Project Report

FACULTY OF TRAINING PROJECT

IR MUSIC TRANSMITTER AND RECEIVER

SYNDICATE1. Punit Kumar Rai LEMR2. Dileep Divakaran LEMR3. Jitendra Singh Sekhawat LA(AH)4. Harendra Kumar LRO(TEL)

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GUIDED BY1. VINOD KUMAR EAP 3

INDEX

SL. NO. CONTENTS PAGE NO1. ACKNOWLEDGEMENT2. CERTIFICATE3. AIM OF THE PROJECT4. GENERAL DESCRIPTION5. INTRODUCTION 6. COMPONENT LIST7. CIRCUIT DIAGRAM8. PCB LAYOUT9. WORKING 10. TRANSMITTER

a. Introductionb. Circuit Diagram and PCB layout c. Workingd. Component use d in transmitter circuite. More about components

11. RECEIVERa. Introductionb. Circuit Diagram and PCB layout c. Workingd. Component use d in transmitter circuite. More about components

12. APPLICATION13. ADVANTAGE

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14. DISADVANTAGE15. CIRCUIT EXPLANATION16. PCB MANUFACTURING PROCEDURE 17. TIPS FOR GOOD SOLDERING18. COMPONENT TESTING

ACKNOWLEDGEMENT

We are thankful to our instructor VINOD KUMAR EAP3 for guiding us to complete this project and we are also thankful to FACULTY OF TRAINING PROJECT for fulfilling every requirement of this project and providing a good platform to work and learn.

The facility provided by the project lab is indispensable need of the trainees and to make them professionally competent.

1. Punit Kumar Rai LEMR2. Dileep Divakaran LEMR3. Jitendra Singh Sekhawat LA(AH)4. Harendra Kumar LRO(Tel)

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FACULTY OF TRAINING PROJECT

CERIFICATE

This is to certify that Punit Kumar Rai, LEMR, Dileep Divakaran LEMR, Jitendra Singh Sekhawat LA(AH) and Harendra Kumar LRO(Tel) have successfully completed the project under my supervision and submitted the project report as per rules and regulations of respective “MEAT” course.

INSTRUCTOR

VINOD KUMAR EAP-3

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AIM OF THE PROJECT

1. To make and prove the circuit of Transmitter using IR LED and Receiver Circuit Using PHOTO Transistor.

2. To learn about PCB designing and fabrication process.

3. To practice methods of good soldering and component testing.

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GENERAL DESCRIPTION

Now-a-days everything in this world is getting wireless, infrared rays’ transmission is one of the most important ways of wireless communication. An infrared transmission/reception apparatus and a method output is changed to transmit a plurality of station finding commands, and an infrared transmission output for such a station finding command out of the plurality of station finding commands as returning a station finding response from a secondary station is used to perform a subsequent communication. Thus, communication can be performed with the minimum infrared output regardless of the opposite apparatus. Infrared communication has heretofore been known in which infrared light is used to perform communication among apparatuses. According to the infrared communication, for a distance of about 1m from a communication object the communication can be performed without performing connection via a cable, and the like, which is convenient for use, and which provides an advantage that the communication can be realized with a simple constitution as compared with the communication using radio waves. From such advantage, the infrared communication is preferably applied to small apparatuses such as a note type personal computer and a portable information terminal. In this project we illustrate the process by which music can be transmitted through IR rays.

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INTRODUCTION

Using this circuit, audio musical notes can be generated and can be heard up to a distance of 10 meters. The receiver can be placed at a maximum distance of 1 meter from the transmitter without any considerable noise interference. The circuits of transmitter and receiver are quite simple and can be placed and carried any where easily. The small apparatus provided with the infrared communication function is in many cases operated by a battery incorporated inside so that it is convenient when a user carries it during movement, and it is preferable the power consumption be minimized also to lengthen the continuous operation possible time of IR modulation techniques when working with IR rays. Hence there is no necessity of carrier generation. This makes the transmitter and receiver designs much simpler. However the communication distance can be improved by using Far IR LEDs. The range of communication can be increased to about 250 meters by using Far IR LEDs. In the apparatus provided with a conventional infrared communication function, however, the infrared light with a constant intensity is constantly radiated regardless of the communication distance. This project emphasizes the way by which music is generated and driven by IR rays and gives an explanation to the one of the methods of receiving IR rays without considerable noise interference.

