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CHAPTER ONE
INTRODUCTION
BACKGROUND OF THE STUDY
Digital usually refers to something using digits, particularly binary digits.
(Wikipedia, 2018). There is pressing need for dentistry to move to the level of
using digital devices or equipment’s to carry our oral health care services both in
clinical procedures and laboratory procedures.
Digital transformation is not necessarily about digital technology, but about the
fact that technology, which is digital, allows people to solve their traditional
problems. And the prefer this digital solution to the old solution. (Dado et al.,
2014). In that case the introduction of the Digital art waxer with bursen burner
can help to eradicate the conventional ways of wax pattern making during
appliance or a prosthetic restoration in other to achieve a well-fitting prosthesis.
The transformation stage means that digital usages inherently enable new types
of innovation and creativity in a particular domain, rather than simply enhance
and support traditional methods. (Michele et al., 2008). In a narrow sense, “digital
transformation” may refer to the concept of “going paperless”, and reaching a
“digital business maturity” (Heinze et al., 2018). This affects both individual
businesses (Keyur & Mary, 2000). And whole segments of society, such as
government, mass communications, art, medicine and science (Baker, 2014).
The use of dental technologies or devices that incorporates digital or computer-
controlled components to carry out dental procedures rather than using
mechanical or electrical tools is paramount to a successful dental restoration. The
use of digital dentistry can make carrying out dental procedures more efficient
than using mechanical tools, both for restorative as diagnostic purposes.
'Godfather' of Digital Dentistry is the French professor François Duret, who
invented dental CAD/CAM in 1973. (Wikipedia, 2018). Some of the technologies
used in digital dentistry include but not limited to;
CAD/CAM and intraoral imaging both laboratory and clinician’s controlled.
Photogrammetry based intraoral scanning (software driven)
3D printing of the digital images taken with intraoral scanner
Caries diagnosis
Computer aided implant dentistry, including design and fabrication of surgical
guides
Electric and surgical/implant hand pieces
Digital radiography- intraoral and extra oral, including cone beam computed
tomography (CBSCT)
Occlusion and TMJ analysis and diagnosis
Photography –extra oral and intraoral
Practice and patient records management –including digital patient education.
Shade matching
3D printing to make appliance, temporaries and surgical guides
Diagnodent
Dental lasers
The wand –used to carry anesthesia
A digital art waxing device (digital wax carving pencil) is an electrically driven
device that is designed to carve and mold a variety of waxes used in the dental
laboratory. The digital art waxing device has variety of wax carving and adding tips
and easy temperature control which allows for precise waxing work. (Michelle,
2014).
A Bunsen burner is a common piece of laboratory equipment that produces a
single open gas flame, which is used for heating, sterilization and combustion
(Wikipedia, 2018). The gas can be natural gas or liquefied petroleum gas, such as
propane, butane or a mixture of both. While the Bunsen burner is driven by gas,
the Bunsen burner attached to this digital art waxing device is electrically driven
to generate heat, thus it can be called an electrical Bunsen burner. Electrical
Bunsen burner combines the advantages of a regular gas burner with the clean
easy operation of the Electro mantles.
This electric Bunsen burner uses radiation to bring about heat transfer. The heater
directs radiation upwards to a focal point. This attached electrical Bunsen burner
is ideal for flaming modeling wax, heating dental hand pieces and instruments.
The heat generated from the heater is controlled by the control panel of the
digital art waxing machine since it is attached to it.
The digital art waxing machine with attached Bunsen burner will foster better
appreciation and practice of digital dental technology in the practice of digital
dentistry.
1.1 STATEMENT OF PROBLEM
There is an increasing need to enlighten the dental professionals on the use of
advanced techniques in manipulating wax from a digital regulated heat source in
other to make precised and accurate wax patterns. The Introduction of a digital
art waxer and perhaps a Digital/ electrical bursen burner will help the dental
world to fabricate a well-fitting prosthesis. In some cases, dental professionals or
dental technologist have had cancers as a result of the inhalation of carbons and
gases using the various conventional sources of heat to make wax patterns in the
course of their work practice. In other to prevent the rate of dental professionals
suffering from these problems there is need for the invention and production of
the digital art waxing devices in the country. This will help reduce the cost of
importation of these devices which some professionals are not even able to
afford. Static and dynamic occlusal interferences frequently need to be corrected
by selective grinding of the occlusal surface of conventional cast, porcelain fused
to metal and all-ceramic restorations. Proper dimensional contours and occlusal
morphologies of these restorations is an important consideration in overall
success of the case. There are cases that some prosthesis was not properly fitted
in the patient mouth as a result of occlusal morphology discrepancies, and with
the use of the digital art waxer for wax pattern designs accurate morphology can
be achieved.
1.2 AIM AND OBJECTIVES
The main aim of this project is the design and fabrication of a digital art waxer and
Bunsen burner.
The specific objectives are:
1. To eliminate carbon found on wax patterns prior to fabrication of
appliances.
2. To reduce the rate at which bursen burners are imported.
3. To help facilitate wax pattern making and achieve accurate occlusal
morphologies.
4. To reduce the exposure of dental professionals to gases using the
conventional ways of wax construction in the dental laboratory.
1.3 RESEARCH QUESTIONS
How can this device be used in the fabrication of prostheses in the dental
laboratory?
How can effective wax manipulation be achieved better with respect to the
device?
Will this device guarantee successful fabrication of dental prosthesis?
1.4 SCOPE OF THE STUDY
This work covers every aspect of a digital art waxer construction, fabrication and
digital Bunsen burner production using stainless steel,
1.5 LIMITATION OF THE STUDY
Despite the efforts made in making this work easy, a lot of challenges were
encountered in the course of carrying out this work.
The challenges are;
Financial constraints: The needed capital to get the apparatus and the materials
needed for the design was huge and not raised on time.
Unavailability of materials: some of the materials were not found in the market
and how to be imported from foreign companies which delayed the work and also
increased cost.
Malfunctioning apparatus: In the course of the fabrication of the device, most of
the equipment’s and materials got faulty and this lead to the yield of improper
output.
1.6 JUSTIFICATION OF STUDY
This study will significantly enlighten dental professionals on how important
a digital art waxer and Bunsen burner can help in effective wax manipulation in
the success of a dental prostheses. It will also provide and foster in-depth
knowledge on digital dental technology in the dental practice.
1.7 DEFINITION OF TERMS
DENTAL: This means pertaining or relating to the teeth in the oral cavity (Eyarefe
and Ugwuda, 2015).
FABRICATION: This is the process of creating a new material from existing
substances. It involves utilization of materials, tools and equipment to obtain a
target appliance (Eyarefe and Ugwuda, 2015).
LABORATORY: A place equipped and used for experimental study, research,
analysis, test or preparations in any branch of science.
CHAPTER TWO
LITERATURE REVIEW
2.0 THEORETICAL FRAMEWORK
2.1 PRODUCTION THEORY
Production is basically an activity of transformation, which connects factor inputs
and outputs (Mishra 2014). Production makes use of resources to make provision
of service that is suitable for use, exchange in a market exchange economy. This
can include manufacturing, construction and packaging.
