Done By:MAJED SULLAIYM SAIF AL-SHABNOTISAEED ALI SAEED AL-NAAMANI

33363SHAKHABOUT HUMAID AL-KAABI

ABDULLAH MASUOD HAMED AL-KALBANI 31978

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PROJECT SUPERVISOR:ENGR. SAYYED AQEEL ASHRAF.

CONTENTS : - Page No: -

ACKNOWLEDGEMWNT 3ACTION PLAN 4CHAPTER-1: INTRUDACTION 5CHAPTER-2: CIRCUIT DIAGRAM 6CHAPTER-3: PICTURE OF OUR PROJECT 7CHAPTER-4: IC, 4017 8CHAPTER-5: IC, 555 TIMER 9CHAPTER-6: 1N914 12CHAPTER-7: LED 9 V, RED, YELLOW, GREEN COULOR 13CHAPTER-8: TRANSISTORS, 2N3904 14CHAPTER-9: 180, 47K, 10K Ohms RESISTORS 16

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CHAPTER-10: CAPACITOR, 10 µF, 30V 17CHAPTER-11: 9 -Volts Battery 18CHAPTER-12: CONCLUSION 19REFERENCE. 20

AKNOWLEDGMENT

In the praise of almighty ALLAH, the beneficent, the merciful who showed the path of righteous ness and blessed me the strength to embark this task.

We would like to express our deep appreciation to our project supervisor Eng.Sayyed Aqeel Ashraf for his incisive comments and skillful

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guidance throughout the design process.

We are also thankful to Dr. Salim Dhofar for his valuable suggestions.

We wish to express our thanks to the HOD, and the Dean of our college for their encouragement and for making

the facilities available.

Finally we are thankful to Mr. Hani Jobron and Mr. Saeed Al-Mahri for their help in experimental studies.

SN ActionDone

ByTarget Date

Date of Comple

tion

Reason for

change Comple

tion Date

1Select

the project

Group

with 25/4/2

00630/4/20

06

Done

4

Guide

2

Study the

project and its working

Group

1/5/2006

15/5/2006

Cultural week

3

Collect the

components

Group

with Hani

23/5/2006

31/5/2006

IC was not

available

4

Collect the

circuit on

bread board

Group

1/6/2006

5/6/2006

Done

5

Collect data

sheet of active

components

Group

with Guid

e

6/6/2006

12/6/2006

Done

6

Testing the

Project Group

15/6/2006

19/6/2006

Capacitor & IC

was damage

d.

7

Writing the

report Group

21/6/2

006

25/6/2006

Done

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ACCCCC PLAN

Chapter 1Introduction

Solid-state LED light sources are known as p-n semiconductor devices. By doping a substrate material with different materials, a p-n junction is formed within the semiconductor crystal. The do pant in the n region provides mobile negative charge carriers (electrons), while the do pant in the p region provides mobile positive charge carriers (holes). Within a semiconductor crystal, when a forward voltage is applied to the p-n junction from the p region to the n region, the charge carriers inject across the junction into a zone where they recombine and convert their excess energy into light. The materials used at the junction determine the wavelength of the emitted light. A clear or diffuse

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ACTIOT PLAN

epoxy lens covers the semiconductor chip and seals the LED. It also provides some optical control to the emitted light; LEDs come in a variety of angular distributions.

Chapter 2Circuit Diagram

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Chapter 3Picture of Our project

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Chapter 4IC, 4017-Decade Counter

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The count advances as the clock input becomes high (on the rising-edge). Each output Q0-Q9 goes high in turn as counting advances. For some functions (such as flash sequences) outputs may be combined

The reset input should be low (0V) for normal operation (counting 0-9). When high it resets the count to zero (Q0 high). This can be done manually with a switch between reset and +Vs and a 10k resistor between reset and 0V. Counting to less than 9 is achieved by connecting the relevant output (Q0-Q9) to reset, for example to count 0,1,2,3 connect Q4 to reset.

The disable input should be low (0V) for normal operation. When high it disables counting so that clock pulses are ignored and the count is kept constant.

The ÷10 output is high for counts 0-4 and low for 5-9, so it provides an output at 1/10 of the clock frequency. It can be used to drive the clock input of another 4017 (to count the tens).

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Chapter 5IC, 555 Timers

The circuit symbol for a 555 (and 556) is a box with the pins arranged to suit the circuit diagram: for example 555 pin 8 at the top for the +Vs supply, 555 pin 3 output on the right. Usually just the pin numbers are used and they are not labeled with their function.

