How do motion sensors work?
In: 14
Your basic motion sensor is Passive Infrared, basically it’s just looking at temperatures
They have a little IR sensor generally with a lens over it and the (fresnel) lens is designed so that something moving across it will cause abrupt jumps from high to low to high. The sensor picks up on these jumps and reports them as movement
Some use ultrasonic, basically sonar/echolocation where they send out a pulse of sound and listen to the echo. If it’s different than last time something has moved. These sensors can kind of see over/around barriers so they can be good for bathrooms
Latest Answers