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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
Sakarya ÜniversitesiTeknoloji FakültesiElektrik Elektronik Mühendisliği Bölümü T4 Blok
• Introducing the department• Introducing the EEE• Engineering ethic• Unit systems• Direct and alternative current• Resistor, capacitor, and coil• Voltage and current supplies• Ohm’s law, Kirchoff’s Laws
• Circuit concept, Serial, Parallel and Mixed circuits
• Semiconductor technology• General Occupational Health and Safety • Occupational Health and Safety in Electrical
1Electrical and Electronics Engineering
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
MEASUREMENT
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Measurement is the assignment of a number to a characteristic of an object or event, which can be compared with other objects or events.
Also measurement is a counting process. If you want to measure your working desk, you should choose a length unit. Suppose that you choose your span and you measured 6 spans. In this example, you measured the desk with your own unit.
Well, if everybody choose their own unit to measure different quantities, how we are going to agree, how we are going to trade, and how the scientists are going to communicate?
Electrical and Electronics Engineering
Different Measuring Instrument
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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A unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same physical quantity. Any other value of the physical quantity can be expressed as a simple multiple of the unit of measurement. Different systems of units used to be very common. Today, there are five important unit systems:MKS unit system: It is also known as metric system. The metric system is a decimal systems of measurement based on its units for length, the metre, for time, the second, and for mass, the kilogram. FPS unit system: The foot–pound–second system or FPS system is a system of units built on the three fundamental units foot for length, pound for either mass or force and second for time.CGS unit system: It is a system of measurement based on its units for length, the centimetre, for time, the second, and for mass, the gram. MKSA unit system: It is known as Giorgi system. In 1946 the International Committee for Weights and Measures (CIPM) approved a proposal to use the ampere as that unit in a four-dimensional system, the MKSA system.SI unit system: The International System of Units (SI) defines seven fundamental units: kilogram, metre, candela, second, ampere, kelvin, and mole.
Electrical and Electronics Engineering
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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A number of metric systems of units have evolved since the adoption of the original metric system in France in 1791. Today, units of measurement are generally defined on a scientific basis, overseen by governmental or independent agencies, and established in international treaties, pre-eminent of which is the General Conference on Weights and Measures (CGPM), established in 1875 by the Treaty of the metre and which oversees the International System of Units (SI) and which has custody of the International Prototype Kilogram.
The International System of Units (Système International d'Unités) is the modern revision of the metric system. It is the world's most widely used system of units, both in everyday commerce and in science. The SI was developed in 1960 from the metre-kilogram-second (MKS) system, rather than thecentimetre-gram-second (CGS) system, which, in turn, had many variants. During its development the SI also introduced several newly named units that were previously not a part of the metric system.
Since the 1960s, the International System of Units (SI) is the internationally recognised metric system. Metric units of mass, length, and electricity are widely used around the world for both everyday and scientific purposes.
Electrical and Electronics Engineering
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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Base quantity Base unit Symbol
time second s
length metre m
mass kilogram kg
electric current Ampere A
temperature Kelvin K
amount of substance mole mol
luminous intensity candela cd
Base quantity Base unit Symbol
angle radian rad
Solid angle steradian sr
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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Meter is defined as the distance travelled by light in a specific fraction – about one three-hundred millionths – of a second (17. CGPM, 1983).Kilogram, manufactured in 1799 and from which the IPK (International Prototype of the Kilogram) is derived, had a mass equal to the mass of 1.000025 liters of water at 4 °C (3. CGPM, 1901).Second: It is quantitatively defined in terms of a certain number of periods – about 9 billion – of a certain frequency of radiation from the caesium-133 atom: a so-called atomic clock (13. CGPM, 1967).Ampere: It is the constant current that will produce an attractive force of 2 × 10−7 newtons per metre of length between two straight, parallel conductors of infinite length and negligible circular cross section placed one meter apart in a vacuum (9.CGPM, 1948).Kelvin: It is defined as the fraction 1⁄273.16 of the thermodynamic temperature of the triple point of water (exactly 0.01 °C or 32.018 °F) (13. CGPM, 1967).
Electrical and Electronics Engineering
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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Mole: It is defined as the amount of any chemical substance that contains as many elementary entities, e.g., atoms, molecules, ions, or electrons, as there are atoms in 12 grams of pure carbon-12 (14. CGPM, 1971).Candela: It is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540×1012 hertz and that has a radiant intensity in that direction of 1⁄683 watt per steradian (16. CGPM, 1979).
Electrical and Electronics Engineering
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
UNIT SYSTEMS
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INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
INTRODUCTION TO ELECTRICITY
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ATOMSThe smallest particle of a material.Consist of electrons and nucleus.Nucleus has a positive charge.Electrons have negative charge and turn around the nucleus in the certain orbits.The number of electrons in an orbit is calculated by 2.n2.Unless there is an external effect, the number of protons is equal to the number of electrons.The outer orbit is called ‘valence orbit’.The electrons in this orbit is also called ‘valence electron’ or‘free electron.
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
INTRODUCTION TO ELECTRICITY
27Electrical and Electronics Engineering
Coulomb’s Law: If the two charges have the same sign, the electrostatic force between them is repulsive; if they have different signs, the force between them is attractive.
