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TABLE OF CONTENTS
CHAPTER NO. TITLE PAGE NO.
ABSTRACT v
LIST OF TABLES vi
LIST OF FIGURES vii
1. INTRODUCTION 1
1.1 AUTOMATIC COOLING SYSTEM 1
2. LITERATURE REVIEW 2
2.1 LATHE 2
2.2 SENSORS 3
2.2.1 Temperature Sensors 4
2.2.2 NTC Thermistors: General 5
Properties and Features
2.2.2.1 Temperature Ranges and 5
Resistance Values
2.2.2.2 Accurate and Repeatable 5
R/T Characteristic
2.2.2.3 Sensitivity to Changes in Temperature 6
2.2.2.4 Interchangeability 7
2.2.2.5 Small Size 7
2.2.2.6 Remote Temperature Sensing 7
Capability
2.2.2.7 Ruggedness, Stability & Reliability 7
2.3 TRANSISTOR 8
2.3.1 Importance 82.3.2 Usage 9
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2.4 RECTIFIER 92.4.1 Half-wave rectification 10
2.4.2 Full-wave rectification 11
2.4.3 Peak loss 13
2.5 PRINTED CIRCUIT BOARD (PCB) 14
2.6 RELAY 14
3. PLAN OF WORK 17
3.1 Selection of project 17
3.2 Design and Drawings 17
3.3 Purchase Consideration 17
3.4 Fabrication 17
3.5 Assembly of the parts 18
3.6 Cost Estimation 18
3.7 Report 18
4. MATERIALS AND METHODS 19
4.1 TEMPERATURE SENSOR 19
4.2 AMPLIFIER 20
4.3 COMPARATOR 20
4.4 RELAY 21
4.5 WASHER PUMP 22
4.6 RESERVOIR 22
4.6.1 Design of reservoir 23
4.6.1.1 Design calculations 23
5. DESIGN AND DRAWINGS 24
5.1 FRONT VIEW 24
5.2 SIDE VIEW 25
5.3 TOP VIEW 26
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6 COST ESTIMAION 27
7. RESULTS AND DISCUSSION 29
7.1 OPERATION 29
7.2 BENEFITS OF AN AUTOMATIC COOLING UNIT 29
8. CONCLUSION 30
9. APPENDICES 31
10. REFERENCES 35
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LIST OF TABLES
CHAPTER NO. TITLE PAGE NO.
4.1 Specification for reservoir 22
7.1 Material cost 27
7.2 Labor charge 27
7.3 Other cost 28
7.4 Total cost 28
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LIST OF FIGURES
CHAPTER NO. TITLE PAGE NO.
2.1 Lathe 2
2.2 NTC Thermistor 4
2.3 Comparative resistance graph 6
2.4 Half-wave rectification 10
2.5 Graetz bridge rectifier: a full-wave rectifier
using 4 diodes 112.6 Full-wave rectifier using a center tap
transformer and 2 diodes 11
2.7 Three-phase bridge rectifier 12
2.8 Full-wave rectifier with vacuum tube having
two anodes 12
2.9 Printed Circuit Board 14
2.10 Relay 15
2.11 Relays switch connection 16
4.1 Temperature sensor 19
4.2 bc 547 transistor 20
4.3 LM358 Comparator 20
4.4 Relay 21
4.5 SPST Relay 21
4.6 Washer pump 22
4.7 Reservoir 23
5.1 Front view 24
5.2 Side view 25
5.3 Top view 26
9.1 Washer pump 31
9.2 Circuit 32
9.3 Reservoir 33
9.4 Automatic cooing unit 34
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ABSTRACT
The project is to introduce automatic cooling unit instead of
manual cooling process through design and fabricating the reservoir of the unit.
Automatic cooling unit is a system typically delivers a controlled amount of coolant to
specific locations on a machine while the machine is operating, at specific times from a
central location. when the temperature at the work piece is increased above the reference
temperature, the automatic coolant unit will activate and automatically pumps coolant
and will reduce the temperature.
