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:
Nov. 25, 2014
Filed:
Mar. 01, 2011
Peter Johannes Wilhelmus Vankan, Eindhoven, NL;
Wai Pang Chow, Eindhoven, NL;
Johannes Theodorus Jacobus Van Haastrecht, Eindhoven, NL;
Peter Johannes Wilhelmus Vankan, Eindhoven, NL;
Wai Pang Chow, Eindhoven, NL;
Johannes Theodorus Jacobus Van Haastrecht, Eindhoven, NL;
Koninklijke Philips N.V., Eindhoven, NL;
Abstract
A method for operating a fluorescent lamp () having a nominal power (WLa) and stabilized with an EM ballast (B) comprises the steps of during normal operation, short-circuiting the lamp during a closing time interval (CTI) during each current period in order to operate the lamp at a reduced power. The method comprises the step of detecting whether the lamp is stabilized by means of an inductive ballast or by means of a capacitive ballast. If it is found that the ballast is capacitive, the timing of the closing time interval (CTI) is set such that the closing time interval (CTI) has a first closing time segment (CTS) immediately before a zero-crossing of the current, having a first duration (Δ) higher than zero, and a second closing time segment (CTS) immediately after said zero-crossing of the current, having a second duration (Δ) higher than zero.