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COMPONENT LISTINTEGRATED CIRCUIT

IC1 - UM66

IC2 :- 741

IC3 :- LM386

TRANSISTOR

T1 :- BC547

T2 :- BD140

T3 :- L14F1 IR PHOTO TRANSISTOR

ZENER DIODE

ZD1 :- 3.3V ¼W

CAPACITORS

C1 :- 1μ 16V

C2 :- 220μ 25V

C3,C5,C7,C9 :- 0.1 μ

C4:- 220 μ 16V

C6:- 10 μ 25V

C8:- 220 μ 25V

C10 :- 220 μ 25V

LED

LED1 :- RED LED

LED2 :- IR LED

LED3 :- IR LED

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RESISTROS

R1 :- 1K ohm

R2 :- 4.7K ohm

R3 :- 22K ohm

R4 :- 82K ohm

R5 :- 10 ohm 1W

R6:- 10K ohm

R7:- 10K ohm

R8:- 15K ohm

R9:- 100K ohm

R10 :- 680ohm

R11 :- 1K ohm

R12 :- 10 ohm

R 13:- 15K ohm

VARIABLE RESISTOR VR1 :- 1M ohm VR2 :- 10 K ohm

LOUD SPEAKER

LS1 :- 8 ohm 1W

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CIRCUIT DIAGRAM

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PCB LAYOUT

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WORKING

The circuit can be divided into two parts: IR music transmitter and receiver. The IR music transmitter works off a 9V battery, while the IR music re- cleaver works off regulated 9V to12V.

It uses popular melody generator IC UM66 (IC1) that can continuously generate musical tones. The output of IC1 is fed to the IR driver stage (built across the transistors T1 and T2) to get the maximum range.

Here the red LED (LED1) flickers according to the musical tones generated by UM66 IC, indicating modulation. IR LED2 and LED3 are infrared transom- fitting LEDs. For maximum sound transmission these should be oriented towards IR phototransistorL14F1 (T3).

The IR music receiver uses popular op-amp IC µA741 and audio- frequency amplifier IC LM386 along with phototransistor L14F1 and some discrete components .

The melody generated by IC UM66 is transmitted through IR LEDs, re- ceiled by phototransistor T3 and fed to pin 2 of IC µA741 (IC2). Its gain can be varied using pot meter VR1. The output of IC µA741 is fed to IC LM386 (IC3) via capacitor C5 and pot meter VR2.The melody produced is heard through the receiver’s loudspeaker. Pot meter VR2 is used to control the volume of loudspeaker LS1(8- ohm,1W).

Switching off the power supply stops melody generation

The IR music receiver uses popular op-amp IC µA741 and audio- frequency amplifier IC LM386 along with phototransistor L14F1 and some discrete components (Fig. 2).

The melody generated by IC UM66 is transmitted through IR LEDs, re- ceiled by phototransistor T3 and fed to pin 2 of IC µA741 (IC2). Its gain can be varied using pot meter VR1. The output of IC µA741 is fed to IC LM386 (IC3) via capacitor C5 and pot meter VR2.The melody produced is heard through the receiver’s loudspeaker. Pot meter VR2 is used to control the volume of loudspeaker LS1(8- ohm,1W).

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INTRODUCTION

Using this circuit, audio musical notes can be generated and can be heard up to a distance of 10 meters. The circuits of transmitter are quite simple and can be placed and carried any where easily. The small apparatus provided with the infrared communication function is in many cases operated by a battery incorporated inside so that it is convenient when a user carries it during movement, and it is preferable the power consumption be minimized also to lengthen the continuous operation possible time of IR modulation techniques when working with IR rays. It uses popular melody generator IC UM66 (IC1) that can continuously generate musical tones. The red LED flickers according to the musical tones generated by UM66 IC, indicating modulation. IR LED are infrared transom- fitting LEDs.

CIRCUIT DIAGRAM AND PCB LAYOUT15

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WORKING

It uses popular melody genertor IC UM66(IC1) that can continuously generate musical tones. The output of IC1 is fed to the IR driver stage (built across the transistors T1 and T2) to get the maximum range.