Some economists define production broadly as all economic activity other than
consumption. They see every commercial activity other than the final purchase as
some form of production.
Production is the process that combines various material and immaterial inputs
(plans, technical know-how) to make something for consumption (output) that
has value and contributes to the utility of an individual or group of people. This
imbibes personality trait. Coon (2004) defines personality traits as “stable
qualities that a person shows in most situations”. To the trait theorists there are
enduring inborn qualities or potentials of the individual that naturally make him
an entrepreneur.
The amounts of the various inputs used determine the quantity of output. In
relation to this study, the fabrication of these digital art waxer and Bunsen burner
has brought fort an impact in which it will be used to improve knowledge and
reduce cost for dental professionals all over Nigeria and also will improve accurate
reproduction of occlusal surfaces prior to crown and bridges construction.
Production is a process, because it is a flow concept, it is measured as a “rate of
output per period of time”.
There are three aspects to production processes:
1. The quantity of the good or service produced
2. The form of the good or service created
3. The temporal and spatial distribution of the good or service produced.
Economic study of production aims at finding an optimum between benefits and
expenditures of manufacture.
Basic concepts of production theory: classifications of Inputs include;
i. Labor
ii. Capital
iii. Land
iv. Raw materials
v. Time
These variables are measured per unit of time and hence referred to as flow
variables.
An input is a good or service that goes into the production process. As economists
refer to it, an input is simply anything which a firm buy for use in its Production.
This implies that in our study different raw materials which severed as an input
was bought in other to be used for the design and production processes which
includes example.
1. At mega 250
2. Micrometer wire
3. Seven-digit display
4. Thermocouple
5. Amplifiers
6. Stainless steel
7. Acrylic casing
An output, on the other hand, is any good or service that comes out of a
production Process. The successful fabrication of the Digital art waxer and Bunsen
burner was our successful output result within the study.
2.2 ENTREPRENUAL THEORY
According to Becker (1975), education and experience are the two factors
underlying the human capital entrepreneurship theory. The knowledge gained
from education and experience represents a resource that is heterogeneously
distributed across individuals and in effect central to understanding differences in
opportunity identification and exploitation (Anderson & Miller, 2003, Chandler &
Hanks, 1998, Gartner et al, 2005, Shane & Venkataraman, 2000).
Entrepreneurship is therefore the act of bringing into innovation a business idea
and strategies to generate profit (Nicole, 2017). It involves effecting social change
to bring about a new life changing solution. Entrepreneurship is an important
factor of growth in the economy. An entrepreneur puts together a business and
accepts the associated risk to make profit.
Murphy, Liao & Welsch (2006) contend that the movement offered a logic
dynamic reality. In explaining this, they point to the fact that knowledge is
communicated throughout a market system (e.g. via price information),
innovation transpires, entrepreneurs satisfy market needs, and system-level
change occurs. If an entrepreneur knows how to create new goods or services, or
knows a better way to do so, benefits can be reaped through this knowledge.
Entrepreneurs effectuate knowledge when they believe it will procure some
individually-defined benefits.
Entrepreneurship closes the gap between the inventors and the consumers.
However, scientists are known as inventors whose inventions have economic
values that need to be commercialized lying within the realm of
entrepreneurship.
Entrepreneurship is also sometimes considered a factor of production combine
with the other factors: land, labor, and capital (Sullivan et al, 2003).
Through the successful local fabrication of a digital art waxer that can be used to
improve the efficiency of wax manipulation in the dental laboratory for all dental
professionals, entrepreneurship could be encouraged. Furthermore, the cost of
treatment for patients can be reduced, the rate at which m gas burners are
purchased are been reduced and then this device is promoted and patronized by
all professionals.
2.3 THEORY OF HEAT
Energy is one of the most important factors to global prosperity in which its
importance cannot be over emphasized ranging from domestic purposes (heat
energy for cooking food and heating water), for industrial use (for heating
furnaces and running electric motors) and for transport purposes which run on
fuel. It is also important because it is the cornerstone of economic and social
development (Elsaeidy, 2004).
(Maxwell, 1872) stated that the distinction between hot bodies and cold ones is
familiar to all, and is associated in our minds with the difference of the sensations
which we experience in touching various substances, according as they are hot or
cold. The intensity of these sensations is susceptible of degrees, so that we may
estimate one body to be hotter or colder than another by the touch
There are many different forms of energy – heat, light, sound, electrical, kinetic,
potential. All of these forms of energy have the ability to do work. One form of
energy may be transformed into another. For example; potential (stored
chemical) energy is converted to heat energy during combustion. Kinetic energy
(as a result of friction) and electrical energy may also be converted to heat. It is
not possible to measure heat directly, Heat is a measure of the total kinetic
energy of the atoms or molecules in a body. Because heat is a form of energy the
units it is measured in are Joules (J) or kilo Joules (kJ). The heat content of a body
will depend on its temperature, its mass, and the material it is made of. What we
experience as heat is simply the kinetic energy of the great numbers of the
particles motion, as we know, this great numbers of the particles motion now is
called as thermal motion (Maxwell, 1872).
However, in thermodynamics, heat only denotes heat exchange or a form of
energy transfer between different temperatures, we don’t know which state
function can denote the energy of thermal motion because the concept of the
heat energy is ill-defined, the major reason for this issue is that the equation of
the first law is an equation of energy exchange
Transmission of Heat: Heat may be transferred from one place to another in three
ways:
1. conduction
2. convection
3. radiation
Often a combination of all four processes takes place at the same time, especially
in a fire situation. If we wish to contain heat, then these processes must be
prevented.
Conduction: conduction is most obvious in solids. All liquids (except mercury) and
gases are very poor conductors of heat. When a solid heat up, its particles gain
kinetic energy and increase the energy with which they vibrate. Conduction
occurs when heat energy travels through a body, passing from particle to particle
as they vibrate against each other. A good conductor must have particles which
are close enough together to collide with sufficient force for energy to be
transferred. Metals are all good conductors of heat especially copper, aluminum
and silver, because they have “free” electrons which are easily able to transfer
heat energy. the energy
Convection: Convection is the transfer of heat by the movement of the heated
particles themselves. This can only take place in liquids and gases because in
solids the particles are not able to move from their fixed positions. When a liquid
or gas is heated, it expands and becomes less dense. The lighter liquid or gas rises
allowing a flow of cooler material to take its place. This in turn becomes heated
and so a current is set up. Heat will continue to be transferred through the
available space in this way until it is evenly distributed conversion has not been
explicitly considered in this fundamental equation (Feynman, 1963).
Radiation: Radiation is the way we receive heat energy from the sun. It does not
require a medium for its transmission (i.e. it can travel through empty space) and
is in the form of electromagnetic energy waves which travel in the same way as
light or radio waves. When these energy waves fall on a body, the energy may be
absorbed, transmitted or reflected.
