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:
May. 06, 2008
Filed:
Aug. 10, 2004
Tetsuo Tanaka, Tokyo, JP;
Tarou Andou, Tokyo, JP;
Tsuyoshi Sekiguchi, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
In a direct-current voltage-driven magnetic contactor, a main contact is in an open circuit condition in an attraction period of an initial period of excitation by an operating coil, and in a closed circuit condition in a subsequent holding period, and a drive circuit includes a direct-current power supply voltage detecting circuit that gives a start signal when an applied voltage of a exciting direct-current power supply exceeds a predetermined value, a first drive circuit that makes a starting semiconductor switching element perform an ON operation on receiving the start signal, and a second drive circuit that makes a current limiting semiconductor switching element perform a switching operation when a terminal voltage of a charging capacitor reaches the predetermined value.