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1. (WO2001033917) ELECTRONIC BALLAST CIRCUIT

Pub. No.:    WO/2001/033917    International Application No.:    PCT/EP2000/010009
Publication Date: Fri May 11 01:59:59 CEST 2001 International Filing Date: Wed Oct 11 01:59:59 CEST 2000
IPC: H02M 5/458
H05B 41/28
H05B 41/282
H05B 41/288
Applicants: KONINKLIJKE PHILIPS ELECTRONICS N.V.
Inventors: SHEN, Eric
BRUNING, Gert
Title: ELECTRONIC BALLAST CIRCUIT
Abstract:
An electronic ballast circuit for driving a gas discharge lamp from a mains voltage signal supply includes a ballast bridge unit that has an upper and lower signal line. A storage capacitor is coupled across the bridge unit. The bridge unit also includes an input converter bridge having at least two switches coupled in series at an input common terminal, wherein the upper switch is coupled to the upper signal line of the ballast bridge unit and the lower switch is coupled to the lower signal line. The ballast bridge also includes an output converter bridge having at least two switches coupled in series at an output common terminal. A reference voltage signal bridge in the ballast bridge unit includes at least two switches coupled in series at a reference voltage common terminal, so as to form a first differential voltage signal between the common input terminal and the reference voltage common terminal and a second differential voltage signal between the common output terminal and the reference voltage common terminal.