Sometimes we need a non-contact liquid level sensor. There are several ways to build that, but the easiest is to try an optical liquid level sensor. You may already have an idea in mind since you are ...

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.