| 摘要 |
PURPOSE:To reduce voltage of a power source for starting electric discharge by providing an auxiliary electrode for starting electric discharge on an outer wall of a luminous tube or an outer wall of an outer tube. CONSTITUTION:A changeover switch 11 connected with a metal vapor discharge tube so as to turn on a high tension power source 12 side of the discharge tube for starting electric discharge. The aforesaid high tension power source supplies 600V, 1A for the electric discharge tube. When high tension is supplied from a triggering power source 13 for generating high tension due to a piezo-electric element, etc., to an auxiliary electrode 14 for starting discharge wound ring-shaped around the outside of the discharge tube, xenon gas contained in the luminous tube 1 causes instantaneous discharge to be effected. Then, glow discharge is started from the power source 12 for starting discharge. When the discharge changes to arcing, a changeover switch 11 is changed over to a normally discharging power souce 10 side providing DC 200V, 1A. The changeover switch 11 uses a timer for 2 to 10sec. |
