Contents Figures Tables Preface xi vii xiii Acknowledgments About the Author xv xvii Chapter 1. Basic Mathematics 1 Addition 1 Subtraction 2 Multiplication 2 Division 3 Exponents 3 Equations 5 Subscripts 7 Binary Numbers 8 Octal Numbers 8 Hexadecimal Numbers 9 Binary Coded Decimal Code 9 American Standard Code for Information Interchange 9 Gray Code 10 Review Questions 10 Chapter 2. The Nature of Electricity 11 Atoms 11 Voltage 12 Current 13 Resistance 13 Introduction to Ohm s Law 14 Introduction to Power Law 14 Review Questions 14 Chapter 3. Galvanic Cells and Batteries 15 Galvanic Cells 15 Batteries 15 Review Questions 18 Chapter 4. Ohm s and Power Laws 19 Circuits 19 Ohm s Law 19 Power Law 19 Ohm s Law Examples 20 Simple Circuits 21 Series Circuits 22 iii
Parallel Circuits 23 Malfunctioning Circuits 24 Switches in Circuits 25 Review Questions 26 Chapter 5. Conductors and Insulators 27 Characteristics of Materials 27 Current-Carrying Capacity of Conductors 28 Relationship Equation 30 Review Questions 32 Chapter 6. Properties and Characteristics of Magnetism 33 Magnets and Magnetism 33 History 33 Earth as a Giant Magnet 33 Magnetic Properties 34 Nature of Magnetism 34 Types of Magnets 36 Current and Magnetic Fields 38 Coils 40 Magnetic Circuits 41 Review Questions 45 Chapter 7. Induction Principles and AC Generators 47 Alternating Current 47 Direct Current 47 Electric and Magnetic Fields 47 Electromagnetic Induction 48 Alternating Current Properties 53 Review Questions 55 Chapter 8. Electrical Components, Impedance, and Power 57 Resistors 57 Potentiometers 63 Inductors and Inductance 66 Capacitors and Capacitance 68 Impedance 77 Power 78 Review Questions 80 Chapter 9. Electromagnetic Equipment 81 Transformers 81 Filter Choke Coils 89 Induction Motors 89 Power Factor 96 Solenoids 100 Electromechanical Relays 101 Review Questions 101 Chapter 10. Semiconductors and Applications 103 Basic Semiconductor Theory 103 Semiconductor Diodes 106 Bipolar Transistors 110 iv
Field-Effect Transistors 117 MOSFETs 119 Solid-State Designations 119 Integrated Circuits 119 Review Questions 126 Chapter 11. Digital Logic 129 Binary Numbers 129 Digital Logic 132 Solid-State Logic Gates 137 Sequential Logic and Memory Devices 140 Flip-Flop Circuits 141 Logic Counter Circuits 147 Encoders and Decoders 150 Storage of Binary Information 152 Review Questions 152 Chapter 12. Electrical Test Instruments 153 d Arsonval Movements 153 Multimeters 159 Oscilloscopes 161 Additional Test and Measuring Instruments 170 Test Instrument Overview 171 Review Questions 171 Chapter 13. Troubleshooting Techniques and Safety 173 Recordkeeping 173 Familiarity with Equipment 174 Operation and Maintenance Manuals 174 Test Instruments 175 Troubleshooting Steps 177 Circuit Testing 180 Troubleshooting Intermittent Malfunctions 181 Field Troubleshooting 181 Remote Terminal Units 181 Field Troubleshooting Instruments 182 Shop Troubleshooting 182 Electrical Safety 183 Safety Summary 189 Review Questions 189 Glossary 191 v
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Figures 1. Beam balance balanced by two 2-pound weights. 5 2. A copper atom has 29 electrons. 12 3. Battery with a conductor connects to + and terminals. Note direction of electron flow and hole flow. 13 4. Circuit diagram showing current flowing from + to terminal of battery. 13 5. Four batteries connected in series. Note that current flows in only one path. 16 6. Three batteries connected in parallel. Note that current flows through two paths, one on the battery s positive side, and the other on the negative side. 17 7. Ohm s law wheel 19 8. Power law wheel 20 9. A simple circuit with a battery, lamp, and copper wire 21 10. A series circuit 22 11. Parallel circuits 23 12. Short circuit 25 13. Open circuit 25 14. Simple switch 25 15. Switch in a simple circuit 25 16. Switch in a series circuit 25 17. Switches in a parallel circuit 26 18. Four types of switches 26 19. Examples of insulated wires 27 20. Earth s poles and magnetic lines of force 33 21. Magnetic lines of force 34 22. A. Magnetic molecules arranged in a random manner. B. Magnetic molecules arranged in an organized manner 34 23. A piece of soft iron placed near a magnet 35 24. The position of a compass needle in relation to north and south poles of magnets 36 25. Reaction between two magnets 36 26. Various shapes of magnets 37 27. Proper storage of magnets 38 28. A and B. Effect of current flow on a compass 38 29. A. Two parallel conductors carrying current that flows in the same direction. B. Parallel conductors with current flowing in opposite directions. 39 30. Two conductors at right angles to each other; current flow in each conductor tries to move the conductors into a parallel position. 39 31. Current flow in a loop; note north and south poles 40 32. Magnetic field around a loosely-wound coil 40 33. Magnetic field around a tightly-wound coil 40 34. Right-hand rule for coils 41 35. Series circuits; magnetic circuit (top) with Rowland s law and electrical circuit (bottom) with Ohm s law 42 36. Magnetizing force vs flux density for three materials 43 37. Magnetic parallel circuit and equivalent parallel electric circuit 44 38. Electromagnet 44 39. A-D. Electric fields and charges 48 vii
