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:
Mar. 27, 2007
Filed:
Oct. 24, 2002
Jacob Dijkstra, Drachten, NL;
Jacob Dijkstra, Drachten, NL;
Koninklike Philips Electronics, N.V., Eindhoven, NL;
Abstract
A driver for driving a gas discharge lamp includes an inductive ballast implemented as auto-transformer having a central tap, connected between one output terminal and a first input terminal, and a triac connected between a second output terminal and a second input terminal. The central tap of the ballast is connected, via a capacitor, to the second output terminal. A control unit has a sense input for sensing the phase of an input voltage at the first input terminal, and is adapted to trigger the triac at a predetermined phase (Φ) after a zero-crossing of the input voltage, the predetermined phase (Φ) being in the range of ΔΦ+10° to ΔΦ+15°, ΔΦ being the nominal phase lag of the lamp current with respect to the input voltage.