Recently, I exhausted my stock of common passive infrared (PIR) motion sensor modules and was looking for a new one to play with. I searched the web for a small type with self-contained electronics.

(Passive InfraRed sensor) A device used to detect motion by receiving infrared radiation. When a person walks past the sensor, it detects a rapid change of infrared energy and sends a signal. PIR ...

This is a simple update to Mr. Hareendran’s PIR Sensor Security Light circuit. It has a shortcoming limits the relay voltage to approximately 3.3V. While this may function with some 5V relays, it will ...