The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Apr. 03, 2007

Filed:

Jun. 21, 2004
Applicants:

Hitoshi Komori, Motosu, JP;

Hideki Shimizu, Motosu, JP;

Kazuhifo Kobayashi, Motosu, JP;

Yoshihiro Matsui, Motosu, JP;

Inventors:

Hitoshi Komori, Motosu, JP;

Hideki Shimizu, Motosu, JP;

Kazuhifo Kobayashi, Motosu, JP;

Yoshihiro Matsui, Motosu, JP;

Assignee:

Lecip Corporation, Gifu, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02H 3/00 (2006.01); H02H 7/122 (2006.01); H01F 17/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

An arrangement is made in a transformer such that voltages induced on the opposite sides of a mid-pointof a secondary windingare unbalanced by an amount on the order of 5%. When a ground terminalis not grounded while a mid-point of a load is grounded, a voltage Vis developed between the mid-pointand a non-active line terminaland is rectified to provide a rectified output which turns a transistoron, causing a light emitting elementL to emit light. The resulting light renders a light receiving elementP conductive, whereby a relayis operated to turn a switchoff. When a ground fault occurs on one side of the secondary windingwhile the ground terminalis not grounded, a ground fault detection circuitfails to detect the ground fault, but the non-grounding protection circuitdetects the ground fault and turns the switchoff.


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