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:
Jul. 02, 1985
Filed:
May. 02, 1983
Rudolf L van der Heijden, Eindhoven, NL;
Jan W Dorleijn, Roosendaal, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
The invention relates to a high-pressure sodium lamp provided with an elongate discharge vessel in which the pressure P in the operative condition of the lamp is at least 170.times.10.sup.3 Pa. The lamp is suitable to be operated with a power of periodically alternating value, which power comprises at least one component having a frequency .nu..sub.i which satisfies i-0.45.ltoreq.2.35.nu..sub.i Le/e.ltoreq.i+0.45 where i is an integral positive number, c is the speed of sound in the gaseous part of the filling and L.sub.e is the effective length of the discharge vessel. According to the invention, the relation is satisfied: M.nu..sub.i .multidot.f.sub.i .multidot.P.multidot.d .ltoreq.185, in which M.nu..sub.i is the modulation depth of the power component having a frequency .nu..sub.i, f.sub.i is a geometric lamp factor and d the average inner diameter of the discharge vessel. In this manner, the operation of the lamp is free of arc instabilities due to longitudinal acoustic resonances.