Here is a Detector Circuit of Gas Leak that detects the arising of LPG gas and alerts the user through acoustic indications. The ambit operates off a 9V PP3 battery. Zener diode ZD1 is acclimated to catechumen 9V into 5V DC to drive the gas sensor module. The gas arising circuit uses the SEN-1327 gas sensor bore from RhydoLABZ. Its achievement goes top if the gas akin alcove or exceeds assertive point. A preset in the bore is acclimated to set the threshold. Interfacing with the sensor bore is done through a 4-pin SIP header.
Pin data of the gas sensor bore are apparent in Fig. 2. An MQ-6 gas sensor is acclimated in the gas sensor module. The sensor can aswell be acclimated to ascertain burnable gases, abnormally methane.
Whenever there is LPG absorption of 1000 ppm (parts per million) in the area, the OUT pin of the sensor bore goes high. This arresting drives timer IC 555, which is active as an astable multivibrator. The multivibrator basically works as a accent generator.
Output pin 3 of IC 555 is affiliated to LED1 and speaker-driver transistor SL100 through current-limiting resistors R5 and R4, respectively. LED1 glows and the anxiety sounds to active the user of gas leakage. The angle of the accent can be afflicted by capricious preset VR1. Use a acceptable heat-sink for transistor SL100.
