Direct current fundamentals

Cover......Page 1
Title Page......Page 5
Copyright......Page 6
CONTENTS......Page 7
PREFACE......Page 15
INTRODUCTION: ELECTRICAL OCCUPATIONS......Page 17
1–1 What are electricity and electronics?......Page 23
1–2 Why this book is called Direct Current Fundamentals......Page 24
1–3 Early history of electricity......Page 25
1–5 The atom analyzed—electrons, protons, and neutrons......Page 27
1–6 The atomic theory—cornerstone of electrical theory......Page 30
SUMMARY......Page 32
Achievement Review......Page 33
2–1 Electricity production by energy conversion......Page 34
2–3 Electricity from magnetism......Page 35
2–4 Electricity from chemical energy......Page 36
2–5 Electricity from light......Page 37
2–6 Electricity from heat......Page 38
2–7 Electricity from mechanical pressure: piezoelectricity......Page 40
Mechanical Pressure from Electricity: The Piezoelectric Effect......Page 41
SUMMARY......Page 42
Achievement Review......Page 43
3–1 Stationary electrons......Page 44
3–2 Electroscopes......Page 45
3–3 Electrostatic induction......Page 47
3–5 Nuisance static charges......Page 49
Painting......Page 50
Xerography (Dry Copying)......Page 51
3–7 Potential energy of electrons......Page 53
3–8 Electrostatic lines of force......Page 55
Achievement Review......Page 57
4–1 Four measurable circuit quantities......Page 58
4–2 Voltage......Page 59
4–3 Current......Page 61
Current Speed......Page 62
4–4 Resistance......Page 63
4–6 A simple electric circuit......Page 65
4–9 Basic circuit notation......Page 66
4–10 The short circuit......Page 67
4–11 Electrical safety......Page 68
4–12 National Electrical Code®......Page 69
SUMMARY......Page 70
Achievement Review......Page 71
5–1 Rationale for studying this unit......Page 72
5–2 Powers of 10......Page 73
5–3 Scientific notation......Page 74
5–5 Rounding off to three significant digits......Page 75
5–6 Metric prefixes......Page 76
5–7 Multiplication and division with powers of 10......Page 77
SUMMARY......Page 78
Achievement Review......Page 79
6–1 Types of meters......Page 86
6–2 Ammeter and voltmeter scale interpretation......Page 90
6–3 Ohmmeter scale interpretation......Page 93
6–4 Electrical meter connection......Page 94
Achievement Review......Page 95
CHAPTER 7 Resistance......Page 103
7–2 Resistivity of materials......Page 104
7–3 Length of a conductor......Page 105
7–4 Cross-sectional area (CSA) of a conductor in circular mils......Page 106
7–5 Effect of temperature on resistance......Page 110
Using the Temperature Coefficient to Find Resistance at Higher Temperature......Page 111
7–6 The American Wire Gauge (AWG)......Page 112
Concentric Stranding......Page 115
7–8 Resistors......Page 116
Carbon Resistors......Page 118
Metal Film Resistors......Page 119
Wire Wound Resistors......Page 120
7–10 Color code......Page 122
Standard Resistance Values......Page 124
7–11 Power ratings......Page 126
7–12 Variable resistors......Page 127
7–13 Schematic symbols......Page 128
SUMMARY......Page 129
Achievement Review......Page 130
8–1 Voltage, current, and resistance......Page 133
8–2 Ohm’s law with metric prefixes......Page 135
SUMMARY......Page 136
Achievement Review......Page 137
9–1 Energy......Page 138
Potential Energy......Page 139
Kinetic Energy......Page 140
9–3 Power......Page 141
The Horsepower......Page 142
Watt—The Unit of Electrical Power......Page 143
A Second Equation for Power......Page 145
A Third Equation for Power......Page 146
9–4 Energy and cost calculations......Page 148
9–5 Efficiency of energy conversion......Page 150
9–6 A practical application—resistance heating......Page 152
SUMMARY......Page 153
Achievement Review......Page 154