The temperature sensor or thermistor is placed near to the
tool or work piece, as a result the thermistor senses the temperature from the tool -work
piece interface and sends an electrical signal to the amplifier. The electrical signal is
amplified by using amplifier, then this signal is send to the comparator then the
comparator compares both input and reference signal. If the input signal is greater than
the reference signal then the relay gets activated automatically to control the temperature
to a certain level. So the coolant is pumped from the reservoir to the tool- work piece
interface. Similarly when the temperature decreases below the reference value the control
unit deactivates the pump by using the relay. The process will continue according to the
increase and decrease of the temperature.
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1. INTRODUCTION
1.1 AUTOMATIC COOLING SYSTEM
The long working schedule in the lathe, drilling machine etc...
leads to increase the temperature at the tool as well as the work piece. This high
temperature will affect the tool life and also will affect the surface finish of the work.
So it is very important to introduce automatic cooling system instead of manual
cooling, which will be very useful in the manufacturing industry.
An Automatic coolant unit comprises apump,reservoir,
valvesand control unit. It typically delivers a controlled amount ofcoolant to specific
locations on a machine while the machine is operating, at specific times from a
central location. When the temperature at the work piece is increased above the
reference temperature, the automatic coolant unit will activate and automatically
pumps coolant and will reduce the temperature. So that we can work for longer time
without any interruptions.
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2. LITERATURE REVIEW
2.1 LATHE
Figure 2.1 Lathe
A lathe is a machine tool which rotates the work piece on its axis to
perform various operations such as cutting, sanding, knurling, drilling, or deformation
with tools that are applied to the work piece to create an object which has symmetry
about an axis of rotation.
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Lathes are used in woodturning, metalworking, metal spinning, and
glass working. Lathes can be used to shape pottery, the best-known design being the
potters wheel. Most suitably equipped metalworking lathes can also be used to producemost solids of revolution, plane surfaces and screw threads or helices. Ornamental lathes
can produce three-dimensional solids of incredible complexity. The material can be held
in place by either one or two centers, at least one of which can be moved horizontally to
accommodate varying material lengths. Other work holding methods include clamping
the work about the axis of rotation using a chuck or collet, or to a faceplate, using clamps
or dogs.
Examples of objects that can be produced on a lathe include
candlestick holders, cue sticks, table legs, bowls, baseball bats, musical instruments
(especially woodwind instruments), crankshafts and camshafts.
2.2 SENSORS
All sensors perform the same basic function. They detect a mechanical
condition, chemical state, or temperature conditioning and change it into an electrical
signal that can be used by the microcomputer makes decisions based on information it
receives from sensors. Each sensor used in a particular system has a specific job to do.
Most sensors present in use are available resistors or potentiometers.
They modify a voltage to or from the computer, indicating a constantly changing status
that can be calculated, compensated for, and modified. That is, most sensors control a
voltage signal from the microprocessor. In addition to the variable resisters, two other
commonly used sensors are switches and thermistors. Thermistors are special types of
resistors that convert temperature into voltage.
Even though there are a variety of different sensors designs, they all
fall under one of two operation categories.
1. Reference voltage sensors
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2. Voltage generation sensors.
Reference voltage sensors provide input to the microprocessor by
modifying or controlling a constant, predetermined voltage signal. This signal which can
have a reference value from 5 to 9 volts, is generated and sent out to each sensor by a
reference voltage regulator located inside the processor. Because the processor knows
that certain voltage value has been sent out, it can indirectly interpret things like motion,
temperature, and component position, based on what comes back. Variable resistors,
switches and thermistors are the example of reference voltage sensors.
Voltage generation sensors include components like the hall-effect
switch, oxygen sensor which are capable of producing their own input voltage signal.
2.2.1Temperature Sensors
Temperature sensor detect a temperature conditioning and change it
into electrical signal that can be used by the microcomputer makes decisions based on
information it receives from sensors.
Two common temperature sensing technologies are based on
thermistors or semiconductor junctions.
A thermistor behaves like a resistor whose resistance changes with
temperature. Thermistor is a combination of the words thermal and resistor. The
thermistor was first invented by Samuel Ruben in 1930.
Figure 2.2 NTC Thermistor
Thermistors are available with either positive or negative temperature
coefficients. Positive temperature coefficient (PTC) thermistors have increasing resistance
with increasing temperature. Negative temperature coefficient (NTC) thermistors exhibit
decreasing resistance at increasing temperature. In either case when the current is passedthrough the thermistor, the voltage drop across it is proportional to the temperature
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being sensed. This voltage can then be applied to a simple meter or via an analog-to-
digital converter.
