| 摘要 |
PURPOSE:To provide an electric discharge lamp lighting device, with which an electric discharge lamp can be surely lighted and a pulse is surely generated at each half-period of an AC power source at the time of starting. CONSTITUTION:The voltage of an electric discharge lamp L is detected by a lamp voltage detection circuit 13 at the time of starting the electric discharge lamp L, and a first switching means SW11 is turned on at each half-period of the voltage of a commercial AC power source E, for example, at a phase angle 60 deg., and is kept ON until the phase is reversed. A TRIAC Q11 is turned on by turning the first switching means SW11 on. The electric charge in a capacitor C12 is discharged by turning the TRIAC Q11 on, and is attenuated in oscillation by an LC at several kHz oscillation frequency, and the voltage is raised by a coil 11 and a high voltage pulse is generated to feed the high voltage pulse to the electric discharge lamp L. When a specific period of time passes, a second switching means SW12 is closed while turning the TRIAC Q11 off. The gate current of rectangular wave runs at a phase angle of 60 deg. or 110 deg. at each half-period, and the TRIAC Q11 is thus turned on. |
