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:
Apr. 07, 2015
Filed:
Jun. 28, 2013
Virginia Tech Intellectual Properties, Inc., Blacksburg, VA (US);
Weiyi Feng, Blacksburg, VA (US);
Fred C. Lee, Blacksburg, VA (US);
Virginia Tech Intellectual Properties, Inc., Blacksburg, VA (US);
Abstract
A multi-channel constant current source particularly suitable for driving an array of light-emitting diodes as an illumination apparatus provides a power source stage voltage regulator for providing a variable voltage using pulse width modulation as an input to a plurality of constant current driver channels to regulate the constant current provided. Pulse width modulation thus allows both the power source stage and the constant current driver operating frequencies to be decoupled and individually optimized to maintain efficiency while emulating dimming effects of, for example, incandescent bulbs, over a full range of light output flux. Pulse width modulation can also be employed in the constant current channel drivers to avoid chromaticity shift during dimming.