Here the red LED (LED1) flickers according to the musical tones generated by UM66 IC, indicating modulation. IR LED2 and LED3 are infrared transmitting LEDs

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COMPONENT USED IN TRANSMITTER CIRCUITINTEGRATED CIRCUIT

IC - UM66

TRANSISTOR

T1 :- BC547

T2 :- BD140

ZENER DIODE

ZD1 :- 3.3V ¼W

CAPACITORS

C1 :- 1μ 16V

C2 :- 220μ 25V

RESISTROS

R1 :- 1K ohm

R2 :- 4.7K ohm

R3 :- 22K ohm

R4 :- 82K ohm

R5 :- 10 ohm 1W

LED

LED1 :- RED LED

LED2 :- IR LED

LED3 :- IR LED

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IC – UM 66

UM66 is a pleasing music generator IC which works on a supply voltage of 3V. therequired 3V supply is given through a zener regulator. its out put is taken from the pinno1 and is given to a push pull amplifier to drive the low impedance lowd speker. Aclss A amplifier before pushpull amplifier can be used to decrese the noise andimprove out put. UM66 is a 3 pin IC pakage just looks like a BC 547 transistor.

Pin out of UM66 IC Pin No Designation Description

1 Out put Melody out put

2 +Vdd Positive power supply

3 -Vss Negative Power supply

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TRANSISTORA transistor is a semiconductor device used to amplify and switch electronic signals. It is made of a solid piece of semiconductor material, with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current flowing through another pair of terminals. Because the controlled (output) power can be much more than the controlling (input) power, the transistor provides amplification of a signal. Today, some transistors are packaged individually, but many more are found embedded in integrated circuits.

BC – 547BC547 is an NPN bi-polar junction transistor. A transistor, stands for transfer of

resistance, is commonly used to amplify current. A small current at its base controls a larger current at collector & emitter terminals.

BC547 is mainly used for amplification and switching purposes. It has a maximum current gain of 800. Its equivalent transistors are BC548 and BC549.

The transistor terminals require a fixed DC voltage to operate in the desired region of its characteristic curves. This is known as the biasing. For amplification applications, the transistor is biased such that it is partly on for all input conditions. The input signal at base is amplified and taken at the emitter. BC547 is used in common emitter configuration for amplifiers. The voltage divider is the commonly used biasing mode. For switching applications, transistor is biased so that it remains fully on if there is a signal at its base. In the absence of base signal, it gets completely off.

Here is a classic drawing for a transistor inside electronic diagrams:

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BD -140

BD 140 is a PNP power transistor. A transistor, stands for transfer of resistance, is commonly used to amplify current. A small current at its base controls a larger current at collector & emitter terminals.

APPLICATIONS

General purpose power applications, e.g. driver stages in hi-fi amplifiers and television circuits.

FEATURES

High current (max. 1.5 A) Low voltage (max. 80 V).

SYMBOL PNP :

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ZENER DIODE

A Zener Diode is a special kind of diode which permits current to flow in the forward direction as normal, but will also allow it to flow in the reverse direction when the voltage is above a certain value - the breakdown voltage known as the Zener voltage. Zener diodes are widely used in electronics circuits as voltage references. Zener diodes provide a stable and defined voltage and as a result Zener diode circuits are often used in power supplies when regulated outputs are needed. Zener diodes are cheap and they are also easy to use and as a result they are used in many applications and many circuits.

SYMBOL

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ZENER DIODE BASICS

Zener diodes are sometimes referred to as reference diodes as they are able to provide a stable reference voltage for many electronics circuits. The diodes themselves are cheap and plentiful and can be purchased in virtually every electronics components store.

Zener diodes have many of the same basic properties of ordinary semiconductor diodes. They conduct in the forward direction and have the same turn on voltage as ordinary diodes. For silicon this is about 0.6 volts.

In the reverse direction, the operation of a Zener diode is quite different to an ordinary diode. For low voltages the diodes do not conduct as would be expected. However, once a certain voltage is reached the diode "breaks down" and current flows. Looking at the curves for a Zener diode, it can be seen that the voltage is almost constant regardless of the current carried. This means that a Zener diode provides a stable and known reference voltage.

HOW A ZENER DIODE WORKS

The Zener diode is particularly interesting in the way that it operates. There are actually two mechanisms that can cause the breakdown effect that is used to provide the voltage reference effect:

1. Zener breakdown: Although the physics behind the effect is quite complicated, it can be considered that this effect occurs when the electric field within the semiconductor crystal lattice is sufficiently high to pull electrons out of the lattice to create a hole and electron. The electron then moves under the influence of the field to provide an electric current.

