ELECTRIC CIRCUITS 1ELECTRIC CIRCUITS 1ENT161/4ENT161/4

En. Mohd ArinalEn. Mohd Arinal

Prof. Madya Dr. Mohd RizonProf. Madya Dr. Mohd Rizon

COURSE STRUKTURECOURSE STRUKTURE

Final Exam : 50%Final Exam : 50%

Assessment : 10%Assessment : 10%

Lab : 40%Lab : 40%

100%100%

COURSE OBJEKTIVECOURSE OBJEKTIVELearn about Electric Circuits component and

AD/DC circuit analysis method

COURSE SYLLABUS COURSE SYLLABUS Circuit Elements and Variables

SI Unit, Voltage and Current, Power, Energy, Basic Circuit Elements ( Passive and Active), Voltage and Current Source, Ohm’s law, Kirchoff’s Law, Circuit Model, Circuit with Dependent Source. Introduction to an Inductor, Voltage relationship, Current, Power and Energy, Capacitor and Combination of Serial-Parallel Inductor and Capacitor.

Resistance Circuit Serial/Series Resistors, Circuit Voltage/Current Dividers, Measurement of

Voltage and Current, Wheatstone Bridge and Equal Circuit Delta-Wye (Pi-Tee)

Circuit Analysis Method Node-Voltage Method and this Method encompass Dependent Source and

Special Case. Introduction to Mesh-Current Method which encompass Dependent Source and Special Case. Point Transformation. Equivalent Circuits of Thevenin and Norton. Maximum Power Transfer and Superposition.

Mutual Inductance Introduction to Self Induction, Concepts of Mutual Inductance, Induced

Mutual Polar Voltage, Energy Calculation, Linear and Ideal Transformer, Coupled Magnet in Equivalent Roll Circuit, Ideal Transformer in Equivalent Circuit.

RL and RC circuits first-order response RL and RC circuit original response, step response (forced function) RL and

RC circuits, general solution of original and step responses, sequential switching, introduction to original and step RLC circuit.

Steady state Sinusoidal analysis Sine Source, Sine Response, Phase Concept, Circuits Passive Element in

Frequency Domain, Impedance and Reactance, Kirchoff’s Law in Frequency Domain, Circuit Analysis Techniques in Frequency Domain.

Step Frequency in AC Circuit Step Frequency (Magnitude Plot and Phase Stripe Pass, Stripe Limit), Cut

Frequency, Typical Filter Type, Low-pass Filter in RL and RC Circuits, High-Pass Filter in RL and RC Circuits, RLC Stripe Pass Filter, Frequency Response using Bode Diagram.

Steady state Sinusoidal Power calculation Real-Time Power, Average and Reactive Power, Force Calculation and

RMS Value, Complex and Triangulation Power, Maximum Force Transfer in Impedance Term.

Power Circuits Systems One and Two Phase Systems, Equal Three Phase Point Voltage, Y-Delta

Circuit Analysis, Power Calculation in Equal Three Phase Circuit, Average Power Calculation in Three Phase Circuit.

Circuit Elements and VariablesCircuit Elements and Variables

Circuits analysis revisionCircuits analysis revision

SI Units SI Units

Voltage and Current, Power, EnergyVoltage and Current, Power, Energy

Basic Circuit Elements ( Passive and Basic Circuit Elements ( Passive and Active)Active)

Voltage and Current SourceVoltage and Current Source

Ohm’s lawOhm’s law

Kirchoff’s LawKirchoff’s Law

Circuit ModelCircuit Model

Circuit with Dependent SourceCircuit with Dependent Source

Circuit Elements and Circuit Elements and VariablesVariables

Introduction to an InductorIntroduction to an Inductor

Voltage relationshipVoltage relationship

Current, Power and EnergyCurrent, Power and Energy

Capacitor and Combination of Serial-Capacitor and Combination of Serial-Parallel Inductor and CapacitorParallel Inductor and Capacitor

Circuits analysis revisionCircuits analysis revision

AnalysisAnalysis : Study (Mathematics) about complex : Study (Mathematics) about complex identity and the mutually parts connection.identity and the mutually parts connection.

CircuitsCircuits : An arrangement of physical : An arrangement of physical components that use voltage, current, and components that use voltage, current, and resistance to perform some useful function.resistance to perform some useful function.

Analisis litarAnalisis litar : Based on mathematical : Based on mathematical techniques and is used to predict the behavior of techniques and is used to predict the behavior of the circuit model and its ideal circuit the circuit model and its ideal circuit components.components.

SI Units SI Units SI : SI : International System of UnitInternational System of Unit introduce by introduce by National Bureau of StandardsNational Bureau of Standards in 1964 in 1964

Quantity Basic Unit Symbol

Length Meter m

Mass Kilogram kg

Time Second s

Electric current Ampere A

Termodynamic Temperature

Kelvin k

Luminous intensity

candela cd

One great advantage of the SI unit is that it uses One great advantage of the SI unit is that it uses prefixes based on the power of 10 to relate prefixes based on the power of 10 to relate larger and smaller units to the basic unit.larger and smaller units to the basic unit.

