ECE

EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

MEN227 PRINCIPLES OF
ELECTRICAL ENGINEERING

By
Dr. Abbas UĞURENVER

0
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Course Flow
Week 1 -2
ELECTRIC CIRCUITS, ELECTROMAGNETISM AND INSTRUMENTS
Week 3-4
DC MACHINES
Week 5-6-7
ALTERNATING QUANTITIES AND AC MACHINES
Week 8
Midterm Exam
Week 9-10
SEMICONDUCTOR DIODE AND APPLICATIONS
Week 11-12
BIPOLAR JUNCTION TRANSISTOR AND APPLICATIONS
Week 13-14
BIPOLAR JUNCTION TRANSISTOR AND APPLICATIONS.
Week 15 - FİNAL EXAM
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Assessment

Assignment 15%
Quizze 1 5% Written Exam
Quizze 2 10% Written Exam
Midterm Exam 30% Written Exam
Final Exam 40% Written Exam
Total 100%
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

TEXT BOOKS:
1. A. Chakrabarti, “Circuit Theory”, Dhanpat Rai Publications, 6 Edition, 2004.
th

2. K. S. Suresh Kumar, “Electric Circuit Analysis”, Pearson Education, 1 Edition, 2013.

st

3. William Hayt, Jack E. Kemmerly S. M. Durbin, “Engineering Circuit Analysis”, Tata

Mc Graw Hill, 7 Edition, 2010.
th

4. J. P. J. Millman, C. C. Halkias, Satyabrata Jit, “Millman’s Electronic Devices and

Circuits”, Tata Mc Graw Hill, 2 Edition, 1998.
nd

5. R. L. Boylestad, Louis Nashelsky, “Electronic Devices and Circuits”, PEI/PHI, 9th

Edition, 2006
REFERENCE BOOKS:
1. David A. Bell, “Electronic Devices and Circuits”, Oxford University Press, 5th
Edition, 2005.
2. M. Arshad, “Network Analysis and Circuits”, Infinity Science Press, 9th Edition,
2016.
3. A. Bruce Carlson, “Circuits”, Cengage Learning, 1st Edition, 2008.
4. S. Salivahanan, N. Suresh Kumar, A. Vallavaraj, “Electronic Devices and Circuits”,
Tata Mc Graw Hill, 2nd Edition, 2011.
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

LECTURE 1- 2
Overview of electrical engineering, Terminology
and circuit variables

1. Electrical Engineering: An Overview

2. Understand and be able to use SI units and the standard prefixes for
powers of 10.

3. Know and be able to use the definitions of voltage and current.

4. Know and be able to use the definitions of power and energy.

5. Be able to use the passive sign convention to calculate the power for
an ideal basic circuit element given its voltage and current
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Electrical Engineering: An Overview

• The electrical engineering profession focuses on systems that
produce, transmit, and measure electric signals.

• Electrical engineering combines the physicist’s models of

natural phenomena with the mathematician’s tools for
manipulating those models to produce systems that meet
practical needs.
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Electrical Engineering: An Overview

There is five major classifications of electrical systems:

1. communication systems

2. computer systems

3. control systems

4. power systems

5. signal-processing systems
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Electrical Engineering: An Overview

1. Communication systems
• electrical systems that generate, transmit, and distribute information.

• Well-known examples include television equipment, such as cameras,

transmitters, receivers, and monitors; radio telescopes, used to
explore the universe; satellite systems, which return images of other
planets and our own; radar systems, used to coordinate plane flights;
and telephone systems.

2. Computer systems
• use electric signals to process information ranging from word
processing to mathematical computations.

• Systems range in size and power from simple calculators to personal

computers to supercomputers that perform such complex tasks as
processing weather data and modeling chemical interactions of
complex organic molecules.
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Electrical Engineering: An Overview

3. Control systems
• use electric signals to regulate processes.

• Examples include the control of temperatures, pressures, and flow

rates in an oil refinery; the fuel–air mixture in a fuel-injected
automobile engine; mechanisms such as the motors, doors, and
lights in elevators; and the locks in the Panama Canal.