2. Impaction ionisation: Again this effect occurs when there is a high level of electric field. Electrons are strongly attracted and move towards the positive potential. In view of the high electric field their velocity increases, and often these high energy electrons will collide with the semiconductor lattice. When this occurs an electron may be released, leaving a hole. This newly freed electron then moves

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towards the positive voltage and is accelerated under the high electric field, and it to may collide with the lattice. The hole, being positively charged moves in the opposite direction to the electron. If the field is sufficiently strong sufficient numbers of collisions occur so that an effect known as avalanche breakdown occurs. This happens only when a specific field is exceeded, i.e. when a certain reverse voltage is exceeded for that diode, making it conduct in the reverse direction for a given voltage, just what is required for a voltage reference diode.

It is found that of the two effects the Zener effect predominates above about 5.5 volts whereas impact ionisation is the major effect below this voltage.

The two effects are affected by temperature variations. This means that the Zener diode voltage may vary as the temperature changes. It is found that the impact ionisation and Zener effects have temperature coefficient in opposite directions. As a result Zener diodes with reverse voltages of around 5.5 volts where the two effects occur almost equally have the most stable overall temperature coefficient as they tend to balance each other out for the optimum performance.

Uses of Zener Diodes

Since the voltage dropped across a Zener Diode is a known and fixed value, Zener diodes are typically used to regulate the voltage in electric circuits. Using a resistor to ensure that the current passing through the Zener diode is at least 5mA (0.005 Amps), the circuit designer knows that the voltage drop across the diode is exactly equal to the Zener voltage of the diode.

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CAPACITOR

Capacitors are often used in electric and electronic circuit as energy storage devices. They can also be used to differentiate between high frequency and low frequency signals. This property makes them useful in electronic filters. Practical capacitor has series resistance, internal leakage of charge, series inductance and other non-ideal properties not found in a theoretical, ideal, capacitor.

Capacitors are occasionally referred to as condenser. This term is considered archaic in English, but most other languages use a cognate of condenser to refer to a capacitor.

A wide variety of capacitors have been invented, including small electrolytic capacitors used in electronic circuit, basic parallel-plate capacitors, and mechanical capacitors.

In away a capacitor is a little like a battery. Although they work in completely different way, capacitors and battery both store electrical energy. If you have read how batteries work, then you know that a battery has two terminals. Inside the battery, chemical reaction produce electron on one terminal and absorb electrons on the other terminal. A capacitor is much simpler then a battery, as it cannot produce new electrons—it only stores them.

SYMBOL:

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RESISTOR

A resister is a two- terminal electronic component design to oppose an electric current by producing a voltage drop between its terminal in proportion to current that is in accordance with Ohms law; V=IR. The voltage drop V across the resister divided by the current I through resister.

Resisters are characterized primarily by their resistance and the power they can dissipate. Other characteristics include temperature coefficient, noise, and inductance.

Practical resister s can be made of resistive wire and various compounds and films and they can be integrated into hybrid and printed circuits. Size and position of leads are relevant to equipment designers; resisters must be physically large enough not to overheat when dissipating their power. Variable resisters, adjustable by changing the position of a tapping on the resistive element and resister with a movable tap (“potentiometers”), either adjustable by the user of equipment or contained within, are also used.

Resisters are used as part of electrical network and electronic circuits. There are special types of resister whose resistance varies quantities, most of which have names and articles, of their own: the resistance of thermistors varies greatly with temperature, whether external or due to dissipation, so they can be used for temperature or current sensing; metal oxide varistors drop to a very low resistance when a high voltage is applied, making them suitable for over-voltage protection; the resistance of a straingauge varies with mechanical load; the resistor of photo transistor varies with illumination; the resistance of a quantum tunneling composite can vary by a factor of 10^12 with mechanical pressure applied; and so on.

Resistance is measured in ohms, after Ohms law. This rule states that electrical resistance is equal to the drop in voltage across the terminals of the resister divided by the current being applied to the resister. A high ohm rating indicates a high resistance to current. Thisrating can be written in a number of different ways depending on theohm rating. For example, 81R represents 81 ohms, while 81K represent 81,000 ohms.

