Power line communication implementation for DC applications

     Power line communication implementation for DC applications

Power line communication (PLC) is a communication technology that sends data over existing power cables. This technology can send both power and data between PLC nodes in a half-duplex manner. Combining power and data over the same lines allows PLC technology to eliminate the need for additional wires to interconnect devices. PLC offers a cost-effective communication media for a wide range of applications in environments that otherwise might be too expensive to network. As a communications technology, PLC can be divided into two categories: Broadband PLC is appropriate for high-speed broadband network connections such as to the Internet. It generally operates at higher frequencies (1.8–250 MHz), high data rates (up to 100s of Mbps) and is used in shorter-range applications. Narrowband PLC is useful for applications requiring narrowband control or low-bandwidth data collection where low cost and high reliability are essential. It generally operates at lower frequencies (3–500 kHz), lower data rates (up to 100s of kbps), and has longer range (up to several kilometres), which can be extended using repeaters. Depending upon the underlying power line characteristic, PLC can be further classified as PLC over AC power lines and PLC over DC power lines. Many utilities around the world have chosen narrowband PLC over AC lines for their smart grid projects. By monitoring electricity usage based on time of day and even by device or application, utility companies can provide pricing structures that give consumers incentives to adjust their energy consumption, thus reducing peak-load and avoiding the need to construct new power plants. The popularity of PLC adoption in smart grid applications has led to significant focus on PLC over AC power lines. However, narrowband PLC over DC lines is also gaining ground in home networking, lighting and solar applications as well as in transportation vehicles (electronic controls in air planes, auto mobiles and trains). The use of PLC in these applications reduces wiring complexity, weight, and ultimately cost of communications. In this article we focus on the use of PLC over DC power lines and present a reference design that can help customers adopt PLC over DC power lines quickly and effectively. One common question asked by system integrators is how to compare PLC over DC versus low-power wireless technology. While both PLC over DC and low-power wireless do not require new wire installation, with PLC, the connection is maintained even underground, through walls, and around corners. The communication channel is owned by the operator or utility, so the risks of sharing bandwidth are eliminated. PLC has no line-of-sight limitation and is not affected by weather.


How to Make a Call using Keyboard, GSM Module and Arduino

The mobile phones have built –in GSM module which enables them to connect with any cellular network around the globe. The GSM stands for Global System for Mobile communications. In certain applications the microcontroller based systems has to be connected with the GSM network which will enable a user to control the system by sending messages or making a call. The systems can also send messages to the user to alert or inform about the status of the system running. In all such cases a separate GSM module is used rather than using the mobile phones.
There are GSM modules available which can do serial communication with microcontroller based systems. The communication is done by sending or receiving AT commands with the GSM module. This particular project demonstrates how to interface a GSM module and dial a call using the standard PS2 keyboard with the help of an Arduino board.
The PS2 keyboard can send the equivalent ASCII value of the key which has been pressed to a host device into which it is connected to. The PS2 Keyboard also uses a simple synchronous serial protocol called PS2 using only two wires for communication. Due to their simplicity in interfacing the PS2 keyboards and GSM modules are widely used with simple microcontroller based boards. 


How to Interface GPS with Arduino


Every single location in the entire globe can be specified in terms of geographical coordinates. The geographical coordinate is a system which specifies any given location on the earth surface as latitude and longitude. There are devices which can read the geographical coordinates of a place with the help of the signals received from a number of satellites orbiting the earth. The system of satellites which helps in the positioning of a place is called Global Positioning System (GPS). The devices which can read the geographical coordinates of a place with the help of at least four GPS satellites are called GPS Receiver or simply GPS module.

The GPS module continuously produces a set of data regarding the position of the earth surface where it is situated which includes the current position with respect to the equator of the earth in terms of Latitude and Longitude. This data can be decoded and printed into the readable format with the help of a microcontroller only. In this project the data regarding the geographical coordinate is extracted from the GPS output with the help of the Arduino. The Arduino can be used as a stand-alone board of which the output or inputs can be taken from the boards or given to the board. They can communicate using standard communication ports like USART, TWI, SPI etc. which enables them to be connected with various kinds of devices. The Arduino board is designed for easy prototyping and the IDE used for coding is very simple and provides so many libraries for interfacing with common external devices.

