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Pyroelectric controlled automatic energy-saving lamps circuit

Published on Jul 22 2010 // Pyroelectric Sensor circuits

This cirucit utilizes a PIR sensor or Pyroelectric sensor as a main component. There are variety of applications for this circuit. It can be used as automatic light circuit, mainly for energy saving purposes, for security of room or home, as a light alarm, for all security purposes.

Pyroelectric controlled automatic energy-saving lamps

Let us see its working by a realistic application of this circuit. The PIR sensor should be connected in entrance to a room. When anyone enters the room, the sensor senses and sends a pulse which switches ON IC1. This immediately triggers IC2, IC3 and IC4, which inturn triggers the 555 IC. This switches the bulb ( ~220V) to ON state. The light remains ON till the sensor sense the human. After some time, the bulb goes OFF automatically. To extend the time of glowing of bulb, we have to adjust the Rp value. If the bulb is replaced by any alarm, it can be used as a burglar alarm or doorbell too.

This circuit finds its application mainly in Energy saving also. Usually people forget to switch OFF the tubes and lamps when they leave the room. But, it is no needed to take care when this circuit is installed. It automatically switches ON and OFF depending upon the presence of a person.