Electrical Circuit Theory and Technology

782 Pages·2014·6.45 MB·English

by  Bird, John

Electrical Circuit Theory and Technology
In Memory of Elizabeth
Electrical Circuit Theory and Technology
Fifth edition
John Bird
,BSc(Hons), CEng, CSci, CMath, FITE, FIMA, FCollT
Fiftheditionpublished2014
byRoutledge
2ParkSquare,MiltonPark,Abingdon,OxonOX144RN
SimultaneouslypublishedintheUSAandCanada
byRoutledge
711ThirdAvenue,NewYork,NY10017
RoutledgeisanimprintoftheTaylor&FrancisGroup,aninformabusiness
©2014JohnBird
TherightofJohnBirdtobeidentifiedasauthorofthisworkhasbeenassertedbyhiminaccordancewithsections77and78
oftheCopyright,DesignsandPatentsAct1988.
Allrightsreserved.Nopartofthisbookmaybereprintedorreproducedorutilizedinanyformorbyanyelectronic,mechanical,
orothermeans,nowknownorhereafterinvented,includingphotocopyingandrecording,orinanyinformationstorageor
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Trademarknotice:Productorcorporatenamesmaybetrademarksorregisteredtrademarks,andareusedonlyforidentification
andexplanationwithoutintenttoinfringe.
FirsteditionpublishedbyNewnes1997
FourtheditionpublishedbyRoutledge2010
BritishLibraryCataloguinginPublicationData
AcataloguerecordforthisbookisavailablefromtheBritishLibrary
LibraryofCongressCataloginginPublicationData
Bird,J.O.
Electricalcircuittheoryandtechnology/JohnBird.—5thedition.
pagescm
Includesindex.
1.Electriccircuits.2.Electricalengineering.I.Title.
TK454.B482013
621.319’2—dc23
2013016404
ISBN:978-0-415-66286-4(pbk)
ISBN:978-1-315-88334-2(ebk)
TypesetinTimesby
ServisFilmsettingLtd,Stockport,Cheshire
Contents
Preface xi 4.5 E.m.f.andinternalresistanceofacell 29
4.6 Primarycells 31
4.7 Secondarycells 32
Part1 Basicelectricalengineering
4.8 Cellcapacity 33
principles 1
4.9 Safedisposalofbatteries 35
4.10 Fuelcells 35
1 Unitsassociatedwithbasicelectrical
4.11 Alternativeandrenewableenergysources 35
quantities 3
1.1 SIunits 3
RevisionTest1 37
1.2 Charge 4
1.3 Force 4
5 Seriesandparallelnetworks 38
1.4 Work 4
5.1 Seriescircuits 39
1.5 Power 5
5.2 Potentialdivider 40
1.6 Electricalpotentialande.m.f. 6
5.3 Parallelnetworks 42
1.7 Resistanceandconductance 6
5.4 Currentdivision 44
1.8 Electricalpowerandenergy 6
5.5 Loadingeffect 47
1.9 Summaryofterms,unitsandtheirsymbols 7
5.6 Potentiometersandrheostats 48
5.7 Relativeandabsolutevoltages 51
2 Anintroductiontoelectriccircuits 8
2.1 Standardsymbolsforelectrical 5.8 Earthpotentialandshortcircuits 52
components 9 5.9 Wiringlampsinseriesandinparallel 52
2.2 Electriccurrentandquantityof
6 Capacitorsandcapacitance 54
electricity 9
6.1 Introductiontocapacitors 55
2.3 Potentialdifferenceandresistance 10
6.2 Electrostaticfield 55
2.4 Basicelectricalmeasuring
6.3 Electricfieldstrength 56
instruments 10
6.4 Capacitance 56
2.5 Linearandnon-lineardevices 11
6.5 Capacitors 56
2.6 Ohm’slaw 11
6.6 Electricfluxdensity 57
2.7 Multiplesandsub-multiples 11
6.7 Permittivity 57
2.8 Conductorsandinsulators 13
6.8 Theparallelplatecapacitor 59
2.9 Electricalpowerandenergy 13
