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. 28, 2015
Filed:
Sep. 09, 2013
Panasonic Corporation, Osaka, JP;
Yoshikazu Kado, Osaka, JP;
Abstract
The LED lighting device of the present invention includes: a power supply circuit connected between a light source including a light emitting diode and a power source and including a series circuit of a switching device and an inductor; an inductor current detector configured to provide a measurement value indicative of an inductor current flowing through the inductor; a drive circuit configured to turn on the switching device at a predetermined period and turn off the switching device when the measurement value is equal to a first threshold or more; a load current detector configured to measure a load current flowing through the light source; and a protection device configured to, when the load current measured is equal to a second threshold or more, perform a protection operation of changing, to reduce the load current, a circuit constant of a power supply path in which the load current flows.