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:
Oct. 08, 2019
Filed:
May. 26, 2017
Panasonic Intellectual Property Management Co., Ltd., Osaka, JP;
Kazuhiko Harada, Hyogo, JP;
Akira Nakajo, Kyoto, JP;
Abstract
The lighting device includes a power conversion circuit and a control circuit. The power conversion circuit includes a high voltage side output terminal and a low voltage side output terminal to be connected to a light source, and a step-down chopper circuit. The control circuit performs a lighting operation of controlling the power conversion circuit to develop a DC output voltage between the high voltage side output terminal and the low voltage side output terminal. The control circuit starts a protective operation of limiting a current to be supplied to the light source when the output voltage is equal to or higher than a threshold value. The threshold value is in a range of 1.2 to 1.3 times a rated voltage of the light source.