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:
Dec. 22, 2020
Filed:
Apr. 08, 2019
Lumileds Llc, San Jose, CA (US);
Yifeng Qiu, San Jose, CA (US);
Jeroen Den Breejen, San Jose, CA (US);
Lumileds LLC, San Jose, CA (US);
Abstract
A control circuit for a light emitting diode (LED) lighting system for achieving a dim-to-warm effect is provided. The control circuit includes an LED controller, a clamp circuit coupled to a set of warm correlated-color-temperature ('CCT') LEDs, a switch coupled to a set of cool LEDs, and a feedback circuit coupled to the clamp and the switch. The LED controller is configured to control the clamp circuit to clamp current through the set of warm LEDs based on the input current, and control the switch to switch on the set of cool LEDs responsive to the input current being greater than a first threshold level and to switch off the set of cool LEDs responsive to the input current being lower than the first threshold level. The feedback circuit is configured to divert current from the set of warm LEDs to the set of cool LEDs.