When radiant energy is absorbed the body will rise in temperature. A rack of
clothes left in front of a radiant heater will continue to absorb heat until it reaches
ignition temperature. Black and dull surfaces absorb (and radiate) heat much
more efficiently than white shiny surface The amount of heat energy received
decreases with the square of the distance from a radiant source, for example, if
an object is moved to twice the distance from a source, it will only receive a
quarter of the heat energy it would have received at the original distance. Radiant
energy is transmitted through clear materials such as glass. The glass does not
heat up. Radiant heat from the sun may be concentrated by means of a
magnifying glass, sufficient to ignite flammable material. Shiny, silver surfaces will
reflect radiant energy and not heat up. This is the reason for the silver coating on
a fire-fighter’s jacket.
Usually heat is transferred by each of these processes at the same time. It is the
fire-fighter's task to prevent this transfer taking place, if possible.
Therefore, the knowledge of the theories of heat energy and its application/ use
in wax pattern making is paramount in Dental technology prior to any denture,
crowns, bridges, skeletal plates fabrication is being carried out. Since the use of
acrylic resin as a denture base material in the fabrication of dentures, wax pattern
making is inevitable during heat cure denture fabrication process.
2.4 THEORY OF TEMPERATURE
Temperature is not the same as heat, Temperature measures the degree of
hotness of a body (“how hot”). It doesn’t depend on the mass or the material of
an object. It can be thought of as a measure of the average kinetic energy of the
atoms or molecules in a body. As the temperature decreases, the kinetic energy
of the particles will decrease. At some point the kinetic energy of the particles
will reach zero. The temperature at which this would occur is known as “absolute
zero”. Temperature is measured using a variety of temperature scales. The most
commonly used are described in the next two sections. The Celsius Scale (°C) This
scale puts the freezing point of water at 0oC and the boiling point of water at 100 oC. The temperatures in between are divided up into 100 units (degrees).
The disadvantages of this scale are:
There may be temperatures below 0oC. The pressures and volumes of gases do
not change in proportion to Celsius temperature. The Kelvin Scale (K)
This scale has absolute zero as the zero point on its scale. The size of the degree
is the same as a Celsius degree.
Advantages:
• There are no negative temperatures
• Pressures and volumes of gases will change in proportion to Kelvin temperature.
Absolute zero is 273 degrees below OoC. To convert from Celsius degrees to
Kelvin degrees: add 273. To convert from Kelvin degrees to Celsius degrees:
subtract 273. For example:
K 0 273 373 oC -273 0 100 There are many different types of thermometer used
for measuring temperature e.g. mercury, alcohol, bi-metallic strip, thermocouple,
electrical resistance, brightness thermometer etc.,
Temperature is an important theory in the design and fabrication a digital art
waxer with electrical burners because in depth knowledge will guide the dental
professional on how to manage this device.
2.5 THEORY OF WAXES
Waxes are esters of fatty acids with high alcohol usually monohydric alcohol. They
are thermoplastic substances of low mean molecular weight with low mechanical
strength capable of being softened on application of heat. (Eyarefe, 2013). They
deform easily when subjected to high temperature because of their amorphous
nature. But become plastic on removal from the source of heat. Waxes can be
natural secretions of plants or animals, artificially produced by purification from
natural petroleum or completely synthetic. In addition to beeswax, carnauba (a
plant epicuticle wax) and paraffin (a petroleum wax) are commonly encountered
waxes which occur naturally. Earwax is an oily substance found in the human ear.
Some artificial materials such as silicone wax that exhibit similar also described as
wax or waxy. (Eyarefe, 2013).
2.5.1 PROPERTIES OF WAXES
The knowledge of the properties of waxes is very paramount in the practice of
dentistry. This is because in depth knowledge on these properties will help a
dental professional know how to manipulate waxes with the Digital art waxer and
Bunsen burner prior to prosthetic fabrication. These properties Include;
Melting range: Waxes have melting range rather than melting points. Mixing of
waxes may change their melting range. Melting range varies depending on its use.
Thermal expansion: Waxes expand when subjected to a rise in temperature and
contract as the temperature is decreased. Dental waxes and their components
have the largest coefficient of thermal expansion among the materials used in
restorative dentistry. Temperature changes in wax patterns after removal from
the mouth can produce inaccuracies in the finished restoration.
Flow: flow is an important property especially in inlay waxes. When melted the
wax should flow readily into all the parts of the die. Flow is dependent on:
Temperature of the wax; this is dependent on the source of heat that is why the
Digital art waxer will help give out accurate and regulated temperature of heat
that will make the wax flow effectively.
Force applied; this is dependent on the professional making the wax pattern. in
that case good manual dexterity of using the device is very important for
accuracy.
The length of time the force is applied; it still goes down to the manual dexterity
of the professional using the device.
Mechanical properties
Residual stress
Ductility
2.6 WAX MANIPULATION
Wax manipulation refers to the ability to create into or have a physical body made
up of wax (Wikipedia, 2018)
METHODS OF WAX PATTERN MANIPULATION
There are two methods involve in wax pattern fabrication, and they include;
Direct method: This is a method of wax pattern fabrication in which the wax
pattern is waxed on the prepared tooth in the mouth.
Indirect method: This is a method of wax pattern fabrication in which the wax
pattern is waxed on a cast model from an accurate impression of the prepared
tooth or mouth.
2.6.1 IDEAL REQUIREMENTS OF A WAX TO ENHANCE EFFECTIVE WAX
MANIPULATION
i. It must flow readily when heated without chipping, flaking, or losing its
smoothness.
ii. It must be able to closely adapt to the surface it is being adapted onto.
iii. The wax must be rigid at a cool state.
iv. The wax should be uniform when softened.
v. The wax must be able to be carved in right precision without chipping,
distortin2.5g, or smearing.
vi. It should have good cohesion, but should not adhere to the cavity.
vii. The wax should be made of different color that differs from the color of the
cast model to distinguish between the wax and the cast model.
viii. It should be hard at oral temperature, but remain plastic at temperature
slightly above oral temperature.
2.6.2EFFECTIVE WAX MANIPULATION IN WAX PATTERN APPLIANCE
FABRICATION
The success of any appliance construction that goes through the wax pattern
process depends on a large extent on efficient and effective manipulation of the
wax to obtain the wax pattern. To achieve effective wax manipulation, the dental
technologist must have the knowledge of four basic factors, and they include;
i. A clear design of the intended prosthesis.
ii. The knowledge of the effect of temperature on wax.
iii. Instrument exposure and handling.
iv. Manual dexterity.
2.7A CLEAR DESIGN OF THE INTENDED PROSTHESIS
Every dental prosthesis which is to be fabricated in the dental laboratory must
have a clear design of what the work piece should look like. Design refers to a
plan or drawing produced to show the look and function or workings of an object
before it is made. It is at this design stage that pencil out lines are made to
determine margins and border lines on which the actual prosthesis must not
exceed. Designs helps to act as blueprint of the intended prosthesis.