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The 555 and 556 can be used with a supply voltage (Vs) in the range 4.5 to 15V (18V absolute maximum).

Standard 555 and 556 chips create a significant 'glitch' on the supply when their output changes state. This is rarely a problem in simple circuits with no other ICs, but in more complex circuits a smoothing capacitor (e.g. 100µF) should be connected across the +Vs and 0V supply near the 555 or 556.

Pin connections and functions: (See schematic below for basic circuits)

Pin 1 (Ground) - The ground (or common) pin is the most-negative supply potential of the device, which is normally connected to circuit common when operated from positive supply voltages.

Pin 2 (Trigger) - This pin is the input, which causes the output to go high and begin the timing cycle. Triggering occurs when the trigger input moves from a voltage above

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2/3 of the supply voltage to a voltage below 1/3 of the supply. For example: using a 12 volt supply, the trigger input voltage must start from above 8 volts and move down to a voltage below 4 volts to begin the timing cycle. The action is level sensitive and the trigger voltage may move very slowly. To avoid retriggering, the trigger voltage must return to a voltage above 1/3 of the supply before the end of the timing cycle in the Monostable mode. Trigger input current is about 0.5 micro amps.

Pin 3 (Output) - The output pin of the 555 moves to a high level of 1.7 volts less than the supply voltage when the timing cycle begins, The output returns to a low level near 0 at the end of the cycle. Maximum current from the output at either low or high levels is approximately 200 mA.

Pin 4 (Reset): - A low logic level on this pin resets the timer and returns the output to a low state. It is

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normally connected to the + supply line if not used.

Pin 5 (Control) - This pin allows changing the triggering and threshold voltages by applying an external voltage. When the timer is operating in the astable or oscillating mode, this input could be used to alter or frequency modulate the output. If not in use, it is recommended installing a small capacitor from pin 5 to ground to avoid possible false or erratic triggering from noise effects.

Pin 6 (Threshold) - Pin 6 is used to reset the latch and cause the output to go low. Reset occurs when the voltage on this pin moves from a voltage below 1/3 of the supply to a voltage above 2/3 of the supply.The action is level sensitive and can move slowly similar to the trigger voltage.

Pin 7 (Discharge) - This pin is an open collector output, which is in phase with the main output on pin 3

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and has similar current sinking capability.

Pin 8 (V +) - This is the positive supply voltage terminal of the 555 timer IC. Supply-voltage operating range is 4.5 volts (minimum) to +16 volts (maximum).

Chapter 61N914

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Signal diodes are used to process information (electrical signals) in circuits, so they are only required to pass small currents of up to 100mA.

General-purpose signal diodes such as the 1N4148 are made from silicon and have a forward voltage drop of 0.7V.

Germanium diodes such as the OA90 have a lower forward voltage drop of 0.2V and this makes them suitable to use in radio circuits as detectors, which extract the audio signal from the weak radio signal.

For general use, where the size of the forward voltage drop is less important, silicon diodes are better because they are less easily damaged by heat when soldering, they have a lower resistance when conducting, and they have very low leakage currents when a reverse voltage is applied.

Chapter 7LED 9 V, RED, YELLOW,

GREEN COULORExample:

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       Circuit symbol:

Testing an LED

Never connect an LED directly to a battery or power supply! It will be destroyed almost instantly because too much current will pass through and

burn it out .

LEDs must have a resistor in series to limit the current to a safe value, for quick testing purposes a 1k resistor is suitable for most LEDs if your supply voltage is 12V or less. Remember to connect the LED the correct way round!

Colures of LEDs

LEDs are available in

red, orange, amber, yellow, green, blue and white. Blue and white LEDs are much more expensive than the

other colures .

The semiconductor material determines the colour of an LED, not by the coloring of the 'package' (the

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plastic body). LEDs of all colors are available in uncolored packages which may be diffused (milky) or clear (often

described as 'water clear'). The coloured packages are also available

as diffused (the standard type) or transparent.

CHAPTER-8 TRANSISTORS, 2N3904

The transistor is considered by many to be one of the greatest inventions in modern history, ranking in importance with the printing press, automobile and telephone. It is the key active component in practically all modern electronics. Its importance in today's society rests on its ability to be mass produced using a highly automated process (fabrication) that achieves vanishingly low per-transistor costs.

