REPORTOn

MINOR PROJECT

Room Noise Detector

To be Submitted in partial fulfillment of the requirements for the award of the Diploma in

Electronics & Communication Engineering

Submitted To Submitted By

Narinder pal singhUnder the guidance of E.C.E

Er. Shavneet Singh (lect ECE Dept) 009356104994

Department of Electronics & Communication Engineering

Bhai Gurdas Global Polytechnic Collabe Rakhra

CERTIFICATE

This is to certify that the following students Harpreet Singh

009356104988

Have successfully completed the project titled “Car over Heater” towards partial

fulfillment of diploma of Electronics & Communication Engg. Of The Punjab State Board

of Technical Education and Industrial Training (PSBTE & IT)

PREFACE

The Seminar report has been developed as a part of the DIPLOMA curriculum that

The Punjab State Board of Technical Education and Industrial Training (PSBTE & IT)

require its students to undergo in the 4th semester. The purpose of the project is to

familiarize the students with the new technologies and trends in the present

Electronics and Communication field and how they present themselves more

effectively.

All the important topics related to the project report and the ones, which are

essential for the knowledge of the entire system, have been explained to the

minutest details.

I hope that after I deliver the project on this topic we all will be well equipped with

enough knowledge so that it can benefit us in the future as engineers who have to

work in related industry.

ACKNOWLEDGEMENT

The project report submission that is a part of Dipoma curriculum is aimed at

providing experience on exploring the new technology, presenting and practical

exposure. During the course of searching for the topic I become familiar to some

new technologies and trends devolping and being followed up in the present

Electronics Industry.

Now that the report is complete, I feel my duty to thank all those who have directly

or indirectly helped us to cross several hurdles.

I owe a debt of gratitude to Mr. Shavneet singh Department of Electronics and

Communication Engineering for his esteemed guidance. I also express my

gratitude to and Mr. Gurmeet singh (HOD) for providing full liberty and guidance

to search for this Project .

Table of Contents

Sr. No. Topic

1. Soldering 2. Technical details of the project

a. Transistors.

b. Register

c. Speakers.

d. Capacitors

e. IC 555

f. Operational amplifier

3. Bibliography / References

What is Soldering?   

A process of joining metallic surfaces with solder, without the melting of the base materials.  The two metallic parts are joined by a molten Filler metal.

Soldering:

Soldering is a process in which two or more metal items are joined together by melting and

flowing a filler metal into the joint, the filler metal having a relatively low melting point. Soft

soldering is characterized by the melting point of the filler metal, which is below 400 °C

Soldering is distinguished from brazing by use of a lower melting-temperature filler metal. The

filler metals are typically alloys that have liquidus temperatures below 350°C. It is distinguished

fromwelding by the base metals not being melted during the joining process which may or may

not include the addition of a filler metal. In a soldering process, heat is applied to the parts to be

joined, causing the solder to melt and be drawn into the joint by capillary action and to bond to

the materials to be joined by wetting action. After the metal cools, the resulting joints are not as

strong as the base metal, but have adequate strength, electrical conductivity, and water-tightness

for many uses.

Soldering Equipment

The Soldering Iron/Gun

The first thing you will need is a soldering iron, which is the heat source used to melt solder.

Irons of the 15W to 30W range are good for most electronics/printed circuit board work.

Anything higher in wattage and you risk damaging either the component or the board. If you

intend to solder heavy components and thick wire, then you will want to invest in an iron of

higher wattage (40W and above) or one of the large soldering guns. The main difference between

an iron and a gun is that an iron is pencil shaped and designed with a pinpoint heat source for

precise work, while a gun is in a familiar gun shape with a large high wattage tip heated by

flowing electrical current directly through it.

A 30W Watt Soldering Iron A 300W Soldering Gun

For hobbyist electronics use, a soldering iron is generally the tool of choice as its small tip and low heat

capacity is suited for printed circuit board work (such as assembling kits). A soldering gun is generally

used in heavy duty soldering such as joining heavy gauge wires, soldering brackets to a chassis or stained

glass work.

