Fire Alarm Circuit using LM358

Fire Alarm Circuit is one of the simple and cool projects in electronics it detects the fire using a thermistor and activates the alarming sound with buzzer. Fire Alarms has important practical application in industries where it is necessary to detect fire on right time and prevent damages to people or property.

Fire Alarm & Smoke Sensors are mostly used in security systems its application is not only restricted to industries but also commercial buildings, offices, movie theatres, shopping malls, and other public places.

Hardware Required

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• LM358 IC with base
• Fire Alarm Circuit PCB
• 10K Thermister
• Small Buzzer
• 10K Trimmer Pot
• 10K Resistor
• 9v Battery with clip

Useful Steps

Follow all steps carefully from the video tutorial at the end of this post (Highly Recommended).

1) Step 1: Solder LM358 IC base and place ic on it

2) Step 2: Solder Trimmer Pot & 10k Resistor

3) Step 3: Solder Thermister and Buzzer

4) Step 4: Solder Power connector

5) Step 5: Power up the Circuit & Adjust Sensitivity

Circuit Diagram