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SYMBOL:- , , Ω

VARIABLE RESISTOR

Variable resistors consist of a resistance track with connections at both ends and a wiper which moves along the track as you turn the spindle. The track may be made from carbon, cermet (ceramic and metal mixture) or a coil of wire (for low resistances). The track is usually rotary but straight track versions, usually called sliders, are also available.

Variable resistors may be used as a rheostat with two connections (the wiper and just one end of the track) or as a potentiometer with all three connections in use. Miniature versions called presets are made for setting up circuits which will not require further adjustment.

Variable resistors are often called potentiometers in books and catalogues. They are specified by their maximum resistance, linear or logarithmic track, and their physical size. The standard spindle diameter is 6mm.

The resistance and type of track are marked on the body:

4K7 LIN means 4.7 k linear track.1M LOG means 1 M logarithmic track.

Some variable resistors are designed to be mounted directly on the circuit board, but most are for mounting through a hole drilled in the case containing the circuit with stranded wire connecting their terminals to the circuit board.

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Standard Variable Resistor

There are two general ways in which variable resistors are used. One is the variable resistor which value is easily changed, like the volume adjustment of Radio. The other is semi-fixed resistor that is not meant to be adjusted by anyone but a technician. It is used to adjust the operating condition of the circuit by the technician. Semi-fixed resistors are used to compensate for the inaccuracies of the resistors, and to fine-tune a circuit. The rotation angle of the variable resistor is usually about 300 degrees. Some variable resistors must be turned many times to use the whole range of resistance they offer. This allows for very precise adjustments of their value. These are called “Potentiometers” or “Trimmer Potentiometers.”

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LIGHT EMITTING DIODE

Light emitting diodes, commonly called LEDs, are real unsung heroes in the electronics world. They do dozens of different jobs and are found in all kinds of devices. Among other things, they form the numbers on digital clocks, transmit information from remote controls, light up watches and tell you when your appliances are turned on. Collected together, they can form images on a jumbo television screen or illuminate a traffic light.

Basically, LEDs are just tiny light bulbs that fit easily into an electrical circuit. But unlike ordinary incandescent bulbs, they don't have a filament that will burn out, and they don't get especially hot. They are illuminated solely by the movement of electrons in a semiconductor material, and they last just as long as a standard transistor.

LED ADVANTAGES

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While all diodes release light, most don't do it very effectively. In an ordinary diode, the semiconductor material itself ends up absorbing a lot of the light energy. LEDs are specially constructed to release a large number of photons outward. Additionally, they are housed in a plastic bulb that concentrates the light in a particular direction. As you can see in the diagram, most of the light from the diode bounces off the sides of the bulb, traveling on through the rounded end.

LEDs have several advantages over conventional incandescent lamps. For one thing, they don't have a filament that will burn out, so they last much longer. Additionally, their small plastic bulb makes them a lot more durable. They also fit more easily into modern electronic circuits.

But the main advantage is efficiency. In conventional incandescent bulbs, the light-production process involves generating a lot of heat (the filament must be warmed). This is completely wasted energy, unless you're using the lamp as a heater, because a huge portion of the available electricity isn't going toward producing visible light. LEDs generate very little heat, relatively speaking. A much higher percentage of the electrical power is going directly to generating light, which cuts down on the electricity demands considerably.

Up until recently, LEDs were too expensive to use for most lighting applications because they're built around advanced semiconductor material. The price of semiconductor devices has plummeted over the past decade, however, making LEDs a more cost-effective lighting option for a wide range of situations. While they may be more expensive than incandescent lights up front, their lower cost in the long run can make them a better buy. In the future, they will play an even bigger role in the world of technology.

METHOD OF OPERATION

When an LED unit is activated, a power supply converts AC voltage into sufficient DC voltage, which is applied across the diode semiconductor crystal. This results in electrons (negative charge carriers [N]) in the diode’s electron transport layer and holes (positive charge carriers [P]) in the diode’s hole transport layer combining at the P-N junction and converting their excess energy into light. The LED is sealed in a clear or

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diffuse plastic lens that can provide a range of angular distributions of the light.

COLOR

The color composition of the light being emitted by the LED is based on the chemical composition of the material being excited. LEDs are available that can produce colors including white, deep blue, blue, green, yellow, amber, orange, red, bright red and deep red.

