GB286317A - Improvements relating to mercury vapour lamps or quartz lamps - Google Patents

Abstract

286,317. Quarzlampen-Ges. March 4, 1927, [Convention date]. Low-pressure metallic-vapour apparatus.-Mercury-vapour quartz lamps have the pole vessels at both ends of the arc tube connected to the tube by tubular connections of smaller inner diameter than the arc tube. A direct-current lamp which can be connected either way to the supply has one pole vessel at each end of the arc tube L, Fig. 1, the pole vessels and capillary connections M being of the same size. During operation, the connection M at the cathode K is half filled with mercury and the connection M at the anode A is empty, a minute vapour chamber B forming at the anode A as shown. An alternating-current lamp has an arc tube L, Fig. 4, with a cathode K at one end and two anodes branched at the ether end, separate capillary connections A<1>, A<2> leading from the end of the tube L to the anode vessels and 'being closed by mercury at the lower ends as shown. To prevent back ignitions, each anode vessel has a condensing chamber, these chambers C<1>, C<2> being connected to the tube L by separate tubes D<1>, D<2> which are preferably straight and sloped so that mercury condensed in them flows back to the chambers C', C<2>. Anode currents passing through the tubes D<1>, D<2> during the period following ignition do not disturb the operation of the lamp. The lamps can be operated at current below 1 amp. The capillary connections prevent movement of the mercury when the lamp is tilted. The quantities of mercury in the pole-vessels are equal in the direct-current lamp and are. small in the case of the anodes of the alternating-current lamp, which is started by emptying the cathode pole-vessel.