This circuit shows how to use an ordinary LED as a light sensor. It makes use of the photovoltaic voltage developed across the LED when it is exposed to light. LEDs are cheaper than photodiodes and ...

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.

NEW DELHI: If you are fascinated by the LED sensor lights, then you must be tempted to use them in your home. But, before adopting this technology for your home, you need to gather up all the relevant ...