| 摘要 |
PURPOSE: To eliminate the consumption of power after a gas discharge lamp is lit by providing a fixed device of a voltage sensitive type in a circuit with the discharge lamp and an ignitor so that relatively high impedance can be applied to a current source when the ignitor is not operated. CONSTITUTION: A starting aid is formed of two Zehner diodes ZD1, ZD2, which are located between a rectifier 12 and an ignitor 14 and connected in parallel to the ignitor 14 and with each other in series with mutually opposite polarities. When the ignitor 14 starts applying high voltage pulse to a gas discharge lamp 10, high impedance is applied to high frequency and high voltage pulse via the rectifier 12 in a return passage. As a result, starting pulse with a higher rate of power tan power consumed in a circuit excluding the gas discharge lamp 10 is given to the discharge lamp 10 and, when the gas discharge lamp 10 is started, the operation of the ignitor is stopped and the Zehner diodes ZD1, ZD2 are in a non-conductive condition. In this way, the consumption of power is eliminated after the gas discharge lamp is lit. |
