulating an overcurrent in the main circuit is fed from an external testing device into a current signal receiving terminal (CST). A test voltage generating resistor (TVGR) is connected between the CST and ground. The current signal flows through the TVGR to develop a test voltage across the TVGR. Thus, the overcurrent signal integrating circuit simulates the overcurrent signal on the basis of the test voltage.

Circuit breaker

In a multicircuit control apparatus (10) including a mechanical main contact (125) and plural semiconductor switching devices such as triacs (13a, --, 13d) each connected in series to the main contact, the main contact is closed by a control circuit 15 prior turning-on of any of the semiconductor switching devices and is also opened by the control circuit 15 after completion of turning-off of all the semiconductor devices.

Multicircuit control apparatus and control method therefor

A novel and improved control and supervisory system for power distribution equipment including a plurality of terminal control and/or supervisory devices each capable of controlling and/or supervising a plurality of power distribution devices in an extremely simple, high-speed and efficient manner without requiring any central control and/or supervisory unit. To such control and/or supervisory operation, no vast and full knowledge of permitted and inhibited operations of varying kinds of power distribution devices connected therewith, as well as of the control and supervisory procedures therefor, is required. To these ends, each of the terminal control devices comprises a control and/or supervisory instruction section operable to output a control or supervisory command for controlling or supervising a plurality of power distribution devices, and a control and/or supervisory section operable to receive the control or supervisory command from the control and/or supervisory instruction section for generating a control or supervisory signal suited to control or supervise a corresponding one of the power distribution devices, and outputting it to the corresponding power distribution device. In one embodiment, the control or supervisory command is conceptually common to the power distribution devices. In another embodiment, the control and supervisory command is intrinsic to a corresponding one of the power distribution devices. Thus, there is no need for a sender terminal device to prepare specific control and supervisory programs suited to the respective power distribution devices.

Control and supervisory system for power distribution equipment

Electronic trip relay

In a four-pole circuit breaker having U, V, W and N poles for protection of corresponding phases, only an N phase signal, which is reproduced by a current signal reproducing circuit in response to a current flowing through an N phase line, is amplified by a rated current reducing circuit and supplied to a maximum phase signal selection circuit together with other phase signals.

Four-pole circuit breaker

In a prealarm circuit breaker which can issue a prealarm signal before occurrence of trip, a pair-transistor is employed in a charging circuit of a pair of capacitors, one of which serves to make a time delay after pickup of an overcurrent and the other of which serves to make a time delay pickup of a current of prealarm level.

Prealarm circuit breaker

A tripping device with burning prevention switch has a electromagnet 10 and a burning prevention switch 14 both of which are cased in each separate insulating bodies. The electromagnet 10 and the burning prevention switch 14 are combined by engagement of projections 15, 16, provided on the burning prevention switch 14 and a hollow 12 and a hole 13, respectively, that are provided on the electromagnet 10.

Growing community of inventors

Fukuyama, Japan

Ichiro Arinobu