| 摘要 |
PROBLEM TO BE SOLVED: To prevent explosion failure of a high pressure mercury lamp due to a short-circuit failure of a power supply of the high pressure mercury lamp. SOLUTION: This lamp power supply driving the high pressure mercury lamp is provided with a cutoff switch in an input side or an output side of a step-down chopper circuit, a difference between the input and output voltage of the step-down chopper circuit is detected, and when the detected input/output voltage difference is a prescribed voltage difference or less, it is determined to be the short-circuit failure and the power supply to the lamp is cut off by the cutoff switch. COPYRIGHT: (C)2004,JPO |
