| 摘要 |
[Object] To perform an output control by certainly detecting a trouble of an LED lamp even in the case where a plurality of LED lamps are lighted in series.
[Means for Settlement] When a voltage between both terminals of the LED lamp 110B having a short-circuit trouble steps down and thus a second detection voltage VS2 falls below a lower limit value, a control part 5 determines that the LED lamp 110B has a trouble, and stops a power conversion part 2. In the same manner, when a voltage between both terminals of the LED lamp 110A having a disconnection trouble rises and thus a difference voltage between a first detection voltage VS 1 and the second detection voltage VS2 exceeds an upper limit value, the control part 5 determines that the LED lamp 110A has a trouble, and stops the power conversion part 2. Accordingly, an output control can be performed by certainly detecting the trouble of the LED lamps 110A and 110B even in the case where the plurality of LED lamps 110A and 110B are lighted in series. |