4. Power systems
• generate and distribute electric power.
• Electric power, which is the foundation of our technology-based
society, usually is generated in large quantities by nuclear,
hydroelectric, solar, and thermal (coal-, oil-, or gas-fired) generators.
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

5. Signal-processing systems
• act on electric signals that represent information.

• They transform the signals and the information contained in them into
a more suitable form.

• There are many different ways to process the signals and their
information.

• For example, image-processing systems gather massive quantities

of data from orbiting weather satellites, reduce the amount of data to
a manageable level, and transform the remaining data into a video
image for the evening news broadcast.
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

ELECTRIC CIRCUITS, ELECTROMAGNETISM AND INSTRUMENTS

• The process of finding the network variables namely the voltage and
currents in various parts of the circuit is known as network analysis.

• Before we carry out actual analysis it is very much essential to

thoroughly understand the various terms associated with the network.
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

1. International System of Units

It is built upon seven basic units. These are meter, kilogram, second,
ampere, Kelvin, mole and candela.
Basic Units
The seven quantities are known to be basic in SI unit System.
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

• In addition, defined quantities are combined to form derived units.

 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

• In many cases, the SI unit is either too small or too large to use
conveniently. Standard prefixes corresponding to powers of 10
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

2. Structure of the Atom

• The atom is the smallest particle of any matter. Everything is made up of
atoms. Atoms have three main parts:

1. Protons, positively charged particles,

make up part of the nucleus, which is
in the center of the atom.

2. Neutrons, uncharged particles, make

up the other part of the nucleus.

3. Electrons, negatively charged particles,

orbit around the nucleus like the planets
orbit the sun in our solar system.
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Valence Shells
• An atom has a certain number of shells that surround the nucleus.
Each shell has a maximum number of electrons that rotate in its orbit.
1st shell – 2 electrons
2nd shell – 8 electrons
3rd shell – 18 electrons
4th shell – 32 electrons
5th shell – 50 electrons

• Electrons in incomplete valence shells may also move freely from

valence shell to valence shell of different atoms or compounds.

• Conductors have 1–3 valence electrons.

• Semiconductors have 4 valence electrons.
• Insulators have 5–8 valence electrons.
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Conductors
• When electrons can move easily from one atom to another in a
material, it is a conductor. In general all the metals are good
conductors, with silver the best and copper at second.

Insulators
A material with atoms in which the electrons tend to stay in their own
orbits is an insulator and it cannot conduct electricity easily. However,
the insulators are able to hold or store electricity better than the
conductors. These are also called dielectric materials.

Semiconductors
Carbon can be considered as semiconductor, conducting less than the
metal conductors but more than the insulators. In the same group are
germanium and silicon which are commonly used for transistor and other
semiconductor components.
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

What is Electricity?
In some materials, particularly metals, the electrons farthest from the
nucleus are not bound to a particular atom - they can move freely from
one atom to another. Electricity is the flow of these free electrons in a
wire:

Such a flow of electrons is called a current.

• the electrons in the wire will be attracted to the positive end and
repelled by the negative end. That's electricity!
• Even though the electrons flow from the negative to the positive
terminals, it is conventional to say that the current flows from positive
to negative :
why? Because we can't see the electrons.
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

BASIC CONCEPTS AND DEFINITIONS

Electric Charge.
•Electric charge, or charge for short, is a fundamental physical property
that causes objects to feel an attractive or repulsive force toward one
another.
The charge of many billions of electrons or protons is necessary for
common applications of electricity.
• Therefore, it is convenient to define a practical unit called coulomb
(C) as equal to charge of =1.6 x 1019 electrons =
16,000,000,000,000,000,000
= 16 billion billion electrons!

• The charge is bipolar, meaning that electrical effects are described in

terms of positive and negative charges.

