LPG DETECTION & ALARMCHAPTER-1 INTRODUCTION The LPG or propane which is flammable mixture of hydrocarbon gases used as fuel in many applications like homes, hostels, industries, automobiles, vehicles because of its desirable properties which include high calorific value, which produce the less smoke, produces less soot, and does not cause much harm to the environment. Natural gas is another widely used fuel in homes. Both gases burn to produce clean energy, however there is a serious problem about their leakage in the air. The gases being heavier than air do not disperse easily and may lead to suffocation when inhaled also when gas leakage into the air may lead to explosion. Due to the explosion of LP gas the number of deaths has been increased in recent years. To avoid this problem there is a need for a system to detect and also prevent leakage of LPG. Gas leak detection is the process of identifying potentially hazardous gas leaks by means of various sensors. These sensors usually employ an audible alarm to alert people when a dangerous gas has been detected. Gas sensors are employed in a wide range of applications in the fields of safety, health, instrumentation etc... Common examples are domestic/commercial alarms for explosive or toxic gases, or in automotive application as gas leakage detectors for LPG powered cars and exhausts detectors inside any fuel powered truck/car. Such sensors, nowadays, are found also in applications involving air quality control systems and pollution monitoring. Today’s sensors, while featuring a high sensitivity to a wide gases variety, are very compact in size and have significantly reduced their power consumption to better adapt to portable solutions. Building a system with a gas sensor is not as easy as it could appear. Despite the sensor could be treated, basically, as a variable resistor (which value depends on gas concentration in air) the practical implementation in a project should be done considering some design rules, especially if the final circuit is a device to be used in a field where reliability is strongly required. This Structure and configuration of MQ-6 gas sensor is (Configuration A or B), sensor composed by micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of sensitive components. The enveloped MQ-6 has 6 pin, 4 of them are used to fetch signals, and other 2 are used for providing heating current. Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 1 LPG DETECTION & ALARM CHAPTER-2 BLOCK DIAGRAM MQ6 LPG sensor LM358 transist or driver circuit IC555 TIMER circuit speaker (or) Buzzer Fig: Block diagram of the LPG detection circuit 2.1 MQ6 SENSOR MQ6 is a semiconductor type gas sensor which detects the gas leakage. The sensitive material of MQ-6 is tin dioxide (SnO2). It has very low conductivity in clean air. This Gas sensor not only has sensitivity to propane and butane but also to other natural gases, the sensor could be used to detect different combustible gas, especially Methane, it is with low cost and suitable for different application. The MQ-6 gas sensor is shown in below fig. Fig2.1.1: MQ6 Sensor This sensor can also be used for detection of other combustible gas such as methane The concentration range of MQ-6 gas sensor is 300-1000 ppm. This sensor is available in 6 pins package, out of which 4 pins are used for fetching the signals and other 2 pins are used for providing heating current. This sensor has fast response time The power need by the Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 2 LPG DETECTION & ALARM sensor is 5V. This sensor has different resistance value in different concentration. For an example, if we calibrate the MQ-6 gas sensor to the 1000ppm of propane concentration in air, then the resistance value would be approximately 20kΩ. The change in the resistance value with respect to the concentration as discussed below is shown in fig. Fig 2.1.2. shows the typical sensitivity characteristics of the MQ-6 gas sensor for several gases. 