| 摘要 |
<p>PROBLEM TO BE SOLVED: To facilitate change in sensitivity by providing a switch operated by the movement of a movable part provided at a part of the housing of a theft preventive detector and varying the sensitivity of the theft preventive detector by the operation of this switch. SOLUTION: A theft preventive detector 1 is a detector having a pyroelectric element detecting infrared rays and is equipped with a body 10 and a cover 11, which has at least its end part 11 made upwardly movable with respect to the body 10; when the cover 11 is pushed up, the end part 11a also moves up. The switch 13 consisting of a microswitch on the reverse surface of a printed board 12 is provided right above this end part 11a, and when a constructor pushes the cover 11 up by using a rod, etc., the top surface of the end part 11a of the cover 11 pushes up the lever 13L of the switch 13, so that the switch 13 operates. The printed board 12 is provided with a light emitting diode 15 which illuminates each time the sensitivity is varied. Thus, the sensitivity can be increased through the operation of the switch 13.</p> |
