This motion detector alarm can detect a moving person from a distance of 1 meter. It uses a dual IR Transmitter-Receiver module HOA1405. When the sensor detects the reflected IR rays, alarm will sound ...

The motion sensor switch circuit can automatically turn on a water sprinkler but you can easily use it as a motion sensor light switch or motion activated alarm too. Before beginning the construction ...

We’re still not sure exactly how [connornishijima]’s motion detector works, though many readers offered plausible explanations in the comments the last time we covered it. It works well enough, though ...

Many close-proximity motion detectors use the classic, widely available passive-infrared (PIR) approach, which is effective but has limited sensitivity and adjustability, and can’t “see” through ...