• Electrical effects are attributed to both the separation of charge and

charges in motion.
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Current : is a flow of electrical charge carriers, usually electrons or

electron-deficient atoms. The common symbol for current is the
uppercase letter I.
• The unit of current is the ampere abbreviated as (A) and corresponds
to the quantity of total charge that passes through an arbitrary cross
section of a conducting material per unit second. Mathematically,

• Here is the symbol of charge measured in Coulombs (C), I is the

current in amperes (A) and t is the time in second (s).
• The current can also be defined as the rate of charge passing
through a point in an electric circuit.
Mathematically,
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

The charge transferred between time t1 and t2 is obtained as

A constant current (also known as a direct current or DC) is denoted by

symbol I whereas a time varying current (also known as alternating

current or AC) is represented by the symbol i or i(t).

ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Example 1.1
Determine the current in a circuit if a charge of 80 coulombs passes a
given point in 20 seconds (s).
Solution:

Example 1.2
How much charge is represented by 4,600 electrons?
Solution:
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Example 1.3
The total charge entering a terminal is given by q=5tsin4πt mC .
Calculate the current at t=0.5 S.
Solution:

Example 1.4
Determine the total charge entering a terminal between t=1 s and t=2 s if
the current passing the terminal is
Solution:
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

VOLTAGE (or) POTENTIAL DIFFERENCE:To move the electron in a

conductor in a particular direction requires some work or energy transfer.
This work is performed by an external electromotive force (emf), typically
represented by the battery in Fig. 1.3. This emf is also known as voltage
or potential difference. The voltage Vab between two points a and b in
an electric circuit is the energy (or work) needed to move a unit charge
from a to b.
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Voltage (or potential difference) is the energy required to move charge

from one point to the other, measured in volts (V). Voltage is denoted by
the letter v or V. Mathematically,

where w is energy in joules (J) and q is charge in coulombs (C). The

voltage Vab or simply Vab is measured in volts (V)
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

• Fig. 1.3 shows the voltage across an element (represented by a

rectangular block) connected to points a and b. The plus (+) and
minus (-) signs are used to define reference direction or voltage
polarity. The Vab can be interpreted in two ways:
(1) point a is at a potential of ab volts higher than point b, or
(2) the potential at point a with respect to point b is Vab . It follows
logically that in general
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Example 1.5 : An energy source forces a constant current of 2 A for

10 s to flow through a lightbulb. If 2.3 kJ is given off in the form of light
and heat energy, calculate the voltage drop across the bulb.

Solution:
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

4 POWER
Power is the time rate of expending or absorbing energy, measured in watts
(W). Power, is denoted by the letter p or P. Mathematically,

Where p is power in watts (W), w is energy in joules (J), and t is time in

seconds (s).
From voltage and current equations, it follows that;

Thus, if the magnitude of current I and voltage are given, then power can be
evaluated as the product of the two quantities and is measured in watts (W).
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Sign of power:
Plus sign: Power is absorbed by the element. (Resistor, Inductor)
Minus sign: Power is supplied by the element. (Battery, Generator)
Passive sign convention:
If the current enters through the positive polarity of the voltage, p = +vi
If the current enters through the negative polarity of the voltage, p = – vi
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

5 ENERGY
The capacity to do work, and is measured in joules (J). The energy
absorbed or supplied by an element from time 0 to t is given by,

The electric power utility companies measure energy in watt-hours (WH)

or Kilo watt-hours (KWH)

Example 1.6
A source e.m.f. of 5 V supplies a current of 3A for 10 minutes. How much
energy is provided in this time?

Solution:
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Example 1.7
Find the power delivered to an element at =3 ms if the current entering its
positive terminals is i=5cos60πt A and the voltage is: (a) v=3 i , (b) =3 di/dt.

