The first generation of burglar alarms was a switch-type alarm that prevented theft of broken doors, which were installed on doors and windows.
The second generation of burglar alarms are glass break alarms and vibrating alarms installed indoors.
The third generation of burglar alarms are space movement alarms (such as ultrasonic, microwave, passive infrared alarms, etc.). The characteristics of this type of alarm are: as long as the space of the alarm is moved, it will cause an alarm. These anti-theft alarm systems have developed rapidly in alarm detectors.
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