2.2.2 NTC Thermistors: General Properties and Features
NTC thermistors are manufactured in a variety of sizes and
configurations. The thermistor element is usually coated with a phenolic or epoxy
material that provides protection from environmental conditions. For applications
requiring sensing tip dimensions with part to part uniformity and/or smaller size, the
devices can be encapsulated in PVC cups or polyimide tubes.
NTC thermistors offer many desirable features for temperature
measurement and control within their operating temperature range. Although the word
thermistor is derived from THERMally sensitive resISTOR, the NTC thermistor can be
more accurately classified as a ceramic semiconductor. The most prevalent types of
thermistors are glass bead, disc, and chip configurations and the following discussion
focuses primarily on those technologies.
2.2.2.1 Temperature Ranges and Resistance Values
NTC thermistors exhibit a decrease in electrical resistance with
increasing temperature. Depending on the materials and methods of fabrication, they are
generally used in the temperature range of -50C to 150C, and up to 300C for some
glass-encapsulated units. The resistance value of a thermistor is typically referenced at
25C (abbreviated as R25). For most applications, the R25 values are between 100 and
100 k . Other R25 values as low as 10 and as high as 40 M can be produced, andresistance values at temperature points other than 25C can be specified.
2.2.2.2 Accurate and Repeatable R/T Characteristic
The resistance Vs temperature (R/T) characteristics (also known as
R/T curve) of the NTC thermistor forms the "scale" that allows its use as a temperature
sensor. Although this characteristic is a nonlinear, negative exponential function, several
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interpolation equations are available that very accurately describe the R/T curve. The
most well known is the Steinhart-Hart equation: 1/T =A + B (lnR) + C(lnR) 3
Where,
T = Kelvin temperature
R = resistance at temperature T
Coefficients A, B, and C are derived by calibrating at three
temperature points and then solving the three simultaneous equations. The uncertainty
associated with the use of the Steinhart-Hart equation is less than 0.005C for 50C
temperature spans within the 0C-260C range, so using the appropriate interpolation
equation or lookup table in conjunction with a microprocessor can eliminate the potential
nonlinearity problem.
2.2.2.3 Sensitivity to Changes in Temperature
The NTC thermistor's relatively large change in resistance Vs
temperature, typically on the order of -3%/C to -6%/C, provides an order of magnitude
greater sensitivity or signal response than other temperature sensors such as
thermocouples and RTDs. On the other hand, the less sensitive thermocouples and RTDs
are a good choice for applications requiring temperature spans >260C and/or operating
temperatures beyond the limits for thermistors.
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Figure 2.3 Comparative resistance graph
From the graph, over the range of -50C to 150C, NTC
thermistors offer a distinct advantage in sensitivity to temperature changes compared to
other temperature sensors. This graph illustrates the R/T characteristics of some typical
NTC thermistors and platinum RTD
2.2.2.4 Interchangeability
Another important feature of the NTC thermistor is the degree of
interchangeability that can be offered at a relatively low cost, particularly for disc and
chip devices. Interchangeability describes the degree of accuracy or tolerance to which a
thermistor is specified and produced, and is normally expressed as a temperature
tolerance over a temperature range. For example, disc and chip thermistors are
commonly specified to tolerances of 0.1C and 0.2C over the temperature ranges of
0C to 70C and 0C to 100C. Interchangeability helps the systems manufacturer or
thermistor user reduces labor costs by not having to calibrate each instrument/system
with each thermistor during fabrication or while being used in the field. A health care
professional, for instance, can use a thermistor temperature probe on one patient, discard
it, and connect a new probe of the same specifications for use on another patient--without
recalibration. The same holds true for other applications requiring reusable probes.
2.2.2.5 Small Size
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The small dimensions of most bead, disc, and chip thermistors
used for resistance thermometry make for a very rapid response to temperature changes.
This feature is particularly useful for temperature monitoring and control systemsrequiring quick feedback.
2.2.2.6 Remote Temperature Sensing Capability
Thermistors are well suited for sensing temperature at remote
locations via long, two-wire cable because the resistance of the long wires is insignificant
compared to the relatively high resistance of the thermistor.