Multiplier Prefix Symbol

1012 Tera T

109 Giga G

106 Mega M

103 Kilo k

100

10-3 Milli m

10-6 Micro

10-9 Nano n

10-12 Pico p

10-15 Femto f

10-18 Atto a

CurrentCurrentElectric current is the time rate of change of charge, Electric current is the time rate of change of charge, measured in amperes (A)measured in amperes (A)

1A=1C/s1A=1C/s

Direct current (dc): current that remains constant with Direct current (dc): current that remains constant with time.time.

Alternating current (ac): current that varies sinusodally Alternating current (ac): current that varies sinusodally with time.with time.

i i = current in ampere= current in ampere

qq= charge in coulomb= charge in coulomb

tt = time in second = time in second

dt

dqi

Current Current

direct current Alternating current

exponential current Damped current

VoltageVoltageVoltage (potential difference): energy required to move a unit Voltage (potential difference): energy required to move a unit charge through an element, measured in volts (V).charge through an element, measured in volts (V).

An honour of Italian Physician, An honour of Italian Physician, Alessandro Antonio Anastasio Alessandro Antonio Anastasio Volta in 18 century.Volta in 18 century.

One voltage equal to one Joule per coulomb.One voltage equal to one Joule per coulomb.

vv = voltage in volt = voltage in volt

ww = energy in Joule = energy in Joule

qq = charge in coulomb = charge in coulomb

dq

dwv

PowerPowerPower is the time rate of expending or absorbing Power is the time rate of expending or absorbing energy, measured in watts (W)energy, measured in watts (W)

Power absorbed = - Power suppliedPower absorbed = - Power supplied

pp = power in watt (W=J/s) = power in watt (W=J/s)

ww = energy in joule (J) = energy in joule (J)

tt = time in second (s) = time in second (s)

vv = voltage in volt (V) = voltage in volt (V)

II = current in ampere (A) = current in ampere (A)

dt

dwp vip

EnergyEnergy

Laws of conservation of energy: sum of Laws of conservation of energy: sum of power absorbed by electric circuit was power absorbed by electric circuit was zero. Otherwords, All supplied energy on zero. Otherwords, All supplied energy on one circuit was equal to absorbed energy. one circuit was equal to absorbed energy.

Energy is the capacity to do work, Energy is the capacity to do work, measured in joules (J).measured in joules (J).

t

t

t

tdtvidtpw

00

)(

Basic Circuit Elements

One element on simple circuit is a One element on simple circuit is a mathematical model for electric apparatus mathematical model for electric apparatus that have two terminals.that have two terminals.

Basic Circuit Elements

Active ElementsCould supplied power to circuitsExample : Voltage and Current source

Passive ElementsOnly could absorb power Example : resistor, inductance, capasitance, diod and etc.

Voltage and Current SourceIndependent sourceIndependent source establishes a voltage or establishes a voltage or current in a circuit without relying on voltages or current in a circuit without relying on voltages or currents elsewhere in the circuit.currents elsewhere in the circuit.Dependent sourceDependent source establishes a voltage or establishes a voltage or current whose value depends on a value of a current whose value depends on a value of a voltage or current elsewhere in the circuit.voltage or current elsewhere in the circuit.Ideal voltage sourceIdeal voltage source is a circuit element that is a circuit element that maintains prescribed voltage across its terminals maintains prescribed voltage across its terminals regardless of the current flowing in those regardless of the current flowing in those terminals.terminals.Ideal current sourceIdeal current source is a circuit element that is a circuit element that maintains a prescribed current through its maintains a prescribed current through its terminals regardless of the voltage across in terminals regardless of the voltage across in those terminals.those terminals.

Independent sourceIndependent source

Voltage Current

Dependent sourceDependent source

dependent voltage-Controlled voltagesource

dependent current-controlled voltage source

dependent voltage-controlled current source

dependent current-controlled current source

Ohm’s law

Ohm’s law states that the voltage Ohm’s law states that the voltage VV across a resistor is directly across a resistor is directly proportional to the current proportional to the current ii flowing flowing through the resistor.through the resistor.

An honour of German Physician, An honour of German Physician, George George Simon OhmSimon Ohm in 19 century. in 19 century.

Thus, equation becomesThus, equation becomes

R = resistance measured in ohm ( )R = resistance measured in ohm ( )

IRV

ConductanceConductance is the ability of an is the ability of an element to conduct electric circuit; it is element to conduct electric circuit; it is measured in siemens (S)measured in siemens (S)

RG

1

Kirchhoff’s laws were first introduced Kirchhoff’s laws were first introduced in 1847 by German physicist Gustav in 1847 by German physicist Gustav Robert Kirchhoff. Robert Kirchhoff.

