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:
Mar. 17, 2015
Filed:
Mar. 27, 2013
O2micro, Inc., Santa Clara, CA (US);
Xinhe Su, Sichuan, CN;
Xiang Geng, Sichuan, CN;
O2Micro, Inc., Santa Clara, CA (US);
Abstract
A circuit for powering a LED light source includes a converter and a controller. The converter provides an output voltage, and includes a first switch which is turned on and off alternately according to a driving signal to control a current. The controller generates the driving signal which is a periodic signal having a first state and a second state per time period. The first switch is turned on when the driving signal operates in the first state, and is turned off when the driving signal operates in the second state. The controller modulates a time period of the driving signal and a time duration of the first state, such that a quotient of the time duration squared and the time period is substantially independent of a change of the time period, and the current is substantially independent of the change.