How to make a fire alarm project – Technoreview85

It is an easy fire alarm system using IC LM358 & an IR Diode. this is a low cost fire alarm circuit which can detect flames and make loud sounds. It has a LED indicator. You can control its sensitivity using a potentiometer which is used in this circuit. The circuit diagram & all details are in this article so you can make this fire sensor mini project easy.

fire alarm
fire alarm

Working of this fire alarm circuit

The IR diode can detect execs light (flame) Appearing in front of it. The IR diode is connected to Op-amp ic LM 358 input pin (3). When the fire is detected the IR diode gives some positive voltage to the IC input pin. Then the Out pin of IC which is pin 1 becomes high. The buzzer & led is connected to ic pin 1 so The buzzer & LED turn on.

working fire alarm
working fire alarm

What is an operational amplifier

An operational amplifier or op-amp is an integrated circuit. It has two inputs. One of them is called an inverted pin which is marked as (-) negative sign and another is called non-inverted pin which is marked (+) positive sign. It has one output pin.

Op-Amp
Op-Amp

Its basic work is to amplify and output the voltage difference between the two input pins.

Ic lm358 has two op-amps.it is a dual op-amp IC.

Application of fire alarm circuit

A fire alarm system is very useful for detecting & preventing a big disaster.

It can be used for schools, labs, offices, homes & industrial purposes. It can prevent the loss of lives & properties.

It can be used as a temporary fire alarm system for construction sites.

how to make fire alarm less sensitive

You can adjust the sensitivity of this fire alarm using the 10K potentiometer. Please look into the circuit diagram.

fire alarm adjustment
fire alarm adjustment

can we make fire alarm

Yes, you can make this fire alarm at home. You need a minimum knowledge of electronics and the following components.

You need to make

Perfboard

LED

Photodiode / IR Receiver

Potentiometer 10K

9V battery

IC LM 358 & IC Base

Active Buzzer

Resistor 1K 2pcs & 2.2K

photo diode
photo diode

Video tutorial & testing

Circuit diagram of fire alarm system

circuit diagram fire alarm
circuit diagram fire alarm

Spacial connection diagram

fire alarm project circuit diagram
fire alarm project circuit diagram

Another fire alarm circuit using a heat sensor

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