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.
Patent No.:
Date of Patent:
Apr. 16, 2019
Filed:
Mar. 28, 2018
Fuji Electric Fa Components & Systems Co., Ltd., Tokyo, JP;
Naoyuki Matsuo, Hachioji, JP;
Akira Morita, Kokubunji, JP;
Takahiro Taguchi, Kounosu, JP;
Kosuke Ishibashi, Konosu, JP;
FUJI ELECTRIC FA COMPONENTS & SYSTEMS CO., LTD., Tokyo, JP;
Abstract
Operation coil drive device of electromagnetic contactor includes current detector and drive controller. The detector, when switching control is performed on operation coils of the contactor, detects coil current flowing through the coils. The controller controls an on/off time ratio of a semiconductor switching element wherein the on/off time ratio during close circuit control becomes larger than the on/off time ratio during holding control. Power supply voltage is switchingly applied to the coils at the on/off time ratio. The controller includes a determination locus setter and a close circuit state determiner. The setter sets a determination locus that continuously increases along a change locus of detected coil current during close circuit control. The determiner determines a contact point close circuit state by contact of a movable contact to a fixed contact based on deviation between the determination locus by the setter and the detected coil current detected.