Block diagram for simple traffic light system: -

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FIG (1) : BLOCK DIAGRAM FOR SIMPLE TRAFFIC LIGHT SYSTEM

POWER SUPPLY: -

For the any electrical power supply there is need of power supply. In this block diagram we have used 230 volt 50 hertz ac supply. This ac supply is given to the transformer of 15 volt dc. According to requirement of our circuit it needs 12 volt dc.

SWITCHING SYSTEM: -

This block contains number of switching diode for switching the power to the particular circuit. Here we have used IC 4044, IC 4041 diodes for switching purpose.

Timing circuit: -

In timing circuit we use IC ne555 along with IC 1n4148 which have high speed of operation.

ROUTING: -

This block is used for shifting the control to the respective output LOED or light and operating mode for particular selected output.

LIGHT OUTPUT: -

This output is last stage of block diagram that is used for controlling the traffic light system.

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POWER SUPPLY

SWITCHING SYSTEM

TIMING CIRCUIT

ROUTING

Circuit diagram of simple traffic light system: -

FIG (2) : CIRCUIT DIAGRAM OF SIMPLE TRAFFIC LIGHT SYSTEM

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Component list for simple traffic light system: -

FIG (3) : COMPONENTLIST FOR SIMPLE TRAFFIC LIGHT SYSTEM

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Information about IC used in circuit diagram: -

1] IC NE555: -

These devices are precision timing circuits capable of producing accurate time delays or

oscillation. In the time-delay or mono-stable mode of operation, the timed interval is

controlled by a single external resistor and capacitor network. In the astable mode of

operation, the frequency and duty cycle can be controlled independently with two external

resistors and a single external capacitor.

The output circuit is capable of sinking or sourcing current up to 200 mA. Operation is

specified for supplies of 5 V to 15 V. With a 5-V supply.

Specification of NE555: -

VCC 11.2 V

IA 200 mA

PD 448 W

Pin diagram of NE555: -

RESET TRIGGER

VOLTAGE

THRSHOLD

VOLTAGE

OUTPUT DISCHARGE

SWITCH

L IRREVELENT IRREVELENT L ON

H < 1/3 VCC IRREVELENT H OFF

H < 1/3 VCC >2/3 VCC L ON

H >1/3 VCC < 2/3 VCC AS PERLAST 1 AS PER LAST 1

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Pin description: -

Pin 1: Ground is made available at this pin

Pin 2: Trigger pulse is given to the IC

Pin 3: Output is taken across this pin with respect to ground

Pin 4: Reset instruction is used to reset the IC for new use of application

Pin 5: Control signals are given to the IC for particular task

Pin 6: Threshold voltage is given to the IC across this pin

Pin 7: Discharge the power given to IC is can be done by this pin

Pin 8: The main power supply +12 V is given at this pin

Application of NE555: -

Mono-stable multivibrator.

Astable multivibrator.

Pulse width modulation.

Frequency divider.

Missing pulse detector.

Pulse position modulation.

Monostable multivibrator : -

For various operations we need multivibrator in Industrial as

well as applied electronics. By using this NE555 we can generate mono-stable multivibrator

for generation of single wave generation. The NE555 used to generate pulse timer for

operaion of square, triangular, saw-tooth wave generation using timer IC.

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2] IC CD4017: -

The CD4017BC is a 5-stage divide-by-10 Johnson counter with 10

decoded outputs and a carry out bit. These counters are cleared to their zero count by a logical

“1” on their reset line. These counters are advanced on the positive edge of the clock signal

when the clock enable signal is in the logical “0” state.

Pin description: -

Pin 1 to 11: Decode output are get across these pins

Pin 8 : VSS provide source voltage.

Pin 14 : Accepts the clock signal

Pin 13 : Play important role to enable or disable the clock pulse.

Pin 15: VDD provides an dc voltage for IC.

Features of CD4017: -

Wide supply voltage range: 3.0V to 15V.

High noise immunity: 0.45 VDD (typ.).

Low power Fan out of 2 driving 74L.

Medium speed operation: 5.0 MHz (typ.).

With 10V VDD.

Low power: 10 mW (typ.).

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Applications of CD4017: -

Automotive.

Instrumentation.

Medical electronics.

Alarm systems.

Industrial electronics.

Remote metering.

Automative: -

In automotive industry we need logical counters for our counting the flow of

pulses, rounds, revolutions and many more. For counting purpose in automotive needs

automatic controlled IC that can operate with it’s own input clock signal for the voltage range

+12V this IC is suitable.

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3] IC CD4001:-

The IC4001 Universal Remote Integrated Circuit is a fully integrated solution for a complete four-in-one universal remote control. The IC4001 includes the comprehensive Innotech library of entertainment remote control codes for the highest possible coverage of consumer products. The IC4001 may be used to control up to four different entertainment devices, typically a TV, VCR, Satellite, and cable box. All basic operations are supported. The IC4001 may be customized to include OEM-specific remote control codes. The choice of programming methods ensures the easiest-possible customer operation.