You should choose a soldering iron with a 3-pronged grounding plug. The ground will help prevent stray

voltage from collecting at the soldering tip and potentially damaging sensitive (such as CMOS)

components. By their nature, soldering guns are quite "dirty" in this respect as the heat is generated by

shorting a current (often AC) through the tip made of formed wire. Guns will have much less use in

hobbyist electronics so if you have only one tool choice, an iron is what you want. For a beginner, a 15W

to 30W range is the best but be aware that at the 15W end of that range, you may not have enough power

to join wires or larger components. As your skill increases, a 40W iron is an excellent choice as it has the

capacity for slightly larger jobs and makes joints very quickly. Be aware that it is often best to use a more

powerful iron so that you don't need to spend a lot of time heating the joint, which can damage

components.

A variation of the basic gun or iron is the soldering

station, where the soldering instrument is attached to a

variable power supply. A soldering station can

precisely control the temperature of the soldering tip

unlike a standard gun or iron where the tip temperature

will increase when idle and decrease when applying

heat to a joint. However, the price of a soldering

station is often ten to one hundred times the cost of a

basic iron and thus really isn't an option for the hobby

market. But if you plan to do very precise work, such as surface mount, or spend 8 hours a day behind a

soldering iron, then you should consider a soldering station.

The rest of this document will assume that you are using a soldering iron as that is what the majority of

electronics work requires. The techniques for using a soldering gun are basically the same with the only

difference being that heat is only generated when the trigger is pressed.

Solder

The choice of solder is also important. There several kinds of solder available but only a few are suitable

for electronics work. Most importantly, you will only use rosin core solder. Acid core solder is common

in hardware stores and home improvement stores, but meant for soldering copper plumbing pipes and

not electronic circuits. If acid core solder is used on electronics, the acid will destroy the traces on the

printed circuit board and erode the component leads. It can also form a conductive layer leading to shorts.

For most printed circuit board work, a solder with a diameter of

0.75MM to 1.0MM is desirable. Thicker solder may be used and will

allow you to solder larger joints more quickly, but will make

soldering small joints difficult and increase the likelihood of creating

solder bridges between closely spaced PCB pads. An alloy of 60/40

(60% tin, 40% lead) is used for most electronics work. These days,

several lead-free solders are available as well. Kester "44" Rosin

Core solder has been a staple of electronics for many years and continues to be available. It is available in

several diameters and has a non-corrosive flux.

Large joints, such as soldering a bracket to a chassis using a high wattage soldering gun, will require a

separate application of brush on flux and a thick diameter solder of several millimeters.

Remember that when soldering, the flux in the solder will release fumes as it is heated. These fumes are

harmful to your eyes and lungs. Therefore, always work in a well ventilated area and avoid breathing the

smoke created. Hot solder is also dangerous. It is surprisingly easy to splash hot solder onto yourself,

which is a thoroughly unpleasant experience. Eye protection is also advised.

Preparing To Solder

Tinning The Soldering Tip

Before use, a new soldering tip, or one that is very dirty, must be tinned. "Tinning" is the process of

coating a soldering tip with a thin coat of solder. This aids in heat transfer between the tip and the

component you are soldering, and also gives the solder a base from which to flow from.

Step 1: Warm Up The Iron

Warm up the soldering iron or gun thoroughly. Make sure that it has fully come to temperature because

you are about to melt a lot of solder on it. This is especially important if the iron is new because it may

have been packed with some kind of coating to prevent corrosion.

Step 2: Prepare A Little Space

While the soldering iron is warming up, prepare a little space to work. Moisten a little sponge and place it

in the base of your soldering iron stand or in a dish close by. Lay down a piece of cardboard in case you

drip solder (you probably will) and make sure you have room to work comfortably.

Step 3: Thoroughly Coat The Tip In Solder

Thoroughly coat the soldering tip in solder. It is very important to cover the entire tip. You will use a

considerable amount of solder during this process and it will drip, so be ready. If you leave any part of the

tip uncovered it will tend to collect flux residue and will not conduct heat very well, so run the solder up

and down the tip and completely around it to totally cover it in molten solder.

Step 4: Clean The Soldering Tip

After you are certain that the tip is totally coated in solder, wipe the tip off on the wet sponge to remove

all the flux residue. Do this immediately so there is no time for the flux to dry out and solidify.

Step 5: You're Done!

