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:
Feb. 19, 2013
Filed:
Sep. 12, 2011
Martin Feldtkeller, Munich, DE;
Antoine Fery, Munich, DE;
Michael Herfurth, Gilching, DE;
Infineon Technologies AG, Munich, DE;
Abstract
A method for use in a lamp ballast includes obtaining a measurement signal representative of a voltage at an output of a half-bridge circuit. The half-bridge circuit includes first and second semiconductor switching elements, a resonant circuit connected to the half-bridge circuit, and a snubber capacitance connected in parallel with one of the semiconductor switching elements. The method also includes providing a comparison signal by comparing the measurement signal with a reference value. The method further includes detecting one of a first type of non-zero-voltage switching operation and a second type of non-zero-voltage switching operation based on evaluations of the comparison signal, wherein the evaluations of the comparison signal occurs in each case before the first semiconductor element is switched on and in each case before the second semiconductor element is switched on.