in-house training project

8/12/2019 In-house Training Project

1/18

Group members-SHASHANK PANDEY 052)SRIJAN UPADHYAY 054)AKHILESH THAPLIYAL 073)


2/18

INTRODUCTION

The traffic signals are used to control the flow of vehicles.In recent years the need of transportation has given rise tonumber of vehicles on road. Due to this reason traffic jamsand road accidents are a common sight in any busy city.Traffic signals provide an easy, cheap, automated and

justified solution to the road points where the vehicles mayturn to the other directions.

CONTROL SIGNALS- The control signals are 4 lights. Toplight is Red(Stop)-Middle Light is Yellow(Wait)-Bottom

Light is Green(Go)-Bottom right Light is also Green(the Gosignal for traffic taking right turn).


3/18

CIRCUIT DIAGRAM


4/18

COMPONENTS USED IC-555Timer

IC -4017Counter

Diode (IN4148, 4007)

LED (Red, Amber, Green)

Preset (100Kohms

variable resistor) Capacitor (10uf Polar)

Power Supply (9-12V)


5/18

ABOUT IC 555 TIMER

The 555 timer ICis an integrated circuit (chip)used in a variety of timer, pulse generation,

and oscillator applications. The 555 can be used toprovide time delays, as an oscillator, and as a flip-flopelement. Derivatives provide up to four timingcircuits in one package.


6/18

PIN DIAGRAM (IC 555)

The connection of the pins for a DIP package is as follow


7/18

PIN CONFIGURATION (IC 555)

Pin Name Purpose

1 Ground Ground reference voltage, low level (0v)

2 Trigger The OUT pin goes high and a timing interval starts when this inputfalls below of CTRL voltage

3 Output This output is driven to approximately 1.7V below +VCC or GND.

4 Reset A timing interval may be reset by driving this input to GND, butthe timing does not begin again until RESET rises above

approximately 0.7 volts. Overrides TRIG which overrides THR.

5 Control Voltage Provides "control" access to the internal voltage divider (bydefault, 2/3 VCC).

6 Threshold The timing (OUT high) interval ends when the voltage at THR is

greater than that at CTRL (2/3 VCC if CTRL is open).

7 Discharge Open collector output which may discharge a capacitor betweenintervals. In phase with output.

8 VCC Positive supply voltage, which is usually between 3 and 15 V

depending on the variation.


8/18

MODE OF OPERATION (555 TIMER)

Astable ModeAn Astable Circuit has no stable state - hence thename "astable". The output continually switches statebetween high and low without any intervention from

the user, called a 'square' wave. This type of circuitcould be used to give a mechanism intermittentmotion by switching a motor on and off at regularintervals. It can also be used to flash lamps and LEDs,

and is useful as a 'clock' pulse for other digital ICs andcircuits.


9/18


10/18

PIN DIAGRAM (IC 4017)


11/18

PIN CONFIGURATION (IC 4017) 1to pin7 and pins 8, 9, 10 are all the outputs of the IC.

Pin16 is for the positive supply and pin 8 is ground.

Pin 15is the reset point of the IC. A logic '0' to this pin (or by connecting it to theground), gives a green signal to the IC, so that it can function. A logic '1' or apositive supply here will bring its proceedings to a stand still and will reset it. Atthis position pin 3of the IC 4017stays at logic '1' where as all other outputs arelogic 'lo'.

Pin 14is the clock input of the IC 4017. An external clock signal to this point willmake a logic '1'to proceed sequentially, beginning from pin 3and ending at pin 11.

The cycle is repeated as long as the clock persists at pin 14. The period of timeeach output stays logic '1'will depend on the time period of the positive peaks ofthe clock signal. With the rising edge of every clock pulse, the 'logic 1' will shiftfrom one output to the other serially.

Pin 13 is the clock enable point. A logic '1'to this pin will stop the IC 4017fromproceeding and its output will freeze at that instant at the particular output. Evenif the clock signal at pin 14is ON, the output cant shift as long as pin 13is held atlogic'1', therefore this point should be grounded. On the contrary if pin 14is heldat logic '1'and clock signal is applied at pin 1, every falling edge of the pulse willmake the outputs to change state sequentially.


12/18

PRESET There are 3 pins/terminals on a preset. The maximum resistance that a

preset can provide is written on it. If 100k is written on preset, it meansthat we can vary its resistance from 0ohm to 100K ohms. A movable metalis rotated in clockwise or anticlockwise direction that changes theresistance of preset.

If we take terminal A and terminal B, and rotate the movable metal

in clockwise direction, the resistance of preset increases from 0 tomaximum. As we move the metal in anticlockwise direction, the resistancedecreases.

If we take terminal A and terminal C, and rotate the movable metalin anticlockwise direction, the resistance of preset increases from 0 to

maximum. As we move the metal in clockwise direction, the resistancedecreases.


13/18

PURPOSE OF MAIN DEVICES

Use of a 555 timer circuit to produce "clock"pulses.

Use of a 4017 decade counter circuit toproduce a sequence of pulses coming fromthe 555 and for frequency division .

Diodes used in the purpose of f lashingsequences.


14/18

METHOD OF TESTINGSTesting through Or Cad Simulation

Testing through BreadboardTesting through General Purpose PCB

Mounting on Main PCB


15/18

WORING PRINCIPLE The circuit is self explanatory by its name and can be used to control traffic in public

places or to demonstrate traffic parks. The given circuit of the Traffic Light control is a combination of the circuits one is a

square wave generator, to provide the pulses and the other is the counter that counts theincoming pulses.

Here, the 555 IC works as the square wave generator. The IC is widely used and popularone. It works as astable multivibrator. When the IC receives the supply, the square waveoutput is available at the pin no. 3 and a regular interval pulse become availablecontinuously. The time interval can be adjusted by varying the preset.

The pulse is then fed to the pin no. 14 (input pin) of 4017 IC. This IC is work as a counterIC. 4017 IC is the heart of the circuit, which is a decade counter. This counter has 10outputs.

The diodes are connected to the output of the 4017 IC. Now the Red LED is connectedwith the first four output of the counter (i.e. Q0- Q3), then straight lane Green LED isconnected to the next five output (Q4- Q8) of the counter, whereas the right turn GreenLED is connected with the first three output of the counter from which straight lane

green LED is connected (i.e. Q4- Q6), the last output of the counter (Q9) is connectedwith the Yellow LED. Now, the Red LED will glow first, then straight lane as well as right turn Green LED will

glow after few seconds the right turn Green LED will be switched off and the straight laneGreen LED will remain glow for few seconds. At last, the Yellow LED will glow just for 4-5seconds then the Red LED will again glow. Thus, the sequence will continue.

By changing the value of capacitor, connected at the pin no. 6 and pin no. 2 of the 555timer IC, as well as by varying the value of 100 Kilo Ohms Preset, the time interval of

glowing of lights can be increased or decreased.


16/18

ADVANTAGES Reduction in normal recurring.

Significantly enhanced operational tools congestion to effectively manage trafficincidents.

It improved public transport service.

Reduction in emergency response limes and safer travel.

Improve traffic guidance and traffic flow

Reduce fuel consumption

Increase safety.

They increase the traffic-handling capacity of the intersection

Less cost.


17/18

DISADVANTAGES

Excessive delay may be caused. These unnecessary delay results in significant fuel

waste and higher motorist costs.

Disobedience of signals.


18/18

APPLICATIONS

Ramp metering.

Timers.

Fire station or medical emergency entrance.

At the entrance and exit of some car washes.

At the landing-stage of a ferry and aboard the ferry.

in-house training project

Documents