Although millions of individual transistors (known as discretes) are still used, the vast majority of transistors are fabricated into integrated circuits (also called

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microchips or simply chips) along with diodes, resistors, capacitors and other electronic components to produce complete electronic circuits. A logic gate comprises about twenty transistors whereas an advanced microprocessor, as of 2005, can use as many as 289 million transistors.

NPN is one of the two types of bipolar transistors, (or BJTs), the second being PNP. The letters "N" and "P" refer to the majority charge carriers inside the different regions of the transistor. Most transistors used today are NPN, since this is the easiest and most cost effective to make from silicon.

NPN transistors consist of a layer of P-doped (the doping agent is often boron) semiconductor (the "base") between two N-doped (often made with arsenic) layers. NPN transistors are commonly operated with the emitter at ground and the collector at a positive voltage.

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A helpful mnemonic for recognizing an NPN BJT symbol is to look at the Emitter region. If the arrow is pointing away from the Base region, (i.e. Not Pointing iN), then it is an NPN BJT. If the arrow is pointing to the Base region, then it's a PNP BJT.

A small current entering the base will allow a large current to travel across the collecter-emmitor.

Chapter 9

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180, 47K, 10K Ohms RESISTORS

Some resistors are cylindrical, with the actual resistive material in the centre (composition resistors, now obsolete) or on the surface of the cylinder (film) resistors, and a conducting metal lead projecting along the axis of the cylinder at each end(axial lead). There are carbon film and metal film resistors. The photo above right shows a row of common resistors. Power resistors come in larger packages designed to dissipate heat efficiently. At high power levels, resistors tend to be wire wound types. Resistors used in computers and other devices are typically much smaller, often in surface-mount packages

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without wire leads. Resistors can also be built into integrated circuits as part of the fabrication process, using the semiconductor material as a resistor. But resistors made in this way are difficult to fabricate and may take up a lot of valuable chip area, so IC designers alternatively use a transistor-transistor or resistor-transistor configuration to simulate the resistor they require.

Chapter 10CAPACITOR, 10 µF, 30V

An electrolytic capacitor is a type of capacitor with a larger capacitance per unit volume than other types, making

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them valuable in relatively high-current and low-frequency electrical circuits. This is especially the case in power-supply filters, where they store charge needed to moderate output voltage and current fluctuations, in rectifier output, and especially in the absence of rechargeable batteries that can provide similar low-frequency current capacity. They are also widely used as coupling capacitors in circuits where AC should be conducted but DC should not; the large value of the capacitance allows them to pass very low frequencies without carrying DC.

Chapter 119-Volt Battery

A PP3 battery, commonly referred to simply as a nine-volt battery, is

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shaped as a rectangular prism and has a nominal output of nine volts. Its dimensions are 48 mm × 25 mm × 15 mm (ANSI standard 1604A). It is widely used in smoke detectors and as backup batteries for digital clocks or for personal alarms.

The battery has both the positive and negative terminals on one end. The negative terminal is fashioned into a snap fitting which mechanically and electrically connects to a mating terminal on the power connector. The power connector has a similar snap fitting on its positive terminal which mates to the battery. This makes battery polarization obvious since mechanical connection is only possible in one configuration. Inside a PP3 there are six 1.5 volt cells arranged in series. These are either long cylindrical cells roughly equivalent to AAAA cells, or special flat, rectangular cells. The exact size of the constituent cells varies from brand to brand -- some brands are slightly longer than others -- as does the manner in which they are joined together. Some brands use soldered tabs on the battery, others

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press foil strips against the ends of the cells.

Chapter 12CONCLUSION

The LED traffic Light circuit controls 6 LEDs (red, yellow and green) for both north/south directions and east/west directions. The timing sequence is generated using a CMOS 4017 decade counter and a 555 timer. Counter outputs 1 through 4 are wire ORed using 4 diodes so that the (Red -North/South) and (Green - East/West) LEDs will be on during the first four counts. The fifth count (pin 10) illuminates (Yellow - East/West) and (Red - North/South). Counts 6 through 9 are also wire ORed using diodes to control (Red - East/West) and (Green - North/South). Count 10 (pin 11) controls (Red - East/West) and (Yellow - North/South). The time period for the red and green lamps will be 4 times longer than for the yellow and the complete cycle time can be adjusted with the 47K resistor. The eight 1N914

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diodes could be substituted with a dual 4 input OR gate (CD4072).

REFERENCES

1. http:// www.electroicsforu.com

2. http:// www.fairchildsemi.com/technical_information/datasheets.html

3. http://www.dir- electronics.com

4. http:// www.kpsec.freeuk.com/components/cmos.htm#4017

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