Lighting device and lighting fixture

Abstract

To reduce the possibility that overvoltage is applied from an AC power supply to a circuit subsequent to a step-down chopper circuit.SOLUTION: A lighting device 2 comprises a full-wave rectifying circuit 4, a first capacitor C1, a first conversion circuit 5, a second capacitor C2, a second conversion circuit 6, a protection circuit 9, a cut-off circuit 13, and a current suppression circuit 15. The first conversion circuit 5 lowers a pulsating voltage smoothed by the first capacitor C1. The second capacitor C2 smooths the pulsating voltage lowered by the first conversion circuit 5. The second conversion circuit 6 converts first DC voltage to second DC voltage. When a potential difference between a pair of second output terminals 52 exceeds a predetermined value, the protection circuit 9 short-circuits between the pair of second output terminals 52. When short-circuit current flows between the pair of second output terminals 52 from an AC power supply PS, the cut-off circuit 13 cuts off an electric path 14. The current suppression circuit 15 suppresses current discharge current flowing from the second capacitor C2 to the protection circuit 9.SELECTED DRAWING: Figure 8

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