Tài liệu Lessons In Electric Circuits, Volume I – DC By Tony R. Kuphaldt

Lessons In Electric Circuits, Volume I – DC
By Tony R. Kuphaldt
Fifth Edition, last update October 18, 2006


Contents
1 BASIC CONCEPTS OF ELECTRICITY 1
1.1 Static electricity . 1
1.2 Conductors, insulators, and electron ow . 7
1.3 Electric circuits 12
1.4 Voltage and current . 14
1.5 Resistance . 23
1.6 Voltage and current in a practical circuit . 28
1.7 Conventional versus electron ow . 29
1.8 Contributors 33
2 OHM's LAW 35
2.1 How voltage, current, and resistance relate 35
2.2 An analogy for Ohm's Law 40
2.3 Power in electric circuits . 42
2.4 Calculating electric power 44
2.5 Resistors 46
2.6 Nonlinear conduction 51
2.7 Circuit wiring . 57
2.8 Polarity of voltage drops . 60
2.9 Computer simulation of electric circuits 61
2.10 Contributors 76
3 ELECTRICAL SAFETY 77
3.1 The importance of electrical safety . 77
3.2 Physiological effects of electricity 78
3.3 Shock current path 80
3.4 Ohm's Law (again!) 86
3.5 Safe practices . 93
3.6 Emergency response . 96
3.7 Common sources of hazard . 98
3.8 Safe circuit design 100
3.9 Safe meter usage . 106
3.10 Electric shock data 116
3.11 Contributors 117
Bibliography . 117
4 SCIENTIFIC NOTATION AND METRIC PREFIXES 119
4.1 Scientic notation 119
4.2 Arithmetic with scientic notation . 121
4.3 Metric notation 123
4.4 Metric prex conversions 124
4.5 Hand calculator use . 125
4.6 Scientic notation in SPICE 126
4.7 Contributors 128
5 SERIES AND PARALLEL CIRCUITS 129
5.1 What are ”series” and ”parallel” circuits? . 129
5.2 Simple series circuits . 132
5.3 Simple parallel circuits . 139
5.4 Conductance 144
5.5 Power calculations 146
5.6 Correct use of Ohm's Law 147
5.7 Component failure analysis . 149
5.8 Building simple resistor circuits 155
5.9 Contributors 170
6 DIVIDER CIRCUITS AND KIRCHHOFF'S LAWS 171
6.1 Voltage divider circuits 171
6.2 Kirchhoff's Voltage Law (KVL) . 179
6.3 Current divider circuits . 190
6.4 Kirchhoff's Current Law (KCL) . 193
6.5 Contributors 196
7 SERIES-PARALLEL COMBINATION CIRCUITS 197
7.1 What is a series-parallel circuit? 197
7.2 Analysis technique 200
7.3 Re-drawing complex schematics 208
7.4 Component failure analysis . 216
7.5 Building series-parallel resistor circuits 221
7.6 Contributors 233
8 DC METERING CIRCUITS 235
8.1 What is a meter? . 235
8.2 Voltmeter design . 241
8.3 Voltmeter impact on measured circuit . 246
8.4 Ammeter design . 253
8.5 Ammeter impact on measured circuit . 260
8.6 Ohmmeter design . 264
8.7 High voltage ohmmeters . 269
8.8 Multimeters 277
8.9 Kelvin (4-wire) resistance measurement . 282
8.10 Bridge circuits . 288
8.11 Wattmeter design . 295
8.12 Creating custom calibration resistances 296
8.13 Contributors 299
9 ELECTRICAL INSTRUMENTATION SIGNALS 301
9.1 Analog and digital signals 301
9.2 Voltage signal systems 304
9.3 Current signal systems . 306
9.4 Tachogenerators . 309
9.5 Thermocouples 310
9.6 pH measurement . 315
9.7 Strain gauges . 321
9.8 Contributors 328
10 DC NETWORK ANALYSIS 329
10.1 What is network analysis? 329
10.2 Branch current method . 332
10.3 Mesh current method 341
10.4 Node voltage method 357
10.5 Introduction to network theorems . 361
10.6 Millman's Theorem 361
10.7 Superposition Theorem . 364
10.8 Thevenin's Theorem . 369
10.9 Norton's Theorem . 373
10.10Thevenin-Norton equivalencies . 377
10.11Millman's Theorem revisited 379
10.12Maximum Power Transfer Theorem 381
10.13¢-Y and Y-¢ conversions 383
10.14Contributors 389
Bibliography . 390
11 BATTERIES AND POWER SYSTEMS 391
11.1 Electron activity in chemical reactions 391
11.2 Battery construction . 397
11.3 Battery ratings 400
11.4 Special-purpose batteries 402
11.5 Practical considerations . 406
11.6 Contributors 408
12 PHYSICS OF CONDUCTORS AND INSULATORS 409
12.1 Introduction 409
12.2 Conductor size 411
12.3 Conductor ampacity . 417
12.4 Fuses 419
12.5 Specic resistance 427
12.6 Temperature coefcient of resistance . 431
12.7 Superconductivity 434
12.8 Insulator breakdown voltage 436
12.9 Data 438
12.10Contributors 438
13 CAPACITORS 439
13.1 Electric elds and capacitance . 439
13.2 Capacitors and calculus . 444
13.3 Factors affecting capacitance 449
13.4 Series and parallel capacitors 452
13.5 Practical considerations . 453
13.6 Contributors 459
14 MAGNETISM AND ELECTROMAGNETISM 461
14.1 Permanent magnets . 461
14.2 Electromagnetism 465
14.3 Magnetic units of measurement 467
14.4 Permeability and saturation 470
14.5 Electromagnetic induction 475
14.6 Mutual inductance 477
14.7 Contributors 480
15 INDUCTORS 481
15.1 Magnetic elds and inductance . 481
15.2 Inductors and calculus 485
15.3 Factors affecting inductance . 491
15.4 Series and parallel inductors 497
15.5 Practical considerations . 499
15.6 Contributors 499
16 RC AND L/R TIME CONSTANTS 501
16.1 Electrical transients . 501
16.2 Capacitor transient response 501
16.3 Inductor transient response . 504
16.4 Voltage and current calculations 507
16.5 Why L/R and not LR? 513
16.6 Complex voltage and current calculations . 516
16.7 Complex circuits . 517
16.8 Solving for unknown time 522
16.9 Contributors 524
A-1 ABOUT THIS BOOK 525
A-2 CONTRIBUTOR LIST 529