| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply device capable of preventing erroneous determination of ground fault and a lighting device for a vehicle using the power supply device.SOLUTION: The power supply device includes: a DC power circuit 1 that outputs a DC power; and a ground fault determination circuit 2 that determines a ground fault occurring at the downstream side of the DC power circuit 1. The ground fault determination circuit 2 includes: a capacitor C2 one end of which is connected to the ground; and a diode D21 the anode of which is connected to the other end of the capacitor C2, and the cathode thereof is connected to the output end at the high voltage side of the DC power circuit 1. The ground fault determination circuit 2 further includes a comparator CP as determination part that determines a ground fault occurs when a constant voltage source 20 for charging the capacitor C2 with a predetermined charging voltage and the voltage Vc at both ends of the capacitor C2 are lower than a predetermined determination reference voltage Vr lower than the charging voltage. Compared to a case where output voltage from a DC power circuit is directly compared with a reference voltage to determine the occurrence of a ground fault, erroneous determination is prevented. |
