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:
Feb. 14, 2012
Filed:
Apr. 21, 2008
Jeroen Snelten, Eindhoven, NL;
Jeroen Snelten, Eindhoven, NL;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
A self-oscillating switch circuit for amplitude modulation dimming for dimming a LED load. The self-oscillating switch circuit comprises a high-power input terminal (S) for supplying a first power to the load and a low-power input terminal (S) for supplying a second power to the load. The switch circuit further comprises a power switch semi-conductor device (Q) configured for controlling a load current from at least one of the high-power input terminal (S) and the low-power input terminal (S) to the output terminal. A control semi-conductor device (Q) is configured to control the power switch semi-conductor device (Q) in response to a sensing voltage. The sensing circuit comprises a first sensing resistor (RA) and a second sensing resistor (RB) for generating the sensing voltage such that a load current has a predetermined first peak current level corresponding to the first power, when power is supplied to the high-power input terminal, and the load current has a predetermined second peak current level corresponding to the second power when power is supplied to the low-power input terminal.