2.1.1 Structure and configuration Structure and configuration of MQ-6 gas sensor is shown as Fig. 3, sensor composed by micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of sensitive components. The enveloped MQ-4 has 6 pin, 4 of them are used to fetch signals, and other 2 are used for providing heating current. Fig 2.1.3: structure and configuration of MQ6 sensor 2.1.2 Test Circuit diagram Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 3 LPG DETECTION & ALARM Fig 2.1.4: Test circuit of MQ6 The above is basic test circuit of the sensor. The sensor need to be put 2 voltages, heater voltage(VH)and test voltage(VC). VH used to supply certified working temperature to the sensor, while VC used to detect voltage (VRL) on load resistance (RL)whom is in series with sensor. The sensor has light polarity, Vc need DC power. VC and VH could use same power circuit with precondition to assure performance of sensor. In order to make the sensor with better performance, suitable RL value is needed Power of Sensitivity body(Ps) Ps=Vc2×Rs/(Rs+RL) Square Resistance of sensor(Rs): Rs=(Vc/VRL-1) ×RL Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 4 LPG DETECTION & ALARM 2.1.3 Technical data Table 2.1.1: technical data 2.1.4 Characters * Good sensitivity to Combustible gas in wide range. * High sensitivity to Propane, Butane and LPG. * Long life and low cost. * Simple drive circuit. 2.1.5 Applications * Domestic gas leakage detector. * Industrial Combustible gas detector. * Portable gas detector. 2.2 IC LM358 Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 5 LPG DETECTION & ALARM The IC or integrated circuit is a little black chip, it is a root of modern electronics, and also an essential component in many electronic circuits. The applications of integrated circuits involve in each and every electronic circuit board, embedded systems and various electronic projects. An integrated circuit is a set of various electrical and electronic components like resistors, capacitors, transistors. All these components are integrated onto a single chip. They are available in various forms like 555 timers, single circuit logic gates, microprocessors, microcontrollers, voltage regulators and op-amps like IC 741, LM324 IC, LM358 IC, LM339 IC and many more. The LM358 IC is a great, low power and easy to use dual channel op-amp IC. It is designed and introduced by national semiconductor. It consists of two internally frequency compensated, high gain, independent op-amps. This IC is designed for specially to operate from a single power supply over a wide range of voltages. The LM358 IC is available in a chip sized package and applications of this op amp include conventional op-amp circuits, DC gain blocks and transducer amplifiers. LM358 IC is a good, standard operational amplifier and it is suitable for your needs. It can handle 3-32V DC supply & source up to 20mA per channel. This op-amp is apt, if you want to operate two separate op-amps for a single power supply. It’s available in an 8-pin DIP package is shown in the below fig. Fig 2.2.1: LM358 2.2.1 Pin configuration Fig2.2.2: pin configuration 2.2.2Functions The pin diagram of LM358 IC comprises of 8 pins, Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 6 LPG DETECTION & ALARM where Pin-1 and pin-8 are o/p of the comparator Pin-2 and pin-6 are inverting i/p Pin-3 and pin-5 are non-inverting i/p Pin-4 is GND terminal Pin-8 is VCC+ 2.2.3 Features Wide Supply Ranges. Single Supply: 3 V to 32 V. Dual Supplies: ±1.5 V to ±16 V. Low Supply-Current Drain, Independent of Supply. Wide Unity Gain Bandwidth: 0.7 MHz Common-Mode Input Voltage Range Includes Ground, Allowing Direct Sensing Near Ground. Low Input Bias and Offset Parameters Input Offset Voltage: 3 mV Typical. A Versions: 2 mV Typical. Input Bias Current: 20 nA Typical. A Versions: 15 nA Typical. Differential Input Voltage Range Equal to Maximum-Rated Supply Voltage: 32 V. Open-Loop Differential Voltage Gain: 100 dB Typical. Internal Frequency Compensation. 2.2.4 Applications Blu-ray Players and Home Theatres. Chemical and Gas Sensors. DVD Recorder and Players. Digital Multimeter: Bench and Systems. Digital Multimeter: Handhelds. Field Transmitter: Temperature Sensors. Motor Control: AC Induction, Brushed DC, Brushless DC, High-Voltage, Low Voltage, Permanent Magnet, and Stepper Motor Oscilloscopes. Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 7 LPG DETECTION & ALARM TV: LCD and Digital. Temperature Sensors or Controllers Using Modbus. Weigh Scales. 