2.2.2.7 Ruggedness, Stability, and Reliability
As a result of improvements in technology, NTC bead, disc, and
chip thermistor configurations are typically more rugged and better able to handle
mechanical and thermal shock and vibration than other temperature sensors.
2.3 TRANSISTOR
A 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.
The transistor is the fundamental building block of modern
electronic devices, and is ubiquitous in modern electronic systems. Following its release in
the early 1950s the transistor revolutionized the field of electronics, and paved the way for
smaller and cheaper radios,calculators, and computers, among other things.
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2.3.1 Importance
The transistor is the key active component in practically all modern
electronics, and is considered by many to be one of the greatest inventions of the twentieth
century. Its importance in today's society rests on its ability to be mass produced using a
highly automated process (semiconductor device fabrication) that achieves astonishingly
low per-transistor costs.
Although several companies each produce over a billion
individually packaged (known as discrete) transistors every year, the vast majority of
transistors now produced are in integrated circuits (often shortened to IC, microchips or
simply chips), along with diodes, resistors, capacitors and other electronic components, to
produce complete electronic circuits. A logic gate consists of up to about twenty
transistors whereas an advanced microprocessor, as of 2011, can use as many as 3 billion
transistors (MOSFETs). "About 60 million transistors were built this year [2002] ... for
[each] man, woman, and child on Earth."
The transistor's low cost, flexibility, and reliability have made it a
ubiquitous device. Transistorized mechatronic circuits have replaced electromechanical
devices in controlling appliances and machinery. It is often easier and cheaper to use a
standard microcontroller and write a computer program to carry out a control function
than to design an equivalent mechanical control function.
2.3.2 Usage
The bipolar junction transistor, or BJT, was the most commonly
used transistor in the 1960s and 70s. Even after MOSFETs became widely available, the
BJT remained the transistor of choice for many analog circuits such as simple amplifiers
because of their greater linearity and ease of manufacture. Desirable properties of
MOSFETs, such as their utility in low-power devices, usually in the CMOS configuration,
allowed them to capture nearly all market share for digital circuits; more recently
MOSFETs have captured most analog and power applications as well, including modern
clocked analog circuits, voltage regulators, amplifiers, power transmitters, motor drivers,
etc.
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2.4 RECTIFIER
A rectifier is an electrical device that converts alternating
current (AC), which periodically reverses direction, to direct current (DC), which is in
only one direction, a process known as rectification. Rectifiers have many uses including
as components ofpower supplies and as detectors ofradio signals. Rectifiers may be made
ofsolid statediodes, vacuum tube diodes, mercury arc valves, and other components.
A device which performs the opposite function (converting DC to
AC) is known as an inverter. When only one diode is used to rectify AC (by blocking the
negative or positive portion of the waveform), the difference between the term diode and
the term rectifier is merely one of usage, i.e., the term rectifier describes a diode that is
being used to convert AC to DC. Almost all rectifiers comprise a number of diodes in a
specific arrangement for more efficiently converting AC to DC than is possible with only
one diode. Before the development of silicon semiconductor rectifiers, vacuum tube diodes
and copper (I) oxide or selenium rectifier stacks were used.
Early radio receivers, called crystal radios, used a "cat's
whisker" of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point-
contact rectifier or "crystal detector". Rectification may occasionally serve in roles other
than to generate direct current per se. For example, in gas heating systems flame
rectification is used to detect presence of flame. Two metal electrodes in the outer layer of
the flame provide a current path, and rectification of an applied alternating voltage will
happen in the plasma, but only while the flame is present to generate it.
2.4.1 Half-wave rectification
In half wave rectification, either the positive or negative half of
the AC wave is passed, while the other half is blocked. Because only one half of the input
waveform reaches the output, it is very inefficient if used for power transfer. Half-wave
rectification can be achieved with a single diode in a one-phase supply, or with three
diodes in a three-phase supply.
