| 摘要 |
PURPOSE:To detect the temperature rise and fall of a discharge lamp at service interruption with a relatively simple structure, and automatically and surely perform the restart. CONSTITUTION:In a pulse generating circuit 26, a high voltage pulse to be applied to a high voltage discharge lamp 28 at start is generated. This high voltage pulse is superposed through a chalk coil 24, raised, and then applied to the high voltage discharge lamp 28. After starting the high voltage discharge lamp 28, the operation of the pulse generating circuit 28 is stopped by a timer circuit 22. Posisters 30, 32 are arranged on the chalk coil 24 heated according to discharge, and connected to the pulse generating circuit 28 and the timer circuit 22 so that the operations of the pulse generating circuit 28 and the timer circuit 22 are stopped by the resistances of the posisters 30, 32 at the temperature rise of the chalk coil 24 by current, and the pulse generating circuit 28 and the timer circuit 22 are normally operated by the resistances at the temperature fall, and the high voltage pulse reset at service interruption is automatically performed. |