You have just tinned your soldering tip. This must be done anytime you replace the tip or clean it so that

the iron maintains good heat transfer.

Welding, brazing, and soldering

The primary difference is that, Welding is done at temperatures of 1400 C, brazing above 700 C and soldering below 450 C.

Through-hole Technology

    Traditionally, the electronic components are manufactured with leads (conductors) that are used to provide both mechanical support as well as electrical conductivity. The leads are soldered to the PCB after insertion.

Soldering Methods

Hand soldering:

It is the oldest method of soldering; it is still popular method in certain kind’s kinds of applications:

Development of prototype boards Low volume production Soldering of extremely temperature sensitive components Solder reflow of fine pitch components using hot bar Rework or repair of machine soldered boards

The main disadvantages are operator training, speed, and consistent quality.

Machine Soldering:

    Two prominently used machine soldering types are:

    A. Wave Soldering - Primarily used for soldering through-hole components on to PCBs.

    B. Reflow Soldering. - Used for soldering SMD components on to PCBs.

Reflow soldering of SM components has the following advantages over manual soldering:

Mass soldering

Consistency in manufacture through precise control of process parameters. Flexible for small production runs as well.

Basic Process Steps Involved in the Manufacture of SMD boards:

3 Technical details of the project

3.1 Transistors.

In electronics, a transistor is a semiconductor device commonly used to amplify or switch

electronic signals. A transistor is made of a solid piece of a 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 larger than the controlling (input) power, the

transistor provides amplification of a signal. The transistor is the fundamental building block of

modern electronic devices, and is used in radio, telephone, computer and other electronic

systems. Some transistors are packaged individually but most are found in integrated circuit

The transistor is a three terminal solid state semiconductor device that can be used for

amplification, switching, voltage stabilization, signal modulation and many other functions.

Transistors are divided into two main categories: bipolar junction transistors (BJTs) and field

effect transistors (FETs). Transistors have three terminals: input, common, and output.

Application of current in BJTs or voltage with FETs between the input terminal and the common

terminal increases the conductivity between the common and output terminals, thereby

controlling current flow between them. The physics of this "transistor action" is quite different

for the BJT and FET; see the respective articles for further details.

In analog circuits, transistors are used in amplifiers, (direct current amplifiers, audio amplifiers,

radio frequency amplifiers), and linear regulated power supplies. Transistors are also used in

digital circuits where they function as electrical switches. Digital circuits include logic gates,

random access memory (RAM), and microprocessors.

Fig 3.1 (a) Simple circuit using a transistor.

Fig 3.1 (b) some transistor

PNP P-channel

NPN N-channel

BJT JFET

Table 3.1 (a) Transistor symbols for BJT and JFET

3.1.1 Transistors are categorized by:

1 Semiconductor material: germanium, silicon, gallium arsenide, silicon carbide

2 Structure: BJT, JFET, IGFET (MOSFET), IGBT, "other types"

3 Polarity: NPN, PNP, N-channel, P-channel

4 Maximum power rating: low, medium, high

Maximum operating frequency: low, medium, high, radio frequency (RF), microwave (The

maximum effective frequency of a transistor is denoted by the term fT, an abbreviation for

"frequency of transition." The frequency of transition is the frequency at which the transistor

yields unity gain).

Application: switch, general purpose, audio, high voltage, super-beta, matched pair

Physical packaging: through hole metal, through hole plastic, surface mount, ball grid array

Thus, a particular transistor may be described as: silicon, surface mount, BJT, NPN, low power,

high frequency switch.

3.1.2 Bipolar junction transistor

The bipolar junction transistor (BJT) was the first type of transistor to be mass-produced. Bipolar

transistors are so named because they conduct by using both majority and minority carriers. The

three terminals are named emitter, base and collector. Two p-n junctions exist inside a BJT: the

base/collector junction and base/emitter junction. The BJT is commonly described as a current-

operated device because the emitter/collector current is controlled by the current flowing

between base and emitter terminals. Unlike the FET, the BJT is a low input-impedance device.

The BJT has a higher transconductance than the FET. Bipolar transistors can be made to conduct

with light (photons) as well as current. Devices designed for this purpose are called

phototransistors.