2.3 BC 547 TRANSISTOR It is named as Transistor which is of two terms: “transfer-of-resistor.” It means that the internal resistance of transistor transfers from one value to another values depending on the biasing voltage applied to the Transistor. Thus it is called TRANSfer resISTOR i.e. TRANSISTOR A Transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. Transistors works wonderfully for computer production. With smart engineering, Transistors help computers power through huge numbers of calculations in a short time. The simple switch operation of transistors is what enables our computer to complete massively complex tasks. In a computer chip, Transistors switch between two binary states 0 and 1. This is the language of computers. One computer chip can have millions of transistors continually switching, helping complete complex calculations. 2.3.1 What is a Transistor made of? Transistors are made from silicon, a chemical element found in sand, which does not normally conduct electricity (it doesn’t allow electrons to flow through it easily). Because electrons have a negative charge, silicon treated this way is called n-type (negative type) and also known as NPN Transistor. We can also dope silicon with other impurities such as boron, gallium, and aluminium. Silicon treated this way will lose some electrons, so electrons in nearby materials will tend to flow into it. A lack of electrons is the same thing as a positive charge, so we call this sort of silicon p-type (positive type) and also known as PNP Transistor. 2.3.2 Brief Introduction to a NPN Transistor The NPN transistor can be used in two different modes: forward biased mode and the reverse biased mode. In forward biased mode, the electric current can easily flow through it. So it acts like a CLOSED SWITCH. However, in reverse biased mode, the current through it is practically zero and thus, it acts like an OPEN SWITCH. Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 8 LPG DETECTION & ALARM Fig 2.3.1: NPN transistor BC547 is an NPN Bi-polar junction transistor (BJT) as shown in below figure. A transistor, stands for transfer of resistance, is commonly used to amplify current. A small current at its base controls a larger current at collector & emitter terminals. C– Collector B – Base Fig 2.3.2: BC 547 transistor pin configuration Together with other electronic components, such as resistors, coils, and capacitors, it can be used as the active component for switches and amplifiers. Like all other NPN transistors, this type has and emitter terminal, a base or control terminal, and a collector terminal as shown in figure 2. In a typical configuration, the current flowing from the base to the emitter controls the collector current. A short vertical line, which is the base, can indicate the transistor schematic for an NPN transistor, and the emitter, which is a diagonal line connecting to the base, is an arrowhead pointing away from the base. BC547 is mainly used for amplification and switching purposes. It has a maximum current gain of 800. Its equivalent transistors are BC548 and BC549. The transistor terminals require a fixed DC voltage to operate in the desired region of its characteristic curves. This is known as the Biasing. For amplification applications, the transistor is biased such that it is partly on for all input conditions. The input signal at base is amplified and taken at the emitter. BC547 is used in common emitter configuration for amplifiers. The voltage divider is the Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 9 LPG DETECTION & ALARM commonly used biasing mode. For switching applications, transistor is biased so that it remains fully on if there is a signal at its base. In the absence of base signal, it gets completely off. 2.3.3 Working Principle of a NPN Transistor The construction for a Bipolar NPN Transistor are shown in figure 3. The voltage between the Base and Emitter (VBE), is positive at the Base and negative at the Emitter because for an NPN Transistor, the Base terminal is always positive with respect to the Emitter. Fig 2.3.3: Circuit symbol of transistor Also the Collector supply voltage is positive with respect to the Emitter (VCE). So for a bipolar NPN Transistor to conduct the Collector is always more positive with respect to both the Base and the Emitter. In Forward biased condition, the collector is connected to high positive voltage with respect to base i.e. Vcb is very high. So C-B junction is reverse biased. Vcb >> Vbe The base is connected to low positive voltage with respect to emitter i.e. Vbe is low. When we increase Vbe ≥ 0.7V (the value 0.7V is a typical value of potential barrier voltage) the Transistor is forward biased. Now large number of electrons in emitter layer is repelled by negative terminal of Vbe and they flow towards B-E junction. They cross the junction and enter into small base layer. Here some electrons combine with holes. Also some of them are attracted by positive terminal of Vbe and remaining maximum number of electrons flow into collector layer, crossing the second junction i.e. C-B junction. Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 10 LPG DETECTION & ALARM The resident electrons of collector are repelled by these (guest) electrons and thus, then all the electrons are present in collector layer are attracted by positive terminal of Vcb Thus, all these electrons complete their journey back into emitter layer and produce conventional currents in the transistor as shown in the above circuit. Thus, as per Kirchhoff Current Law, we can write, Ic + Ib = Ie Now when Vbe is still increased, more electrons are repelled by negative terminal of Vbe. So base-emitter junction is more and more forward biased. Thus the base current (Ib) increases, which in turn increases Ic. Hence, we can say that collector current (Ib) is the function of base current (Ib). But there is a typical value of Vbe for each transistor, at which the collector current I no longer remain the function of base current Ib. Also collector current is directly proportional to the base current. In all this process, maximum number of electrons from emitter layer flow into collector layer. So collector current is almost equal to emitter current. Hence we say that, collector current is proportional to emitter current. In Reverse Biased condition, both the junctions are reverse biased as the batteries are connected in opposite direction. Due to Vcb battery, the collector-base junction is reverse biased. Similarly, due to Veb battery, the base-emitter junction is also reverse biased. So charges cannot flow and current in the Transistor is practically zero. This method is not useful as the Transistor is in “cut-off” state since current is zero. 2.3.4 Equivalent Replacement The BC547, BC548, and BC549 are a group of general-purpose transistors with similar electrical characteristics. For basic and simple low voltage audio applications, they are almost equivalents. The BC548 and BC549 are very similar to the BC547 in every respect apart from a difference in operating breakdown voltages. BC547 has a 50 V rating for Vcbo and Vces, and 45 V for Vceo. The BC546 has an 80 V rating for Vcbo and Vces, and 65 V for Vceo. Current Rating The absolute maximum current this transistor can handle is 100 mA. This is the DC current rating. The peak current rating is 200 mA. 2.3.5 Uses Typical applications include audio amplification and small signal circuits. It has a transition frequency range up to 100 MHz When using the transistor as a switch, the max current rating poses a limit on the type of loads that it can drive. This transistor has a max collector rating of 100 mA which is enough to drive an LED circuit, or an LDR circuit, or a Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 11 LPG DETECTION & ALARM NOT gate. In addition, this transistor can switch low current Arduino microcontroller circuits, and even a low current micro relay. 2.4 IC NE555 (TIMER) The NE555 monolithic timing circuit is a highly stable controller capable of producing accurate time delays or oscillation. In the time delay mode of operation, the time is precisely controlled by one external resistor and capacitor. For a stable operation as an oscillator, the free running frequency and the duty cycle are both accurately controlled with two external resistors and one capacitor. The circuit may be triggered and reset on falling waveforms, and the output structure can source or sink up to 200 mA. 2.4.1 Package Fig 2.4.1:NE555 IC 2.4.2 Pin Details Fig 2.4.2:pin diagram of NE555 TIMER 2.4.3 Schematic Diagram Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 12 LPG DETECTION & ALARM Fig 2.4.4:schematic diagram of NE555 TIMER 2.4.4 Applications Monostable operation In the monostable mode, the timer generates a single pulse. As shown in Figure the external capacitor is initially held discharged by a transistor inside the timer. The circuit triggers on a negative-going input signal when the level reaches 1/3 VCC. Once triggered, the circuit remains in this state until the set time has elapsed, even if it is triggered again during this interval. Fig 2.4.5: Schematic diagram of monostable operation of NE555 IC Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 13 LPG DETECTION & ALARM Note that because the charge rate and the threshold level