elec130 electrical engineering 1
DESCRIPTION
ELEC130 Electrical Engineering 1. Gunilla BurrowesFernando Martinez EA G24EE 102 (p) 4921 63524921 6149 email gunilla@eefmm@ecemail Mon &Fri 2-3pmHelp Desk HELP - EA G08 - during office hours. Material. 5 modules 1 - Introductory Circuit Techniques Week 1 & 2 - PowerPoint PPT PresentationTRANSCRIPT
ELEC130 Electrical Engineering 1
Gunilla Burrowes Fernando MartinezEA G24 EE 102(p) 4921 6352 4921 6149email gunilla@ee fmm@ecemailMon &Fri 2-3pm Help Desk
HELP - EA G08 - during office hours
Material 5 modules
1 - Introductory Circuit Techniques Week 1 & 2 2 - DC Circuit Tools Week 2 3 & 4 3 - AC Circuit Tools Week 5 & 6 4 - Applications in Power Week 7 & 8 5 - Applications in Communications & Week 9 10 11
Instrumentation Week 12 & 13
Electronic Workbench: Faculty PC’s Rm. ES210 - Go to Diomedes Login: cstudentnumber Password: access keys on students card +
daymonth (ddmm) of birth
TopClass: http://www.newcastle.edu.au:86/topclass/ Username: first name.last name Password: date of birth ddmmyy
Email: first name.last name@studentmail
Lectures 2 hour / week for 13 weeks - Monday 5 -7pm
Quizzes - Weeks 3 6 8 11 13
Course Information Booklet
Student Responsibility
Survey
Student Responsibility Expect CIVIL Behavior
Work consistently
Progressive assessment
Teaching / Learning
Rote Learning
Where to go for help
Material may not always seem relevant
Its Up To YouThe onus is shifted to you to “learn”
(independently)
Majority of learning will take place when you tackle the subject material
BURY NOW the natural tendency to assume a passive role (waiting to be taught)
Text & References Course information Booklet & Safety Notes
$12.00 Purchase after this lecture - Foyer EA Several Alternative Texts
Floyd - Principles of Electric Circuits Dorf - Introduction to Electric Circuits Hambley - Electrical Engineering Johnson - Electric Circuit Analysis
Student Problem Sets - Library Text references Study Guide
Tutorials1 hours / week. Start next week Check your group on Noticeboard Foyer EA
You must Enroll Tonight
ASK QUESTIONS Electronic Workbench - ES 210
Introduction - Tutorial 2 Week 3 Matrix - textbook
Tutorial 1
Laboratory 2 hours / week - start next week Voluntary Laboratory THIS WEEK Check your group on Noticeboard Foyer EA
You Must Enroll Tonight - Foyer EA
EE 103(a) 9 laboratory exercises (Lab 1 goes for 2 weeks) 2 practical tests - 15 % each (Total 30%) All experiments are considered “examinable” Keep a Laboratory diary
Laboratory Attendance Sheets
Safety - notes will be attached to course information booklet- READ THEM
Use Common Sense
Keep the Laboratory Tidy
BE PREPARED
Help Desk - EE 102 / EE 103
Monday 9 - 11 am
Wednesday 8 - 9 am 1 - 2 pm 8 - 9 pm
AssessmentFinal grade for ELEC 130 will be
5 quizzes @ 4% each 20% 2 laboratory tests @ 15%30% June Exam @ 50% 50%
Engineering Concerned with creation of solutions to problems,
based on science and technology
Systems Engineering emphasises a wholistic design methodology encompasses the whole life cycle of the product
Role taken on by engineering in technology-based enterprises creative element to convert a need into a service or
product integration of all processes into a single coherent process
Multi-disciplinary & Integrating Nature
Economics Manufacturing
Social Reliability
Legal Maintainability
Environmental Human Engineering
Engineering as a Process
Technology, R & D
Market
Marketresearch Engineering
Marketing,sales andsupport
Changing Nature of Engineering
The essence of engineering is a product of the human mind
For the mind to be creative, it must operate on concepts (not just facts)
Swing back to the wholistic view complexity of the interaction with society rapid and fascinating development of engineering
science
EngineeringInvolves two complementary
subjects
the body of knowledge known as engineering science
the process of applying that knowledge
Aims of ELEC 130To study the concepts of basic electrical
elements & circuits
Start with laws of physics to derive simple ‘rules’ for electrical circuits
Same rules apply to ‘light’ current i.e. computers, communication ‘heavy’ current i.e. power grid, motors
Overview of DC CircuitsUnits & NotationWhat is a circuit?What is Charge / Current?What is Voltage?Voltage & Current sourcesPowerResistanceOhm’s Law
UnitsSI system - kg,m,sOthers derived from these - Volts, FaradsScaling of Units
p pico 10-12
n nano 10-9
micro 10-6
m milli 10-3
_ unit 1 K kilo 103
M mega 106
G giga 109
NotationTime varying quantities - lower case
e.g. v(t), i(t) sometimes assume time - v(t) = v
Time invariant quantities - upper casee.g. V, R,
Remember to include units of measuree.g. 15 Volts
What is a circuit?In ELEC130 we assume that a circuit
comprises of two or more elements connected by electrical conductors. Electrical conductors allow electricity to flow
(unimpeded) between elements
Electricity must flow in a CLOSED path or circuit
Open Circuit A ‘Break’ in a circuit is
called an open circuit
Short Circuit A ‘bypass’ of an
element is called a short circuit
Different Geography Two circuits may have
the same topology but different geography
ChargeCharge is the phenomenon giving rise to those
forces observed between electrical charged bodies. There are 2 kinds of charges: pos & neg
Symbol Q (constant) or q(t) (time varying)
Defined in terms of the charge on 1 electron ~=1.6x10-19 Coulombs
or stated as Charge on 6.2x1018 electrons is 1 Coulomb
Current Motion of charge constitutes an electric current
Conventional current is the flow of positive charges
Electron current is negative charges
Measure of rate of flow of charge1 Ampere = 1 Coulomb/sec
or Charge is the sum or ‘accumulation’ of current
Symbol I i(t)
Current cont..The primary purpose of electric circuits is
to move or transfer charges along specific paths
3 Acircuit
- 3 Acircuit
=
Voltage Fix one Coulomb of charge in space … energy input (work)
is required to bring another Coulomb of charge from a point A to a new point B closer to the fixed charge ……. the potential energy difference between points B & A is known as voltage:
1 Volt = 1 Joule / Coulomb
Charge tends to flow from a higher voltage (potential) to a lower voltage - resulting charge flow is current
Symbol V v(t)
Power Power is energy / time
P = VI Watts
p = v(t).i(t) W
i.e. need voltage and current (at the same time) to do work
Power can be +ve and -ve; it can be ‘absorbed’ or delivered
Symbol: P p(t) Units: Watts W
Power ConventionIf v(t) 0 and
i(t) 0 then p 0
Power is said to be absorbed by the circuit
NB polarity of voltage and direction of current
+
v(t)
-
i(t)
Circuit or element
Voltage & Current SourceAn ideal voltage source maintains its stated
voltage regardless of the load attachedIndependent voltage source
An ideal current source supplies its stated current regardless of the load attached
independent current sourceVA VA VA
IB IB
Ohm’s LawSome materials are good conductors of
electricity, some are poor
In a ‘good’ conductor, the current flowing through the conductor is (approx.) proportional to the voltage across it.
Constant of proportionality is known as resistance, given symbol is R
Ohm’s Law: v(t) = R i(t)
Example
4 V
10
i(t)