Synopsis

LPG gas is supplied in pressurized steel cylinders. As this

gas is heavier than air, when it leaks from a cylinder it

flows along floor and tends to settle in low spots such as a

basement. This can cause fire or suffocation if not dealt

with. Here is a circuit that detects the leakage of LPG gas

and alerts the user through audio-visual indications.

This LPG Gas Sensor (MQ6), ideal sensor for use to

detect the presence of a dangerous Liquefied petroleum

gas (LPG) and it has high sensitivity to propane, butane,

isobutene, natural gas. The sensor can also be used to

detect combustible gases, especially methane. This circuit

can detect leakages in your Home, car or in a service

station, storage tank environment. This unit can be easily

implemented to industrial level by upgrading its ranges.

  This project is designed to detect the LPG from 200parts

per million (PPM) to 10,000 PPM. Whenever there is LPG

concentration of 1000 ppm (parts per million) in the area,

the OUT pin of the sensor module goes high. This signal

drives timer IC 555, which is wired as an astable

multivibrator. The multivibrator basically works as a tone

generator. A buzzer is connected to produce audible alert

signal.

 This LPG Gas Sensor can be used to make wireless Gas

leak detector in home security system .The LPG Gas

Sensor Module is designed to enable LPG detection

interface to Microcontroller without ADC Channels. By

providing a GSM modem we can receive “SMS ALERTS”

also..

 Design Of the Project:

In this project we have used MQ-6 gas sensor. Whenever LPG gas is leaked the sensor detects  and it passes signal to timer circuit. Here we have used IC 555 timer which acts as astable multivibrator.Then it will be given to Transistor driver circuit which activates buzzer and LED and alerts  the user through audio-visual indications.

COMPONENTS U:

S.n

o

  Components used    Range/Type Quantit

y

1 SEN-1327 gas

sensor

200ppm-

10,000ppm

1no

2 IC 555 TIMER (8

pin)

 4.5 to 15 V(Vcc) 1no

3 Transistor SL100 1no

4 Zener diode 5V 1no

5 Speaker 0.5W,8 Ω 1no

6 Battery 9V 1no

7 LED 1V 1no

8 Capacitors 0.1uf 2no

9 Resistors

Variable resistor

10kΩ

 4.7kΩ

1kΩ

22 Ω

560Ω

10kΩ

1no

1no

1no

1no

1no

1no

10 On /off switch  and

Connecting wires

   ______ ______

The SEN-1327 gas sensor module from

RhydoLABZ,kochi is used in this circuit. This LPG Gas

Sensor (MQ6), ideal sensor for use to detect the presence

of a dangerousLiquefied petroleum gas (LPG) and it has

high sensitivity to propane, butane, isobutene, natural gas.

The sensor can also be used to detect combustible gases,

especially methane. This sensor has a high sensitivity and

fast response time. The drive circuit is very simple. This

circuit can detect leakages in your Home, car or in a

service station, storage tank environment. This unit can be

easily implemented to industrial level by upgrading its

ranges.

FEATURES:

Uses the MQ-6 LPG Gas Sensor Easy SIP interface Compatible with most microcontrollers we can

upgrade this to provide SMS alerts also Onboard Status and Power LED Onboard Pot for threshold setting On board microcontroller This sensor has a fast response time Good sensitivity to Combustible gas in wide

range Long life and low cost Simple drive circuit High sensitivity to Propane, Butane and LPG

Circuit Working:

Pin details of the gas sensor module are shown in Fig. 2.

An MQ-6 gas sensor is used in the gas sensor module. As

per its datasheet, it has high sensitivity to propane,

butane, isobutene, LPG and natural gas. The sensor can

also be used to detect combustible gases, especially

methane. This circuit has been tested with LPG gas and

was found to work very fine.  Whenever there is LPG con-

centration of 1000 ppm (parts per million) in the area, the

OUT pin of the sensor module goes high. This signal

drives timer IC 555, which is wired as an astable

multivibrator. The multivibrator basically works as a tone

generator. Output pin 3 of IC 555 is connected to LED1

and speaker-driver transistor SL100 through current-

limiting resis-tors R5 and R4, respectively. LED1 glows

and the alarm sounds to alert the user of gas leakage. The

pitch of the tone can be changed by varying preset VR1.

Use a suitable heat-sink for transistor SL100.