PERFORMANCE OF POWER LINE COMMUNICATION SYSTEMS WITH NOISE REDUCTION SCHEME FOR SMART GRID APPLICATIONS-Electronics ProjectsPosted: March 8, 2012
X10 protocol is meant for data communication over the power line which carries 230V, 50 Hz Ac supply. Here we are going to use the power line in the industry for data acquisition purpose. This is an improvement of data communication over the power line.
X10 is an international and open industry standard for communication among electronic devices used for home automation, also known as domotics. It primarily uses power line wiring for signaling and control, where the signals involve brief radio frequency bursts representing digital information.Whether using power line or radio communications, packets transmitted using the X10 control protocol consist of a four bit house code followed by one or more four bit unit code, finally followed by a four bit command.
In this paper, we propose clipping scheme and equalizer as methods to reduce the effects of impulsive noise and channel attenuation in power line communication (PLC) system. Clipping is cutting off the amplitude of the received signal over threshold level without its phase change in order to reduce noise effects. The equalizer compensates for effects of PLC channel. The performance is evaluated in terms of bit error rate (BER). From simulation results, it is confirmed that the proposed clipping scheme has slightly better performance than conventional PLC system. The results of the paper can be applied to PLC systems for smart grid.
The device is a hardware interface that allows control data communication over the power line. Its purpose is that of translating the serial output provided by some digital service, like a microcontroller, into a coded pulse train that is suitable for being transmitted over the usual domestic power lines. Conversely, the interface is able to extract such messages from the power line and to convert them into serial streams that the connected digital device can read. The interface therefore acts like a modem, allowing the employment of the common electrical supply network of a building as a local area network.
When coupled with a programmable digital device, such as a microprocessor or a microcontroller, the device allows the realization of “intelligent” and “communicative” equipments that can interact with similar objects over a domestic network, without the need of installing a dedicating wiring. Typical applications are in the field of Home and Building Automation (management of surveillance and alarm systems, home appliances automation, AMR (Automatic Meter Reader), Home automation control, Security and surveillance, General-purpose isolated transceiver.
The innovative feature of these devices is that they transmit data on the power line, using the concept of conveyed wave (zero crossing).We use an 8051 based microcontroller the at89c51 for the transmitter and the receiver. From a keypad on the transmitter the relay section on the receiver can be controlled.
- 565 Tone Generator
- 555 Timer
- LM386 Amplifier
- Power Supply.
- UM91214 DTMF Encoder s
- UMC 8870 DTMF Decoder
- Isolation Transformer
The aim of this article is to get familiarized with the modern field of robotics and to find the technology know -how. Also here we are using the sophisticated emerging technology -embedded system. Here we have designed a robot arm, controlled by a microcontroller. We choose this deign because it is the most common form of robot we can find anywhere in industries like car assembling, bottling plant, packing section etc. The driver circuits for these motors are to be controlled using 8051 microcontroller with a control key panel. The movement is established using stepper motors. pick and place robots are the small robots using for continuous purpose in the industries then let us go through some thing about pick and place robot by this article .
WHAT IS A ROBOT?
Robot is any machine that does work on its own, automatically after it is programmed by humans. HISTORY OF ROBOTS:
The first robot’s name was Electro and his dog’s name was Sparko .They appeared at the New York world’s fair in 1939. While plugged in, Elektro could say 77 words and move backwards and forwards.
In1920’s, Karl Capek from Czechoslovakia introduced the words first robot on stage.
PICK AND PLACE ROBOT
We are going to design & implement a small model of pick and place robot, which pick and place object any where with in 360degrees and 30 cm diameters around it. The reason for choosing project is, the most extensively form of machine is used in most of the industries like car manufacturing, shipyards, assembling machine etc.
MICROCONROLLERS FOR EMBEDDED SYSTEMS
Microprocessors and microcontroller are widely used in embedded system products.
An embedded system is a system which is dedicated for a single purpose remains unchanged through out its entire life time. An embedded product uses a microprocessor (or microcontroller) to do one task and one task only.
A stepper motor is a widely used device that translates electrical pulses into mechanical movement. It is used for precise position control. # Increase or decrease the RPM (speed) of it.
To vary the RPM of motor we have to vary the PRF (Pulse Repetition frequency). Number of applied pulses will vary number of rotations and last to change direction we have to change pulse sequence.
The circuit mainly consists of three modules -control system, user interface module & a high voltage driver. A control system is nothing but the microcontroller. It has got the following modules.
- User Interface Module.
- Pulse Generator Module.
- Timing Control Module.
- Output Module.
When the keys are pressed the current flows directly to the ground due to the low resistive path making no more current available to the port pins pulling it down to low state, so when ever the keys are pressed the corresponding pins are pulled down. So normally every pin are at a high state giving a value of 1 when ever the keys are pressed the pins are to the low state giving the value 0.
This change is constantly monitored to check for any user interaction. The microcontroller constantly monitors port 0 for any change in port value and if it finds any change it generates the appropriate control signals. The stepper motor driver circuit consists of two stages-low power switching stage& high power switching stage. The function of the low power switching stage is to boost up the low power signal output from the micro controller to a high power signal so as to drive the power transistor.
Care should be taken while connecting the circuit to the motor as stepper has got a tendency to produce very high reverse current compared to DC motor.
To protect the circuit for this reverse current we have connected a diode in reverse bias across the coil supply so that whenever reverse current is present this diode will sink it protecting the circuit.
The main objective of this project is to implement an Pass word Based Door Locking System Using AT89c51 Microcontroller.
Security is a prime concern in our day-today life. Everyone wants to be as much secure as possible. An access control for doors forms a vital link in a security chain. The microcontroller based Door locker is an access control system that allows only authorized persons to access a restricted area. The system is fully controlled by the 8 bit microcontroller AT89C51 which has a 2Kbytes of ROM for the program memory. The password is stored in the EPROM so that we can change it at any time.
The system has a Keypad by which the password can be entered through it. When the entered password equals with the password stored in the memory then the Stepper motor rotate forward side so that the door is opened. If we entered a wrong password for more than three times then the Alarm is switched on. When we go inside and come back then the microcontroller will sense the person using the IR, the microcontroller will automatically open the door for you.
The default password is 1111 and you can change the password by dialing 1234, old password, and new password #button. for example if you want to change the password from the default to 4523 then dial 123411114523# after dialing you can hear a beep sound which confirm the operation goes successful.
- AT89c51 Microcontroller
- Stepper motor
- ULN2003 Motor Driver
- 5V Buzzer
- Embedded C
- KEIL Demo Version with Simulator