10–1 Characteristics of series circuits......Page 156
10–2 The voltage drop......Page 157
10–3 Resistance and current in series circuits......Page 158
10–4 Power consumption in series circuits......Page 159
10–5 Calculation of series circuit quantities......Page 161
10–6 Voltage drop on a line......Page 167
10–8 Series circuits as voltage dividers......Page 170
10–9 The general voltage divider formula......Page 172
10–10 Polarity considerations......Page 173
10–11 Ground as a reference point......Page 174
10–12 Voltage sources in series......Page 176
Achievement Review......Page 177
11–1 The nature of parallel circuits......Page 184
(1) Use of Ohm’s law for computing Rτ......Page 186
(2) Use of the reciprocal equation......Page 187
(3) A practical method......Page 188
(4) The product over the sum formula......Page 189
(5) A special condition: all equal resistors......Page 190
11–3 Power dissipation in parallel circuits......Page 192
Dual Voltage and the Three-Wire Supply......Page 195
The Range Top Heating Element......Page 196
11–6 Current dividers......Page 198
SUMMARY......Page 199
Achievement Review......Page 200
12–1 Simplifying series-parallel circuits......Page 205
12–2 Kirchhoff’s voltage law......Page 212
12–3 Kirchhoff’s current law......Page 213
12–4 Loaded voltage dividers......Page 215
Achievement Review......Page 220
13–1 The ionization process......Page 228
13–2 Useful chemical compounds......Page 231
13–3 Electroplating and electrolysis......Page 232
Electrolysis of Sulfuric Acid in Water......Page 234
Sparks and Arcs......Page 235
How Ionization Occurs......Page 236
Why Low-Pressure Gas Conducts Better Than High-Pressure Compressed Gas......Page 238
13–7 Conduction in a vacuum......Page 239
SUMMARY......Page 242
Achievement Review......Page 243
14–1 Chemical energy: a source of emf......Page 244
The Carbon-Zinc Cell (Leclanché Cell)......Page 247
14–2 Anodes and cathodes......Page 248
14–3 Primary cells......Page 249
14–4 Fuel cells......Page 251
The Polymer Electrolyte Membrane (PEM) Fuel Cell......Page 252
The Lead Storage Battery......Page 253
Battery Charging......Page 256
Battery Care......Page 258
Nickel-Cadmium and Nickel-Iron (Edison) Storage Batteries......Page 259
Lithium-Ion Cells......Page 262
Internal Resistance (R1) of Cells......Page 263
Cells Connected in Parallel......Page 265
Cells Connected Series-Parallel......Page 266
SUMMARY......Page 267
Achievement Review......Page 268
15–1 Electricity and magnetism......Page 271
15–2 Simple magnets......Page 272
15–3 The magnetic field......Page 273
15–4 Ferromagnetic materials and the magnetizing process......Page 274
15–5 Magnetic materials and the atomic theory......Page 275
15–6 Permanent magnets......Page 276
15–7 Electromagnetism of a straight wire......Page 277
15–8 Electromagnetism of a coil......Page 280
15–9 The magnetic core in the coil......Page 281
Flux Density......Page 284
Permeability (μ)......Page 285
Ohm’s Law for Magnetic Circuits......Page 286
Core Design......Page 287
Demagnetizers......Page 288
Residual Magnetism......Page 289
SUMMARY......Page 290
Achievement Review......Page 291
16–1 Solenoids for lateral motion......Page 292
16–2 The electromagnetic relay......Page 293
16–3 Magnetic vibrators and bell......Page 294
16–4 Electromagnetism for rotational motion......Page 295
16–5 Other applications of the motor effect......Page 296
16–6 Electromagnetism at work......Page 299
Achievement Review......Page 301
CHAPTER 17 Electrical Measuring Instruments (Another Application of Electromagnetism)......Page 304
17–1 d’Arsonval meters......Page 305
17–2 DC ammeters......Page 308
17–3 Multirange ammeters......Page 310
17–4 Voltmeters......Page 311
