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:
Aug. 25, 2015
Filed:
Dec. 11, 2014
Yi-wei Lee, Taipei, TW;
Isaac Y. Chen, Zhubei, TW;
Tong-cheng Jao, Taichung, TW;
Chien-yang Chen, Taipei, TW;
Yi-Wei Lee, Taipei, TW;
Isaac Y. Chen, Zhubei, TW;
Tong-Cheng Jao, Taichung, TW;
Chien-Yang Chen, Taipei, TW;
RICHTEK TECHNOLOGY CORPORATION, Zhubei, Hsinchu, TW;
Abstract
The present invention provides a light emitting device power supply circuit with dimming function and a control circuit thereof. The light emitting device power supply circuit includes: a phase-cut dimming circuit, a rectifier circuit, a transformer circuit, and a control circuit. The transformer circuit includes an auxiliary winding, which is coupled to a primary winding, for generating a bleeder current to keep a conduction current higher than a holding current and prevent the phase-cut dimming circuit from turning OFF when the phase-cut dimming circuit operates in conductive phase. The control circuit includes a waveform analysis circuit, a bleeder current control circuit, and a bleeder current source. The bleeder current source includes a linear regulator or a variable current source. The bleeder current source controls the bleeder current so that the bleeder current is generated in a continuous and non-switching manner within the conductive phase.