The dental technologist must have a clear design of the intended prosthesis and
transfer this design onto the working cast using pencil preferably. This clear
design helps to guide the technologist while adapting wax on the working cast
model during wax pattern fabrication.
2.7.1 THE KNOWLEDGE OF THE EFFECT OF TEMPERATURE ON WAX
To effectively manipulate wax, one must have firsthand knowledge of the effect of
temperature on wax, this knowledge helps the dental technologist to know how
and how long to heat a particular wax to achieve optimum manipulation. To this
effect some thermal parameters are considered and they include;
COEFFECIENT OF THERMAL EXPANSION (CTE)
This is a thermal property of wax that describes how the size of wax changes with
a change in temperature. Specifically it measures the fractional change in size per
degree change in temperature at a constant pressure. (Wikipedia, 2018)
Thermal expansion: This is the tendency of matter to change in volume in
response to change in temperature, through heat transfer.
Linear coefficient of expansion: This refers to change in length per unit of the
original length of a material when its temperature is raised by 1k.
For most solid materials, the volumetric CTE can be considered to be thrice that of
linear CTE of wax. Waxes have very high CTE, particularly around the melting
range, and very high residual stress. Waxes have the highest CTE as compared to
all other materials used in dentistry. The CTE of a typical wax pattern is 323x10-
6/oc, but that of dental porcelain is twenty times less 14x10-6/oc. Therefore, changes
in temperature can cause a sufficient change in dimension to make the pattern
inaccurate.
Thermal conductivity of wax is low, and sufficient time must be allowed both to
heat them uniformly throughout and to cool them to body or room temperature.
Waxes have solid transition temperature
Solid-solid transition temperature (Tg): This is the temperature at which a sharp
increase in coefficient of thermal expansion occurs indicating increased molecular
mobility.
This is also called softening temperature or glass transition temperature, it is at
this temperature in waxes that transition from a stable crystal lattice
(orthorhombic) to hexagonal forms occurs, which is present below the melting
point of wax, and thus it allows the wax to be manipulated easily without flaking
or tearing. Wax at this stage is softened and not melted. For instance, inlay wax
may be softened over a flame in water at 54-60oc (130-140of) to enable their flow
in the liquid state and adaptation to the prepared tooth or die.
A harder or medium type inlay wax that has low flow property is indicated for use
in warm weather, (Phillip’s science of Dental materials, 11th edition.)
Wax does not melt immediately on heating but passes through several
intermediate states. Eyarefe. (2013) enlisted various stages waxes undergo with
the application of heat; they are solid-plastic-semi plastic-semi liquid-liquid. A
typical wax undergoes these phases of change unlike other homogenous chemical
compounds.
2.7.2 INSTRUMEMENT EXPOSURE AND HANDLING
An instrument is a tool or implement, especially one use for a precised work.
Instruments are specially built or manufactured to carry out a precised work.
Instrument exposure and handling refers to the knowledge about particular
instruments and its mode operation. It entails having a sounding knowledge of
what a particular instrument is made for and how best that instrument can be
used to achieve optimum satisfaction of desired intent.
To achieve effective and efficient wax manipulation the dental technologist must
have instrumental exposure (knowledge) and how best to handle those
instrument to best manipulate wax, during wax pattern fabrication.
2.7.3 SOME HAND INSTRUMENTS USE FOR WAX MANIPULATION IN THE DENTAL
LABORATORY
The instruments use in the dental laboratory for wax manipulation during wax
pattern fabrication can be grouped as follows;
WAX ADDERS: This refers to instruments basically use for adding wax onto a work
piece , they are as follows,
PKT #1(large) – This hand instrument is designed and used to add large amount of
wax to a work piece.
PKT #2 (smaller) – This is a hand instrument designed and used to add small
amount of wax to a work piece.
Wax spatula #7 – This is used to hold small bit of wax over a flame.
Wax is added by heating the in the Bunsen flame, touching it to the wax and
quickly reheating its shank in the flame. Wax flows away from the hottest part of
the instrument, so if the shank is heated a bead of wax will flow off the tip,
however if the tip is heated the wax will flow up the shank of the instrument.
WAX CARVERS: This refers to instrument basically use for shaping and carving
wax into various forms, they are as follows;
1. Half Hollenbeck – This hand instrument is designed and for carving and
shaping the wax.
2. PKT #3 – This is used to perfect and enhance the supplemental grooves and
developmental grooves.
3. Lecron carver – This has a small spoon at one end and a knife at the other,
used for carving and trimming.
4. Discoid cleiod – These instrument are used to incorporate and enhance
concave surface and grooves respectively.
5. PKT #4 – This instrument is designed as an all-purpose carving instrument,
but it is modified to perfect external contours and remove excess wax at the
cavo-surface margins.
6. PKT #5 – This instrument is designed to be used to refine triangular ridges
and occlusal grooves, it helps to remove excess wax as cusp ridge are
developed, it maintains desired convexity at these ridges.
7. Tanner
8. #3 Hollenbeck carver.
WAX SOFTENING INSTRUMENT/EQUIPMENT: This refers to
instruments/equipment’s used in bringing wax to its solid-solid transition
temperature (softening temperature). There are various instrument/ equipment’s
which uses heat in softening wax, and they include;
Bunsen burner – This involves softening of wax over the flames of a Bunsen
burner of gas.
Warm water bath – This involves the softening of wax with warm water in a bath.
Infra-red lamp – This is an equipment that uses an electric current of 250w to
soften wax used in standardization testing of wax. The distance of the wax from
the lamp must be carefully controlled in order to cause softening but not melting.
Wax annealed – This is a thermostatically controlled oven that can be set at
constant temperature, just above softening temperature of wax to soften and
keep the wax in a softened state ready for use. This method of wax softening is
regarded as the ideal method of softening wax. This equipment is most useful for
inlay waxes.
Instrumentation gives the dental technologist enhancement while manipulating
waxes, because with the knowledge of various instrument used to soften wax,
add and carve wax, and how to use these instruments, the dental technologist will
know and have better ways to manipulate wax efficiently and effectively to
achieve optimum desired intent.
2.7.4 IMPORTANCE OF EFFECTIVE WAX MANIPULATION
The importance of effective wax manipulation cannot be over emphasized, to
achieve optimum success during dental prosthesis fabrication, effective
manipulation of wax is paramount and pertinent. Here is some of the importance
of manipulating waxes;
i. Effective wax manipulation engenders no or little trimming and polishing of
a denture after processing.
ii. Effectively manipulated wax pattern serves as a blueprint of what the
intended final restoration would look like.
iii. Effective manipulation of wax helps to enhance efficiency during dental
laboratory practice.
iv. Effective manipulation of wax helps to save time during dental laboratory
appliance fabrication.
v. Effective wax manipulation fosters better appreciation of dental prostheses
fabrication.
vi. Effectively manipulated wax pattern fosters successful appliance fabrication.
2.8 ADVANCEMENT OF WAX MANIPULATION; DIGITAL ART WAXER IN FOCUS
There are several mediums in which heat is produced in the dental laboratory for
wax patterns to be made. And this heat may vary from different conventional way
to another. And the advancement of these heat forms which is used for this
dental wax pattern making is very vital in dental technology in other to achieve a
well neat, smooth and accurate wax patterns.
