Electronic and Electrical Engineering Principles and Practice Third edition Lionel Warnes ©L.A.A.Warnes1994,1998,2003 Allrightsreserved.Noreproduction,copyortransmissionof thispublicationmaybemadewithoutwrittenpermission. Noparagraphofthispublicationmaybereproduced,copiedor transmittedsavewithwrittenpermissionorinaccordancewith theprovisionsoftheCopyright,DesignsandPatentsAct1988, orunderthetermsofanylicencepermittinglimitedcopying issuedbytheCopyrightLicensingAgency,90TottenhamCourt Road,LondonW1T4LP. Anypersonwhodoesanyunauthorisedactinrelationtothis publicationmaybeliabletocriminalprosecutionandcivil claimsfordamages. Theauthorhasassertedhisrighttobeidentified astheauthorofthisworkinaccordancewiththe Copyright,DesignsandPatentsAct1988. Firstedition1994 Secondedition1998 Thirdedition2003 Publishedby PALGRAVEMACMILLAN Houndmills,Basingstoke,HampshireRG216XSand 175FifthAvenue,NewYork,N.Y.10010 Companiesandrepresentativesthroughouttheworld PALGRAVEMACMILLANistheglobalacademicimprintofthePalgrave MacmillandivisionofSt.Martin’sPress,LLCandofPalgraveMacmillanLtd. Macmillan®isaregisteredtrademarkintheUnitedStates,UnitedKingdom andothercountries.PalgraveisaregisteredtrademarkintheEuropean Unionandothercountries. ISBN 978-0-333-99040-7 ISBN 978-0-230-21633-4 (eBook) DOI 10.1007/978-0-230-21633-4 Thisbookisprintedonpapersuitableforrecyclingandmadefromfully managedandsustainedforestsources. AcataloguerecordforthisbookisavailablefromtheBritishLibrary. 10 9 8 7 6 5 4 3 2 1 12 11 10 09 08 07 06 05 04 03 Dedicated to Alexis Warnes Contents Physical constants ix 6 Semiconductors 129 6.1 Electrons and holes in Unit prefixes ix semiconductors 129 6.2 Electrical conductivity 130 6.3 The p-n junction 133 Units x 6.4 A glossary of terms 134 Problems 136 1 Circuit analysis 1 1.1 Sources 1 7 Diodes 137 1.2 Passive circuit elements 3 7.1 Junction diodes 137 1.3 Practical circuit elements 8 7.2 Schottky diodes 143 1.4 Circuit analysis and Kirchhoff’s laws 13 7.3 Zener diodes 145 1.5 Circuit theorems and transformations 18 7.4 Light-emitting diodes (LEDs) 147 1.6 Power and energy 27 7.5 Solar cells 149 1.7 Mesh analysis and nodal analysis 30 7.6 Applications for ordinary p-n Problems 35 junction diodes 151 Problems 157 2 Sinusoidally-excited circuits 39 2.1 Sinusoidal excitation 39 8 Bipolar junction transistors 161 2.2 Phasors 47 8.1 Theory of operation 161 2.3 Circuit analysis with AC 50 8.2 The common-emitter amplifier 163 2.4 Power in AC circuits 58 8.3 The emitter follower, or common- 2.5 Resonant circuits 62 collector amplifier 174 Problems 67 8.4 BJT switches 176 8.5 BJT specifications 177 3 Operational amplifiers 71 Problems 178 3.1 The golden rules 71 3.2 Some common op amp circuits 72 9 Field-effect transistors 181 3.3 Analogue computing 75 9.1 The junction field-effect transistor 3.4 Practical op amps 76 (JFET) 182 3.5 Comparators 80 9.2 The practical common-source 3.6 Schmitt triggers 81 amplifier 184 Problems 82 9.3 MOSFETs 187 9.4 Specifications of some popular 4 Transients 85 FETs 189 4.1 Transients in RC and RL circuits 85 Problems 190 4.2 Transient analysis by the Laplace transformation 91 10 Integrated circuits 193 4.3 Transients in RLC circuits 104 10.1 Integrated circuit fabrication 194 Problems 109 10.2 Hybrid circuits 198 Problems 199 5 Bode diagrams and 2-port networks 111 11 Analogue circuits 201 5.1 The steady-state frequency 11.1 Filters 201 response of circuits 111 11.2 Oscillators 211 5.2 Two-port networks 119 11.3 Phase-locked loops 216 Problems 126 11.4 Waveform-generator ICs 219 v vi Contents 11.5 Voltage regulators 220 17.3 Slip 320 11.6 Analogue-to-digital (A/D) and 17.4 The equivalent circuit of an digital-to-analogue (D/A) converters 221 induction machine 322 Problems 224 17.5 Torque and slip in an induction machine 323 12 Power amplifiers, power 17.6 Evaluating the components of the supplies and batteries 227 equivalent circuit 324 17.7 Power and efficiency 327 12.1 Class-A amplifiers 227 17.8 Practical induction machines 330 12.2 Class-B amplifiers 231 17.9 Domestic-supply induction motors 333 12.3 Class-C amplifiers 233 Problems 335 12.4 Class-D amplifiers 235 12.5 Power supplies 236 12.6 Switch-mode