Railway tracking System

      Research on Rail Safety Security System
This paper analysis of  the integrated use of safety monitoring with the domestic and international latest research on rail safety protection system, and focus on the implementation of an organic whole system, with the monitoring and early warning, risk assessment, predictive control and emergency rescue system. The system framework, contents and system structure of Security system is proposed completely. It’s pointed out that the Security system is a negative feedback system composed of by safety monitoring and warning system, risk assessment and emergency rescue system. Safety monitoring and warning system focus on the monitoring target monitoring, early warning, tracking, integration of decision-making, for objective and subjective risks factors. Risk assessment system analysis the occurrence of a major Security risk mechanism, determines the standard of the future short, medium and long term safety conditions, and give prop for development of safety indicators, accident analysis and safety standards. Emergency rescue system is with the goal of rapid and effective rescue work for accident, to minimize casualties and property losses.
Along with the transportation develops towards high-speed, high-density, over loading, technique concentrated, complex of the technique systemic constitute, and the high linkage between business system, the safety Security work will face exceptional severe challenge. The objects related to safety Security consist of natural disasters, foundation devices and emergencies. Any local damage and un-control may evolve to a global damage and un-control during the subway is in motion and do business. However, now the question of safety Security system is that the apply and analysis on information of safety monitoring is on start-up period, the whole benefit of prediction control and emergency rescue by monitor data has not yet been fully developed, the primary cause of the problem is lack of systemic rail transportation Security and technology criterion which is adaptive to the system and possess the industry characteristic. Following the development of the system on safety monitoring and early warming, it will accumulate a mass of Security monitoring data. If the data is effectively fusion, storage, and synthetically applied, the Co-relational research on rail transportation safety Security system is becoming highly valued step by step in recent years. Research on the theory and technology of rail transportation safety Security has bear fruit according to the literatures. Literature [1] described the depart control of rail transportation operating system and presented the optimal strategy and realize of depart intelligent decision support system based on Petri net. Literature [2] formally modeled definition, design and realization of the self-check function in automatic driving control software. Literature [3] had researched the analysis and design of the train strategic decision supporting system by using the method facing objects. Literature [4] optimized the train’s initiative driving by using linear quadratic Gaussian (LQG) method and hereditary algorithm. Literature [5] presented and brought out the distributed strategy decision supporting system of the train station and train control along the line. Literature [6] researched the optimized operation of the train based on the neural networks. All of these achievements paved the path to build and improve the rail intelligent train control system and rail transportation scourges prevention facing the safety Security. It also invested abundant of labour power and financial resources to keep away and control the scourges, thereby the whole scourge early warning and monitor political system is formed. The system of scourge early warming used scientific early warming methods, gathered every kind of external data leading to scourge, advanced early warming to scourges such as flooded line and collapsed line, carried out responding scourge warming, formulated travelling regulation under scourges, which prevented the accidents of scourge and Security transportation safety. Scourge monitoring system directly monitored the scourges which are difficultly predicted, such as rolling stones, collapse, broken bridges, which ensured the running train can stop in time and transferred the information to any departments. The system frame of American rail traffic intelligent transportation system, which named IRS, contained system frame of proactive train controlling system, which can be used to control train safety, reliable, punctual, effective operating, and by avoiding train colliding, decreasing the negligence of rail road workers, reducing facilities broken and over speed accidents. The standard current situation of international standardization institution and each country safety Security system concerning is:
