| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device enhancing switching characteristics of a switching means and requiring no separate power source for a switching control circuit. SOLUTION: After a power source circuit is closed, a switching control circuit 39 is started with the voltage of starting circuits 40, 41, the start is transmitted to a pulse generation circuit 51 with a photocoupler 43, and start of a step-down chopper circuit 34 necessary to retain lighting and pulse generation for starting with a pulse generation circuit 51 are synchronized. Since a switching driving transformer to a switching means 35 is eliminated, the switching means 35 is arranged on a negative side power source line. A capacitor in the starting circuit 41 is charged by the functions of a transformer 37 also serving as a primary coil arranged in a current path of the step-down chopper circuit 34 and a rectifier diode 42 connected to a secondary coil, and the power source of the switching control circuit 39 is obtained from the capacitor 41. |
