Fire Alarm System Using MQ-2 Gas-Smoke Detector and Flame Sensor I. Introduction Most of us do not have fire alarm systems installed in their homes. Many assume that they were able to smell smoke when they are asleep and wake up in time to escape in case of a fire emergency. Well, this is not true at all. Studies have been conducted and it has been proven that people’s sleep are disrupted when there is sound or noise, but it is not the case with smell. Our sense of smell is lost when we are asleep, and we will not wake up no matter how strong the smell of smoke is. An early detection can get you out of a situation that would potentially turn into a tragedy. Problems that might occur: 1. If the fire, flame, gas, or smoke are not in range yet of the sensors, the device will not work. 2. If the power supply doesn’t work when there is a brownout, then the device would not work too. Solutions to the problem: 1. To make it more efficient, we should add more sensors surrounding the entire house so that it will detect fire, gas, or smoke anywhere in the house. 2. Put a generator to ensure that the device will be always operational. II. Block Diagram The device is supplied with a 6VDC power supply, and the buzzer and lamp are supplied by 220VAC from the outlet. If the Flame Sensor Module or the MQ-2 Smoke-Gas Detector Module detects it sends a signal to the NAND Gate which is composed of two 2N2222 NPN Transistors that decides if it going to send a signal to the relay driver. If the output received in both sensor is 0-0, then the device will turn ON but in this case the modules are doing the opposite way. It was supposed to be OR Gate to achieve 0-0 = 0, 1-0 = 1, 0-1 = 1 and 1-1 = 1. Which means if it detects the buzzer will turn on. But to make it work I used the NAND Gate which exhibits 0-0 = 1, 1-0 = 1, 0-1 = 1 and 1-1 = 0 which is the opposite of the OR Gate. So, if any or both sensors detect, there will be an output that will be sent to the relay driver. The relay driver is connected to the coil #2 of the relay and the positive terminal of the 6VDC power supply is connected to coil #1 of the relay. After the relay receives the signal from the relay driver it will automatically turns on and it will go the NO (normally open pin) and that would supply the buzzer and lamp to turn on. The 220VAC line to ground wire is connected to the relay, buzzer, and lamp. The Buzzer and Lamp is both connected to the 220VAC, but the other wire is connected to the relay, so if the relay is turned on the other 220VAC supply is connected the load and it will turn on. III. Schematic Diagram Components and Materials Used: Flame Sensor Module x 1 MQ-2 Smoke-Gas Detector Module x 1 220V 5W Red Light Bulb x 1 Light Bulb Socket x 1 220V Oval Buzzer x 1 6V 6A 5 Pin Relay x 1 2N2222 NPN Transistor x 2 BC547 NPN Transistor x 1 LM7806 Voltage Regulator x 1 9V 500mA Transformer x 1 10kΩ Resistor x 2 4.7kΩ Resistor x 1 1kΩ Resistor x 1 1N4001 x 4 1N4007 x 1 Heat Sink x 1 470uF 35V Capacitor x 1 0.1nF Capacitor x 1 Connecting Wires Terminal x 2 Switch x 1 Acrylic Sheet 1 Square Foot x 1 Bolt and Nut x 12 Outlet Wire Male & Female Port x 2 IV. Computations The flame sensor can detect up-to 760 – 1100 nanometer from the presence of fire/flame also it depends on how big the fire/flame is. The detection angle is roughly 60 degrees, and the sensor is particularly sensitive to the flame spectrum. While the smoke-gas detector can detect whenever the smoke/gas reaches to the holes of the enclosure. The MQ-2 is a smoke and combustible gas sensor from Winsen. It can detect flammable gas in a range of 300 - 10000ppm V. Summary and Conclusions Fire Alarm Systems are designed to discover fires early in their development when time will still be available for the safe evacuation of occupants. Early detection also plays a significant role in protecting the safety of emergency response personnel. Property loss can be reduced and downtime for the operation minimized through early detection because control efforts are started while the fire is still small. Most alarm systems provide information to emergency responders on the location of the fire, speeding the process of fire control. In conclusion it is important to have a fire alarm system in place as a part of a building’s safety plan. Without a fire alarm system, the lives of those who are inside the building are placed at a high risk in the event an emergency. It is recommended to use the fire alarm systems, sprinkler systems, fire pumps, and smoke control systems use some number of actions to notify of the fire and smoke conditions, help slow the growth of the fire or to help put out the fire altogether. If they are put into use, your home/workplace will be a safe place and in case of a fire the place will include protections that will result in minimum loss. VI. Appendices a) Datasheets Flame Sensor Module (https://datasheetspdf.com/pdf/1402037/Joy-IT/KY-026/1) MQ-2 Smoke- Gas Detector (https://www.pololu.com/file/0J309/MQ2.pdf) 2N2222 NPN Transistor (https://pdf1.alldatasheet.com/datasheet-pdf/view/75121/MICROELECTRONICS/2N2222.html) BC547 NPN Transistor (https://html.alldatasheet.com/html-pdf/586720/FAIRCHILD/BC547/484/1/BC547.html) LM7806 Voltage Regulator (https://html.alldatasheet.com/html-pdf/33409/UTC/LM7806/45/1/LM7806.html) 6V 5 Pin Relay (https://components101.com/switches/5v-relay-pinout-working-datasheet) 9V 500mA Transformer (https://pdf1.alldatasheet.com/datasheet-pdf/view/392118/EPCOS/B78408A1208A003.html) b) Picture of the Project