UTC (Union International des Chemise defers, International Union of railways), UTC is the biggest international standardization institution of the world rail transportation. This organization is a non-government international rail transportation institute, which is subject of European rail transportation, and China is one member country in it. A set of standardizations related to safety Security system quickly developed for it. (2) ISO, ISO related to the rail transportation standard is the 45 item-rail transportation projects. Although now the part of ISO rail transportation is emphasized on project material, but these standards are closely interrelated to transportation safety. (3) IEEE (Institute of Electrical and Electronics Engineers), IEEE standardization committee is responsible for the survey, impel, management of IEEE standard, pondering and proposing IEEE standard. For the past few years, IEEE standardization committee is very active in standardization research part of rail transportation information and control, closely follow after releasing many standards in this region, and some parts is related to transportation safety [7]. (4) ERRI (ERRI European Rail Research Institute)ERRI is under the lead of UIC and it is a rail technical research institute which gathers rail traffic engineers in every country. Meanwhile, along with the typical RITS system-ERTMS continually deepens, ERRI plays a decisive role in the forming of the world rail traffic standard. (5) JIS, section E in JIS standard object is directly related to rail transportation, including line general standard, locomotive signal, signal servicing installation, rail traffic vehicle general standard , high-speed train , passenger and freight vehicle, tight wire railway standard. JIS present standardization strategy of the same.
 Rail traffic safety system is composed of three parts: the safety monitoring and early warning system, risk assessment system and emergency rescue system. Emergency rescue system is centre, safety monitoring and early warning and risk assessment system is the means. In this system, safety monitoring warning system is controller and transportation safety factors is the object; the input is a closed-loop system of emergency rescue level. Among them, safety factors are generalized concepts, including not only individual subjective and objective factors which lead to the danger, but also the relationship between factors and combination Safety monitoring and early warning system Rail traffic safety monitoring and early warning system is aiming at subjective and hidden danger factors. Monitoring network is composed by monitoring stations, and observing monitoring target, tracking, early warning, recognizing, monitoring and reporting the development state. The monitoring content is composed of operation action of person in key position, the running condition of vehicle, the vehicle loading condition and infrastructure condition; transportation safety synthetically monitoring information base is formed by information fusion, providing timely information to prevention, predicting of hidden danger and emergency rescue. Safety monitoring and early warning system uses distributed network monitoring stations to monitor, track the safety station of targets. The key technology of rail traffic safety monitoring and early warning system is system interface. System interface contains not only integration technology of site safety monitoring system, but also information exchange technology of safety subsystems interconnection or integration. The contents include the classification of the interface, form of structure and realization. According to the technical content and layer of structure, system interface is divided into: system interface and monitoring level interface. System interface: system interface refers to the safety monitoring system and the interface of each safety subsystem. System interface integrates and plans subsystem information base on the aspects of system interconnection, part function, characteristic and structure, builds uniform standard information storage structure, organization structure, circulation mechanism, Monitoring level interface: monitoring level is that safety subsystem interface processes the data collection and forms standardized interface. Monitoring level interface is related to their own function features of safety device. ii. Early warning decision-making of monitoring network the same major safety monitoring system in monitoring network which deployed at the site is independence. Because of the monitoring results are influenced by many random factors, the single point estimation judgement may not be necessarily accurate in monitoring and warning, which means false alarm and leakage alarm(false alarm is that target under monitoring system is out of action, but it actual trouble-free. False alarm rate is in a period, the number of fault alarm displaying contrast to the total alarm displaying). Therefore, the result of judgement will objective, when the monitoring network stations increase a participant of fusion judgement node, judge monitoring system become integrated, the participants with the determination results objectively.
The monitoring network system containing several stations and a decision fusion monitoring network system can be divided into two kinds of structure ,a kind of monitoring and early warning decision-making model which composes by many stations and a fusion centre, called MDOF model.