6.9 Capacitorsconnectedinparallelandseries 60
2.10 Maineffectsofelectriccurrent 16
6.10 Dielectricstrength 64
2.11 Fuses 16
6.11 Energystored 65
2.12 Insulationandthedangersofconstant
6.12 Practicaltypesofcapacitor 65
highcurrentflow 17
6.13 Supercapacitors 67
3 Resistancevariation 18 6.14 Dischargingcapacitors 68
3.1 Resistorconstruction 19
3.2 Resistanceandresistivity 19 7 Magneticcircuits 69
3.3 Temperaturecoefficientofresistance 21 7.1 Introductiontomagnetismand
magneticcircuits 70
3.4 Resistorcolourcodingandohmicvalues 23
7.2 Magneticfields 70
4 Batteriesandalternativesourcesofenergy 26 7.3 Magneticfluxandfluxdensity 71
4.1 Introductiontobatteries 27 7.4 Magnetomotiveforceandmagnetic
4.2 Somechemicaleffectsofelectricity 27 fieldstrength 71
4.3 Thesimplecell 28 7.5 PermeabilityandB–Hcurves 72
4.4 Corrosion 29 7.6 Reluctance 73
vi Contents
7.7 Compositeseriesmagneticcircuits 75 11 Semiconductordiodes 128
7.8 Comparisonbetweenelectricaland 11.1 Typesofmaterial 129
magneticquantities 78 11.2 Semiconductormaterials 129
7.9 Hysteresisandhysteresisloss 78 11.3 Conductioninsemiconductormaterials 131
11.4 Thep–njunction 131
RevisionTest2 80 11.5 Forwardandreversebias 132
11.6 Semiconductordiodes 135
11.7 Characteristicsandmaximumratings 136
8 Electromagnetism 81 11.8 Rectification 136
8.1 Magneticfieldduetoanelectriccurrent 82 11.9 Zenerdiodes 136
8.2 Electromagnets 83 11.10 Siliconcontrolledrectifiers 138
8.3 Forceonacurrent-carryingconductor 85 11.11 Lightemittingdiodes 138
8.4 Principleofoperationofasimple 11.12 Varactordiodes 139
d.c.motor 88
11.13 Schottkydiodes 139
8.5 Principleofoperationofamoving-coil
instrument 89 12 Transistors 141
8.6 Forceonacharge 89 12.1 Transistorclassification 142
12.2 Bipolarjunctiontransistors(BJTs) 142
12.3 Transistoraction 143
9 Electromagneticinduction 91
12.4 Leakagecurrent 144
9.1 Introductiontoelectromagneticinduction 92
12.5 Biasandcurrentflow 145
9.2 Lawsofelectromagneticinduction 92
12.6 Transistoroperatingconfigurations 145
9.3 Rotationofaloopinamagneticfield 95
12.7 Bipolartransistorcharacteristics 145
9.4 Inductance 96
12.8 Transistorparameters 147
9.5 Inductors 97
12.9 Currentgain 148
9.6 Energystored 98
12.10 TypicalBJTcharacteristicsandmaximum
9.7 Inductanceofacoil 99
ratings 149
9.8 Mutualinductance 100
12.11 Fieldeffecttransistors 150
12.12 Fieldeffecttransistorcharacteristics 150
10 Electricalmeasuringinstrumentsand 12.13 TypicalFETcharacteristicsandmaximum
measurements 103 ratings 152
10.1 Introduction 104 12.14 Transistoramplifiers 152
10.2 Analogueinstruments 104 12.15 Loadlines 155
10.3 Moving-ironinstrument 104
10.4 Themoving-coilrectifierinstrument 105 RevisionTest3 159
10.5 Comparisonofmoving-coil,moving-iron
andmoving-coilrectifierinstruments 105 MainformulaeforPart1Basicelectricaland
10.6 Shuntsandmultipliers 106 electronicprinciples 161
10.7 Electronicinstruments 107
10.8 Theohmmeter 108
Part2 Electricalprinciplesand
10.9 Multimeters 108
technology 163
10.10 Wattmeters 108
10.11 Instrument‘loading’effect 109
10.12 Theoscilloscope 111 13 D.c.circuittheory 165