power supplies 238 18 Synchronous machines 337 12.7 Batteries 241 18.1 Synchronous generators 337 12.8 Cooling 245 18.2 Synchronous torque 338 Problems 248 18.3 The equivalent circuit of a synchronous generator 338 13 Magnetism and 18.4 Per-unit values and the short- circuit ratio 339 electromagnetism 249 18.5 The generator under load 340 13.1 Magnetic units and quantities 249 18.6 The generator on an infinite bus 341 13.2 The magnetic circuit 251 18.7 The construction of synchronous 13.3 Faraday’s law of electromagnetic machines 343 induction 253 18.8 Synchronous motors 345 13.4 Hysteresis 256 Problems 349 13.5 Eddy currents 258 13.6 Inductors 259 19 Power electronics 350 Problems 259 19.1 The three-phase bridge rectifier 350 19.2 Power semiconductor devices 352 14 DC machines 261 19.3 Power-control circuits using 14.1 A prototype generator 261 thyristors 358 14.2 DC generators 264 19.4 Motor control with power 14.3 DC motors 273 electronics 362 14.4 Efficiency and losses 282 Problems 368 Problems 285 20 Combinational logic 369 15 Three-phase systems 287 20.1 Binary and hexadecimal numbers 369 15.1 The generation of three-phase 20.2 Logic functions and Boolean electricity 287 algebra 372 15.2 Balanced loads 290 20.3 Logic ICs 376 15.3 Unbalanced loads 293 20.4 De Morgan’s theorems 377 15.4 Power measurement in three- 20.5 Minterms and maxterms 379 phase circuits 295 20.6 Karnaugh mapping and circuit Problems 297 minimisation 381 20.7 Practical examples 385 16 Transformers 298 20.8 Logic families 390 16.1 The ideal transformer 298 20.9 Practical aspects of logic 16.2 Transformer testing 302 integrated circuits 393 16.3 Practical transformers 308 20.10 Multiplexers and demultiplexers 397 16.4 Transformer design 310 20.11 Programmable logic arrays 399 16.5 Special types of transformer 312 Problems 400 Problems 315 21 Sequential logic 403 17 Induction motors 317 21.1 Unclocked flip-flops 403 17.1 Construction of a squirrel-cage 21.2 Clocked flip-flops 405 motor 318 21.3 Counters and shift registers 407 17.2 The rotation of the stator field 318 21.4 The monostable multivibrator 414 Contents vii 21.5 Timers 415 26 Fibre-optic communications 519 Problems 417 26.1 Pros and cons of fibre-optics 519 26.2 The transmitter 520 22 Computers 419 26.3 The channel: optical fibres 522 26.4 Optoelectronic signal detectors 529 22.1 Computer architecture 421 26.5 The ultimate performance of 22.2 The CPU 421 optical receivers 532 22.3 Memory 424 Problems 533 22.4 Input and output devices 428 22.5 Computer networks 436 22.6 Programming languages 439 27 Telephony 535 27.1 Signalling 536 23 Microprocessors and micro- 27.2 Transmission systems 537 27.3 Multiplexing 539 controllers 443 27.4 Companding 540 23.1 The 8051 microcontrollers 445 27.5 Telephone exchanges 541 23.2 The 8051 clock and the machine 27.6 Telephone-traffic theory 542 cycle time 448 27.7 SPC exchanges 545 23.3 The special-function registers 27.8 The integrated-services digital (SFRs) 449 network (ISDN) 547 23.4 Moving data 456 27.9 Mobile telephony 548 23.5 Logical operations 460 Problems 550 23.6 Arithmetic operations 463 23.7 Jumps 467 28 Electromagnetic compatibility 551 23.8 Calls and subroutines 470 23.9 Look-up tables 471 28.1 Sources of electromagnetic 23.10 Interfacing 472 interference 552 28.2 Conductor shielding 553 28.3 Grounding 557 24 Analogue communications 478 28.4 Shielding with sheet conductors 559 24.1 The elements of a communications 28.5 EMI filtering 563 system 478 28.6 Legal requirements for EMC 5 66 24.2 The electromagnetic spectrum 479 Problems 567 24.3 Amplitude modulation 480 24.4 Frequency modulation 484 24.5 AM and FM compared 490 29 Measurements and 24.6 Pulse modulation 491 instruments 569 24.7 Noise 492 29.1 Accuracy 569 Problems 503 29.2 Standards and transducers for measurements 572 25 Digital communications 505 29.3 Instruments 574 25.1 Binary modulation 505 Problems 585 25.2 Pulse-code modulation 511 25.3 The theoretical maximum channel Index 587 capacity 516 Problems 517 Physical constants The speed of light in a vacuum, c 3 × 108 m/s The permeability of free space or the magnetic constant, (cid:29) 4(cid:37) × 10(cid:4)7 H/m 0 The