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. 27, 1977
Filed:
Mar. 19, 1976
Applicant:
Inventors:
Jan Evert van der Werf, Eindhoven, NL;
Jean Johan Heuvelmans, Eindhoven, NL;
Hendricus Franciscus VAN Tongeren, Eindhoven, NL;
Assignee:
U.S. Philips Corporation, New York, NY (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H05B / ; H05B / ;
U.S. Cl.
CPC ...
315106 ; 315 98 ; 315107 ; 315260 ; 315307 ; 315334 ; 315D / ; 315D / ;
Abstract
A device for operating a low-pressure sodium vapor discharge lamp without a ballast. The electrode voltage drop near a main electrode of the sodium lamp is influenced by a change in the pre-heating current of that electrode and/or a change in the effective area of the electrode. The changed electrode voltage drop thus obtained provides a mechanism whereby any changes in the lamp current are opposed so as to produce ballast-free lamp operation.