| 摘要 |
PURPOSE:To certainly detect occurrence of burglary, so as to improve burglary prevention performance by watching temperature rise rate per unit time, much greater than that due to outside air temperature, that due to insolation or the like, caused by destruction of a cylinder by means of a drill. CONSTITUTION:A door outer casing 20 is equipped with a key cylinder 10 and formed in order to detect its temperature by a temperature sensor 12 on the outer peripheral part and to send it as a temperature signal THS to a microcomputer 14 for watching any temperature rise rate. In this case, the set value is made not to be exceeded by temperature rise of ordinary outside air temperature or insolation in order not to raise an alarm. Then, occurrence of temperature rise rate, which exceeds the set value for abnormal temperature rise in a short time, caused cutting heat caused by drilling a hole in the key cylinder 10 by means of an electric drill for burglary, is recognized by the microcomputer 14, so that an alarm command is sent to an alarm device 16. And, buzzer sound is raised in order to conquer a thief and to announce burglary occurrence, so that burglary can be prevented. |
