This circuit uses a PIR sensor to detect human motion. When motion happens, PIR output goes high. This high signal turns ON an LED through a resistor. Simple PIR Motion Detector Circuit is easy to make and works with 12V supply. Circuit Working: Parts List: Part Name Value Quantity Resistors 220Ω 1/4 watt 1 Semiconductors […]
Sensors and Detectors
Simple Thermistor Based Fire Alarm Circuit
This Simple Thermistor Based Fire Alarm Circuit is very small, simple and smart. It uses a thermistor to sense heat fast. When temperature goes high the circuit wakes up and makes loud sound. No microcontroller, no complex parts. Only few components and we get a working fire alert that anyone can build at home Circuit […]
Fire Alarm Circuit using IC LM358
This Fire Alarm Circuit using IC LM358 is simple but smart. It uses a 10k thermistor and LM358 IC. It watches heat using a thermistor and makes buzzer ring when danger comes. This circuit is cheap and is good for home, school projects and safety demos. Circuit Working: Parts List: Component Value / Type Resistors […]
Smoke Detector Circuit using IC LM358
This circuit is for simple Smoke Detector Circuit using IC LM358. It uses MQ2 gas sensor to sense smoke. It uses LM358 IC to compare sensor voltage. When smoke is present the buzzer and LED turn ON. This circuit is good for beginners. Circuit Working: Parts List: Component Quantity Resistors 10k 1/4 watt 1 100Ω […]
MQ2 Gas Sensor Circuit with Arduino
The MQ2 Gas Sensor Circuit with Arduino is a low-cost sensor. 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. This circuit is very simple to make […]
Gas Alarm Circuit using MQ Sensor and Buzzer
A Gas Alarm Circuit using MQ Sensor and Buzzer gives quick warning when gas level becomes dangerous. MQ Sensor senses gas leak fast and buzzer makes loud sound when gas is found. Circuit runs on 5V and uses very few parts. It is good for low-cost safety at home, kitchen and workplace. Circuit Working: Parts […]