| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a trespasser alarm device which prevents a sensor from malfunctioning and exhibits effects on birds, etc., in daytime and operates effectively to a general animal or burglar in nighttime. SOLUTION: The trespass alarm device equipped with a detection unit 2 having a light quantity sensor 5 which generates an output when the measured quantity of ambient light is larger than a set value and an infrared sensor 4 which decreases in sensitivity with the output of the light quantity sensor 5, a random signal generator 8 which operates with the output of the light quantity sensor 5 and outputs an actuation signal at irregular intervals of time, and an alarm generator 11 which generates an alarm is constituted so that it is placed in operation with at least one of the output from the infrared sensor 4 of the detection unit 2 and the output of the random signal generator 8. Consequently, the sensor is prevented from malfunctioning in daytime and the alarm is generated at irregular intervals of time to obtain effect on birds, etc.</p> |
