Abstract: A starter circuit for use with a fluorescent lamp includes an inductor coupled in series with the lamp electrodes and a semiconductor bilateral trigger, such as a Sidac, connected between the lamp electrodes. The semiconductor bilateral switch is selected to conduct electricity at a value below the instantaneous peak voltage applied and to cease conduction at a level above the operating voltage of the lamp. When the voltage reaches the predetermined level at which the semiconductor switch turns on, current is conducted through the electrode and the bilateral trigger. When the bilateral switch turns off, a large voltage pulse is generated in the inductor which voltage pulse appears at one of the lamp electrodes. A voltage potential is therefore set up across the electrodes to the lamp fixture which is grounded ionizing ionizable material, for example, mercury, within the lamp.

Abstract: A safe "phantom" lamp structure for replacing a fluorescent lamp in a two-lamp series circuit connected fluorescent fixture which permits the remaining lamp of the two-lamp fixture to operate. The structure includes, in different embodiments, one or more magnetically or thermally actuated switches which must be closed for completion of the phantom lamp circuit and the switches are closed only after connection of both ends of the phantom lamp to the appropriate fixture sockets.

Abstract: An energy saving fluorescent lamp utilizing a krypton-neon fill gas mixture and shielded electrode structures having a getter material thereon to operate at a reduced power consumption while serving as a direct replacement for another lamp, consuming a larger amount of energy, with the same ballast transformer. The getter material improves the starting characteristics of the lamps.

Abstract: An energy saving fluorescent lamp utilizing a krypton-neon fill gas mixture and shielded electrode structures to operate at a reduced power consumption while serving as a direct replacement for another lamp, consuming a larger amount of energy, with the same ballast transformer.

Abstract: An annealed tungsten filament wire for electric lamps having substantially the same amounts of impurities therein as was present prior to annealing.

Abstract: A low pressure discharge lamp, particularly a fluorescent lamp, having a plurality of separate and continuous grooves along its length each of which is formed for 360.degree. around the envelope. The groove configuration maintains a generally arcuate cross-section of varying radius to thereby alter the wall recombination rate of the plasma ions with the phosphor. In the embodiments where the cross-section of the envelope as deformed by the groove is non-circular, the invention also acts to increase the plasma arc stream length thereby changing the electrical and luminous properties of the lamp. A method and apparatus for making the grooves using a plurality of heat sources is also described.