He introduced two laws :He introduced two laws :

1.1. Kirchhoff’s Current law (KCL)Kirchhoff’s Current law (KCL)

2.2. Kirchhoff’s Voltage law (KVL)Kirchhoff’s Voltage law (KVL)

Kirchhoff’s Current law (KCL)Kirchhoff’s Current law (KCL)

KCL states that the algebraic sum KCL states that the algebraic sum of currents entering a node (or a of currents entering a node (or a closed boundary) is zero.closed boundary) is zero.

Mathematically, KCL implies thatMathematically, KCL implies that

entering current=leaving currententering current=leaving current

By this law, currents entering a node By this law, currents entering a node may be regarded as positive, while may be regarded as positive, while currents leaving the node may be currents leaving the node may be taken as negative.taken as negative.

01

N

nni

Kirchhoff’s Voltage law (KVL)Kirchhoff’s Voltage law (KVL)

KVL states that the algebraic sum KVL states that the algebraic sum of all voltages around a closed of all voltages around a closed path (or loop) is zero.path (or loop) is zero.

Expressed mathematically, Expressed mathematically, KVL states thatKVL states that

01

M

mmv

Circuit ModelCircuit Model

Circuit model is mathematic Circuit model is mathematic model that described electrical model that described electrical system. system.

An ideal circuit component is a An ideal circuit component is a mathematically model of an actual mathematically model of an actual electric component that connect electric component that connect series or parallel.series or parallel.

Series CircuitSeries Circuit

Two element connect series if:Two element connect series if:

1.1. This two circuit element only This two circuit element only have one point connection.have one point connection.

2.2. Point between this two element Point between this two element wasn’t connected with other wasn’t connected with other current supply.current supply.

Example : Series circuit Example : Series circuit

Parallel CircuitParallel Circuit

Two element, branch or Two element, branch or sequence are parallel if sequence are parallel if connect with two point.connect with two point.

Example : Parallel circuitExample : Parallel circuit

Series-Parallel circuit Series-Parallel circuit combinationcombination

Series-Parallel circuit could Series-Parallel circuit could combine to have one complex combine to have one complex sequence circuit.sequence circuit.

Example : Series-Parallel circuit Example : Series-Parallel circuit combinationcombination

CIRCUIT WITH DEPENDENT CIRCUIT WITH DEPENDENT SOURCESOURCE

By using Kirchhoff’s Voltage By using Kirchhoff’s Voltage Law at first loop,Law at first loop,

(1)(1)0205500 ii

By using Kirchhoff’s Current By using Kirchhoff’s Current law at second loop, law at second loop,

(2)(2)

ii

iii

6

5

0

0

Solve equation (1) and (2)Solve equation (1) and (2)

Ai

Ai

24

4

0

By using Ohm’s law at 20Ω By using Ohm’s law at 20Ω resistorresistor

Vv 4800

Question 1Question 1

Vva 8)8)(1(

Aib 10)2.0)(50(

a)

b)

Wp 8)8()1(8

)8( 22

8

Wp 500)2.0()50( 22.0

Vvc 20)20)(1(

Wp 20)20()1(20

)20( 22

20

Aid 225

50

Wp 100)25()2(25

)50( 22

25

c)

d)

Question 2Question 2

Calculate I and V0

AI

I

III

2

126

032186

V

IV

10)2)(5(

50

Answer:

1 2 0 V

3 0

1 5

3 0 V

Question 3Calculate current value for this circuit by using Kirchhoff Volatage law.

Current flows clockwise direction

AI

I

II

2

9045

0153030120

AI

I

II

2

9045

0303015120

Current flows anti-clockwise direction

Voltage at resistor:Voltage at resistor:

VIRV

VIRV

30)15)(2(

60)30)(2(

15

30

Power absorbed by resistor :Power absorbed by resistor :

W

RIVIp

W

RIVIp

60

)15()2()2)(30(

120

)30()2()2)(60(

2

215

2

230

Question 4Question 4

By using Kirchhoff Voltage law By using Kirchhoff Voltage law at those two loop, below at those two loop, below equation can be define:equation can be define:

00 323

610

iii

i

s

s

Solve those two equationSolve those two equation

Ai

Ais1

67.1

0

By using Ohm’s law at 3Ω By using Ohm’s law at 3Ω resistorresistor

Viv 33 00

ReferenceReference

Nilson And Riedel. (1996). Nilson And Riedel. (1996). Electric Electric CircuitsCircuits. 7th E. Addison Wesley, Reading, . 7th E. Addison Wesley, Reading, Massachusetts Massachusetts

Alexander and Sadiku. Fundamentals Of Alexander and Sadiku. Fundamentals Of Electric Circuits. 3th E. McGraw-Hill IE.Electric Circuits. 3th E. McGraw-Hill IE.