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. 14, 1999
Filed:
Sep. 06, 1996
Louis R Nerone, Brecksville, OH (US);
Gordon A Grigor, Cleveland Heights, OH (US);
Kurt W Haas, Chesterland, OH (US);
General Electric Company, Schenectady, NY (US);
Abstract
A ballast circuit for a gas discharge lamp comprises a resonant load circuit incorporating the gas discharge lamp and including a resonant inductance and a resonant capacitance. A d.c.-to-a.c. converter circuit induces an a.c. current in the resonant load circuit. The converter circuit comprises first and second switches serially connected between a bus conductor at a d.c. voltage and a reference conductor, and which are connected together at a common node through which the a.c. load current flows. A voltage-breakover (VBO) device is effectively connected between the common node and a second node. A network is provided for setting the voltage of the second node with respect to the common node at less than the breakover voltage of the VBO device when the lamp is operating at steady state. A polarity-determining impedance is connected between the common node and one of the bus conductor and the reference conductor, to set the initial polarity of pulse to be generated upon the firing of the VBO device.