Gas and smoke detector

Posted on Feb 26, 2013

This circuit can detect smoke and a number of gases (CO, CO2, methane, coal gas and others) with a 10 ppm sensitivity. It uses a heated surface semiconductor sensor. Detection occurs when the gas concentration increase causes a decrease of the sensor element internal resistance

Gas and smoke detector
Click here to download the full size of the above Circuit.

The switch in series with the SCR is used for resetting the alarm.

Leave Comment

characters left:

New Circuits



Popular Circuits

Digital Pressure Gauge
Simple Curve Tracer Circuit
10 led VU Meter using LM3915
Incorrect frequency from crystal oscillator
Some Voltage Regulator Ciruits for Microcontroller based Projects
sequential led bar graph circuit
A High Power Planar Triode Oscillator Designed by Using FEM Modeling
TDA8920BTH 200 watts d class amplifier circuit diagram
How I built a shortwave Armstrong FET regenerative receiver
Power Supply
30W Hybrid amplifier 01