ELCT 221 - ELECTRIC CIRCUITS

Instructor: Grigory SIMIN

simin@cec.sc.edu

Electric Circuits – what are they?

Who need them?

Do you need to know them?

Electric circuit is an interconnection of electric elements.

Electric circuit is also a model that describes, predicts and/or

explains the behavior of any actual electrical system.

Electric circuit is a KEY component of any field related to

Electrical Engineering

Electrical Components, Circuits and Circuits

Diagrams

Actual system:

100W Audio Amplifier

Model (electric circuit):

100W Audio Amplifier

An electric circuit is an interconnection of electrical elements.

Electrical Engineering – what is it?

Electrical engineering is the profession concerned with systems

that produce, transmit, and measure electric signals.

Over the past century and a half, electrical engineers have

played a dominant role in the development of systems that have

changed the way people live and work.

Satellite communication links, telephones, digital computers,

televisions, diagnostic and surgical medical equipment,

assembly-line robots, and electrical power tools define a

modern technological society.

Electrical systems pervade our lives; they are found in homes,

schools, workplaces, and transportation vehicles - everywhere.

National Academy of Engineering:

GRAND CHALLENGES FOR ENGINEERING

•A diverse committee of experts from around the world

•The most accomplished engineers and scientists of their

generation

• Proposed 14 GRAND challenges

•Committee Chair, WILLIAM PERRY, Former

Secretary of Defense, U.S. Department of Defense

Professor of Engineering, Stanford University

National Academy of Engineering:

GRAND CHALLENGES FOR ENGINEERING

Communication systems:

televisions, cameras,

transmitters, receivers, and

VCRs; radio telescopes, used to

explore the universe; network

and satellite systems, radar

systems, telephone systems...

Electrical systems and components

Communications: 100 years ago

Telegraph operator printing telegram, 1908, courtesy

Library of Congress

On January 27, 2006, Western Union sent its final telegram.

Communications: 100 years ago

Communications today:

Mobile Satellite Services

Convergence of Terrestrial and Satellite mobile

communication systems

Terrestar Satellite Phone has

satellite, quad-band GSM, tri-

band WCDMA/HSPA

connectivity along with

Bluetooth and WiFi.

Communication system: GPS

The GPS system combined with

computer electronics and

software also forms a Signal

Processing System

Control systems: use electric

signals to regulate processes.

Examples: Temperature, pressure,

flow rates regulators; fuel-air

mixture control in a fuel-injected

automobile engine.

Motors, doors, elevators controls.

Locks in the Panama Canal.

The autopilot and autolanding

systems.

Control system example: dark activated switch

Actual system Model (electric circuit)

Signal-processing systems:

transform the signals and the information contained

in them into a suitable form.

Computerized tomography

takes signals generated by an X-

ray machine and transforms

them into an image.

Original X-ray signals are of

little use to a physician;

once they are processed into a

recognizable image the

information they contain can be

used in the diagnosis of disease

or injury.

Modern electronic systems are highly sophisticated; they combine

control, signal processing, communication, power and computer

systems

A sophisticated communications system enables the

pilot and the air traffic controller to monitor the

plane’s location.

Onboard computer system manages engine functions,

implements the navigation and flight control systems,

and generates video information on screens in the

cockpit.

A complex control system uses cockpit commands to

adjust the position and speed of the airplane.

Power system provide and distribute the electric

power needed for computers, to control the engines,

keep the cabin lights on, A/C, show the movie etc.

Signal-processing systems reduce the noise in air

traffic communications and transform information

about the plane’s location into the image on display.

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The five major classifications of electrical systems:

ELCT 221 textbook

1) Fundamentals of Electric

Circuits, by Charles

Alexander, Matthew

Sadiku, 4th edition, ISBN

0077263197 /

9780077263195, McGraw

Hill

2) PSpice for Basic Circuit

Analysis with CD, by

Joseph G. Tront, ISBN

0073263192 /

9780073263199, McGraw

Hill.

Supplemental readings (recommended, optional):

Lessons In Electric Circuits

A free series of textbooks by Tony R. Kuphaldt

http://ibiblio.org/obp/electricCircuits/

Schaum's Outline of Basic Electricity“ by Milton Gussow, ISBN:

0070252408, McGraw-Hill

"Getting to Know Semiconductors" by M.E Levinshtein and G. S. Simin,

World Sci. Publ. Co., Singapore, London, NY, 1992; ISBN: 9810207603

MATLAB Programming for Engineers

by Stephen Chapman (3rd edition) August 2004, ISBN: 0534424171

Publisher: Thomson

ELCT 221 contents

Part I – DC circuits

Chapter 1: Basic concepts

Systems of Units, Charge and Current, Voltage, Power and Energy, Circuit Elements

Chapter 2: Basic Laws

Ohm's Law, Nodes, Branches, and Loops, Kirchhoff's Laws, Series Resistors and Voltage

Division, Parallel Resistors and Current Division

Chapter 3: Methods of Analysis

Nodal Analysis, Mesh Analysis, Nodal and Mesh Analyses by Inspection, Nodal Versus Mesh Analysis, Circuit Analysis with PSpice,Applications examples

Chapter 4: Circuit Theorems Linearity, Superposition, Source Transformation, Thevenin's and Norton's Theorem

ELCT 221 contents

Part II – AC circuits

Chapter 6: Capacitors and InductorsCapacitors, Series and Parallel Capacitors, Inductors, Series and Parallel Inductors

Chapter 7: RC and RL Circuits Step Response of an RC and RL Circuits, Transient Analysis with PSpice

Chapter 9: Sinusoids and PhasorsSinusoids, Phasors, Impedance and Admittance, Kirchhoff's Laws in the Frequency Domain

Chapter 10: Sinusoidal Steady-State Analysis

AC Nodal and Mesh Analysis, Superposition, Thevenin and Norton Equivalent Circuits, AC Analysis Using PSpice

Chapter 11: AC PowerInstantaneous and Average Power, Maximum Average Power Transfer, Effective or RMS Value, Power Factor

Chapter 12: Three-Phase Circuits

Balanced Three-Phase Voltages, Balanced Wye-Wye, Wye-Delta, Delta-Delta and Delta-Wye Connections, Power in a Balanced System

Computer tools and simulators

In ELCT 221

(Room 1D15)

MATLAB

PSPICE

Class WEB Page:

http://www.ee.sc.edu/classes/Spring10/ELCT221/

The most important

link for you

http://www.ee.sc.edu/classes/Spring10/ELCT221/

Homework assignments will be given mostly using LON-CAPA

http:// lon-capa.engr.sc.edu

Login name: same as your EE account

name

Initial password:

LC+xxxx

where “+” is the “plus sign” and xxxx are

the last 4 digits of your SSN.

After the first logon you can change the

password. A good practice would be to

match your ENGINEERING password.

http://loncapa2.ee.sc.edu/adm/roles