2.8.1OVERVIEW OF A DIGITAL ART WAXER
According to Whip Mix, all options for the Digital Wax Carving Pencils have built-in
circuitry to accurately maintain desired temperature. The silicone cool-grip handle
reportedly reduces hand fatigue and temperature transfer when in use. Previous
working temperatures can be stored in the memory which is designed to make
carving and waxing more efficient. Other features included are digital
temperature display in either Celsius or Fahrenheit scales, 115V or 230V options,
and a translucent compartment in the rear of the unit to store carving tips (Note:
this feature is not included with the Digital Wax Carving Pencil – dual line). Both
dual-line circuit units reportedly are designed for simultaneous work, minimal
temperature deviation, and include a convenient magnetic cradle on the unit’s
surface where the hot silicone handle is placed so as not to burn the cover tops.
2.8.2 DEFINITION OF DIGITAL ART WAXER
The Digital art waxer is a digital device that is designed to carve and mold a
variety of waxes used in the dentistry. The easy, touch-style temperature control
and variety of carving tips enable precise waxing work.
Fig. 1: Digital art waxer (source: Wikipedia, 2018)
The digital art waxer has various Tips which helps for effective wax manipulation
during wax up and they include the following below.
2.8.3TIPS OF A DIGITAL ART WAXER
1. Offset explorer
2. Pkt 1
3. Pkt 3
4. Hollen back
5. Cleoid carver
6. Discoid carver
7. Large beaver
Fig. 2: Carving tips (Pinterest, 2018)
Some additional tips can be incorporated for effective wax up which includes the
Pk Thomas instruments 4 and 5, small beaver and half (1/2) hollen back.
Fig. 3: Carving tips (Pinterest, 2018)
PKT 1: Itis used for positioning of functional and nonfunctional cusps. The
marginal, cusp and triangular ridges are also added with PKT No. 1
PKT 2: Itis used for eliminating voids remaining on the occlusal surface
PKT 3: Developmental and supplemental grooves are smoothened with this tip
Fig. 4: Waxing technique using PKT instruments (Wikipedia, 2018).
Smoothening of axial surfaces is done with PKT No. 4. and PKT No. 5 is used to
refine the ridges (Dawson, 1974).
Hollenback carver: To contour and carve occlusal and interproximal anatomy in
amalgam restoration. It has sharp stiff metal blade, sharp point; ends are protrude
at different angles; carves other restorative materials.
Discoid-Cleoid Carver: To carve occlusal anatomy into amalgam restorations.
Discoid is disk shaped; cleoid is pointed, sharp.
Half-Hollenbeck Carver: To contour and carve occlusal and interproximal
anatomy in amalgam
restorations Characteristics: Half the size of Hollenbeck; double ended, sharp
stiff metal blade, sharp point; ends are protrude at different angles; carves other
restorative materials.
2.8.4 FEATURES OF A DIGITAL ART WAXER
1. Touch controlled temperature setting.
2. Clearly visible control buttons and indicator LED.
3. Easy to use.
4. Excellent heat conductivity.
5. Long service life.
6. Two-line circuit, designed for simultaneous work.
7. Accurate temperature maintenance with reset function.
8. Built-in digital CPU circuit accurately maintains desired temperature.
9. Digitally displays temperature in either Celsius or Fahrenheit.
10. Previous working temperature is kept in memory, even if the unit has
been turned off.
11. Usable with AC100-240V without additional adjustment.
12. Silicon handle reduces hand fatigue.
13. Convenient magnetic cradle on surface.
14. Translucent compartment in rear of unit for easy storage of carving
tips.
15. Comes complete with six of the most commonly used waxing tips
2.8.5 OPERATING INSTRUCTIONS OF A DIGITAL ART WAXER
Plug in unit and press the ON/OFF switch.
Green light appears and a temperature reads in the display window.
After the first use, this number will be the last temperature setting used.
Insert desired tip into the pencil and insert cord into the “OUT” jack.
Set the desired temperature by using the UP/DOWN buttons. Press the M1 or M2
button. LED will blink.
Temperature of the blinking line will be changed.
Press C/F to select either Celsius or Fahrenheit scale (C/F will appear in display
window).
If an error occurs, a buzzer will sound and the window will display ERR. Turn
Power switch off and then back on to reset.
2.8.6 SAFEGUARDS OF THE DIGITAL ART WAXER
Caution: Failure to follow these safeguards may result in fire or electric shock.
1. Make sure that the unit is connected to a power source that is grounded.
2. To prevent burning, do not touch unit when in use.
3. Never touch unit, pencil, cord or plug with wet hands.
4. Protect the unit from bumps or scrapes, which may cause mechanical
problems.
5. If unit is on, do not leave unattended.
6. Do not use the unit if the power cord or plug is damaged in any way.
7. Make sure that the power cord is not twisted, bent or pinched.
8. To prevent possible overheating, do not block the ventilation openings at the
bottom of the unit.
9. Unplug the unit during storms and when it will not be used for an extended
period.
10. Do not pull on the cord when unplugging the unit.
11. Do not store or use the unit in a room with high humidity or near dust or
spraying water.
12. Keep unit away from heating instruments and other heat sources.
13. Always unplug the unit before cleaning. Do not spray water directly on the
unit. Avoid chemical cleaning products.
14. Keep power plug prongs free of dust and water.
15. If you detect noise or smell smoke coming from the unit, unplug immediately.
16. Do not disassemble or attempt to repair the unit.
17. Turn the unit off and let cool before changing carver tip.
18. Do not allow tip of carver to touch the wire.
2.9 WAXING TECHNIQUES TO DEVELOP PROPER OCCLUSAL MORPHOLOGY IN
DIFFERENT OCCLUSAL SCHEMES USING THE PK THOMAS TIP OF A DIGITAL ART
WAXER.
2.9.1AIMS AND OBJECTIVES OF SELECTING CORRECT OCCLUSAL SCHEME AND
GIVING CORRECT OCCLUSAL MORPHOLOGY WHILE RESTORING PATIENTS’ TEETH
ARE:
1. To direct the occlusal forces properly by minimizing lateral forces during
excursive movements of the mandible.
2. To make the occlusion stable.
3. To increase the masticatory efficiency.
4. To reduce the frictional wear.
5. Waxing Technique to Develop Cusp to Marginal Ridge Relationship.
To develop this relationship, functional waxing technique given by E.V.Payne is
used. It was the first wax added technique (Huffman, 1969).
Fig. 5: Wax pattern showing cusp to marginal ridge relationship (Wikipedia, 2018).