3.1.3 Field-effect transistor

The field-effect transistor (FET), sometimes called a unipolar transistor, uses either electrons (N-

channel FET) or holes (P-channel FET) for conduction. The three main terminals of the FET are

named source, gate and drain. On some FETs a fourth connection to the body (substrate) is

provided, but normally the body is connected internally to the source.

A voltage applied between the gate and source controls the current flowing between the source

and drain. In FETs the source/ drain current flows through a conducting channel near the gate.

This channel connects the source region to the drain region. The channel conductivity is varied

by the electric field generated by the voltage applied between the gate/source terminals. In this

way the current flowing between the source and drain is controlled. Like bipolar transistors,

FETs can be made to conduct with light (photons) as well as voltage. Devices designed for this

purpose are called phototransistors.

FETs are divided into two families: junction FET (JFET) and insulated gate FET (IGFET). The

IGFET is more commonly known as metal-oxide-semiconductor FET (MOSFET), from their

original construction as a layer of metal (the gate), a layer of oxide (the insulation), and a layer of

semiconductor. Unlike IGFETs, the JFET gate forms a PN diode with the channel which lies

between the source and drain. Functionally, this makes the N-channel JFET the solid state

equivalent of the vacuum tube triode which, similarly, forms a diode between its grid and

cathode. Also, both devices operate in the depletion mode, they both have a high input

impedance, and they both conduct current under the control of an input voltage.

MESFETs are JFETs, in which the reverse biased PN junction is replaced by a semiconductor-

metal Schottky-junction. These, and the HEMFETs (high electron mobility FETs), in which a

two-dimensional electron gas with very high carrier mobility is used for charge transport, are

especially suitable for use at very high frequencies (microwave frequencies; several GHz).

3.2 Register

Resistors resist the flow of electricity. They are used in a wide variety of electronic subsystems

to regulate current and control voltage.

3.2.1 How does it operate?

The circuits for many electronic subsystems include resistors which are needed to enable the

subsystem to work. Sometimes, by changing the resistance value of the resistors (measured on

ohms – symbol W), we can change the details of the operation of the subsystem, for example,

changing the gain of an amplifier.

3.2.2 Colour Code

The resistance of resistors is found by using the resistor colour code.

The three bands close together identify the resistance value.

The colour of the first band gives the first digit. The colour of the second band gives the second

digit. And the colour of the third band gives the number of zeros after these first two digits.

The resistor at the bottom of the graphic on the left has bands of brown, black and orange. So its

resistance value is ‘1’ (brown), then ‘0’ (black) and then three zeros (orange) i.e. 10,000W.

If you are colour blind, check the resistance value with a multimeter on the ohms setting.

Silver 10%

Gold 5%

Red 2%

Brown 1%

A colour code is used for the fourth band and this represents the tolerance of the resistor (ie how

accurate the value is).

So in the example of the 10,000Ù shown above with a brown tolerance band, the tolerance is +

or -1%. The resistance value is therefore between 9900Ù and 10100Ù

Fig 3.2 (a) colour coding

3.2.3 Thousands and Millions

Resistors used in electronics are often in the range of thousands or sometimes millions of ohms.

To make it easier to write down these large values thousand of ohms are called ‘kilohms’ and

millions of ohms are called ‘megohms’.

When writing down these values we use the initials ‘k’ or ‘M’. So, 10,000W = 10 kilohms and is

written 10k. (Note that ‘k’ is the correct symbol, but ‘K’ is often incorrectly used). The ‘k’ is

often used in place of a decimal place. So, 2,700W = 2.7 kilohms and this is often written as 2k7.

Similarly, ‘M’ is used as a symbol for megohms. 3,300,000W is therefore 3.3 megohms and is

written 3M3.

In the case of resistors below 1,000W, the symbol ‘R’ is used after the numerical value of the

resistance. Eg 270 ohms would be written as 270R

W, the symbol ‘R’ is often used in place of W, so 330W would be written 330R, and 4.7W as

4R7.

3.2.4 Preferred Values

Resistors are available in various preferred values. A common series of resistors is called the E12

series and the preferred values in this series are: 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, and 82

(i.e. 12 values). The next set of values is higher by a factor of 10: 100, 120, 150 … and then

1,000, 1,200, 1,500 …

3.2.5 Voltage, Current and Resistance

When current passes through a resistor it produces a voltage (V) across the resistor, proportional

to the current (I). The value of the voltage, divided by the current is the resistance value of the

resistor (R). This is expressed by Ohm’s law, which is very useful for calculating the voltage,

current or resistance value if we know the other two quantities.

