| 摘要 |
PROBLEM TO BE SOLVED: To achieve power saving, and to prevent breakage of an LED element due to overcurrent.SOLUTION: A lighting device 1 for an LED illumination device supplies DC power to an LED unit 3. A lighting circuit of the lighting device 1 includes a step-up chopper circuit 11, and an overvoltage protection circuit 12 connected to the step-up chopper circuit 11. The overvoltage protection circuit is composed of a Zener diode which is a passive element. Even when an output voltage of the step-up chopper circuit 11 exceeds a prescribed value, the overvoltage protection circuit 12 suppresses the output voltage thereof so as to become a prescribed output voltage of the step-up chopper circuit 11. |
