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:
Nov. 26, 1991
Filed:
Jan. 24, 1990
Goichi Oda, Shimizu, JP;
Masaya Shidoh, Shimizu, JP;
Atsushi Toda, Shimizu, JP;
Akiyoshi Ozaki, Shimizu, JP;
Akihiro Matsumoto, Shimizu, JP;
Soichi Yagi, Shimizu, JP;
Atsuhiko Murata, Shimizu, JP;
Koito Manufacturing Co., Ltd., Shizuoka, JP;
Abstract
A lighting circuit for a metallic halide lamp for vehicular headlight applications is disclosed. Included are a pair of input terminals between which a battery is connected for feeding the lamp via a normally open relay switch which is closed upon energization of an associated relay coil. The relay coil is connected in series with an operator actuated lamp switch and a protection switch, so that both lamp switch and protection switch must be closed to energize the relay coil and hence to close the relay switch. The protection switch is automatically opened to deenergize the relay coil when the battery develops overvoltage or when the lamp will not glow upon closure of the lamp switch. In an alternate embodiment, the protection switch is also opened in response to the development of overcurrent or overvoltage by a d.c. voltage booster circuit included in the lighting circuit.