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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.