Steps involved in the technique are (Shillinburg, Hobo, whittset, Jacobi & Brackett,
1997; Shillinburg, Wilson, Morrison, 2000; Tamura, 1987):
Functional and non functional cusps are located. Wax cones are placed for these
cusps with PKT No. 1. Cones for non functional cusps should be shorter than
functional cusps to provide easy disocclusion during excursion. Articulator is
closed and moved in various lateral and protrusive movements to obtain optimal
heights for the cuspal cones (Tamura, 1987). Then the marginal and axial ridges
are added with PKT No. 1. Marginal ridges should never be at a higher level than
cuspal cones. And proximal contacts with posterior natural teeth are located in
the occlusal thirds of the pattern Burch & Miller, 1973). Triangular ridges are
added next. They are necessarily triangular in shape extending from central
groove to the cuspal tip. Tip of the triangular ridge is at the cusp tip and base in
the central groove. They are convex buccolingually and mesiodistally. If triangular
ridges are developed correctly proper groove pattern will occur as a natural by-
product. Articulated casts are moved in all the excursions and unwanted contacts
are removed. Axial contours are then developed with PKT No. 4. Straight profile
should be developed in the gingival third of the axial contour [Tjan, Freed &
Miller, 1980; Koidis, Burch &Melfi, 1987]. Over contouring should be avoided
because of its destructive potential [Jameson & Malone, 1982]. Finally grooves are
smoothened with PKT No. 3 and marginal ridges are smoothened with PKT No. 5
to form the refined final wax pattern with proper occlusal morphology. Zinc
Stearate powder is dusted on the wax pattern intermittently before checking the
occlusal contacts. The contacts formed by each opposing cusp should form a
tripod configuration
Fig. 6: Occlusal morphology of the wax pattern (Pinterest, 2018).
Fig. 7: Tripodal occlusal contacts (Pinterest, 2018).
Waxing technique to achieve this occlusal scheme was developed by Thomas
(1967). In this occlusal scheme, mandibular functional cusps arise opposite the
middle of maxillary teeth; similarly maxillary functional cusps are positioned half
way between the mandibular buccal and lingual cusp tips. Hence occlusal forces
are transmitted parallel to long axes of teeth. The development of a cusp to fossa
occlusion is best accomplished by waxing two opposing quadrants simultaneously
in the following sequence [Shillinburg et al, 1997]. Location of cusps and the
contacts made by the cusps are identified and marked on the casts. Cones are
placed for the mandibular functional cusps first. They should be located
approximately one third the distance from the buccal to lingual surface. Also they
should fall into appropriate fossae mesiodistally. Then the cones for maxillary
palatal cusps are placed. Next non functional cusps are placed, i.e. maxillary
buccal and mandibular lingual. Then marginal ridges, cuspal ridges are developed
simultaneously for opposing teeth. Dust the occlusal surfaces with zinc stearate
and close the casts together on the articulator to remove unwanted contacts.
Fig. 8: Tripodal occlusal contacts on maxillary teeth (Wikipedia, 2018).
Fig. 9: Tripodal occlusal contacts on mandibular teeth (Wikipedia, 2018).
2.9.2 CONVECTIONAL WAYS OF HEAT SOURCE IN DENTISTRY
Different sources of heat had been used in the past for wax pattern making Ken,
2005. These sources of heat include:
Candle;
Hot plates/ stove;
Alcohol burners/ spirit lamps; and
Gas burners.
Fig. 10: Candle light (wikipedia, 2018)
Fig. 11: Hot plate (Wikipedia, 2018).
Fig. 12: alcohol burners (Wikipedia, 2018).
Fig. 13: Bunsen burner (Wikipedia, 2018).
Emphasizing on one the most commonly used convectional sources of heat is the
bursen burner.
Bunsen burner: This is used frequently in the laboratory as a source of heat. This
burner is designed so that gaseous fuel may be mixed with the correct amount of
air to yield the maximum amount of heat. The three principal parts of the burner
are: barrel, needle valve, and base. The quantity of gas admitted to the burner is
controlled by the needle valve, while the air needed for combustion is admitted at
the small opening around the bottom of the barrel. The air is controlled by turning
the barrel so as to make the air holes larger or smaller. Always open the desk
outlet valve fully and regulate the gas supply to the burner by the needle valve.
Light the burner in an open space on the lab counter ensuring that the match is lit
prior to turning on the gas. Always extinguish your burner by turning off the desk
outlet valve, and then closing the needle valve and barrel.
2.9.3 DISADVANTAGES OF THE CONVENCTIONAL SOURCES OF HEAT FOR WAX
MANIPULATION
1. Less accurate reproduction or the occlusal features of crowns.
2. Carbon generated makes the work look dirty on the wax patterns.
3. Explosion of gases can occur in the dental laboratory.
4. Inhalation of gas substances which can be toxic to the body.
5. Cost of gases.
6. The fire that is been generated sometimes can burn a dental technologist by
accident when in use.
2.9.4 REASONS FOR USING DIGITAL ART WAXER AS A PREFERED HEAT SOURCE
TO BE USED FOR WAX PATTERN MAKING
1. Heats wax tools fast without flame;
2. Reduces carbon build up-on instruments;
3. Energy efficient as power is used only at the moment of heating;
4. No gas lines required, making unit mobile and operational anywhere an
electric outlet is available;
5. Indicator light glows green for ready mode and red for when in use;
6. Safety light blinks if instrument is left heating too long; Replaceable inserts
keep unit clean of wax residue (5 included); and It helps for precise wax
pattern in other to achieve accurate occlusal harmony.
CHAPTER THREE
3.0 MATERIALS AND METHODS
3.1 INTRODUCTION
This chapter covers the description of the materials used and the processes
involved in the construction of the digital art waxer with Bunsen burner project
which is referred to as the methodology. The process of the development of this
project is divided into several parts. The block diagram below explains the process
flow. This project work is based on the design and implementation of a
microcontroller based art waxer which could effectively perform the waxing
operation.
3.2 PROPOSED SYSTEM MODEL
The following assumptions were taken into consideration for effective
performance of the design. These assumptions include:
The temperature of the waxer should not be less than 10 degrees
The temperature of the waxer should not be greater than 200 degrees
3.3 DESIGN
The different parts of the block diagram which are the materials used, they
include:
1. Four digit seven segment display with driver
2. Microcontroller (Arduino Mega)
3. 20A Relay
4. Power Supply Unit
5. Acrylic sheet casing
Fig 3.1 Block diagram of the system
3.3.2 ARDUINO MICOCONTROLLER
SEVEN SEGMENT DISPLAY
RELAY UNIT AND HEATER
ARDUINOTEMPERATURE SENSOR
POWER SUPPLY UNIT
The Arduino got its start at the Interaction Design Institute in the city of Ivrea,
Italy, in 2005. Professor Massimo Banzi was looking for a low-cost way to make it
easier for the design students there to work with technology. He discussed his
problem with David Cuartielles, a researcher visiting from Malmö University in
Sweden who was looking for a similar solution, and Arduino was born. There have
been a number of Arduino versions, all based on an 8-bit Atmel AVR reduced
instruction set computer (RISC) microprocessor. The first board was based on the
ATmega8 running at a clock speed of 16 MHz with 8 KBflash memory; later boards
such as the Arduino NGplus and the Diecimila (Italian for 10,000) used the
ATmega168 with 16 KBflash memory. The most recent Arduino versions,
Duemilanove and Uno, use the ATmega328 with 32KBflash memory and can
switch automaticallybetween USBand DCpower. For projects requiring more I/O
and memory, there’s the Arduino Mega1280 with 128KBmemory or the more
recent Arduino Mega2560 with 256 KB memory.
