| 摘要 |
PURPOSE:To make momentary restarting property and wear reduction of discharge lamp electrode compatible by providing a control means for varying a power source voltage by a starting pulse generating power source according to the extinguishing time of a high voltage discharge lamp. CONSTITUTION:A predetermined time after switching in a lighting switch 10, a pulse generating relay 8 is conducted, and a high voltage is applied from a starting pulse generating high voltage power source 9 to the primary sides of pulse transformers PT1, PT2. The output voltage value of the power source 9 is varied according to the extinguishing time integrated by a time counter 11, and particularly varied so that it is linearly reduced 30 seconds after extinguished. According to this constitution, at the time of restarting just after extinguishing, a starting pulse with large energy is given to perform momentary restart, and at the time of restarting a certain time after extinguishing, arc transition can be performed with smaller energy to the extent of general start, and momentary restart and wear reduction of the electrode of a high voltage discharge lamp 6 can be made compatible. |
