Patent · US Expired

AC high pressure discharge lamp, especially for high current level operation

US5081396A · kind A · utility

8Cited by

9References

20Claims

0Family size

Assignee

Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbH · DE

Inventors

Johannes Schneider · Kirchlengern, DE
Bernd Lewandowski · Feldafing, DE

Key dates

Filing date	Jan 22, 1990
Grant date	Jan 14, 1992
Priority date	—
Expiry date	Jan 22, 2010

Classification

Technology area (CPC H)Electricity
CPC primaryH01J61/0732
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

To prevent the formation of melt-back slugs or granules on electrodes of h pressure, high power discharge lamps, when the lamps are operated under alternating current conditions of between about 20 to 60 A, for example, the electrodes are terminated in regions of decreasing diameter and, in accordance with the invention, comprise tungsten doped with lanthanum oxide (La.sub.2 O.sub.3) between about 0.5 to 2%, by weight, preferably about 1%. The doping intensity may increase towards the inside region of the electrode.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.