The circuit of IR burglar alarm system comprises transmitter and receiver-cum-alarm sections. It works off 6V DC, 500mA uninterrupted supply and uses low-cost readily-available electronic components.

Class 2 circuits typically involve low-energy, low-voltage loads such as thermostats, programmable controllers, burglar alarms, and security systems. Class 2 circuits also include twisted-pair or ...

This circuit can compare the Light level in an area. It uses a PN Photodiode as the light sensor and IC CA 3140 as voltage comparator. The circuit is ideal as the front end of burglar alarm circuits.