U.S. Philips Corporation

Auke G Van Der Kooi

Johannes A Van Vliet

Antonius Johannes Van Stratum

Johan B Van Overveld

The invention relates to starting and supplying a low-pressure discharge lamp which comprises two electrodes between which a main discharge path is formed, a shunt path being electrically in parallel with at least a portion of said main discharge path. In accordance with the invention the lamp is started by means of a glow-discharge starter which is shunted by a VDR the threshold voltage of which is lower than a value determined by the geometry of the shunt path, and is higher than the minimum voltage for starting a discharge in the main discharge path. The discharge then only starts in the main discharge path.

Electric arrangement for starting and supplying a low-pressure discharge

The invention relates to a compact low-pressure mercury vapor discharge lamp consisting of a glass inner member which is closely surrounded by a glass cylindrical outer member, one end of which is hemispherical. The edge at the other end of the outer member is sealed in a gas-tight manner to the inner member. The discharge path between the electrodes may be folded as shown. The discharge is present in a groove, formed in the wall of one of the members. Near the said sealed edge there is an amalgam which is accessible to the discharge space via a narrow channel.

Low-pressure mercury vapor discharge lamp with mercury amalgam

Low-pressure mercury vapor discharge lamp having in the discharge vessel a vapor pressure-controlling mercury amalgam which is secured to the inner surface of a wall of a container which is provided with an opening to the discharge vessel. Such securing reduces the risk that small portions of the amalgam might become dislodged by vibration or shock and escape from the container into the discharge vessel. The amalgam is secured to the container wall by fusion thereto by means of an intermediate 'wetting' agent formed by a thin layer of nickel.

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Eindhoven, Netherlands

Auke G Van Der Kooi