U.S. Philips Corporation

Jan De Ridder

Germain R T'Jampens

Bertus De Vrijer

Leonard C Eijkelenboom

Rolf E De Man

Leo M Sprengers

Friedrich Hermann Almer

Jozef I Peeters

An arrangement including a frequency converter (4) and a discharge lamp (10) connected thereto wherein the frequency converter (4) is of a type whose output frequency is at least 80 kHz, while the lamp is a low-pressure sodium vapor discharge lamp. This lamp supply system provides a high luminous efficacy for the lamp.

Arrangement including a metal vapor discharge tube provided with at

In the electric incandescent lamps having an infrared radiation-reflecting filter which is pervious to visible light, the efficiency can be increased by adapting the geometry of the filter and the geometry of the filament to each other. According to the invention, the filter comprises a major portion of a prolate ellipsoid of revolution and a cylindrical filament extends between the foci thereof, the distance between focal points being from 1-2 times the length of the filament.

Electric incandescent lamp

In a two-pinch halogen lamp having an axial filament and an envelope diameter of less than 3.5 mm the envelope diameter is chosen as a function of the envelope and filament temperature, the coil diameter and the filling pressure.

Gas-filled electric incandescent lamp having a cylindrical envelope and

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Eindhoven, Netherlands

Jan De Ridder