Introduction Embedded systems are designed to do some specific task, rather than be a general-purpose computer for multiple tasks. An embedded system is not always a separate block - very often it is physically built-in to the device it is controlling.
Description to project The purpose of the project is to control the traffic problem presently observed in cities. where due to large population and inadequate infrastructure, road safety enforcement and traffic regulation is very difficult. The speed of the vehicle can be varied by varying the “duty cycle” of the pulse input. This project uses regulated 5V, 500MA power supply, 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac output of secondary of 230/12V step down transformer.
Vehicle section: LCD DISPLAY BATTERY (16 X 2 LINES) MICRO CONTROLLER DECODER MOTOR AT89S52 DRIVER RF RX MOTORS
BLOCK DIAGRAM EXPLANATIONMicro controller: In this project work the micro-controller is plays major role. Micro-controllers were originally used as components in complicated process-control systems. Micro-controllers are small in size and less cost. One of the major differences between a Microprocessor and a Micro controller is that a controller often deals with bits not bytes as in the real world application.
RF transmitter section RF transmitters are electronic devices that create continuously varying electric current, encode sine waves, and broadcast radio waves. Modulators encode these sign wives and antennas broadcast them as radio signals. Radio techniques limit localized interference and noise. Additional considerations when selecting RF transmitters include supply voltage, supply current, RF connectors, special features, and packaging.
RF TRANSMITTER Pin Description of the Transmitter module
RF receiver section RF receivers are electronic devices that separate radio signals from one another and convert specific signals into audio, video, or data formats. RF receivers use an antenna to receive transmitted radio signals and a tuner to separate a specific signal from all of the other signals that the antenna receives. RF receivers vary in terms of performance specifications such as sensitivity, digital sampling rate, measurement resolution, operating frequency, and communication interface.
IR-SENSOR Infrared (IR) radiation is part of the electromagnetic spectrum, which includes radio waves, microwaves, visible light, and ultraviolet light, as well as gamma rays and X-rays. A sensor network is a computer network of spatially distributed devices using sensors to monitor conditions (such as temperature, sound, vibration, pressure, motion or pollutants) at a variety of locations IR wavelengths are usually expressed in microns, with the lR spectrum extending from 0.7 to 1000microns. Based on the sensors calibration equation and the targets emissivity. This temperature value can be displayed on the sensor or, in the case of the smart sensor, converted to a digital output and displayed on a computer terminal.
L293D: The L293 is an integrated circuit motor driver that can be used for simultaneous, bi-directional control of two small motors. The L293 is limited to 600 mA, but in reality can only handle much small currents unless you have done some serious heat sinking to keep the case temperature down. The L293 comes in a standard 16-pin, dual-in line integrated circuit package. There is an L293 and an L293D part number.
LINEAR KEYPAD This section basically consists of a Linear Keypad. Basically a Keypad can be classified into 2 categories. One is Linear Keypad and the other is Matrix keypad. Linear Keypad: This Keypad got „n‟ no. of keys connected to „n‟ data lines of microcontroller. This Keypad is used in places where one needs to connect less no. of keys. Here in this project, a linear keypad is used with switches connected in a serial manner. Linear keypad is used in this project because it takes less no. of port pins.
Liquid crystal display Liquid crystal displays (LCDs) have materials, which combine the properties of both liquids and crystals An LCD consists of two glass panels, with the liquid crystal material sand witched in between them. The LCD‟s are lightweight with only a few millimeters thickness. Since the LCD‟s consume less power, they are compatible with low power electronic circuits, and can be powered for long durations. Changing the display size or the layout size is relatively simple which makes the LCD‟s more customers friendly.
Power supply The power supplies are designed to convert high voltage ACmains electricity to a suitable low voltage supply for electronicscircuits and other devices.
Transformer A transformer is an electrical device which is used toconvert electrical power from one Electrical circuit to anotherwithout change in frequency. A step-down transformer has a large number of turns on itsprimary (input) coil which is connected to the high voltagemains supply, and a small number of turns on its secondary(output) coil to give a low output voltage.
RECTIFIER A circuit which is used to convert a.c to dc is known asRECTIFIER. The process of conversion a.c to d.c is called“rectification”. A bridge rectifier makes use of four diodes in a bridgearrangement to achieve full-wave rectification. OPERATION
Regulator Voltage regulator ICs is available with fixed (typically5, 12 and 15V) or variable output voltages. The maximum current they can pass also rates them. Negative voltage regulators are available, mainly foruse in dual supplies.
CIRCUIT DISCRIPTION The objective of the paper is to present a conceptual model of a microcontroller based variable electronic speed governor that can be implemented to control the speed of any vehicle depending on the local speed limit. The circuit is cost effective, efficient and easy to implement on already existing vehicles. Every city, town or a village, can be marked and divided into individual zones. The division depends upon the area under which the business, residential, and industrial regions come under. The central business district being a very busy traffic zone demands the least speed limit, with the residential and industrial zones having lesser traffic densities, the speed limits will vary accordingly.
CONCLUSION The project “MICRO CONTROLLER BASED AUTOMATION VARIABLE FREQUENCY ELECTRONIC SPEED GOVERNOR” has been successfully designed and tested. It has been developed by integrating features of all the hardware components used. Presence of every module has been reasoned out and placed carefully thus contributing to the best working of the unit. Secondly, using highly advanced IC‟s and with the help of growing technology the project has been successfully implemented.