The Lumen Maintenance Photocell (LMPC) is a sensor that’s attached to a wall that reads the amount of light in an area, and relays the information to a control unit that can make adjustments according ...
This Circuit can compare the Light level in an area. It uses a PN Photodiode as the light sensor and IC CA3140 as voltage comparator. The circuit is ideal as the front end of burglar alarm circuits.