Fuji Electrochemical Co., Ltd.

Noboru Kato

Fumiaki Nakao

Toshihiro Shimizu

Hideji Matsuura

Masami Nonaka

Shinichiro Umemura

Kazuhiro Hibi

A rectified ac voltage which is not smoothed is compared with a reference voltage directly, and a pulse is generated when the instantaneous value of the rectified ac voltage exceeds the reference voltage. Based on the pulse generation, a judgement is performed on whether the ac voltage is reaching a predetermined value or not. These operations allow the abnormality of the ac voltage to be rapidly detected with improved accuracy.

Method for detecting input AC voltage

In an automatic voltage switching power source having a full-wave rectifier circuit and a voltage doubler circuit, a controller comprises a plurality of voltage level detectors which are associated with an input ac voltage and detect different voltages, and a switching signal generator which generates a delayed signal for switching between the full-wave rectifier and voltage doubler circuits based on the logical product of the outputs of the voltage level detectors, thereby preventing the electric circuit of the power source and the electric device to be supplied with the power from being damaged by excessively high voltages.

Dual input voltage power source for selectively switching between

An electronic circuit module having a magnetic base plate, a plurality of coils wound on the magnetic base plate, a circuit pattern formed on the surface of the magnetic base plate, a circuit component connected to the circuit pattern, and a plurality of lead pins mounted on the magnetic base plate for connecting external circuits. The magnetic base plate has projections along one side of it and the coils are wound on the projections.

Electronic circuit module

A noise filter for an electric wire of star-connected three-phase four-wire system, in which a neutral conductor has a sectional area which is larger than a sectional area of each of voltage conductors. Three voltage conductors are wound on a magnetic core that constitutes a closed magnetic path. The neutral conductor is coupled to the three voltage conductors via three respective capacitors.

Growing community of inventors

Shizuoka, Japan

Noboru Kato