Solution:

be aware
that ur
calculator
in rad
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

OHM’S LAW

• Georg Simon Ohm (1787–1854), a German physicist, is credited with finding

the relationship between current and voltage for a resistor.
• This relationship is known as Ohm’s law.
• Ohm’s law states that at constant temperature, the voltage (V) across a
conducting material is directly proportional to the current (I) flowing through
the material. Mathematically,

• Where the constant of proportionality R is called the resistance of the

material. The V-I relation for resistor according to Ohm’s law is depicted in
Fig.1.6
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Limitations of Ohm’s Law:

1. Ohm’s law is not applicable to non-linear elements like diode, transistor etc.
2. Ohm’s law is not applicable for non-metallic conductors like silicon carbide.
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

CIRCUIT ELEMENTS
An element is the basic building block of a circuit. An electric circuit is simply
an interconnection of the elements. Circuit analysis is the process of
determining voltages across (or the currents through) the elements of the circuit.

There are 2 types of elements found in electrical circuits.

a) Active elements (Energy sources): The elements which are capable of

generating or delivering the energy are called active elements. E.g., Generators,
Batteries

b) Passive element (Loads): The elements which are capable of receiving the
energy are called passive elements. E.g., Resistors, Capacitors and Inductors
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

ACTIVE ELEMENTS (ENERGY SOURCES)

• The energy sources which are having the capacity of generating the energy
are called active elements.
• The most important active elements are voltage or current sources that
generally deliver power/energy to the circuit connected to them.
• There are two kinds of sources
a) Independent sources

b) Dependent sources
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

INDEPENDENT SOURCES:
• An ideal independent source is an active element that provides a specified
voltage or current that is completely independent of other circuit elements.
Ideal Independent Voltage Source:
• is an active element that gives a constant voltage across its terminals
irrespective of the current drawn through its terminals.
• In other words, an ideal independent voltage source delivers to the circuit
whatever current is necessary to maintain its terminal voltage.
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Practical Independent Voltage Source:

• Practically, every voltage source has some series resistance across its
terminals known as internal resistance, and is represented by Rse.
• For ideal voltage source Rse = 0. But in practical voltage source
Rse is not zero but may have small value. Because of this Rse voltage across
the terminals decreases with increase in current as shown in Fig. 1.8

• Terminal voltage of practical voltage source is given by

 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Ideal Independent Current Source:

• An ideal independent Current source is an active element that gives a
constant current through its terminals irrespective of the voltage appearing
across its terminals.
• That is, the current source delivers to the circuit whatever voltage is
necessary to maintain the designated current. The symbol of idea
independent current source and its V-I characteristics are shown in Fig. 1.9
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

Practical Independent Current Source:

• Practically, every current source has some parallel/shunt resistance across its
terminals known as internal resistance, and is represented by Rsh. For ideal
current source Rsh = ∞ (infinity).
• In practical voltage source Rsh is not infinity but may have a large value.
Because of this Rsh current through the terminals slightly decreases with
increase in voltage across its terminals as shown in Fig. 1.10. Terminal
current of practical current source is given by
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

DEPENDENT (CONTROLLED) SOURCES

• An ideal dependent (or controlled) source is an active element in which the
source quantity is controlled by another voltage or current.

• Dependent sources are usually designated by diamond-shaped symbols, as

shown in figure below.
•
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

• Since the control of the dependent source is achieved by a voltage or current

of some other element in the circuit, and the source can be voltage or
current, it follows that there are four possible types of dependent sources,
namely:
1. A voltage-controlled voltage source (VCVS)
2. A current-controlled voltage source (CCVS)
3. A voltage-controlled current source (VCCS)
4. A current-controlled current source (CCCS)
 ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

• Dependent sources are useful in modeling elements such as transistors,

operational amplifiers, and integrated circuits.
• An example of a current-controlled voltage source is shown on the right-
hand side of Fig. 1.12, where the voltage 10i of the voltage source depends
on the current i through element C.
• Students might be surprised that the value of the dependent voltage source is
10i V (and not 10i A) because it is a voltage source.
• The key idea to keep in mind is that a voltage source comes with
polarities (+ -) in its symbol, while a current source comes with an arrow,
irrespective of what it
depends on.

Fig. 1.12 The source in right

hand side is current-controlled
voltage source
ECE
EE 8443
3512 – Pattern
– Signals:
MEN227 Recognition
Continuous
PRINCIPLES and Discrete
OF ELECTRICAL ENGINEERING

THE END