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.

This file type includes high resolution graphics and schematics. The photodiode remains the basic choice for photo-detection among solid-state detectors (Fig. 1). It is widely used in optical ...

Sensors are energy conversion devices. Sensors or transducers convert the physical world of light, pressure, temperature, flow, level, acceleration, force, etc. to electrical signals but generally ...