of the comparator are both directly proportional to supply voltage, the timing interval is independent of supply. Applying a negative pulse simultaneously to the reset terminal (pin 4) and the trigger terminal (pin 2) during the timing cycle discharges the external capacitor and causes the cycle to start over. The timing cycle now starts on the positive edge of the reset pulse. During the time the reset pulse is applied, the output is driven to its LOW state. When a negative trigger pulse is applied to pin 2, the flip-flop is set, releasing the short circuit across the external capacitor and driving the output HIGH. The voltage across the capacitor increases exponentially with the time constant t = R1C1. When the voltage across the capacitor equals 2/3 VCC, the comparator resets the flip-flop which then discharges the capacitor rapidly and drives the output to its LOW state. Figure13 shows the actual waveforms generated in this mode of operation. When Reset is not used, it should be tied high to avoid any possibility of unwanted triggering. Waveforms in Monostable Operation Fig 2.4.6: waveforms of monostable operation Astable operation When the circuit is connected as shown in Figure 15 (pins 2 and 6 connected) it triggers itself and free runs as a multi-vibrator. The external capacitor charges through R1 and R2 and discharges through R2 only. Thus the duty cycle can be set accurately by adjusting the ratio of these two resistors. Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 14 LPG DETECTION & ALARM In the astable mode of operation, C1 charges and discharges between 1/3 VCC and 2/3 VCC. As in the triggered mode, the charge and discharge times and, therefore, frequency are independent of the supply voltage. Fig 2.4.7: schematic diagram of astable operation Waveforms in astable operation Fig:waveforms of astable operation Pulse width modulator When the timer is connected in the monostable mode and triggered with a continuous pulse train, the output pulse width can be modulated by a signal applied to pin 5. Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 15 LPG DETECTION & ALARM Linear ramp When the pull-up resistor, RA, in the monostable circuit is replaced by a constant current source, a linear ramp is generated. 2.4. 5Features ■ Low turn-off time ■ Maximum operating frequency greater than 500 kHz ■ Timing from microseconds to hours ■ Operates in both astable and monostable modes ■ Output can source or sink up to 200 mA ■ Adjustable duty cycle ■ TTL compatible ■ Temperature stability of 0.005% per °C 2.5 BUZZER A buzzer or beeper is an audio signalling device,which may be mechanical,electromechanical, or piezoelectric. Typical uses of buzzers and beepers include alarm devices,timers, and confirmation of user input such as a mouse click or keystroke. 2.5.1 Appllicatios While technological advancements have caused buzzers to be impractical and undesirable, there are still instances in which buzzers and similar circuits may be used. Present days applications include: Novelty uses Judging Panels Modern applications Educational purposes Annunciator panels Electronic metronomes Game show lock-out device Microwave ovens and other household appliances Sporting events such as basketball games Electrical alarms Joy buzzer- a mechanical buzzer used for pranks CHAPTER-3 CIRCUIT DIAGRAM Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 16 LPG DETECTION & ALARM Presented here a circuit for raising an alarm on detecting smoke or LPG cooking gas leakage, or alcohol vapours in breath. This is achieved by using a basic unit with different sensors for smoke, LPG and alcohol. so, alarms can be made by simply changing the sensor. Here we are using MQ6 sensor for LPG gas detection. Fig 3.1: Circuit diagram for LPG detection alarm 3.1 COMPONENTS LIST IC1 : LM358 dual op-amp IC2 : NE555 timer T1 : BC547 NPN transistor R1 : 10K ohm R2 : 4.7K ohm R3 : 220ohm R4 : 1K ohm R5 : 56K ohm VR1 : 10K ohm potentiometer C1 : 100uf, 16V electrolytic Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 17 LPG DETECTION & ALARM C2 : 0.047uf ceramic disk C3 : 0.01uf, ceramic disk C4 :47uf, 16V electrolytic S1 : On/Off switch LS1 : 8ohm, 0.5-watt speaker MQ* : MQ6 sensor : 5V regulated supply : 8 pin IC bases (2) 3.2 CIRCUIT DIAGRAM AND WORKING Above figure shows the smoke alarm. The basic unit employs dual op-amp LM358(IC1), transistor T1 and timer NE555(IC2), configured in astable mode. Selection of MQ6sensor is