CONCLUSION:

The paper based on analysing and summarizing co-relational research results of rail traffic safety Security, and it presents systematically the traffic safety Security system which should be served as a unity including safety monitoring and early warning system, risk evaluation system and emergency rescuing system. It realizes information fusion, information sharing and technical standardization. In the paper, rail traffic safety management system and Security management system is proposed and founded to adapt to the new features nowadays. After minutely stating the detailed technical frame design of safety monitoring and early warning system, risk evaluation system and emergency rescuing system, the paper integrally presents the system frame, research contents and system constitute of safety Security system. Synthetic safety Security system can develop synthetically monitoring, forecasting, early warning, disaster prevention and rescuing strategy service function, make that it can cohere with the work of some department, such as safety operating, infrastructure maintenance, quick emergency, and give full play to the function of Security safety devices and safety monitoring system.

CURRENT SENSOR

High-wattage appliances like electric irons, ovens and heaters result in unnecessary power loss if left ‘on’ for hours unnoticed. Here is a circuit that senses the flow of current through the appliances and gives audible beeps every fifteen minutes to remind you of power-’on’ status. This is a non-contact version of current monitor and can sense the flow of current in high-current appliances from a distance of up to 30 cm .It uses transistors in the input to provide very a standard step-down transformer (0- 9V, 500mA) as the current sensor. Its secondary winding is left open, while the primary winding ends are used to detect the current. The primary ends of the transformer are connected to a full-wave bridge rectifier comprising diodes D1 through D4. The rectified output is connected to the non-inverting input of IC CA3140 (IC1). IC CA3140 is a 4.5MHz BIMOS operational amplifier with MOSFET input and bipolar transistor output. It has gate-protected MOSFET (PMOS) transistors in the input to provide very high input impedance (1.5 T-ohms), very low input current (10 pA) and high-speed switching performance. The inverting input of IC1 is preset with VR1. In the standby mode, the primary of the transformer accepts e.m.f. from the instrument or surrounding atmosphere, which results in low-voltage input to IC1. This low voltage at the non-inverting input keeps the output of IC1 low. Thus transistor T1 doesn’t conduct and pin 12 of IC2 goes high to disable IC2. As a result, the remaining part of the cir gets inactivated. When a high-current appliance is switched on, there will be a current drain in the primary of the transformer to the negative rail due to an increase in the e.m.f. caused by the flow of current through the appliance. This results in voltage rise at the non-inverting input and the output of IC1 becomes high. This high output drives transistor T1 into conduction and the reset pin of IC2 becomes low, which enables IC2. IC CD4060 (IC2) is a 14-stage ripple counter. It is used as a 15-minute timer by feeding Q9 output to the piezo buzzer for aural alarm through the intermediate circuitry. Resistors R5 and R6 along with capacitor C1 maintain the oscillations in IC2 as indicated by blinking LED1. The high output from IC2 is used to activate a simple oscillator comprising transistors T2 and T3, resistors R8 and R10, and capacitor C2. When the Q9 output of IC2 becomes high, zener diode ZD1 provides 3.1 volts to the base of transitor T2. Since transistor T2 is biased by a high value resistor (R8), it will not conduct immediately. Capacitor C2 slowly charges and when the voltage at the base of T2 increases above 0.6 volt, it conducts. When T2 conducts, the base of T3 turns low and it also conducts. The piezo buzzer connected to the collector of T3 gives a short beep as capacitor C2 discharges. This sequence of IC2 output at Q9 becoming high and conduction of transistors T2 and T3 resulting in beep sound repeats at short intervals.

REMOTE OPERATED DOMESTIC APPLIANCES CONTROL BY ANDROID APPLICATION

The project is designed to operate electrical loads using an Android application device.  The system operates electrical loads depending on the data transmitted from the Android application device. Operating conventional wall switches is difficult for elderly or physically handicapped people. This proposed system solves the problem by integrating house hold appliances to a control unit that can be operated by an Android smart-phone/Tablet etc.
Remote operation is achieved by any smart-phone/Tablet etc., with Android OS, upon a GUI (Graphical User Interface) based touch screen operation, interfaced to the microcontroller of 8051 family. The program on the microcontroller serially communicates with Bluetooth device to generate respective output based on the input data (sent from Android application device) to operate a set of relays through a relay driver IC. The loads are interfaced to the control unit through the relays. The system can be used in existing domestic area for either operating the loads through conventional switches.
The power supply consists of a step down transformer 230/12V, which steps down the voltage to 12V AC. This is converted to DC using a Bridge rectifier. The ripples are removed using a capacitive filter and it is then regulated to +5V using a voltage regulator 7805 which is required for the operation of the microcontroller and other components.

RF BASED HOME AUTOMATION SYSTEM

The main objective of this project is to develop a home automation system with a RF controlled remote. As technology is advancing so houses are also getting smarter. Modern houses are gradually shifting from conventional switches to centralized control system, involving RF controlled switches. Presently, conventional wall switches located in different parts of the house makes it difficult for the user to go near them to operate. Even more it becomes more difficult for the elderly or physically handicapped people to do so. Remote controlled home automation system provides a simpler solution with RF technology.

In order to achieve this, a RF remote is interfaced to the microcontroller on transmitter side which sends ON/OFF commands to the receiver where loads are connected. By operating the specified remote switch on the transmitter, the loads can be turned ON/OFF remotely through wireless technology. The microcontroller used here is of 8051 family. The loads are interfaced to the microcontroller using opto-isolators and triacs.