permittivity of free space or the electric constant, (cid:15) 8.85 × 10(cid:4)12 F/m 0 Planck's constant, h 6.626 × 10(cid:4)34 J.s Boltzmann's constant, k 1.38 × 10(cid:4)23 J/K The magnitude of the electronic charge, q 1.6 × 10(cid:4)19 C The ice point 273.2 K Notes: c = 1/(cid:82)((cid:29) (cid:15) ). Impedance of free space, Z = (cid:82)((cid:29) /(cid:15) ) = 377 (cid:54). The above, where 0 0 0 0 0 approximated, are accurate to ±0.14%. Unit prefixes a atto 10(cid:4)18 f femto 10(cid:4)15 p pico 10(cid:4)12 n nano 10(cid:4)9 (cid:29) micro 10(cid:4)6 m milli 10(cid:4)3 k kilo 103 M mega 106 G giga 109 T tera 1012 P peta 1015 E exa 1018 Notes: Order is important, so that 1 ms.V = 1 millisecond-volt while 1 V.m.s = 1 volt-metre- second; for clarity a dot may be used to separate the different units. Lower and upper case styles for units and prefixes must be carefully followed: 1 K.gm = 1 Kelvin-gram- metre, while 1 kg.m = 1 kilogram-metre and 1 kg = 1 kilogram; 1 mS = 1 millisiemens, 1 ms = 1 millisecond. Note also that 1 mm2 = 1 square mm = 10(cid:4)6 m2 . Submultiples in denominators should be removed to the numerator, so that 1 pF/mm2 becomes 1 (cid:29)F/m2. ix Units Base units quantity unit symbol dimension Mass kilogram kg M Length metre m L Time second s T Currentampere A I Derived units quantity unit symbol dimensions frequency hertz Hz T(cid:4)1 speed metre/second m/s LT(cid:4)1 acceleration metre/sec/sec m/s2 LT(cid:4)2 force newton N MLT(cid:4)2 work, energy joule J ML2T(cid:4)2 power watt W ML2T(cid:4)3 charge coulomb C TI potential volt V ML2T(cid:4)3I(cid:4)1 resistance ohm (cid:54) ML2T(cid:4)3I(cid:4)2 conductance siemens S M(cid:4)1L(cid:4)2T3I2 capacitance farad F M(cid:4)1L(cid:4)2T4I2 inductance henry H ML2T(cid:4)2I(cid:4)2 magnetic field ampere/metre A/m L(cid:4)1I flux density tesla T MT(cid:4)2I(cid:4)1 magnetic flux weber Wb ML2T(cid:4)2I(cid:4)1 x 1 Circuit analysis BEFORE any use can be made of electricity or of any electrical machine or device, it must form part of an electrical circuit. Even complex machines may be modelled by simple elements that, when assembled into a circuit in the right way, can be analysed and so predict the machine’s behaviour. Accordingly, circuits are the foundation of any study of electrical or electronic engineering. We begin by defining simple circuit elements, then we shall incorporate them into circuits for analysis with the help of a number of laws and theorems. There are not many laws to remember (cid:4) Ohm’s law and Kirchhoff’s laws are almost the only ones (cid:4) but from these a number of theorems have been deduced to assist in circuit analysis. In this chapter we shall primarily be concerned with direct currents and voltages (DC for short), but the principles developed will serve for analysing circuit behaviour with alternating currents and voltages (or AC). The five circuit elements considered initially are voltage and current sources and three passive elements: resistance, inductance and capacitance. Though simple these can be combined to form powerful equivalent circuits. 1.1 Sources No electricity can flow continuously in a circuit lacking a source, because sources are essential for supplying power. Practical sources include batteries, radio antennas and electromechanical generators, all of which can be modelled by ideal sources in combination with other circuit elements. Two sources are defined: the voltage source and the current source, the symbols for which are shown in Figure 1.1; the small circles, A and B, represent terminals. Figure 1.1 Ideal sources. (a) An ideal voltage source and (b) An ideal current source. Both send positive current in the direction of the arrow Polarity signs are usually omitted and the strength of the source is written next to the arrow. An ideal voltage source always maintains the voltages across its terminals at the value indicated. An ideal current source always drives the stated current out of the positive terminal (A) and it returns to the source at the negative terminal (B). A car battery makes a good approximation to an ideal voltage source. Constant-current sources (cid:4) within limits (cid:4) can be 1