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Pin description: -

Pin 1 to 8 : Input are accepted for IC

Pin 10 to 17 : output are collected here for IC

Pin 12, 13: Interrupts are added to IC

Pin 18,19 : Crystal oscillator is accepted here

Pin 20 : Ground connection is provided here

Pin 31 : The enable all pins control is done here

Pin 37 : Low voltage operation are done across this pin

Pin 38 : Infrared connection are made here

Pin 39 : LED connection are made here

Pin 40 : +12 volt supply is provided here

Features of IC 4001: -

Fully Integrated Solution

Low power “Sleep Mode” for long battery

Program code read-back

Easy to program

Ratings: -VCC : 11.8 VIA : 500 µAPD : 448mW

Application: -

This IC is been used for remote sensing operations of any kind of programs,

instruments and many more. It can be used for different sensing operations as well Infrared

and LED detection and connections for input and outputs.

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4] IC CD4081: -

The CD4081B, types are supplied in 14-lead hermetic dual-in-line ceramic

packages (F3A suffix), 14-lead dual-in-line plastic packages (E suffix), 14-lead small-outline

packages (M, MT, M96, and NSR suffixes), and 14-lead thin shrink small-outline packages

(PW and PWR suffixes). It has medium speed of operation along with less noise margin. It

has CMOS configuration showing same requirement of JEDEC standard specification.

Features of CD4081: -

VDD= 10V

VPP = -0.5 V to +20V

I/P Voltage range = -0.5V to VDD+0.5 V

DC I/P current = 0.5mA

PD = 500mW ( for TA = -500 to 1000)

Application: -

This IC is been used for connection for LED and Infrared transceiver connections.

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5] IC CD4069: -

The UTC CD4069 is a CMOS IC with six inverter circuits and designed for using of wide

power supply operating range, low power consumption, high noise immunity, and symmetric

controlled rise and fall times. The IC is capable of ESD protection by diode clamps to VDD

and VSS.

FEATURES

Wide supply voltage range: 3.0V ~ 15V.

High noise immunity: 0.45 VDD typ.

Low Power TTL compatibility: Fan out of 2 driving 74L

VDD = -0.5V to +18V

Vin = -0.5V to +0.5V

PD = 500mW

6] IC 7812: - These applications include on-card regulation for elimination of noise and distribution problems associated with single-point regulation. Each of these regulators can deliver up to 1.5 A of output current. The internal current-limiting and thermal-shutdown features of these regulators essentially make them immune to overload. In addition to use as fixed-voltage regulators, these devices can be used with external components to obtain adjustable output voltages and currents, and also can be used as the power-pass element in precision regulators.

Rattings: -

VD : 12 V

ID : 1.5 A

PD : 18 W

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Features: -

3-Terminal Regulators High Power-Dissipation Capability Output Current up to 1.5 A Internal Short-Circuit Current Limiting Internal Thermal-Overload Protection Output Transistor Safe-Area Compensation

7] IC 1N4148: -

The 1N4148 and 1N4448 are high-speed switching diodes fabricated in planar

technology, and encapsulated in hermetically sealed leaded glass SOD27 (DO-35) packages.

FEATURES

Hermetically sealed leaded glass SOD27 (DO-35) package

High switching speed: max. 4 ns

General application

Continuous reverse voltage: max. 100 V

Repetitive peak reverse voltage: max. 100 V

Repetitive peak forward current: max. 450 mA.

APPLICATIONS

· High-speed switching.

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8] IC 1N4007: -

Features

Low forward voltage drop.

High surge current capability.

This is one kind of analog IC used for surge current only.

9] Resistors: -

Resistors are the electronic component that control flow of electrons i.e. current. In our project we had used following resistors

NAME OF RESISTOR NUMBER OF RESISTORS UNITVariable resistor 1 1 MΩVariable resistor 1 10 KΩR1 1 15K ΩR2 1 2.2 K ΩR 2 10 KΩR 12 1 KΩ

10] Capacitors: -

Those electronic devices stores charges are called as capacitor. In our projects we have used following capacitors

TYPE NO. UNITElectrolyte 1 1000 µF 35 VElectrolyte 1 100 µF 50VCeramic disc 1 0.01 µFCeramic disc 1 0.1 µF

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11] Miscellaneous : -

We have used here 1 transformer and switch to ON/OFF switch along with push to on switch and some LED’s.

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Application: -

To reduce the stop, wait and go time on traffic light system. To change the traffic according to need.

To change traffic according to need: -

In normal traffic light system, we can’t alter the time interval when there are national functions like Independence Day or various programs like Common Wealth Games. For that purpose should change the timing and traffic way. This can be done by this project.

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Future scope: -

In traffic control of sub-urban area. In all cities meanwhile of any function or program. Using sharp pointers to stop the rule breakers.

Using sharp pointers to stop the rule breakers.

In normal life we see that some unsocial elements who break the traffic rule. To avoid this kind of element we can use sharp metallic pointers to puncture the tire of the bike or car. This can be used for awaking people about the traffic light system.

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References: -

www.EFYMAG.com

www.wikipedia.com

www.google.com

Magazine: Electronics For You!

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