The boards have 14 digital pins, each of which can be set as either an input or out-
put, and six analog inputs. In addition, six of the digital pins can be programmed
to provide a pulse width modulation (PWM) analog output. A variety of
communication protocols are available, including serial, serial peripheral interface
bus (SPI), and I2C/ TWI. Included on each board as standard features are an in-
circuit serial programming (ICSP) header and reset button.
Fig.3.3: The example of Arduino MEGA microcontroller
3.3.3 TM1637 Seven segment display unit
The TM1637 display serves as the main display unit which displays the
temperature ranges and thresholds for the system.
Sensor unit
The temperature sensor is made of LM35 integrated circuit. TheLM35 is used to
acquire signal more especially, the body temperature while a microcontroller
processes it. The three common sensors used for this particular task are
thermistors, thermocouples and resistance thermometers but here, an LM35 was
used because it can measure temperature more accurately than thermistors and
generates a higher outputvoltage than thermocouples. LM35 sensor may not
require that the output voltage be amplified.
Fig. 3.5: Schematic Design of the System
3.4 POWER SUPPLY UNIT
This is about the most important aspect of the entire setup. Without power no
other part of the setup will function. Basically our power supply unit feed a 5V dc
to the other units of the liquid Level Monitor by stepping down the mains supply,
rectifying it and regulating it at 5V. Fig 3.2 below is the block diagram of the
power supply unit.
Fig. 3.2 Block Diagram of Power Supply Unit
240V/50Hz
REGULATORFILTERRECTIFIERL TRANSFORMER
N
3.2.1 The transformer Unit
This unit performs two basic functions
Isolates the mains power supply from the systems devices.
Steps down the mains voltage from 220V ac to I 2V ac
3.2.2 The rectifier unit
This converts the AC voltage from the transformer secondary into unidirectional
pulses. This is achieved by using four 1N4001 diodes configured as a bridge.
3.2.3 The Filter Unit
Following the rectifier is the filter unit which serves in smoothening out the pulse
received in the rectifier. Filter unit can have either a capacitive or an inductive
input. The inductive filter or choke input filter is more commonly used when the
power unit has to supply a large load current. On low power systems, like ours, a
capacitive input filter is more appreciated.
3.2.4 The Regulator Unit
The regulator is used to keep the output voltage constant irrespective of changes
in L c mains input voltage and of changes in the load current. Those two functions
are called line stabilization and load regulation respectively.
The circuit designed for the power supply section is shown in the figure 3.3 below:
Fig. 3.3: Diagram of Power Supply Unit
3.2.5 Transformer Circuit
The transformer used for the design is a step down transformer of a ratio of 20:1.
The following relationship applies
N 2
N1=V 2
V 1………………………………………………. equ.3.1
Where N2 is the number of turns in the secondary
N1 is the number of turns in the primary
V2 is the secondary voltage
V1 is the primary voltage
But N2 = 1
N1=20
V1 = 240V
Hence, 1
20=V 2
240
V 2=24020
=12V
The peak secondary voltage is given thus
Peak value = √2 x root mean square value √2 x 12 =16.971V
3.2.6 Rectifier Circuit
The rectifier circuit unit is operated on a full-wave bridge rectifier diode D1 to D4
are general purpose diode 1N4001. The four diodes are connected in bridge form
to rectify the 1 2V AC to I2V DC. The output of the bridge rectifier is s shown in the
figure 3.4 as follows:
VLM = maximum value of load voltage
VL = RMS value of load voltage
Fig. 3.4: Output of a bridge rectifier
The fact that the output of the rectifier circuit is pulsating should not be
overlooked. It has a DC value and sonic AC components called ripples.
u
V
t
D1 D2 D3 D4
This type is not useful for driving sophisticated electronic circuits/devices. In fact,
these circuits require a very steady DC output that approaches the smoothness of
a battery’s output.
Consider the rectifier and filter circuits of the figure 3.5 below where capacitor is
connected across a load resistance RL
Fig 3.5 Rectifier and filter circuit
The output of voltage waveform of the full wave rectifier is as shown in the figure
3.6;
Fig. 3.6: Output voltage waveform of the full wave rectifier
The ripple voltage which occurs under light conditions can be approximated by a
triangular wave which has a peak to peak value of Vr(p-p) and a time of Trcentered
around the DC level.
V r ( p−p)=dQC ………………………………………equ 3.2
But dQ=1dc x T r
V r ( p−p)=1dc X T rC
=V dc
f rC RL
Where
V r ( p−p)is the amount by which capacitor voltage falls during discharge period,T r
dQ is the charge lost in time,T r
The triangular ripple has an RMS value given by:
V r (rms)=V r (p− p )2√3
V r (rms)=V dc
2√3 f rC RL ……………………………………..…equ 3.3
The ripple factor of the shunt capacitor given thus
γ= 14 √3 f rC RL
……………………………………….equ 3.5
A shunt capacitor of ripple factor 0.01 is normally preferred
Assuming load resistance to be 280Ω
0.01= 14√3 x50 x C x280
C = 1.031x 10-3F
C = 1.031μ
But a capacitor of 100μF is chosen as it is readily available the limiting resistor
R1 = Vcd-Vd
Imax
Where
Vdc = 16.971V
Vd = voltage drop across D5 I 6V(given)
Imax = maximum current of 2OmA
Thus
R1 = 6.97−1.620x 10−3
A preferred value of I KΩ was used.
3.2.7 Regulator Circuit
The IC used for the regulator is LM7805. Manufacturer’s specification indicates
that the maximum input voltage to LM7805 is 35V and the minimum input voltage
is 7Vwhilethe output voltage is 5V. What LM7805 does is that it regulates the
output voltage to a steady 5V±O.5%. This helps in stabilizing the output provided
that the input voltage is within the manufacturer’s specification.
Capacitor C3 and inductor LI Forms a low pass Filter which filters the signals and
spikes that are still remaining in the 5V output of the voltage regulator. Voltage
spikes and surges as well as line noise are removed by this filter. The output of the
capacitor C3 goes to Vcc and ground. This is used to supply power to all other part
of the circuitory.
The Relay Unit
Figure showing the internal components of a relay
ULN-2003 Driver
ULN2003 is a high voltage and high current Darlington array IC. It contains seven
open collector Darlington pairs with common emitters.
A Darlington pair is an arrangement of two bipolar transistors.
ULN2003 belongs to the family of ULN200X series of ICs. Different versions of this
family interface to different logic families. ULN2003 is for 5V TTL, CMOS logic
devices. These ICs are used when driving a wide range of loads and are used as
relay drivers, display drivers, line drivers etc. ULN2003 is also commonly used
while driving Stepper Motors.