WHITE LIGHT LEDs

The utilization of indium gallium nitride (InGaN) as a semiconductor material resulted in the brightest LEDs and enabled the development of the white light LED.

White light LEDs feature a phosphor added to a blue LED that converts some of the light emission into yellow, resulting in a bluish-white light. White light LEDsare therefore a cool light source with a spectrum of correlated color temperatures of4,000-11,000K. Color rendering is considered poor. White light can also be achieved by color mixing the light produced by red, blue and green LEDs. The production of visible white light offers the promise that LEDs can be used in general lightingapplications. As the light output and color rendering capabilities of LEDs improve, many more architectural applications will open up for this source.

Several manufacturers currently offer a range of LED fixtures for replacing MR16 lamps, display lighting, cove lighting, underwater lighting, architectural details and other applications. Come manufacturers are using colored LED arrays in these applications, combining red, blue and green LEDs to produce millions of colors, including white light. Designers should carefully consider requisite lumen packages, source brightness, viewing angles and color rendering when considering use of this technology.

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IR LEDs

An infrared emitter is an LED made from gallium arsenide, which emits near-infrared energy at about 880nm.

The infrared phototransistor acts as a transistor with the base voltagedetermined by the amount of light hitting the transistor.

Hence it acts as a variable current source. Greater amount of IR light cause greater currents to flow through the collector-emitter leads.The phototransistor is wired in a similar configuration to the voltage divider.

The variable current traveling through the resistor causes a voltage drop in the pull-up resistor. This voltage is measured as the output of the deviceIR reflectance sensors contain a matched infrared transmitter and infrared receiver pair. These devices work by measuring the amount of light that is reflected into the receiver.

Because the receiver also responds to ambient light, the device works best when well shielded from abient light, and when the distance between the sensor and the reflective surface is small(less than 5mm).

IR reflectance sensors are often used to detect white and black surfaces. White surfaces generally reflect well, while black surfaces reflect poorly

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INTRODUCTION

Using this circuit, audio musical notes can be generated and can be heard up to a distance of 10 meters. The receiver can be placed at a maximum distance of 1 meter from the transmitter without any considerable noise interference. The circuits of transmitter and receiver are quite simple and can be placed and carried any where easily. For maximum sound transmission these should be oriented towards IR phototransistorL14F1.The IR music receiver uses popular op-amp IC µA741 and audio-frequency amplifier IC LM386 along with phototransistor L14F1 and some discrete components. The output of IC µA741 is fed to ICLM386 via capacitor and pot meter VR2.The melody produced is heard through the receiver’s loudspeaker. Pot meter VR2 is used to control the volume of loudspeaker.

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CIRCUIT DIAGRAM AND PCB LAYOUT

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WORKING

For maximum sound transmission these should be oriented towards IR phototransistorL14F1 (T3).

The IR music receiver uses popular op-amp IC µA741 and audio- frequency amplifier IC LM386 along with phototransistor L14F1 and some discrete components (Fig. 2).

The melody generated by IC UM66 is transmitted through IR LEDs, received by phototransistor T3 and fed to pin 2 of IC µA741 (IC2). Its gain can be varied using pot meter VR1. The output of IC µA741 is fed to IC LM386 (IC3) via capacitor C5 and pot meter VR2.The melody produced is heard through the receiver’s loudspeaker. Pot meter VR2 is used to control the volume of loudspeaker LS1(8- ohm,1W).

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COMPONENT USED IN RECEIVER CIRCUITINTEGRATED CIRCUIT

IC2 :- 741

IC3 :- LM386

TRANSISTOR

T3 :- L14F1 IR PHOTO TRANSISTOR

CAPACITORS

C3,C5,C7,C9 :- 0.1 μ

C4:- 220 μ 16V

C6:- 10 μ 25V

C8:- 220 μ 25V

C10 :- 220 μ 25V

RESISTROS

R6:- 10K ohm

R7:- 10K ohm

R8:- 15K ohm

R9:- 100K ohm

R10 :- 680ohm

R11 :- 1K ohm

R12 :- 10 ohm

R 13:- 15K ohm

VARIABLE RESISTOR VR1 :- 1M ohm VR2 :- 10 K ohm

LOUD SPEAKER

LS1 :- 8 ohm 1W

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IR PHOTO TRANSISTOR L14F1DESCRIPTION

The L14F1/L14F2 are silicon photodarlingtons mounted in a narrow angle.

