| 摘要 |
PURPOSE: To provide a discharge lamp lighting device in which a discharge lamp which is internally leaked is put out and other discharge lamps are surely lit. CONSTITUTION: When current flowing through arc tubes HID1a, HID1b of a high pressure sodium lamp HID1 exceeds a specified value, current of a specified value or more flows in a secondary winding CT1b of a current transformer CT1, and a capacitor C2 becomes specified value or more. A light emitting diode LED1 emits light, a photo-triode AC switch is turned on, current flows in a latching relay X1, an off-switch XS1 is opened, and the high pressure sodium lamp HID1 is put out. increased current causes internal leak in the arc tubes HID1a, HID1b to put out the high pressure sodium lamp HID1, and a high pressure sodium lamp HID 2 having go sbnormal current retains lighting. |
