摘要 |
Equipment for lighting a work area has a plurality of light sources, at least one of which is usually lighted; the others are spare light sources and are usually turned off. The equipment has means such as an optical fiber to conduct light from the light source to the work area. Converting means is provided with the equipment to distribute electric power selectively to the light sources. Detecting means is also installed in the equipment to detect cutting off of the light source which is in the lighted condition. The converting means changes the distribution of the output from the power supply to a light source other than the light source which was cut off.
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