U.S. Philips Corporation

Gijsbert Johannes Ponsen

Gustaaf A Wesselink

Hendrik Roelofs

Wilhelmus Jacobus Witteman

The invention relates to a device for operating a low-pressure sodium vapor discharge lamp without a stabilizing ballast. The lamp is provided with a discharge tube having first and second main electrodes opposing a third main electrode. An automatically operating change-over switch occasionally switches the lamp current to either the first or second electrodes. A reservoir of liquid sodium near the first electrode affects sodium vapor pressure in the discharge tube by the switching action.

Discharge lamp operating circuit

In an electric discharge tube, for example, for an argon ion laser, the cathode is formed by a double-walled tube of tantalum or tungsten, the inner tube of which is the shorter. Under the influence of the discharge in the order of 100 A, said inner tube starts glowing. An auxiliary anode may be present near the end of the cathode.

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Eindhoven, Netherlands

Gijsbert Johannes Ponsen