| 摘要 |
PURPOSE:To reduce the loss during the stationary lighting of a discharge lamp by by-passing a high voltage pulse generating circuit with a relay switch just after starting the discharge. CONSTITUTION:When a discharge starting switch 51 is switched on a capacitor 54 for generation of a primary high voltage is charged up, and when the charged voltage exceeds the break-over voltage of a thyristor 55, the capacitor 54 is discharged so as that the voltage is applied to a transformer 56 generating a primary high voltage pulse. Then the induced voltage is applied to a capacitor 60 through a rectifier 59. When the charged voltage of the capacitor 60 exceeds the break-over voltage of a spark gap 61, the discharge current of the said capacitor is flowed in a transformer 39 generating a secondary high voltage pulse to light a discharge lamp 34. When the discharge is started as described above, the thyristor 55 is cut off and the generation of the high voltage pulse is stopped. Then a Zener diode 44 is cut off by the voltage drop in a stabilizer coil 38 for current control and a relay coil 45 is demagnetized to switch on a relay switch 47. Therefore the loss during the stationary lighting of the lamp can be reduced. |
