The main principle of the circuit is to provide security using PIR sensor. This can be used in the museums to protect the valuable things and also in defense applications to detect the humans in war ...

Here is one simple circuit of a general-purpose white LED security light with Passive Infrared (PIR) Motion sensing mechanism. At the heart of the circuit is a PIR sensor module SB0061. SB0061 is a ...

This circuit is from the GLOLAB web page. The document referenced here includes an excellent design as well as an excellent tutorial on PIR devices. You've probably seen these devices in homes and ...