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Figure 2.4 Half-wave rectification
The output DC voltage of a half wave rectifier can be calculated
with the following two ideal equations:
V rms = V peak / 2
V dc = V peak/
2.4.2 Full-wave rectification
A full-wave rectifier converts the whole of the input waveform to
one of constant polarity (positive or negative) at its output. Full-wave rectification
converts both polarities of the input waveform to DC (direct current), and is more
efficient. However, in a circuit with a non-center tapped transformer, four diodes are
required instead of the one needed for half-wave rectification. (See semiconductors,
diode). Four diodes arranged this way are called a diode bridge or bridge rectifier.
Figure 2.5 Graetz bridge rectifier: a full-wave rectifier using 4 diodes
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For single-phase AC, if the transformer is center-tapped, then
two diodes back-to-back (i.e. anodes-to-anode or cathode-to-cathode) can form a full-
wave rectifier. Twice as many windings are required on the transformer secondary toobtain the same output voltage compared to the bridge rectifier above.
Figure 2.6 Full-wave rectifier using a center tap transformer and 2 diodes
A very common vacuum tube rectifier configuration contained
one cathode and twin anodes inside a single envelope; in this way, the two diodes required
only one vacuum tube. The 5U4 and 5Y3 were popular examples of this configuration.
Figure 2.7 Three-phase bridge rectifier
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Figure 2.8 Full-wave rectifier with vacuum tube having two anodes
For three-phase AC, six diodes are used. Typically there are
three pairs of diodes, each pair, though, is not the same kind of double diode that would
be used for a full wave single-phase rectifier. Instead the pairs are in series (anode to
cathode). Typically, commercially available double diodes have four terminals so the user
can configure them as single-phase split supply use, for half a bridge, or for three-phase
use.
Most devices that generate alternating current (such devices are
called alternators) generate three-phase AC. For example, an automobile alternator has
six diodes inside it to function as a full-wave rectifier for battery charging applications.
The average and root-mean-square output voltages of an ideal
single phase full wave rectifier can be calculated as:
Where,
Vdc, Vav - the average or DC output voltage,
Vp- the peak value of half wave,
Vrms - the root-mean-square value of output voltage. = ~ 3.14159
2.4.3 Peak loss
An aspect of most rectification is a loss from the peak input
voltage to the peak output voltage, caused by the built-in voltage drop across the diodes
(around 0.7 V for ordinary silicon p-n-junction diodes and 0.3 V for Schottky diodes).
Half-wave rectification and full-wave rectification using two separate secondaries willhave a peak voltage loss of one diode drop. Bridge rectification will have a loss of two
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diode drops. This may represent significant power loss in very low voltage supplies. In
addition, the diodes will not conduct below this voltage, so the circuit is only passing
current through for a portion of each half-cycle, causing short segments of zero voltage toappear between each "hump.
2.5 PRINTED CIRCUIT BOARD (PCB)
A printed circuit board, or PCB, is used to mechanically support
and electrically connect electronic components using conductive pathways, or traces,
etched from copper sheets laminated onto a non-conductive substrate. It is also referred
to as printed wiring board (PWB) or etched wiring board. A PCB populated with
electronic components is a printed circuit assembly (PCA), also known as a printed
circuit board assembly (PCBA).
Figure 2.9 Printed Circuit Board
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PCBs are rugged, inexpensive, and can be highly reliable. They
require much more layout effort and higher initial cost than either wire-wrapped or
point-to-point constructed circuits, but are much cheaper and faster for high-volumeproduction. Much of the electronics industry's PCB design, assembly, and quality control
needs are set by standards that are published by the IPC organization.
2.6 RELAY
A relay is an electrically operated switch. Current flowing
through the coil of the relay creates a magnetic field which attracts a lever and changes
the switch contacts. The coil current can be on or off so relays have two switch positions
and they are double throw (changeover) switches. Relays allow one circuit to switch a
second circuit which can be completely separate from the first. For example a low voltage
battery circuit can use a relay to switch a 230V AC mains circuit. There is no electrical
connection inside the relay between the two circuits; the link is magnetic and mechanical.
The coil of a relay passes a relatively large current, typically
30mA for a 12V relay, but it can be as much as 100mA for relays designed to operate
from lower voltages. Most ICs (chips) cannot provide this current and a transistor is
usually used to amplify the small IC current to the larger value required for the relay coil.
The maximum output current for the popular 555 timer IC is 200mA so these devices can
supply relay coils directly without amplification.