3.2.6 Variable Resistors

Sometimes it is necessary to have a resistor in a circuit whose value can be changed after the

circuit has been built.

This might be to allow the circuit to be ‘fine tuned’ by the manufacturer, or adjusted by the user

e.g. to change the volume on a radio.

The type of resistor required in this situation is called a ‘potentiometer’. The reason for the name

is that this type of resistance can also be used as a potential divider (see below).

These resistors can be mounted on the front panel of the case (usually when the operation of the

system is adjusted by the user with a knob). Or they can be PCB-mounted (usually to allow

adjustment by the manufacturer).

Fig.3.2 (b) Panel-mounted variable resistor and PCB-mounted preset variable resistor

3.2.7 Resistors in Series

Occasionally it is necessary to produce a resistor by combining several resistors together. The

easiest way to do this is to combine them in ‘series’ (in a line). The resistance of resistors in

series is found by adding them together:

3.2.8 Resistors in Parallel

Very occasionally resistors are combined in ‘parallel’ (both ends are connected together). The

resistance of resistors in parallel is found from the formula:

Fig 3.2(c)

3.2.9 Possible applications

1. Limiting the current through a LED to a safe value

2. Controlling the ‘on’ time of a 555 monostable

3. Setting or adjusting the gain of a non-inverting amplifier Making

When designing the PCB, the two pads for the ends of the resistor can be spaced at any

convenient distance apart greater than 0.3 inches. This can make PCB designs simpler and

neater.

It is often convenient to use resistors as ‘bridges’, with PCB tracks running underneath.

3.3 Speakers.

Speakers are used to produce sounds

Fig 3.3 (a) PCB-mounted loudspeaker Case-mounted loudspeaker

Speakers convert an a.c. signal voltage into a sound. The signal voltage needs to have a

frequency in the range 20 to 20,000 Hz (the range of frequencies that the human ear can hear).

Speakers come in various forms. They can be mounted on the PCB or mounted on the case and

attached to the PCB with flying leads. PCB-mounted loudspeakers only need quite a small

current. They can therefore be driven directly by PICs, 555 timers and most operational

amplifiers.

3.3.1 Possible applications

1. Playing tunes with a PIC

2. Part of a radio or other communication system

3.3.2 Making

Make sure that the subsystem providing the a.c. signal voltage to the loudspeaker is working

correctly before adding the loudspeaker.

Loudspeakers with flying leads can be connected to the PCB using a terminal block.

A PCB-mounting terminal block.

In the case of a PCB-mounted loudspeaker the position of the pads on the PCB needs to be

adjusted to fit the pin spacing of the loudspeaker and allowance needs to be made for the size of

the loudspeaker.

3.3.3 Testing

Send signal voltages of various frequencies to the loudspeaker and check that it responds.

3.3.4 Fault finding

If there is a fault, check that an a.c. signal voltage is coming into the loudspeaker

3.3.5 Alternatives

1. Piezo transducers do a very similar task. The uncased piezo transducer is cheaper than the

PCB-mounted loudspeaker, but it only produces very quiet sounds. Most piezo transducers

are slightly smaller than the PCB-mounted loudspeaker, but they are more expensive and

produce poorer sound quality.

2. Buzzers and piezo sounders can be used to produce a single tone. They are simple to use

and require a d.c. signal voltage.

3.4 Capacitors

Capacitors store electric charge.  They are used with resistors in timing circuits because it

takes time for a capacitor to fill with charge.  They are also used in filter circuits because

capacitors easily pass AC (changing) signals but they block DC (constant) signals.

3.4.1 Capacitor Values

This is a measure of a capacitor's ability to store charge.  A large capacitance means that more

charge can be stored.  Capacitance is measured in farads, symbol F.  However 1F is very

large, so prefixes are used to show the smaller values.

