| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce cost of device itself of installation cost without requiring change of electric wiring even when it is applied to general existing housing by using an inexpensive switch by providing a single off switch for alternately switching one of two modes: auto or forcible on modes and a forcible off mode. SOLUTION: A single off switch 12 is an on-off switch, power is supplied to four devices such as illumination detector 14 and a control device 18 via an illuminaire 11 and a power circuit 20 during on operation, and power supply to such device is interrupted and forcible off mode is executed during off operation. When the single off switch 12 is off-operated from an on operation state for a given short time (0.5 to 1.5 seconds) and restored to an on operation state, power supply interruption is detected by a zero cross detection signal 16, and a control device 18 alternately switches auto and forcible on modes. When it is off operated for a time exceeding such a given short time, forcible off mode is executed.</p> |