Figure 2.10 Relay
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Relays are usually SPDT or DPDT but they can have many
more sets of switch contacts, for example relays with 4 sets of changeover contacts are
readily available. Most relays are designed for PCB mounting but you can solder wiresdirectly to the pins providing you take care to avoid melting the plastic case of the relay.
The animated picture shows a working relay with its coil and switch contacts. You can see
a lever on the left being attracted by magnetism when the coil is switched on. This lever
moves the switch contacts. There is one set of contacts (SPDT) in the foreground and
another behind them, making the relay DPDT.
Figure 2.11 Relays switch connection
The relay's switch connections are usually labeled COM, NC and NO:
COM = Common, always connect to this; it is the moving part of the switch.
NC = Normally Closed, COM is connected to this when the relay coil is off.
NO = Normally Open, COM is connected to this when the relay coil is on.
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3. PLAN OF WORK
Planning is an important part of every project. Nobody plans to
fail, but they fail to plan. So before staring our project work we made some planning for
the successful completion of the project.
3.1 SELECTION OF PROJECT
By considering the benefits of the project with the present
conditions, the amount of money can be invested, availability of the material, duration of
project, design and fabrication area the project can be planned.
3.2 DESIGN AND DRAWINGS
Having been decided about the project to be manufactured, it
must be designed. The work of the design should be done very carefully by considering all
the relevant factors. After designing the project its detailed drawing are prepared so that
no doubts are left for future, detailed specifications of raw materials and finished
products should be decided carefully along with the specification of the machine required
for their manufacture.
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3.3 PURCHASE CONSIDERATION
It is very difficult to fabricate each and every components of the
project. Fabrication must be based on the accuracy that can be obtained from the
components. If the project have some electronic components, then it is better to buy the
components from the market, and assemble it to the requirement.
3.4 FABRICATION
Fabrication of the components can be done with the help of
designed calculations and drawings through different manufacturing process like cutting,
welding, drilling etc
3.5 ASSEMBLY OF THE PARTS
The fabricated and purchased components are assembled
together to complete the fabrication process.
3.6 COST ESTIMATION
Cost estimation can be calculated by considering the material
cost, labor cost, transportation charges etc...
1. Material cost
2. Labor cost
3. Transportation expenses
3.7 REPORT
At the end of the project work, a report is prepared for future
references. The project report consists of all the items done during the project work.
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4. MATERIALS AND METHODS
4.1 TEMPERATURE SENSOR
The Sensor used for the temperature measurement is
thermistor. Temperature sensor detect a temperature conditioning and change it intoelectrical signal that can be used by the microcomputer makes decisions based on
information it receives from sensors.
Name : Thermistor
Type : NTC Thermistor
Temperature range : -50C to 150C
Resistance tolerances : 2%
Overall lengths : 18mm- 78mm
Figure 4.1 Temperature sensor
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4.2 AMPLIFIER
Amplifier is any device that will convert one signal often with
a small Amount of energy into another signal often with a larger amount of energy. In
automatic coolant unit the electrical signal from the thermistor is amplified by using
amplifier.
Figure 4.2 bc 547 transistor
4.3 COMPARATOR
The comparator is used to compare the amplified electrical
signal from the amplifier to the comparator with the reference signal.
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Figure 4.3 LM358 Comparator
4.4 RELAY
A relay is an electrically operated switch. Current flowing through
the coil of the relay creates a magnetic field which attracts a lever and changes the switch
contacts. The coil current can be on or off so relays have two switch positions and they
are double throw (changeover) switches. Relays allow one circuit to switch a second
circuit which can be completely separate from the first.
Figure 4.4 Relay
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Figure 4.5 SPST Relay
4.5 WASHER PUMP
Washer pump, various style12Vwindscreenwasher pumps,pumps for the transfer of water from reservoir to the specific location through nozzles.
Figure 4.6 Washer pump
4.6 RESERVOIR
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Reservoir is the storage area for the coolant and the coolant is
supplied to the specific location from the reservoir with the help of pump.
Sl.
