LIGHTING DEVICE, AND METHOD OF CONTROLLING LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a lighting device that can more accurately detect that an output voltage is an overvoltage.SOLUTION: In a first mode, a current control circuit of the lighting device controls a duty ratio corresponding to an on period per cycle of on/off switching of a switch element such that a current flowing through a first resistor becomes a desired value, and a reference voltage generation circuit of the lighting device sets a reference voltage at a first value. In a second mode, on the other hand, the current control circuit periodically and forcibly controls off the switch element for a limited period while controlling the duty ratio such that the current flowing through the first resistor becomes the desired value, and the reference voltage generation circuit sets the reference voltage at a second value lower than the first value.