| 摘要 |
PROBLEM TO BE SOLVED: To secure power supply for a control circuit in a lighting device for intermittently supplying a high pulse voltage to a discharge lamp in a non- loaded state by a chopper operation even when a pulse voltage is suspended with load. SOLUTION: The discharge lamp La is connected via a DC power supply circuit 1 such as a power factor improving chopper and a lighting circuit 2 for power control to an AC power supply Vs. When the discharge lamp La is not lighted, an ignitor circuit IG intermittently applies the high tension pulsed voltage to the discharge lamp La. When the discharge lamp La is not lighted due to the output from a lighting judging circuit 4, a resistance R0 is connected to the output end of the DC power supply 1, causing a current to flow in an inductor L1 for chopper, thereby charging a capacitor C3 of a control power supply circuit 3 through the secondary winding thereof. COPYRIGHT: (C)2003,JPO |
