Last Updated on May 4, 2022 by 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.
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.
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.
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.
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
Video tutorial & testing
Circuit diagram of fire alarm system
Spacial connection diagram
