motion-sensor

A motion detector is an electrical device that utilizes a sensor to detect nearby motion (motion detection). Such a device is often integrated as a component of a system that automatically performs a task or alerts a user of motion in an area. They form a vital component of security, automated lighting control, home control, energy efficiency, and other useful systems. It can be achieved by either mechanical or electronic methods. When it is done by natural organisms, it is called motion perception.

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