Matsushita Electric Works, Ltd.

Yoshihisa Ishigami

Hiromi Nishimura

Nobuhiro Kitamura

Yukihiro Murata

Kiyoshi Goto

Yoichi Kunimoto

Tetsuo Mori

Yoshinori Akinari

Tadaharu Kitado

Yasumasa Hashimota

A ground fault interrupter including a zero-phase current transformer configured to detect unbalanced current flowing in electric lines. A switch is provided in the electric lines. A detection resistor is connected in parallel to the zero-phase current transformer and configured to convert current outputted from the zero-phase current transformer to voltage. A controller is configured to determine based on the voltage of the detection resistor whether an electric leak occurs and to open the switch when the controller determines that an electric leak occurs. At least one filter is provided between the detection resistor and the controller and is configured to remove high frequency elements in the voltage of the resistor. The at least one filter includes an input side resistor connected in series to the controller and configured to limit current input to the controller; and a capacitor connected in parallel to the controller.

Ground fault interrupter

A solar battery SB for detecting the surrounding brightness is provided and a switching element SW is controlled based on output voltage of the solar battery SB. The switching element SW is made up of MOSFETs Q and Q . To form an electronic automatic on/off switch, a triac Q is controlled by turning on/off the switching element SW.

Illumination sensor with spectral sensitivity corresponding to human luminosity characteristic

A current detecting device includes high frequency oscillation detecting circuits which, when a saturable reactor oscillates at a high frequency, detect the high frequency oscillation of the reactor and generate a high level output. Thus, when a large current flows through the reactor and the magnetization characteristic of the reactor is varied to generate a normal detection output, the reactor oscillation due to the large current is detected and an operating circuit for driving an external device is energized.

Current detecting apparatus

Growing community of inventors

Tsu, Japan

Yoshihisa Ishigami