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:
Sep. 20, 2011
Filed:
Mar. 13, 2009
Martin Feldtkeller, Munich, DE;
Antoine Fery, Munich, DE;
Michael Herfurth, Gilching, DE;
Infineon Technologies AG, Munich, DE;
Abstract
A method detects a non-zero-voltage switching operation of a lamp ballast, the lamp ballast including a half-bridge circuit with a first and a second semiconductor switching element, 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 includes obtaining a voltage measurement signal representative of a voltage at an output of the half-bridge circuit. The method also includes providing a comparison signal representative of a comparison of the voltage measurement signal with a reference value. The method further includes evaluating the comparison signal in each case before the first semiconductor element is switched on and in each case before the second semiconductor element is switched on, and detecting one of a first and second non-zero-switching operations based on these evaluations.