based on the purpose for which the alarm circuit is being designed. For the smoke alarm circuit, you will need MQ2 sensor. Similarly, for detection of alcohol, MQ3 sensor is used, while MQ6 sensor is used for detecting LPG cooking gas. MQ6 sensor has six pins. Heater filament, between pins H-H, is directly connected to5V and ground. Two sets of inputs/output (I/O) pins A-a and B-B are present. Select any one set for input to the basic unit. Arrangement of pins is shown in figure. IC1 is wired in the non-inverting comparator mode, the reference voltage is applied to inverting input (IN1-) and the voltage to be compared is applied to non-inverting input (IN1+). Whenever voltage to be compared (IN+) goes above reference voltage (IN-), output of the op-amp swings to high, and vice-versa. The alarm circuit is built around NE555. The frequency of the astable multivibrator is dependent on the values of resistors R4 and R5, and capacitor C2. After connecting to 5V supply, wait for about 10 seconds for the filament to heat properly adjust 10K potentiometer (VR1) till the alarm stop sounding. Under normal conditions (that is, no fumes from LPG or no alcohol in breath near MQ6), output of IC1 at pin 1 remains low. As a result, transistor T1 does not conduct, which make pin 4 of IC 2low. It keeps timer NE555 on reset. There is no output at pin 3 of IC2 , and no sound comes out of the speaker. Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 18 LPG DETECTION & ALARM On the other hand, when there are fumes from LPG, or there is alcohol in breath near MQ6, output of IC1 at pin 1 goes high. As a result, transistor T1 drives into saturation and its emitter goes high. Pin 4 of IC2 also goes into astable mode, producing pulsed wave at output at pin 3 of IC2, which is coupled to speaker LS1 through coupling capacitor C4, and an alarm is set on. 3.2.1 Test Points TP0 TP1 TP2 TP3 TP4 TP5 : 0V (GND) : 5V when switch S1 is on : around 1.8V when no gas leakage : 2.6V set using VR1 : low when no gas leakage and high when there is a gas leakage : low when no gas leakage and high when there is a gas leakage 3.3 COMPONENTS DESCRIPTION 3.3.1 Resistor Resistor is one of the Basic component found in almost all electronic circuits. The property exhibited by a resistor is known as resistance.as it name suggests, a resistor resists or opposes the flow of current through it. the resistance of resistor is said to be linear if it obeys ohm’s law it is called nonlinear resistance and consequently the resistors are known as Nonlinear resistors. It is represented by letter R. Classification of resistors Fixed resistors Variable resistors Fixed resistor resistors whose ohmic values remain fixed at a constant value, are known as Fixed resistors example: carbon resistors and wire wound resistors. Variable resistors Variable resistors are the resistors whose resistance value can be varied.in some electrical/electronic circuits sometimes it is necessary to change the current values of current and voltages. For example, it is often necessary to change the volume of sound and brightness in T. V, volume of sound and tone in radios and to regulate the speed of fan. such adjustments Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 19 LPG DETECTION & ALARM can be done by using variable resistors the different types of variable resistors were mentioned below Potentiometer Rheostat Tapped potentiometer 3.3.2 Capacitor A capacitor or condenser is a two terminal positive component which Has ability to store electric charge Opposes instantaneous changes of voltage in the circuit in which it is connected Blocks the passage of direct current and allows the alternating through it A capacitor essentially consists of two conducting surfaces separated by an insulating medium called dielectric.it has the property of capacitance ‘represented by letter C Classification of capacitor Fixed capacitors Variable capacitor Fixed capacitors Capacitors whose capacitance value cannot be varied mechanically or by any other external means. These capacitors are usually having the fixed value with tolerance baring from +- 1 to +- 20%. they are of various type depending on the use of dielectric between the plates. The different fixed capacitors are Paper capacitors Mica capacitors Glass capacitors Polyester capacitors Polystyrene capacitors Ceramic capacitors Electrolytic capacitors Variable capacitors Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 20 LPG