Each channel or Darlington pair in ULN2003 is rated at 500mA and can withstand
peak current of 600mA. The inputs and outputs are provided opposite to each
other in the pin layout. Each driver also contains a suppression diode to dissipate
voltage spikes while driving inductive loads. The schematic for each driver is given
above.
WORKING PRINCIPLE OF THE DIGITAL ART WAXER
The temperature sensor LM35 senses the temperature and converts it into an
electrical (analog) signal, which is applied to the micro controller through ADC.
The analog signal is converted into digital format by the analog-to-digital
converter (ADC). The sensed and set values of the temperature are displayed on
the 16x2-line TM1637. The micro controller drives control relays by means of ULN
driver circuit to control the fan speed with the help of high wattage tagged wire
wound resistor. Single pole double throw (SPDT) relays are connected to the
micro controller through a ULN driver circuit. The relays require 5 volts at a
current of around 50 mA, which cannot be provided by the micro controller. So
the ULN driver circuit is added. The relays are used to operate the electrical fan or
for operating any other electrical device. Normally the relays remain off. As soon
as pin of the micro controller goes high, the relays operate. This project uses
regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used
for voltage regulation. Bridge type full wave rectifier is used to rectify the ac
output of secondary of 230/12V step down transformer. The circuit maintains the
temperature of the system in a particular range. A fan and a heater are used for
controlling the temperature of the system. The fan RPM increases with increase in
temperature and vice versa. The working of the heater is also the same. The
current temperature within the server room is measured by using a temperature
sensor. When the current temperature is below the lower limit of the desired
range, the system must be heated by using a heating element, air heater. When
the current temperature is below the lower limit of the desired range, the system
must be cooled by using a fan. When the current temperature is within or
successfully turned back to the required range, no control action is needed. The
current temperature of the room must be continuously displayed on the TM1637.
The controller should use LEDs as backup display to indicate the current state of
temperature. This makes user is easily to know current temperature of the
system. The Temperature Sensor detects the temperature of the system. The
Temperature Sensor consists of an LM35 IC. The temperature sensor is connected
to the ADC input of the MICROCONTROLLER µC. It converts the analog input to a
digital value. The MICROCONTROLLER is connected to a switching device relay. It
is used to switch on the heater. The MICROCONTROLLER generates PWM
according to the temperature sensor value. The PWM generated output control
signals are sent to the Motor Driver IC L293D. Motor Driver IC L293D is fed with
the PWM generated output from MICROCONTROLLER. By using the L293D, two dc
motors can be connected. The speed of the fan is controlled by the ON time of the
PWM generated by the controller. With increasing ON time, the speed of the fan
or the heater increases reducing the temperature of the system. The TM1637
module is also connected to the MICROCONTROLLER microcontroller. The
TM1637 module displays the current temperature of the electric Bunsen burner.
Software Requirement
Cross Compiler : AVR Studio 6.0
Atmel Studio 6 is the integrated development platform (IDP) for developing and
debugging Atmel ARM Cortex-M and Atmel AVR microcontroller (MCU) based
applications. The Atmel Studio 6 IDP gives you a seamless and easy-to-use
environment to write, build and debug your applications written in C/C++ or
assembly code.
Atmel Studio 6 is free of charge and is integrated with the Atmel Software
Framework (ASF)—a large library of free source code with 1,600 ARM and AVR
project examples. ASF strengthens the IDP by providing, in the same environment,
access to ready-to-use code that minimizes much of the low-level design required
for projects. Use the IDP for our wide variety of AVR and ARM Cortex-M processor
based MCUs, including our broadened portfolio of Atmel SAM3 ARM Cortex-M3
and M4 Flash devices.
Atmel Studio 6.2 is now available, adding advanced debugging features such as
Data and Interrupt Trace, improved RTOS integration, and better ability to debug
code that has been optimized.
With the introduction of Atmel Gallery and Atmel Spaces, Atmel Studio 6 further
simplifies embedded MCU designs to reduce development time and cost. Atmel
Gallery is an online apps store for development tools and embedded software.
Atmel Spaces is a cloud based collaborative development workspace allowing you
to host software and hardware projects targeting Atmel MCUs.
In summary, standard integrated development environments (IDEs) are suited for
creating new software for an MCU project. By contrast, the Atmel Studio 6 IDP
also:
Facilitates reuse of existing software and, by doing so, enables design
differentiation.
Supports the product development process with easy access to integrated tools
and software extensions through Atmel Gallery.
Reduces time to market by providing advanced features, an extensible software
eco-system, and powerful debug integration.
Programming Language: Embedded C looking around, we find ourselves to be
surrounded by various types of embedded system. Be it a digital camera or a
mobile phone or a washing machine, all of them has some kind of processor
functioning inside it. Associated with each processor is the embedded software. If
hardware forms the body of an embedded system, embedded processor acts as
the brain, and embedded software forms its soul. It is the embedded software
which primarily governs the functioning of embedded systems.
During infancy years of microprocessor based systems, programs were developed
using assemblers and fused into the EPROMs. There used to be no mechanism to
find what the program was doing. LEDs, switches, etc. were used to check correct
execution of the program. Some ‘very fortunate’ developers had In-circuit
Simulators (ICEs), but they were too costly and were not quite reliable as well.
As time progressed, use of microprocessor-specific assembly-only as the
programming language reduced and embedded systems moved onto C as the
embedded programming language of choice. C is the most widely used
programming language for embedded processors/controllers. Assembly is also
used but mainly to implement those portions of the code where very high timing
accuracy, code size efficiency, etc. are prime requirements.
Initially C was developed by Kernighan and Ritchie to fit into the space of 8K and
to write (portable) operating systems. Originally it was implemented on UNIX
operating systems. As it was intended for operating systems development, it can
manipulate memory addresses. Also, it allowed programmers to write very
compact codes. This has given it the reputation as the language of choice for
hackers too.
ACRYLIC SHEET CASING
The outer casing was done using 3mm acrylic sheet board of size 2’ by 4’. This was
chosen due to its ease of forming when heated by a heat gun. The design of the
system indicated that the usual rectangular pvc box would not be suitable rather a
new form was needed.
DESIGN OF THE BUNSEN BURNER
MATERIALS USED
a) Heating element
b) Fan
c) Relay
d) Integrated circuit
e) Stainless steel pipe
HEATING ELEMENT: the heating element converts electrical energy into heat
through the process of resistive or joule heating. Electric current passing through
the element encounters resistance, resulting in heating of the element.
FAN: the fan used in this case was used as an electrical device in moving air and
used in cooling the burner during work.
RELAY: they relay used in this case was used acts a switch
INTEGRATED CIRCUIT: this is a monolithic integrated circuit which is also referred
to as an IC, is a set of electronic circuits one one small flat piece of semiconductor
material, normally silicon.
STAINLESS STEEL PIPE: stainless steel pipe comprises of steel alloy and a small
percentage of chromium adds to the materials corrosion resistance. And it was
used here because of its resistance to corrosion.