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. 18, 1997
Filed:
Dec. 29, 1994
Peter Wood, Rolling Hills Est., CA (US);
International Rectifier Corporation, El Segundo, CA (US);
Abstract
A circuit and method for driving a load such as a gas discharge illumination device from an ac main supply with a high power factor. The circuit includes a pair of electronic switches arranged in a half bridge configuration and a self oscillating driver circuit having two outputs for driving respective ones of the electronic switches, the electronic switches being coupled across a dc bus voltage and having a switched output coupled to the load. The circuit further includes a voltage regulator circuit coupled across the dc bus voltage and coupled to the self oscillating driver circuit, the voltage regulator circuit maintaining the dc bus voltage within a preset range and preventing the dc bus voltage from exceeding the range if the load is removed or becomes an open circuit. The voltage regulator preferably is a boost regulator switching an inductance. The circuit is particularly suitable for driving gas discharge illumination devices, e.g., fluorescent lamps, at a high power factor with minimum instability of the dc bus.