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:
Dec. 13, 2011
Filed:
Apr. 18, 2008
Paulus Adrianus Hypolytus Jozef Huijbrechts, Eindhoven, NL;
Godfried Cornelius Gerardus Maria Manders, Eindhoven, NL;
Paulus Adrianus Hypolytus Jozef Huijbrechts, Eindhoven, NL;
Godfried Cornelius Gerardus Maria Manders, Eindhoven, NL;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
A driver apparatus () for driving a gas discharge lamp (L) comprises a commutator circuit () having a bridge topology with four switches (T-T) controlled by a controller (), with an inductor (L) arranged in series with the lamp and a capacitor (C) arranged in parallel with the lamp, the inductor (L) and the capacitor (C) having a parallel resonance frequency f. In a steady-state mode, the controller drives the four switches (T-T) at a relatively low commutation frequency of the order of 100 Hz. For igniting the lamp when it is still hot, the controller drives the four switches (T-T) at a first ignition frequency f=f/n, nbeing an odd integer. For igniting the lamp when it is cold, the controller drives the four switches (T-T) at a second ignition frequency f=f/n, nbeing an odd integer larger than n