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Fire Alarm Circuit using Transistor

In this amazing article we are going to make a fir alarm circuit. A Fire Alarm System is a device that makes a loud sound to warn people when there is a fire. In this project we have design a Simple and inexpensive fire alarm circuit by using a transistor BC547 and an IR receiver sensor. This Fire circuit alert through buzzer sound whenever any kind of fire detected in the air or an environment. It can detect any kind of fire such as radiation, heat, etc. Depending on the types of sensor that matches an application is selected. In the market, most of the circuits are expensive and difficult to buy. An Infrared Light sensor, on the contrary, is sensitive and very easy to use.

Block Diagram of Fire alarm circuit

Components Required for fir alarm circuit

The list of necessary components items required for Fire Alarm Circuit:

Infrared IR LED
LED for Indication any color
Transistor c945 or any NPN
Buzzer
3.7V Battery
Breadboard if needed
some peace of wires for connections

Fire alarm circuit diagram

The circuit diagram of this device is given below.

Fir Alarm circuit Diagram for 9v

You can operate this circuit by suing 9 to 12v battery with a slight change in the circuit. We have to use only 1 resistor with LED because LED will burn without a resistor if we use more than 6 volts.

Working Explanation

The working of fire alarm circuit is very easy. An IR sensor is an electronic device that is used to detect infrared radiation falling on it. The heart of the fire alarm circuit is an infrared receiver and infrared transmitter. In default operating conditions when infrared light is shining from the infrared transmitter it will have low impedance. So the voltage at the base will be very low and the transistor will remain in off position. In case when a fire is detected by the infrared beam will not be able to pass to a receiver. The resistance of the receiver rises and the voltage at the base will become positive and the transistor turns on. Buzzer and LED are connected with the transistor will also be on.

Application

Some important applications of Fire Alert circuit are as follows

Industries
Hospitals
Banks
Homes
Security departments

Advantages

Some advantages of fire alarm system are given below

Early Fire Detection
Decreased Risk of Fire Damage
Discounts on Insurance
Home Fire & Life Safety

Classes of Fire Alarm

There are total seven classes of fire alarm system. These classes don’t show how to wire anything, these classes show what happens when things go wrong.