WELCOME AUTOMATIC LEVEL CROSSING SUBMITTED BY LENIN C

WELCOME

AUTOMATIC LEVEL CROSSING

SUBMITTED BY LENIN C

INTRODUCTION • Railways - cheapest mode of transportation. • Aims to avoid accidents. • Using simple electronic components- automate the control of railway gates. • Indicator light - alert the motorists about approaching train.

BLOCK DIAGRAM POWER SUPPLY UNIT PIC 16 F 877 A MICROCONTROLLER TRANSMITTER RECEIVER UNIT GATE CONTROL UNIT

BLOCK DIAGRAM DESCRIPTION 1. POWER SUPPLY UNIT • Consists of transformer, Bridge rectifier & regulator. • Power supply -230 V ac single phase. • Output - rectifier circuit. • Regulator 7805 provide 5 V –microcontroller operation.

2. TRANSMITTER RECEIVER UNIT � 2 powerful IR transmitters and two receivers. �IR LED � Fixed at 2 KM. �Sensor along the train direction -‘foreside sensor’ , other - ‘aft side sensor’.

3. GATE CONTROL UNIT �Consists of motor driver, H Bridge and DC motor. �Major components used - PIC microcontroller 16 F 877 A, ULN 2803 and 30 rpm geared DC motor. �DC motor controls gate opening and closing. �Driver IC 2803 decodes the coding - conveys necessary data to DC motor.

FLOWCHART START GATE OPENS, GREEN SIGNAL FOR ROAD USERS IF TRAIN REACHES SENSOR 2 IF TRAIN REACHES SENSOR 1 NO NO YES GATE OPENS, BUZZER STOPS, GREEN LIGHT FOR ROAD USERS YES GATE CLOSES, BUZZER SOUNDS RED SIGNAL FOR ROAD USERS STOP

SCHEMATIC DIAGRAM FOR GATE CONTROL UNIT

CIRCUIT DIAGRAM

CIRCUIT DIAGRAM DESCRIPTION 1. POWER SUPPLY UNIT �Step down transformer-reduce high voltage. �Rectifier -ac to dc. �Regulator -regulates output , avoid fluctuations. �Input filter -remove harmonics and ripples. �Output filter –remove ripples in output.

2. IR TRANSMITTER • IR LED series with resistor. • IR LED- detection. • IR led - constantly emits light. • Power consuming. • Optimized for low ranges.

3. IR RECEIVER �Detects transmitted IR pulses. • Train crosses sensor, output transits to low state. • IR light falls , emitter to collector voltage increases. • More light intensity - more voltage drop. • As voltage drop increases- output of op-amp high.

4. PIC MICROCONTROLLER

PIC DESCRIPTION • • • PIC 16 F 877 A- 40 pin IC Crystal oscillator- 16 MHz Input pins - RA 0 & RA 1 Output - port B pins RA 0 low – outputs 0 1 sequence – rotate motor clockwise. RA 1 low – RA 1 high – outputs 1 0 sequence – rotate motor anticlockwise.

5. DC MOTOR • 30 RPM geared DC motor. • Simple electromagnetism. • DC motor – clockwise direction – gate closes. • DC motor – anticlockwise direction – gate opens. • Forward and reverse operation - changing the direction of current.

6. ULN - 2803 • Motor driver IC. • No VCC pin. • Decodes coding - conveys data to DC motor • Port B drives DC motor through ULN 2803. • PIC outputs 0 1 - ULN outputs 1 0 - one terminal of DC motor to VCC- other terminal to gnd -DC motor rotates clockwise and viceversa.

OPERATION �Two pairs of IR sensors. �Gate operated by DC motor. �DC motor interfaced to ULN 2803. �Train arrives sensor 1 - DC motor rotates forward – gate closesred signal glow-buzzer beeps. �Train reaches sensor 2 - DCmotor rotates reverse- gate opens green signal glow-buzzer stops.

PROGRAM FLOWCHART START 1 INITIALIZE RA 0 & RA 1 NO NO IF RA 1= 0 YES IF RA 0= 0 YES RED LIGHT GLOWS, BUZZER STARTS, GATE CLOSED IF RA 1 =1 NO YES GREEN LIGHT GLOWS, BUZZER STOPS , GATE OPENS 1 STOP

ADVANTAGES �Accidents are avoided. �High accuracy. �No time lag.

DISADVANTAGES �Regular assessment of safety performance. �Motor requires 223 v ac power supply. REMEDY: Using solar cell batteries.

SCOPE OF PROJECT � Better working of INDIAN RAILWAY. � User friendly. � Can be expanded according to demand. � Additional modules can be added.

CONCLUSION �Improving safety level crossings. � Priority of safety enhancement.

REFERENCES SITES �www. scribd. com �www. google. com

THANK YOU