DANGERS OF INFLAMMABLE GASES LEAKING
Some of the inflammable Gases are not toxic. But they are extremely flammable and will cause an explosion; it will also kill you by asphyxiation if it leaks into an enclosed space and deprives you of oxygen. In case of methane it only becomes poisonous when it forms part of another gas and is subject to certain circumstances. The bad news is that this happens quite often.
Don’t worry…. Here is a solution for detecting the inflammable gas leakage. The circuit uses a gas sensor which can detect the presence of LPG, Propane, Methane and Hydrogen also other combustible streams.
|MY CIRCUIT PROTOTYPE|
SEMICONDUCTOR SENSOR FOR COMBUSTIBLE GAS
Sensitive material of MQ-2 gas sensor is SnO2, which with lower conductivity in clean air. When the target combustible gas exist, the sensor’s conductivity is higher along with the gas concentration rising. These electronic circuit converts the change of conductivity to correspond output signal of gas concentration. MQ-2 gas sensor has high sensitivity to LPG, Propane and Hydrogen, also could be used to Methane and other combustible steam, it is with low cost and suitable for different application.
BASIC TEST LOOP
The Op-amp HT17358 is designed in a comparator mode which compares the signal received from the sensor to a threshold value. When the input increases by threshold value the output of comparator goes high which drives the transistor and thereby the LED. This invokes the oscillator circuit for generating Alarm. The circuit for oscillator is designed using the Schmitt trigger IC CD 40106. That drives the Buzzer to produce alarm.
Also the relay is driven by the output of the transistor BC547. Which makes the external water pump to run and pump water in case of fire ignition or connects to another indicator or warning system which depends upon application of the circuit in different situations.
CIRCUIT DIAGRAM OF POWER SUPPLY
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