DETECTION & ALARM The capacitors whose capacitance value can be varied are known as variable capacitors. Based on the type of application the variable capacitors are divided into two types namely Tuning capacitors Trimming capacitors CHAPTER-4 Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 21 LPG DETECTION & ALARM APPLICATIONS AND ADVANTAGES 4.1 APPLICATIONS Protection from any gas leakage in cars For safety from gas leakage in heating gas fired appliances like boilers, domestic water heaters Large industries which uses gas as their production For safety from gas leakage in cooking gas fired appliances like ovens, stoves etc. 4.2 ADVANTAGES It is used in house as LPG leakage detection It also detects alcohol so it is used as liquor tester. The sensor has excellent sensitivity combined with a quick fast response time. The system is highly reliable, tamper-proof and secure. In the long run the maintenance cost is very less when Compared to the present systems. It is possible to get instantaneous results and with high accuracy. CHAPTER-5 Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 22 LPG DETECTION & ALARM RESULT AND FUTURE SCOPE 5.1 RESULT Overall system was designed and tested by introducing the small amount of LPG as near gas sensor module. The system detects the level of gas in the air if it exceeds the safety level it activates the alarm which includes Buzzer to alert the user at home in abnormal condition and to take the necessary action. 5.2 FUTURE SCOPE With recent development in technology, improvement would be to accommodate with GSM&GPS technology with multiple receiver MODEMS at different positions in the geographical areas by using microcontrollers and temperature sensors. Multilingual display can be another added variation in the project. Audio output can be introduced to make it user Friendly. CHAPTER-6 Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 23 LPG DETECTION & ALARM CONCLUSION Overall system is to be designed and tested by introducing the small amount of LPG gas near gas sensor module. The system detects the level of gas in the air if it exceeds the safety level, this system automatically alerts the people by Buzzer and take the necessary action of preventing the gas leakage. In recent households, the use of LPG is taking a big roll. From the use of cylinder up to the use of petroleum pipelines. The biggest advantage by using this technology is security. And our project will prove to be boom for households, hostels, vehicles and industries. It is an efficient home security system and also can be used in industries and other places to detect gas leaks. The cost involved in developing the system is significantly low and is much less than the cost of gas detectors commercially available in the market. REFERENCES Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 24 LPG DETECTION & ALARM [1]http://www.electronicsforu.com/electronicsforu/circuitarchives/view_article.asp?sno=600 &title=gas sensor [2] http://en.wikipedia.org/wiki/Electronic_component [3] http://octopart.com/tda2005m-stmicroelectronics-407800 [4] en.wikipedia.org/wiki/555Timer [5] Huawei Electronics Co. Ltd, MQ 5 sensor Datasheet [6] P.Meenakshi Vidya, S.Abinaya, G.Geetha Rajeswari, N.Guna ,“Automatic LPG detection and hazard controlling “ published in April 2014. [7] K.Padmapriya, Surekha, Preethi, “Smart Gas Cylinder Using Embedded System”, published in 2014. [8] C.Selvapriya, S.Sathyaprabha, M.Abdul rahim,” LPG leakage monitoring and multilevel alerting system”, published in 2013. [9] R.Padmapriya, E.Kamini,”Automatic LPG Booking, Leakage Detection and a Real Time LPG Measurement Monitoring System”, published in 2013. [10] V.Ramya, B.Palaniappan,”Embedded system for Hazardous Gas detection and Alerting”, published in 2012. [11] A.Mahalingam, R.T.Naayagi, N.E.Mastorakis, “Design and Implementation of an Economic Gas Leakage Detector”, published in 2012. [12] M.B.Frish, R.T.Wainner, B.D.Green, M.C.Laderer, M.G.Allen, “Standoff Gas Leak Detectors Based on Tunable Diode Laser Absorption Spectroscopy”, published in 2011. [13] W. Chung, and D. Lee, "Real time muti-channel gas leak monitoring system using CPLD chip," Sensors and Actuators B, Vol. 77, pp. 186- 189, 2001. [14] Rajkamal,” Embedded Systems: Architecture, Programming and Design”, Tata McGraw- Hill Education. Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 25 LPG DETECTION & ALARM Dept. of ECE(B.Tech.)SVCET College, Chittoor Page 26