Acknowledgement ********** “As it is said a single flower doesn’t make a garland”. This thought hold true for this project. I would like to thank my teachers who have always supported me throughout, and have given me the extra motivation to succeed during difficult times. I would like to thank the members of the Traffic light team. I have thoroughly enjoyed working with my team as it has given me the opportunity to gain valuable work experience and gain some practical skills which complement my college studies. I would like to specially thank our supervisor, Mr Taher and Mr Abubacker for all his time, invaluable advice and encouragement throughout the project. 09003 Faisal Chowdhury
Traffic Light Electronic Project - design and Fabrication of a smart Traffic Light. Basic design with Smart Integration.
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Acknowledgement
**********
“As it is said a single flower doesn’t make a garland”.
This thought hold true for this project. I would like to thank my teachers who have always
supported me throughout, and have given me the extra motivation to succeed during difficult
times. I would like to thank the members of the Traffic light team. I have thoroughly enjoyed
working with my team as it has given me the opportunity to gain valuable work experience
and gain some practical skills which complement my college studies.
I would like to specially thank our supervisor, Mr Taher and Mr Abubacker for all his time,
invaluable advice and encouragement throughout the project.
**************
09003 Faisal Chowdhury
TABLE OF CONTENTS
Page
ACKNOWLEDGEMENT
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION
CHAPTER 2 DISCUSSION
CHAPTER 3 RESULT AND CONCLUSION
CHAPTER 4 RECOMMENDATION
CHAPTER 5 REFRENCES
09003 Faisal Chowdhury
1. Introduction
Traffic Light
Traffic lights, which may also be known as stoplights, traffic lamps, traffic signals,
are signaling devices positioned at road intersections, pedestrian crossings and other
locations to control competing flows of traffic. Traffic lights have been installed in
most cities around the world. They assign the right of way to road users by the use of
lights in standard colors (Red - Amber - Green), using a universal color code (and a
precise sequence, for those who are color blind). Traditionally, incandescent and halogen
bulbs were used. Because of the low efficiency of light output and a single point of failure
(filament burnout) municipalities are increasing retrofitting traffic signals with LED arrays
that consume less power, have increased light output, last significantly longer, and in the
event of an individual LED failure, still operates albeit with a reduced light output. With the
use of optics, the light pattern of an LED array can be comparable with the pattern of an
Connect the correct way round. They will be marked with a + or - near one lead.
5 Diodes Connected the correct way round.
6 LEDs
Connected the correct way round. The diagram may be labelled a or + for anode and k or - for cathode; yes, it really is k, not c, for cathode! The cathode is the short lead and there may be a slight flat on the body of round LEDs.
7
Wire Links between points on the circuit board.
single core wire
Use single core wire, this is one solid wire which is plastic-coated. If there is no danger of touching other parts you can use tinned copper wire, this has no plastic coating and looks just like solder but it is
stiffer.
8
Battery clips, buzzers and other parts with their own wires
Connected the correct way round.
10 ICs (chips)
Connected the correct way round. Many ICs are static sensitive.
Carefully inserted ICs in their holders: make sure all the pins are lined up with the socket then push down firmly with your thumb.
Three prefixes (multipliers) are used, µ (micro), n (nano) and p (pico):
µ means 10-6 (millionth), so 1000000µF = 1F
n means 10-9 (thousand-millionth), so 1000nF = 1µF
p means 10-12 (million-millionth), so 1000pF = 1nF
Resistors
Function
Resistors restrict the flow of electric current, for example a resistor is placed in series with a light-emitting diode (LED) to limit the current passing through the LED.
Connecting and soldering
Resistors may be connected either way round. They are not damaged by heat when soldering.
Resistor values - the resistor color code
Resistance is measured in ohms, the symbol for ohm is an omega . 1 is quite small so resistor values are often given in k and M . 1 k = 1000 1 M = 1000000 .
Resistor values are normally shown using coloured bands. Each colour represents a number as shown in the table.
Most resistors have 4 bands:
The first band gives the first digit. The second band gives the second digit.
The third band indicates the number of zeros.
The fourth band is used to shows the tolerance (precision) of the resistor.
09003 Faisal Chowdhury
The ResistorColour Code
Colour Number
Black 0
Brown 1
Red 2
Orange 3
Yellow 4
Green 5
Blue 6
Violet 7
Grey 8
White 9
IC
Integrated Circuits are usually called ICs or chips. They are complex circuits which have
been etched onto tiny chips of semiconductor (silicon). The chip is packaged in a plastic
holder with pins spaced on a 0.1" (2.54mm) grid which will fit the holes on stripboard and
breadboards. Very fine wires inside the package link the chip to the pins.
Pin numbers
The pins are numbered anti-clockwise around the IC
(chip) starting near the notch or dot. The diagram shows
the numbering for 8-pin and 14-pin ICs, but the principle is the same for all sizes.
IC holders (DIL sockets)
ICs (chips) are easily damaged by heat when soldering and their short pins cannot
be protected with a heat sink. Instead we use an IC holder, strictly called a DIL
socket (DIL = Dual In-Line), which can be safely soldered onto the circuit board. The IC is
pushed into the holder when all soldering is complete.
09003 Faisal Chowdhury
IC holders are only needed when soldering so they are not used on breadboards.
Commercially produced circuit boards often have ICs soldered directly to the board without
an IC holder, usually this is done by a machine which is able to work very quickly. Please
don't attempt to do this yourself because you are likely to destroy the IC and it will be
difficult to remove without damage by de-soldering.
Removing an IC from its holder
If you need to remove an IC it can be gently prised out of the holder with a small flat-blade
screwdriver. Carefully lever up each end by inserting the screwdriver blade between the IC
and its holder and gently twisting the screwdriver. Take care to start lifting at both ends
before you attempt to remove the IC, otherwise you will bend and possibly break the pins.
Using diodes to combine outputs
The outputs of ICs must never be directly connected together.
However, diodes can be used to combine two or more digital
(high/low) outputs from an IC such as a counter. This can be a
useful way of producing simple logic functions without using
logic gates!
09003 Faisal Chowdhury
The diagram shows two ways of combining outputs using diodes. The diodes must be capable
of passing the output current. 1N4148 signal diodes are suitable for low current devices such
as LEDs.
For example the outputs Q0 - Q9 of a 4017 1-of-10 counter go high in turn. Using diodes to
combine the 2nd (Q1) and 4th (Q3) outputs as shown in the bottom diagram will make the
LED flash twice followed by a longer gap. The diodes are performing the function of an