| 摘要 |
PURPOSE:To improve convenience by lighting off a discharge lamp in an abnormal condition to protect circuits, while maintaining a lighting condition of a normal discharge lamp, when one of the two discharge lamps falls into the abnormal condition such as a no-load condition or emitter consumed condition. CONSTITUTION:A discharge lamp DL1 is connected to one end of a balancer T3, and a discharge lamp DL2 is connected to the other end of the balancer T3, so the discharge lamps DL1, DL2 are lighted in parallel. Detection means KT1, KT2 to detect abnormal conditions of the discharge lamps DL1, DL2 separately are provided, a switching means SW1 to disconnect feed to the discharge lamp DL1 only is provided, a switching means SW2 to disconnect feed to the discharge lamp DL2 only is provided, and a switch control means SC1 to open the switching means SW1 in response to an output of the detection means KT1, and open the switching means SW2 in response to an output of the detection means KT2 is provided. |
