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:
Aug. 31, 2010
Filed:
Dec. 19, 2006
Vijay Mangtani, Nashua, NH (US);
Nai-chi Lee, Nashua, NH (US);
Tseng-nan Tsai, Allentown, PA (US);
John Humenick, Lansdale, PA (US);
Vijay Mangtani, Nashua, NH (US);
Nai-Chi Lee, Nashua, NH (US);
Tseng-Nan Tsai, Allentown, PA (US);
John Humenick, Lansdale, PA (US);
Allegro Microsystems, Inc., Worcester, MA (US);
Abstract
A capacitor charging circuit is provided with a primary side output voltage sensing circuit including an RC network having an RC time constant with a predetermined relationship to the RC time constant of the output capacitor. Once the capacitor voltage reaches a fully charged level, the charging mode is terminated. The output voltage is continuously detected by measuring the voltage across the primary side RC network that decays at a predetermined rate with respect to the output capacitor and the charging mode is commenced once the RC voltage falls to a predetermined level. According to a further aspect of the invention, a switch control circuit in a flyback converter controls the switch off time in response to detection of a change in the slope polarity of the voltage at a terminal of the switch.