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:
Jul. 17, 2012
Filed:
Feb. 08, 2010
Patrizio Vinciarelli, Boston, MA (US);
Patrizio Vinciarelli, Boston, MA (US);
VI Chip, Inc., Andover, MA (US);
Abstract
A method and apparatus for efficiently converting power from an AC line is disclosed. The power converter supplies power to the load, performing power factor correction at nominal and high loads, i.e. above a predetermined output power threshold, and operating in an on-demand burst mode at low loads, i.e. below a predetermined output power threshold, e.g. to supply power in a green mode to supervisory circuitry during a powered off state. The duration of an operating interval during which power conversion takes place may be reduced and varied at low loads as a function of the output power demands to increase overall conversion efficiency. The operating interval may be centered about a peak in the input voltage waveshape for operating intervals that are less than a full rectification period. For operating intervals that are less than a full rectification period a modified power factor correction may be used, in which the input current waveshape approximates the input voltage waveshape during the operating interval.