10.13 Virtualtestandmeasuringinstruments 116 13.1 Introduction 165
10.14 Virtualdigitalstorageoscilloscopes 116 13.2 Kirchhoff’slaws 166
10.15 Waveformharmonics 120 13.3 Thesuperpositiontheorem 169
10.16 Logarithmicratios 120 13.4 Generald.c.circuittheory 172
10.17 Nullmethodofmeasurement 123 13.5 Thévenin’stheorem 174
10.18 Wheatstonebridge 123 13.6 Constant-currentsource 178
10.19 D.c.potentiometer 123 13.7 Norton’stheorem 178
10.20 A.c.bridges 124 13.8 ThéveninandNortonequivalentnetworks 181
10.21 Measurementerrors 125 13.9 Maximumpowertransfertheorem 184
Contents vii
14 Alternatingvoltagesandcurrents 187 18.3 Opampinvertingamplifier 256
14.1 Introduction 188 18.4 Opampnon-invertingamplifier 258
14.2 Thea.c.generator 188 18.5 Opampvoltage-follower 259
14.3 Waveforms 189 18.6 Opampsummingamplifier 259
14.4 A.c.values 190 18.7 Opampvoltagecomparator 260
14.5 Electricalsafety–insulationandfuses 193 18.8 Opampintegrator 261
14.6 Theequationofasinusoidalwaveform 193 18.9 Opampdifferentialamplifier 262
14.7 Combinationofwaveforms 196 18.10 Digitaltoanalogue(D/A)conversion 264
14.8 Rectification 199 18.11 Analoguetodigital(A/D)conversion 264
14.9 Smoothingoftherectifiedoutputwaveform 200
RevisionTest5 266
RevisionTest4 202
19 Three-phasesystems 267
15 Single-phaseseriesa.c.circuits 203 19.1 Introduction 268
15.1 Purelyresistivea.c.circuit 204 19.2 Three-phasesupply 268
15.2 Purelyinductivea.c.circuit 204 19.3 Starconnection 268
15.3 Purelycapacitivea.c.circuit 205 19.4 Deltaconnection 271
15.4 R–L seriesa.c.circuit 206 19.5 Powerinthree-phasesystems 273
15.5 R–C seriesa.c.circuit 209 19.6 Measurementofpowerinthree-phase
15.6 R–L–C seriesa.c.circuit 211 systems 274
15.7 Seriesresonance 214 19.7 Comparisonofstaranddeltaconnections 279
15.8 Q-factor 215 19.8 Advantagesofthree-phasesystems 279
15.9 Bandwidthandselectivity 217
15.10 Powerina.c.circuits 217 20 Transformers 280
15.11 Powertriangleandpowerfactor 219 20.1 Introduction 281
20.2 Transformerprincipleofoperation 281
16 Single-phaseparallela.c.circuits 221
20.3 Transformerno-loadphasordiagram 283
16.1 Introduction 222
20.4 E.m.f.equationofatransformer 285
16.2 R–L parallela.c.circuit 222
20.5 Transformeron-loadphasordiagram 287
16.3 R–C parallela.c.circuit 223
20.6 Transformerconstruction 288
16.4 L–C parallela.c.circuit 224
20.7 Equivalentcircuitofatransformer 288
16.5 LR–C parallela.c.circuit 226
20.8 Regulationofatransformer 290
16.6 ParallelresonanceandQ-factor 229
20.9 Transformerlossesandefficiency 291
16.7 Powerfactorimprovement 233
20.10 Resistancematching 293
17 D.c.transients 238 20.11 Autotransformers 296
17.1 Introduction 239 20.12 Isolatingtransformers 298
17.2 Chargingacapacitor 239 20.13 Three-phasetransformers 298
17.3 TimeconstantforaC–Rcircuit 240 20.14 Currenttransformers 299
17.4 TransientcurvesforaC–Rcircuit 240 20.15 Voltagetransformers 300
17.5 Dischargingacapacitor 244
17.6 Cameraflash 246 RevisionTest6 301
17.7 CurrentgrowthinanL–Rcircuit 246
17.8 TimeconstantforanL–Rcircuit 247