FEATURES

Hermetically sealed package Narrow reception angle

• Narrow reception angle

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INTEGRATED CIRCUITS (ICs)LM 386

Low Voltage Audio Power Amplifier

General Description

The LM386 is a power amplifier designed for use in low voltage consumer applications. The gain is internally set to 20 to keep external part count low, but the addition of an external resistor and capacitor between pins 1 and 8 will increase the gain to any value from 20 to 200.The inputs are ground referenced while the output automatically biases to one-half the supply voltage. The quiescent power drain is only 24 milliwatts when operating from a 6 volt supply, making the LM386 ideal for battery operation.

Features

Battery operation Minimum external parts Wide supply voltage range: 4V–12V or 5V–18V Low quiescent current drain: 4mA Voltage gains from 20 to 200 Ground referenced input Self-centering output quiescent voltage Low distortion: 0.2% (AV = 20, VS = 6V, RL = 8, PO = 125mW, f =

1kHz) Available in 8 pin MSOP package

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Applications

AM-FM radio amplifiers Portable tape player amplifiers Intercoms TV sound systems Line drivers Ultrasonic drivers Small servo drivers Power converters

EQUIVALENT SCHEMATIC AND CONNECTION DIAGRAM

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IC 741Operational Amplifier

General Description

An operational amplifier, often referred as an op-amp, is a very high gain performance amplifier designed to amplify ac and dc voltage voltages. Modern IC technology and large scale production techniques have brought down the prices of such amplify within reach of all amateurs, experimenters and hobbyists. The op-amp is now used as a basic gain element, like an elegant transistor, in electronic circuits.

A symbol used to represent an op-amp in schematics is shown. The op-amp has two inputs and only one output. One input is called the inverting input and is denoted by a minus sign. A signal applied to this input appears as an amplified but phase inverted signal. The second input is called a non-inverting input and is denoted by a plus sign. A signal applied to this input appears at the output as an amplified signal which has the same phase as that of the input signal.

The availability of two input terminals simplifies feedback circuitry and makes the op – amp a highly versatile device. If a feedback is applied from the output to the inverting input terminal, the result is a negative feedback which gives a stable amplifier with precisely controlled gain characteristics. On the other hand, if the feedback is applied to the non-inverting input, the result is positive feedback which gives oscillators and multi vibrators. Special effects are obtained by combination of both types of feedbacks.

uA741.Of the different types of op – amps produced, type 741 has achieved a very ide popularity. It is available in 14- pin dual-in line, 8 – pin dual-in line or in TO- style packages.Integrated circuit type 747 accommodates two type 741 operational amplifiers in a single package.

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The op-amp needs a dual symmetrical power supply. With its center tap grounded. This enables the op-amp to amplify dc signals of both polarities, positive or negative, with respect to ground. The circuit is so designed that if both inputs are connected to ground, the dc output voltage is zero. However, because of small internal unbalances, a small dc voltage may appear at the output. It is too small to be objectionable in normal applications. For critical applications, the output voltage can be set precisely to zero by connecting a 10K potentiometer between terminals marked “offset-null”.

It is possible to operate the 741 on a single rail supply also. This is usually done by raising the standing dc input voltage to the non-inverting input terminal to approximately half the supply voltage by a voltage divider network. The output dc voltage in such cases stands at half the supply voltage. Bt this does not matter because the dc can be easily blocked by a capacitor allowing only the ac signal to be passed on to the next stage.

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.

The operational amplifier type 741 has many features that have made it so popular. It has an in-built circuitry that provides full protection against output overloads or even shorts to ground for any length of time. The 741 does not need any external component for phase compensation or adjusting its frequency response. This simplifies its circuit design and minimizes the number of components used. Its frequency response has a smooth roll off at the high end which keeps the circuit fully stable in all feedback configurations.

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LOUD SPEAKER

DIAGRAM

A loudspeaker (or "speaker") is an electro acoustic transducer that converts an electrical signal into sound. The speaker moves in accordance with the variations of an electrical signal and causes sound waves to propagate through a medium such as air or water.