No
SPECIFICATION
1 Material Sheet metal
2 Length 30cm
3 Breadth 20cm
4 Height 17cm
5 Nozzle diameter 1.2cm
Table 4.1 Specification for reservoir
4.6.1 Design of reservoir
Figure 4.7 Reservoir
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4.6.1.1 Design calculations
( i ) Volume ( V ) =l*b*h
=30*20*17=10200 cm3
5. DESIGN & DRAWINGS
5.1 FRONT VIEW
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Figure 5.1 Front view
5.2 SIDE VIEW
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Figure 5.2 Side view
5.3 TOP VIEW
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Figure 5.3 Top view
6. COST ESTIMAION
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MATERIAL COST
Sl.
NoMATERIAL COST COST
1 Metal Sheet 200
2 Electronic devices 300
3 Washer pump 200
TOTAL 700
Table 7.1 Material cost
LABOR CHARGE
Sl.
NoLABOR CHARGE COST
1 Gas cutting 100
2 Welding 200
3 Drilling 25
4 Other operations 50
TOTAL 375
Table 7.2 Labor charge
OTHER COST
Sl.
No
OTHER COST COST
1 Transportation charges 50
2 Paintings 30
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TOTAL 80
Table 7.3 Other cost
TOTAL COST
Sl.
NoTOTAL COST COST
1 Material costs 700
2 Labor charges 375
3 Other costs 80
TOTAL 1155
Table 7.4 Total cost
7. RESULT AND DISCUSSIONReservoir has been fabricated successfully as designed and also
assembled the components such as temperature sensor, amplifier, comparator, and relay
in the PCB board to full fill the requirements of complete operation of the automatic
cooling unit.
7.1 OPERATION
a) The temperature sensor or thermistor is placed near to the tool or work piece.
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b) The thermistor senses the temperature from the tool or work piece and sends an
electrical signal to the amplifier.
c) The electrical signal is amplified by using amplifier, then this signal is send to the
comparator then the comparator compares both input and reference signal.
d) If the input signal is greater than the reference signal then the relay gets activated
automatically to control the temperature to a certain level
e) The drive pumps the lubricant or coolant from the reservoir to the tool- work piece
interface.
f) Similarly when the temperature decreases below the reference value the control unit
deactivates the pump by using the relay.
g) The process will continue according to the increase and decrease of the temperature.
7.2 BENEFITS OF THE AUTOMATIC COOLING UNIT
Automatic cooling unit have many advantages over traditional methods of manual cooling
process:
a) The process is an automatic with the increase in temperature.
b) Cooling occurs while the machinery is in operation.
c) Proper cooling ensures safe operation of the machinery.
d) Extended tool life, fewer breakdowns, reduced downtime, reduced replacement
costs, reduced maintenance costs and good surface finish.
e) Measured cooling means no wasted coolant.
f) Lower power consumption.
8. CONCLUSION
The automatic cooling unit has been successfully introduced instead of
manual cooling process by design and fabricating the components of the unit.
As temperature in the tool- work piece interface comes above the
reference temperature, the unit successfully activated and reduced the temperature.
Similarly, as the temperature comes below the reference temperature, the unit gets
deactivated successfully.
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9. APPENDICES
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PHOTOGRAPHY
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Figure 9.1 Washer pump
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Figure 9.2 Circuit
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Figure 9.3 Reservoir
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Figure 9.4 Automatic cooling unit
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10. REFERENCES
Books1. Manufacturing Technology II, G.K. Vijayaraghavan, A.R.S. Publications, fifth edition,
nov 2009
2. Electronics and Microprocessors, V. Thiyagarajan, A.R. Publications, fourth edition,
dec 2008
3. Automobile Engineering, G.K. Vijayaraghavan, A.R.S. Publications, fifth edition, nov
2010
Websites1. Automatic cooling system,www.koolmist.com/automatic_cooling_unit
2. BTS Room Automatic cooling unit FCU, www.damcon.com.pk/proinfo.php
3. Automatic air cooling unit, www.prodeco/srl.com/eng/accessori.html
4. Wikipedia , www.wikipedia.com/automaticlubrication
http://www.koolmist.com/automatic_cooling_unithttp://www.koolmist.com/automatic_cooling_unithttp://www.damcon.com.pk/proinfo.phphttp://www.wikipedia.com/automatichttp://www.koolmist.com/automatic_cooling_unithttp://www.damcon.com.pk/proinfo.phphttp://www.wikipedia.com/automatic