17.9 TransientcurvesforanL–Rcircuit 247 21 D.c.machines 302
21.1 Introduction 303
17.10 CurrentdecayinanL–Rcircuit 249
21.2 Theactionofacommutator 303
17.11 Switchinginductivecircuits 251
21.3 D.c.machineconstruction 304
17.12 Theeffectoftimeconstantona
rectangularwaveform 251 21.4 Shunt,seriesandcompoundwindings 304
21.5 E.m.f.generatedinanarmaturewinding 305
18 Operationalamplifiers 253 21.6 D.c.generators 306
18.1 Introductiontooperationalamplifiers 254 21.7 Typesofd.c.generatorandtheir
18.2 Someopampparameters 255 characteristics 307
viii Contents
21.8 D.c.machinelosses 311 23.6 DeMoivre’stheorem–powersandroots
21.9 Efficiencyofad.c.generator 311 ofcomplexnumbers 352
21.10 D.c.motors 312
21.11 Torqueofad.c.machine 313 24 Applicationofcomplexnumberstoseries
a.c.circuits 354
21.12 Typesofd.c.motorandtheir
24.1 Introduction 354
characteristics 314
24.2 Seriesa.c.circuits 355
21.13 Theefficiencyofad.c.motor 318
24.3 Furtherworkedproblemsonseries
21.14 D.c.motorstarter 320
a.c.circuits 361
21.15 Speedcontrolofd.c.motors 321
21.16 Motorcooling 323
25 Applicationofcomplexnumberstoparallel
22 Three-phaseinductionmotors 324 a.c.networks 366
22.1 Introduction 325 25.1 Introduction 366
22.2 Productionofarotatingmagneticfield 325 25.2 Admittance,conductanceandsusceptance 367
22.3 Synchronousspeed 327 25.3 Parallela.c.networks 370
22.4 Constructionofathree-phaseinduction 25.4 Furtherworkedproblemsonparallel
motor 328 a.c.networks 374
22.5 Principleofoperationofathree-phase
26 Powerina.c.circuits 377
inductionmotor 328
26.1 Introduction 377
22.6 Slip 329
26.2 Determinationofpowerina.c.circuits 378
22.7 Rotore.m.f.andfrequency 330
26.3 Powertriangleandpowerfactor 380
22.8 Rotorimpedanceandcurrent 331
26.4 Useofcomplexnumbersfor
22.9 Rotorcopperloss 331 determinationofpower 381
22.10 Inductionmotorlossesandefficiency 332 26.5 Powerfactorimprovement 385
22.11 Torqueequationforaninductionmotor 333
22.12 Inductionmotortorque–speed RevisionTest8 390
characteristics 335
22.13 Startingmethodsforinductionmotors 336
27 A.c.bridges 391
22.14 Advantagesofsquirrel-cageinduction
27.1 Introduction 391
motors 337
27.2 Balanceconditionsforana.c.bridge 391
22.15 Advantagesofwoundrotorinduction
27.3 Typesofa.c.bridgecircuit 393
motor 338
27.4 Workedproblemsona.c.bridges 397
22.16 Doublecageinductionmotor 338
22.17 Usesofthree-phaseinductionmotors 338 28 SeriesresonanceandQ-factor 401
28.1 Introduction 402
RevisionTest7 339 28.2 Seriesresonance 402
28.3 Q-factor 404
28.4 Voltagemagnification 406
MainformulaeforPart2Electricalprinciples
28.5 Q-factorsinseries 408
andtechnology 340
28.6 Bandwidth 409
28.7 Smalldeviationsfromtheresonant
frequency 413
Part3 Advancedcircuittheory
29 ParallelresonanceandQ-factor 416
andtechnology 343
29.1 Introduction 416
29.2 TheLR–C parallelnetwork 417
23 Revisionofcomplexnumbers 345
29.3 Dynamicresistance 418
23.1 Introduction 345
29.4 TheLR–CRparallelnetwork 418
23.2 OperationsinvolvingCartesiancomplex
29.5 Q-factorinaparallelnetwork 419
numbers 347