After the acoustics of the listening space, loudspeakers (and other electro acoustic transducers) are the most variable elements in a modern audio system and are usually responsible for most distortion and audible differences when comparing sound systems.

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APPLICATION-Wireless Speaker System

-Welcome Tone generators at entrance

ADVANTAGE-Highly sensitive

-Two stage Gain control

-Very low noise

-Low cost and reliable circuit

-Can transmit up to 10 meter

DISADVANTAGE

-Not for long distance

-work in fixed range

-Noise if object between transmitter and receiver

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PCB MANUFACTURING

STEP I (MASTER ART WORK)

Draw the master art work. It may be drawn 4 to 30 times larger than its final expected size of the board

STEP II (NEGATIVE PHOTOGRAPHY)

Obtain negative photography of the master art work reduced to the final size.

STEP III (CLEAN AND LAMINATE)

Clean the copper clad laminate using solvent like Tri Chloro Ethylene.

STEP IV (COATING OF LAMINATE)

Coat the laminate with photosensitive resist keep it nearly in a vertical position for drying at room temperature (minimum for 5 min)

STEP V (EXPOSURE)

The resist coated laminate in contact with master art negative to be expose to UV radiation in UV printer (apprx. 5-6 min).

STEP VI (DEVELOPING)

Immerse the exposed copper clad laminate in photo resist developer for 60-90 sec. remove the board and dry thoroughly.

STEP VII (DRYING THE IMAGE)

Immerse the board into the for about 10-20 sec. remove the board and wash it under spray of water

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STEP VII (ETCHING)

Immerse the board in FeCl3 solution (40-60 in) for etching unwanted copper portions.

STEP IX (RESIST REMOVER)

Wash the board under running water and remove the resist from image area with solvent like Tri Chloro Ethylene.

STEP X (DRILLING)

Drill the fabricated PCB for mounting component.

STEP XI (TINNING)

The solder in the tinning machine is heated up starting from 150 degree to 300 degree Celsius. When the solder gets heated properly, put the PCB in the rack and rotate the handle.

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TIPS FOR GOOD SOLDERING

DO’S

Use low wattage soldering irons for IC’s. While soldering IC’s make sure that the soldering iron is

properly earthed. Clean the PCB pads, tracks and base pins of the components

with blade or sand paper before soldering. Clean the tin of soldering iron frequently while soldering. Where possible first try to make mechanical joints before

applying solder. Flux should be applied to allow the solder to have proper flow

on the joint. Clean the joint after soldering and inspect for any short circuit

between tracks and pins.

DON’TS

Do not hold the soldering iron on any joint than the necessary period to get a good joint.

Do not use too much solder. Do not move joint till the time solder gets hardened.

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COMPONENT TESTING

RESISTOR TESTING

1. Select the appropriate function button from multimeter.2. Select the required range scale on rotary switch.3. Place the resistor between terminals of meter.4. Observe and note the reading.5. LCR meter can also be used for this purpose.

NOTE: - WE CAN ALSO KNOW THE VALUE OF THE RESISTOR BY THE COLORS OF THE RESISTOR

4 Band Resistor Color Codes

First Band -----------

Black = 0 Brown = 10 Red = 20 Orange = 30 Yellow = 40 Green = 50 Blue = 60 Violet = 70 Grey = 80 White = 90

Second Band ------------

Black = 0 Brown = 1 Red = 2 Orange = 3 Yellow = 4 Green = 5

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Blue = 6 Violet = 7 Grey = 8 White = 9

Third Band Multiplier ----------------------

Black = 1 Brown = 10 Red = 100 Orange = 1000 Yellow = 10000 Green = 100000 Blue = 1000000 Violet = 10000000 White = 100000000 Gold = 0.1 Silver = 0.01

Fourth Band Tolerance % ------------------------

Brown = 1 Red = 2 Green = 0.5 Blue = 0.25 Violet = 0.10 Grey = 0.05 Gold = 5 Silver = 10 None = 20

The Formula For Four Band Resistor -----------------------------------

(First Band + Second Band) * Third Band = Total

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CAPACITOR TESTING

1. Select the appropriate function button from multimeter.2. Select the required range scale on rotary switch.3. Place the capacitor between terminals of meter.4. The capacitor voltage will appear on the screen and suddenly

start decreasing due to discharging of the capacitor.5. LCR meter can also be used for this purpose.

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