IN-VEHICLE DISCHARGE LAMP LIGHTING DEVICE AND VEHICULAR HEADLIGHT DEVICE

摘要

PROBLEM TO BE SOLVED: To eliminate erroneous determination in which the life of a halogen lamp is always determined to be expired when the lamp is displaced with a discharge lamp in a vehicle having a disconnection detecting circuit for the lamp. SOLUTION: A discharge lamp lighting device comprises a high-pressure pulse generation circuit 1; a step-up/step-down convertor 2; an invertor 3; and a control circuit 6 for controlling the convertor 2 and the invertor 3 based on outputs from a lamp current detecting circuit 4 and a lamp voltage detecting circuit 5. The lighting device provided with a power supply voltage detecting circuit 7 for detecting a power supply voltage; an opening/closing device for applying the power supply voltage to a serial circuit of a resistor 2 and a switching device Q8; and a opening/closing control circuit for turning on the opening/closing device in a state that the power supply voltage is low and turning off the opening/closing device in a state that the power supply voltage is high. COPYRIGHT: (C)2005,JPO&NCIPI