Coulomb's law can also be stated as a simple mathematical expression.
where ke is Coulomb’s constant (ke =8.9875517873681764 x 109 N∙m2∙C-2), and q1 and q2 are the signed magnitudes of the charges, the scalar r is the distance between the charges. the charge of 1 e- : 1,6 ∙ 10-19 Coulombs
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
INTRODUCTION TO ELECTRICITY
28Electrical and Electronics Engineering
CONDUCTORS: They conduct electricity.
The number of valence
electrons are less than 4.
The conductivity depends on
the number of valence
electrons. If it is one, good
conductivity!
Copper, gold, silver,
aluminum, iron…
Cupper Atoms
Valence electron
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
INTRODUCTION TO ELECTRICITY
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INSULATORSThey don’t conduct electricity basically.
The number of valence electrons is higher than 4. (5-8)
The number of electrons in the valence orbit can’t be more than 8.
If the number of electrons in this orbit is less, insulation level is
also low.
If high voltage and frequency signal is applied to an insulator, it
may conduct electricity a little.
Plastic, rubber, glass, ceramic, air…
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
INTRODUCTION TO ELECTRICITY
30Electrical and Electronics Engineering
SEMICONDUCTOR: It conducts electricity under certain conditions.
The number of valence electrons is 4.
Silicon, Germanium (they are insulators in their
pure state)
Can be inductor with doping elements
(Arsenic, Galium, İndium etc.).
Used to produce some electronic devices such
as diode, transistor, integrated circuits, etc.
a) Silicon Atoms
b) Germanium Atoms
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
INTRODUCTION TO ELECTRICITY
31Electrical and Electronics Engineering
Energy bands in conductor, semiconductor, and insulator atoms:
a) Conductor c) Insulatorb) Semiconductor
valence band valence bandvalence band
bandgap (forbidden) bandgap (forbidden)
bandgap (forbidden)
conductivity band conductivity band
conductivity band
ene
rgy
leve
l
ene
rgy
leve
l
ene
rgy
leve
l
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
Current, Voltage, Resistance
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Electricity can be liken to running water from a tap plugged to a container filled with water, as illustrated in figure. The height of the water
VoltageThe quantity of running water
CurrentThe tap
ResistanceVo
lt
resis
tanc
e
current
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
Current, Voltage, Resistance
33Electrical and Electronics Engineering
Moving electrons in a conductor is called
‘CURRENT’.Electron flow occurs from
negative to positive. Hole flow occurs from
positive to negative.
Copper wire
Electron flowElectron
nucleus
Copperatoms
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
Current, Voltage, Resistance
34Electrical and Electronics Engineering
Unit: Ampere (A)1A current: It represents 1 coulomb charge
movement in a second. 1A= 1C/S (Coulomb/Second)
1 C = 6,250,000,000,000,000,000 electron1,610-19C = 1electron
I=current (Ampere)Q: charge quantity (coulomb)
t: time (second)
I,i
I,i+
-
Akım kaynağıCurrent Source
tQI
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
Current, Voltage, Resistance
35Electrical and Electronics Engineering
The energy forced the electrons to flow is called ‘VOLTAGE’.
It is a measure of potential difference between two points.
Unit: Volt (V)Example: The voltages in a circuit have been
measured as VA=5 V (at the point A), and
VB=2 V (at the point B). So, what is the potential difference from A to
B point (VAB)? What is the potential difference from B to A
point (VBA)?
VA B
+
-
+
-V1
E, U +-
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
Current, Voltage, Resistance
36Electrical and Electronics Engineering
The opposition to the flow of electric current is called ‘RESISTANCE’.
It consists of friction between atoms and other particles in the conductor, and electrons, moving in the conductor.
Unit: Ohm ()
R
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
Current, Voltage, Resistance
37Electrical and Electronics Engineering
On which physical conditions the resistance of a conductor depends?
It is inversely proportional to the cross section,
It is proportional to the length,
It is proportional to the temperature,
It depends on the type of conductor. Resistivity of all conductors are different.For example, the resistances of Cupper and Aluminum wires in the same length and same cross section are different. Resistivity: It is the resistance of a conductor 1 meter in length and 1 mm2 in cross sectional area. (20 C) ̊
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
Current, Voltage, Resistance
38Electrical and Electronics Engineering
SLR
Bir iletkenin direnci:
Cross-section (mm2)
Resistivity (ohm)
Length (meter)
Resistivities of some metalsCONDUCTOR RESISTIVITY (ρ)
Silver 0,016Cupper 0,017
Gold 0,023Aluminum 0,028
Iron 0,012
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
Current, Voltage, Resistance
39Electrical and Electronics Engineering
2
1
2
1tTtT
RR
R1 : value of a resistor at t1 temperature
R2 : value of same resistor at t2 temperature
All metals have a ‘T coefficient’.
CONDUCTOR T COEFFICIENT ( ̊C)Lead 218Silver 243
Cupper 235Aluminum 236
Zinc 250Brass 650
Resistance
INTRODUCTION TO ELECTRICAL AND ELECTRONICS ENGINEERING
Current, Voltage, Resistance
40Electrical and Electronics Engineering
Example: The resistance of a Cupper wire at 20 ̊ C is 5 . Find the resistance at 60 ̊ C.
for Cupper, T=235 20 5 60 5,78
Example: The resistance of a Lead wire at 20 ̊ C is 5 . Find the resistance at 60 ̊ C.
for Lead, T=21820 5 60 5,84