| 摘要 |
PROBLEM TO BE SOLVED: To perform an operation with safety even in a state that a power supply voltage is received, at removal and attachment of an LED lamp in an LED illuminating device.SOLUTION: An LED illuminating device system comprises: a power supplying device 1 for supplying a DC power to an LED lamp; and the LED lamp physically removable and attachable from and to the power supplying device 1. The power supplying device 1 comprises: a current feedback controller having a detection resistor R3 for detecting a current flowing in the LED lamp, and comparing a current detection value of the detection resistor R3 with a predetermined reference value to perform constant current control; and a voltage feedback controller reducing a voltage of the power supply device at the time when the LED lamp is removed to a safe voltage. A semiconductor switch element M2 connected in series between the LED lamp and the detection resistor R3 is further provided. A removal state of the LED lamp is detected by a drain voltage of the semiconductor switch element M2. |
