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:
Jun. 14, 2016
Filed:
Jan. 27, 2015
Universal Lighting Technologies, Inc., Madison, AL (US);
Universal Lighting Technologies, Inc., Madison, AL (US);
Abstract
An LED driver circuit includes circuitry for indirect sensing of an isolated output current. A rectifier circuit produces DC power to a power factor correction circuit including a switch and a primary transformer winding. An LED array is coupled to a secondary winding of the transformer. An auxiliary transformer winding is coupled to a feedback circuit which generates a feedback signal that is representative of the output current without receiving any direct feedback from the secondary side of the transformer. A capacitor may be coupled across the auxiliary winding, which charges and discharges energy as the switch is driven on and off. A controller further drives the switch based on comparison of an average voltage across the capacitor with respect to a reference value corresponding to desired output current through the load. The reference value may be provided to the controller from an external dimming control circuit.