How Does a Motion Detector Light Work?

A motion detector light is a great way to both be on the lookout for people outside of your home and to ward off potential intruders. Motion detector lights automatically turn themselves off after a certain amount of time passes. Motion detecting lights use one of several types of sensors to detect movement. Among the signals they emit are microwaves, ultrasonic waves, radar and infrared waves. 

How Motion Detecting Lights Work

A motion detector light beams a signal out onto a particular area, usually a driveway, yard or near an entrance. When an object moves through that signal, the object reflects the signal back to the sensor, which then controls a light by means of a pulse. This process takes less than a second. 

Types of Motion Detecting Lights

A motion detector light may use ultrasonic waves, microwaves, radar or infrared sensors to detect movement. Ultrasonic detectors send sound waves while infrared motion detectors uses the presence of body heat as its indicator. Microwave and radar detectors use electromagnetic waves that reflect off of passing objects and measure the distance between the sensor and the object. 

By detecting the movement of passing objects in one manner or another, a motion detector light accurately gauges the proximity of nearby people and triggers a light in the process.