DISCHARGE LAMP LIGHTING APPARATUS AND LIGHTING SYSTEM

摘要

PURPOSE:To keep voltage detecting work from becoming unstable and properly detect the life terminal of a discharge lamp by connecting capacitors or d.c. cut capacitors in series with a plurality of discharge lamps connected in parallel, respectively. CONSTITUTION:A discharge lamp 13 is lighted by supplying electric energy to the discharge lamp 13 through a discharge stabilizing means 12 from an electric power source 11. The lamp voltage of the discharge lamp 13 is monitored by a lamp voltage detecting means or apparatus 16 and when the discharge lamp 13 is in the life terminal stage and half-wave discharge occurs, the lamp voltage exceeds a prescribed level and the output of the lamp voltage detecting means or apparatus 16 increases and a life terminal detecting means or apparatus 17 determines that the lamp is in the life terminal stage. A controlling apparatus 18 then starts operation and lighting of the discharge lamp 13 is controlled. In the case the controlling apparatus 18 controls an electronic stabilizer, the apparatus stops the electronic stabilizer or chokes the output. Even in the case the output is choked, the driving electric power energy for the controlling means or apparatus can be supplied stably from the electronic stabilizer after the control.