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, 1990
Filed:
Oct. 26, 1988
Applicant:
Inventors:
Haruo Nagase, Nara, JP;
Akira Satomi, Shijounawate, JP;
Assignee:
Matsushita Electric Works, Ltd., Kadoma, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
315244 ; 315226 ; 315D / ;
Abstract
A discharge lamp driving circuit includes a chopper with a first switching circuit and an inverter with a second switching circuit. The chopper and inverter are connected to a dc voltage source and controlled to produce a composite lamp driving current composed of a high frequency alternating current interrupted by a dc current in order to keep the discharge lamp free from an acoustic resonance. The chopper and the inverter are arranged to have at least one common switching element in their first and second switching circuits.