Three prefixes (multipliers) are used, μ (micro), n (nano) and p (pico):

1.μ means 10-6 (millionth), so 1000μF = 1F

2. n means 10-9 (thousand-millionth), so 1000nF = 1μF

3. p means 10-12 (million-millionth), so 1000pF = 1nF

There are many types of capacitor but they can be split into two groups, polarised (for large

values, 1μF or more) and unpolarised (for small values, up to 1μF).  Each group has its own

circuit symbol.

3.4.2 Polarized Capacitors

Electrolytic capacitors are polarised and they must be connected the correct way round - at

least one of their leads will be marked + or -.  They are not damaged by heat when soldering.

Fig 3.4(a)

There are two designs of electrolytic capacitors; axial where the leads are attached to each end

(left of figure 1) and radial where both leads are at the same end (right of figure 1).  Radial

capacitors tend to be a little smaller and they stand upright on the circuit board.

It is easy to find the value of electrolytic capacitors because they are clearly printed with their

capacitance and voltage rating. The voltage rating can be quite low (6V for example) and it

should always be checked when selecting an electrolytic capacitor.  If the circuit parts list

does not specify a voltage, choose a capacitor with a rating which is greater than the circuit's

power supply voltage.  25V is a sensible minimum for most circuits.

3.4.3 Tantalum Bead Capacitors

Tantalum bead capacitors are polarised and have low voltage ratings like electrolytic

capacitors.  They are expensive but very small, so they are used where a large capacitance is

needed in a small size.

Modern tantalum bead capacitors are printed with their capacitance and voltage in full. 

However, older ones use a colour-code system which has two stripes (for the two digits) and a

spot of colour for the number of zeros to give the value in μF.  The standard capacitor colour

code is used (see later in this article), but for the spot, grey is used to mean x0.01 and white

means x0.1 so that values of less than 10μF can be shown.  A third colour stripe near the leads

shows the working voltage (yellow 6.3V, black 10V, green 16V, blue 20V, grey 25V, white

30V, pink 35V).  Here are some examples:

1. Blue, grey, black spot means 68μF

2. Blue, grey, white spot means 6.8μF

3. Blue, grey, grey spot means 0.68μF

3.4.4 Unpolarised Capacitors

Small value capacitors are Unpolarised and may be connected either way round.  They are not

damaged by heat when soldering, except for one unusual type (polystyrene).  They have high

voltage ratings of at least 50V, usually 250V or so.

Fig3.4 (b)

It can be difficult to find the values of these small capacitors because there are many types of

them and several different labelling systems!

Many small value capacitors have their value printed but without a multiplier, so you need to

use experience to work out what the multiplier should be:

For example, 0.1 means 0.1μF = 100nF.

Sometimes the multiplier is used in place of the decimal point:

For example, 4n7 means 4.7nF.

3.4.5 Polystyrene Capacitors

This type, shown on the right of figure 3, is rarely used now.  Their value (in pF) is normally

printed without units. Polystyrene capacitors can be damaged by heat when soldering (it melts

the polystyrene!) so you should use a heatsink (such as a crocodile clip).  Clip the heatsink to

the lead between the capacitor and the joint.

3.4.6 Capacitor Number Code

A number code is often used on small capacitors where printing is difficult:

1. The 1st number is the 1st digit of the value.

2. The 2nd number is the 2nd digit of the value.

3. The 3rd number is the number of zeros to give the capacitance in pF.

4. Ignore any letters - they just indicate tolerance and voltage rating.

Here are some examples:

102   means 1000pF = 1nF   (not 102pF!)

472J means 4700pF = 4.7nF (J means 5% tolerance)

3.5.1 IC1 LM358 Low Power Dual Op-amp

The LM158 series consists of two independent, high gain, internally frequency compensated

operational amplifiers which were designed specifically to operate from a single power supply

over a wide range of voltages. Operation from split power supplies is also possible and the low

power supply current drain is independent of the magnitude of the power supply voltage.

Application areas include transducer amplifiers, dc gain blocks and all the conventional op amp

circuits which now can be more easily implemented in single power supply systems. For

example, the LM158 series can be directly operated off of the standard +5V power supply

voltage which is used in digital systems and will easily provide the required interface electronics

without requiring the additional ±15V power supplies.

The LM358 and LM2904 are available in a chip sized package (8-Bump micro SMD) using

National's micro SMD package technology.