29.6 Furtherworkedproblemsonparallel
23.3 Complexequations 349
resonanceandQ-factor 423
23.4 Thepolarformofacomplexnumber 349
23.5 Multiplicationanddivisionusingcomplex
RevisionTest9 426
numbersinpolarform 350
Contents ix
30 Introductiontonetworkanalysis 427 36.10 Resonanceduetoharmonics 536
30.1 Introduction 427 36.11 Sourcesofharmonics 538
30.2 Solutionofsimultaneousequationsusing
determinants 428
37 Anumericalmethodofharmonicanalysis 542
30.3 NetworkanalysisusingKirchhoff’slaws 429
37.1 Introduction 542
31 Mesh-currentandnodalanalysis 437 37.2 Harmonicanalysisondatagivenintabular
31.1 Mesh-currentanalysis 437 orgraphicalform 542
31.2 Nodalanalysis 441 37.3 Complexwaveformconsiderations 546
32 Thesuperpositiontheorem 448
32.1 Introduction 448 38 Magneticmaterials 549
32.2 Usingthesuperpositiontheorem 448 38.1 Revisionoftermsandunitsusedwith
magneticcircuits 550
32.3 Furtherworkedproblemsonthe
superpositiontheorem 453 38.2 Magneticpropertiesofmaterials 550
38.3 Hysteresisandhysteresisloss 552
33 Thévenin’sandNorton’stheorems 458 38.4 Eddycurrentloss 556
33.1 Introduction 458
38.5 Separationofhysteresisandeddycurrent
33.2 Thévenin’stheorem 459 losses 559
33.3 FurtherworkedproblemsonThévenin’s 38.6 Non-permanentmagneticmaterials 561
theorem 465
38.7 Permanentmagneticmaterials 562
33.4 Norton’stheorem 469
33.5 ThéveninandNortonequivalentnetworks 476
RevisionTest12 563
RevisionTest10 481
39 Dielectricsanddielectricloss 564
34 Delta–starandstar–deltatransformations 482 39.1 Electricfields,capacitanceandpermittivity 564
34.1 Introduction 482 39.2 Polarization 565
34.2 Deltaandstarconnections 482 39.3 Dielectricstrength 565
34.3 Delta–startransformation 483 39.4 Thermaleffects 566
34.4 Star–deltatransformation 491 39.5 Mechanicalproperties 567
39.6 Typesofpracticalcapacitor 567
35 Maximumpowertransfertheoremsand
39.7 Liquiddielectricsandgasinsulation 567
impedancematching 495
39.8 Dielectriclossandlossangle 567
35.1 Maximumpowertransfertheorems 496
35.2 Impedancematching 501
40 Fieldtheory 571
40.1 Fieldplottingbycurvilinearsquares 572
RevisionTest11 504
40.2 Capacitancebetweenconcentriccylinders 575
40.3 Capacitanceofanisolatedtwinline 580
36 Complexwaveforms 505
40.4 Energystoredinanelectricfield 583
36.1 Introduction 506
40.5 Inducede.m.f.andinductance 585
36.2 Thegeneralequationforacomplex
40.6 Inductanceofaconcentriccylinder(or
waveform 506
coaxialcable) 585
36.3 Harmonicsynthesis 507
40.7 Inductanceofanisolatedtwinline 588
36.4 Fourierseriesofperiodicandnon-periodic
40.8 Energystoredinanelectromagneticfield 590
functions 514
36.5 EvenandoddfunctionsandFourierseries
overanyrange 519 41 Attenuators 593
36.6 R.m.s.value,meanvalueandtheform 41.1 Introduction 594
factorofacomplexwave 523 41.2 Characteristicimpedance 594
36.7 Powerassociatedwithcomplexwaves 526 41.3 Logarithmicratios 596
36.8 Harmonicsinsingle-phasecircuits 528 41.4 SymmetricalT-andπ-attenuators 598
36.9 Furtherworkedproblemsonharmonics 41.5 Insertionloss 603
insingle-phasecircuits 532 41.6 AsymmetricalT-andπ-sections 606