General Electric Company

Robert G Frey

Charles I McVey

An improved high pressure sodium vapor lamp is described having resistance heater means contained within a tubular light-transmitting ceramic envelope that further contains a reservoir of sodium-mercury amalgam in excess of the quantity vaporized during lamp operation and which are supplied by electric current other than the lamp current responsive to a rise in the lamp operating voltage to reduce the quantity of amalgam being vaporized during lamp operation to help maintain said lamp operation at a relatively constant voltage. In a preferred embodiment, said resistance heater means comprises a refractory metal coil wound around the tungsten shank at one thermionic electrode and electrically insulated therefrom, with said thermionic electrode including a tubular metal inlead serving as the amalgam reservoir, and with the electric current being supplied at a lower value to said refractory metal coil than being supplied to said thermionic electrode.

High pressure sodium vapor lamp having resistance heater means

An improved high pressure sodium vapor lamp is described having resistance heater means contained within a tubular light-transmitting ceramic envelope that further contains a reservoir of sodium-mercury amalgam in excess of the quantity vaporized during lamp operation in order to heat the ceramic envelope before lamp starting and thereby reduce the starting voltage requirements. In the preferred embodiment, said resistance heater means comprises a refractory metal coil wound around the tungsten shank of one thermionic electrode and electrically insulated therefrom and which is supplied with lower current than is subsequently applied to said electrodes for the lamp operation.

An improved high pressure sodium vapor lamp is described having resistance heater means contained within a tubular light-transmitting ceramic envelope that further contains a reservoir of sodium-mercury amalgam in excess of the quantity vaporized during lamp operation in order to increase the quantity of amalgam being vaporized during lamp operation and thereby help maintain the desired lamp color temperature. In a preferred embodiment, said resistance heater means comprises a refractory metal coil wound around the tungsten shank of one thermionic electrode and electrically insulated therefrom with said thermionic electrode including a tubular metal inlead serving as the amalgam reservoir.

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Strongsville, OH, United States of America

Robert G Frey