Sensitivity of Voltmeters......Page 312
17–5 Ohmmeters......Page 313
17–6 Megohmmeters......Page 315
17–7 Wattmeters......Page 316
17–8 Bridge circuits......Page 318
17–9 Clamp-on meters......Page 319
17–10 Digital multimeters......Page 321
Digital Ohmmeters......Page 323
Low-Impedance Voltage Tester......Page 325
SUMMARY......Page 327
Achievement Review......Page 328
18–1 Moving coils–stationary fields......Page 331
18–2 Moving fields–stationary coils......Page 333
18–3 Fleming’s left-hand rule for generators......Page 335
18–4 Lenz’s law......Page 336
18–5 Induction in rotating machines......Page 338
SUMMARY......Page 340
Achievement Review......Page 341
CHAPTER 19 DC Generators......Page 344
19–1 Principles of DC generators......Page 345
19–2 Armature design......Page 350
Lap Windings Analyzed......Page 352
19–3 Generator field structures......Page 355
Field Connections for Self-Excited Generators......Page 357
19–4 Armature reaction......Page 359
Remedies......Page 360
19–5 Buildup of self-excited fields......Page 362
Failure to Develop Voltage......Page 363
The Series Generator......Page 364
The Shunt Generator......Page 365
The Compound Generator......Page 367
19–8 Generator calculations......Page 369
Generator emf......Page 370
19–9 Power losses......Page 372
19–11 Magnetohydrodynamic (MHD) generation......Page 375
Achievement Review......Page 377
20–1 Basic motor action......Page 380
20–2 Torque and rotary motion......Page 382
20–3 The need for commutation......Page 385
20–4 The need for added armature coils......Page 386
20–5 From torque to horsepower......Page 389
SUMMARY......Page 391
Achievement Review......Page 392
21–1 DC machines—motor or generator?......Page 394
21–2 The counter-emf in a motor......Page 396
The Lap Winding......Page 398
The Wave Winding......Page 400
21–4 Field distortion and the need for interpoles......Page 402
21–5 The shunt motor......Page 404
Speed Regulation......Page 405
21–6 The series motor......Page 406
21–7 The compound motor......Page 408
21–8 Speed control of DC motors......Page 410
Electronic Speed Control......Page 411
21–9 Reversal of rotation......Page 412
Determining the Direction of Rotation of a DC Motor......Page 414
21–10 Power losses......Page 415
21–11 Permanent-magnet motors......Page 417
Brush-Type PM Motors......Page 418
Brushless PM Motors......Page 419
SUMMARY......Page 422
Achievement Review......Page 423
CHAPTER 22 Starters and Speed Controllers......Page 426
Three-Terminal Starting Rheostat......Page 427
Four-Terminal Starting Rheostat......Page 429
Above-Normal Speed Controller......Page 430
Above-and-Below-Normal Speed Controller......Page 432
22–5 Starters for series motors......Page 434
22–6 Drum controllers......Page 435
22–7 Magnetic controllers......Page 438
22–8 The counter-electromotive force motor controller......Page 443
Dynamic Braking......Page 444
Counter-emf Controller with Reversing and Dynamic Braking......Page 446
22–9 The voltage drop acceleration controller (lockout acceleration)......Page 448
22–10 Definite time controller......Page 450
22–11 Electronic controllers......Page 452
SUMMARY......Page 453
Achievement Review......Page 454
CHAPTER 23 Solid-State Control of DC Motors......Page 461
23–1 The shunt field power supply......Page 462
23–2 Armature control......Page 465
23–4 Speed control......Page 466
Achievement Review......Page 468
24–1 The loop current method......Page 470
24–2 The superposition theorem......Page 474
24–3 Thevenin’s theorem......Page 480
Current Sources......Page 485
SUMMARY......Page 488
Achievement Review......Page 490
APPENDIX......Page 493
GLOSSARY......Page 513
SELECTED ANSWERS TO ODD-NUMBERED PROBLEMS......Page 521
INDEX......Page 529