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Security and Protection

Simple Thermistor Based Fire Alarm Circuit

Last updated on 29 June 2026 by Admin-Lavi Leave a Comment

This Simple Thermistor Based Fire Alarm Circuit is very small, simple and smart, as it uses a thermistor to sense heat fast; when temperature goes high the circuit wakes up and makes loud sound. Here, this circuit uses no microcontroller or complex parts, but it uses only a few components and provides a working fire […]

Filed Under: Alarm Circuits, Heater and Temperature Controllers, Hobby Circuits, Mini Projects, Security and Protection, Sensors and Detectors

Fire Alarm Circuit using IC LM358

Last updated on 29 June 2026 by Admin-Lavi Leave a Comment

This Fire Alarm Circuit using IC LM358 is simple but smart, as it uses a 10k thermistor and LM358 IC; also it watches heat using a thermistor and makes buzzer ring when danger comes. Additionally, this circuit is cheap and is good for home, school projects and safety demos. Circuit Working: Parts List: Components Value […]

Filed Under: Alarm Circuits, Hobby Circuits, Mini Projects, Security and Protection, Sensors and Detectors

Smoke Detector Circuit using IC LM358

Last updated on 29 June 2026 by Admin-Lavi Leave a Comment

This circuit is for simple Smoke Detector Circuit using IC LM358, as it uses MQ2 gas sensor to sense smoke; also it uses LM358 IC to compare sensor voltage. Therefore, when smoke is present the buzzer and LED turn ON and, in addition, this circuit is good for beginners. Circuit Working: Parts List: Components Quantity […]

Filed Under: Alarm Circuits, Hobby Circuits, Security and Protection, Sensors and Detectors

MQ2 Gas Sensor Circuit with Arduino

Last updated on 29 June 2026 by Admin-Lavi Leave a Comment

The MQ2 Gas Sensor Circuit with Arduino is a low-cost sensor, as it can catch bad gas in air very quickly. When we connect it with Arduino, we make small gas alarm system; it reads gas level, show number on LCD and buzzer make sound when gas goes high. Also, this circuit is very simple […]

Filed Under: Alarm Circuits, Arduino Projects, Security and Protection, Sensors and Detectors

Gas Alarm Circuit using MQ Sensor and Buzzer

Last updated on 29 June 2026 by Admin-Lavi Leave a Comment

A Gas Alarm Circuit using an MQ Sensor and a buzzer gives a quick warning when the gas level becomes dangerous; also the MQ Sensor quickly detects a gas leak, and the buzzer produces a loud sound when it detects gas. Moreover, circuit runs on 5V and uses very few parts and it is good […]

Filed Under: Alarm Circuits, LED and Lamps, Security and Protection, Sensors and Detectors

Electronic Eye Circuit using IC 4049

Last updated on 29 June 2026 by Admin-Lavi Leave a Comment

This project is for small Electronic Eye Circuit using IC 4049, which can sense darkness or shadow. When light falls on the LDR, the circuit remains OFF and when an object blocks the light, the LED and buzzer turns ON; moreover, this circuit also works like a magic eye and is useful for security systems […]

Filed Under: Alarm Circuits, LDR Circuits, LED and Lamps, Mini Projects, Security and Protection, Sensors and Detectors

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