40. Inducing voltage by moving the conductor 49 41. Inducing voltage by moving the magnet 50 42. Inducing voltage in a rotating coil 51 43. Coil connected to a generator 51 44. Voltage waveforms produced by a rotating coil 52 45. Three-phase voltage 54 46. Two types of resistors and the symbol for a resistor 57 47. Resistor color code 58 48. Relative resistor sizes in various power ratings 62 49. Series and parallel resistors 63 50. AC voltage and current relationship in resistive circuits 63 51. Types of potentiometers 64 52. Schematic symbols of a potentiometer and a rheostat 64 53. Multiple-stacked potentiometers 65 54. Inducing voltages in inductive circuits 66 55. The retarding effect of inductance in a circuit 67 56. Waveforms of current values and voltage values in an inductive AC circuit 67 57. Coil-wrapped capacitor 68 58. Rectangular capacitor plates 68 59. Variable capacitor 68 60. Charging and discharging a capacitor 69 61. Relative size and voltage ratings of capacitors 72 62. Two types of electrolytic capacitors 72 63. Color code chart for capacitors 75 64. Time delay using capacitors 75 65. Graph of current values and voltage values in a capacitive alternating current circuit 76 66. Single-phase AC induction motor 77 67. Vector diagram of an R, H, and C circuit to determine impedance 77 68. Combining R, H, C vectors into impedance 78 69. Vector representation of Watts and VAR 79 70. Use of transformers in a distribution system 81 71. Induction of current in a secondary circuit 82 72. An iron ring provides a path for magnetic lines. 83 73. Using coils to intensify the magnetic field 83 74. Laminated transformer core 83 75. Core with coils in place 83 76. Examples of transformer windings 84 77. Variable voltage transformers 85 78. Current and voltage relationship 85 79. Identification of transformer terminals (electrical) 87 80. Identification of transformer terminals (electronic) 87 81. Power transformer 88 82. A filter choke, two types of transformers, and a schematic diagram for the audio output transformer 89 83. AC squirrel-cage induction motor 90 84. Squirrel-cage rotor 90 85. A squirrel-cage induction motor s stator 91 86. Stator core of an induction motor 91 87. Partially-wound stator for a squirrel-cage motor 91 88. A typical squirrel-cage rotor, or armature 92 89. Revolving magnetic fields in the stator of a three-phase induction motor 93 90. Three-phase currents in the armature of an induction motor 93 viii
91. Speed-torque specifications for NEMA designs A, B, C, and D 6-pole motors 96 92. Connections for determining the power factor of an induction motor circuit 97 93. Power triangle for the circuit in figure 92 98 94. Power factor improvement with an increased load on the motor shown in figure 92 100 95. Solenoid valve 101 96. Single-pole, single-throw (SPST) relay 101 97. Double-pole, double-throw (DPDT) relay 101 98. Lattice structure of semiconductor crystals 103 99. Lattice structure of n-type material 104 100. Lattice structure of p-type material 104 101. Movement of free holes through semiconductor crystal 105 102. Electron flow in n-type crystal 105 103. Hole flow in p-type crystal 106 104. Interaction of free electrons and holes at a p-n junction 106 105. Effect of reverse bias on a p-n junction 107 106. Forward bias of a p-n junction 107 107. Symbols for diodes 107 108. Forward-reverse characteristics of a diode 108 109. Check valve analogy of a diode 108 110. Power rectifier 109 111. Zener diode characteristic 110 112. Npn transistor 111 113. Pnp transistor 111 114. Npn transistor biasing 112 115. Pnp transistor biasing 113 116. IGBT power transistor 115 117. SCR construction and terminals 116 118. Power SCRs 116 119. SCR Characteristics p-n junction field-effect transistor 116 120. P-n junction field-effect transistor 117 121. Source-drain current characteristics as a function of gate bias 118 122. MOSFET construction 119 123. Operational amplifier circuit diagram 121 124. Symbol for an op amp 121 125. Op amp with feedback resistor 121 126. Op amp differentiating circuit 122 127. Op amp as an integrating amplifier 122 128. Half-wave transformer-rectifier 122 129. Transformer center-tap full wave rectifier 123 130. Full-wave rectifier with LC filter 123 131. Full-wave rectifier with RLC filter 124 132. Rectifier bridge full-wave rectifier 124 133. Zener regulated circuit 125 134. DC regulators 125 135. Sophisticated adjustable voltage regulator 126 136. Three-phase half-wave rectifier 127 137. Printed wiring board voltage regulator 127 138. Logic-relay logic symbols 136 139. Diode AND circuit 137 140. Diode OR circuit 138 141. Transistor AND circuit 138 142. Transistor OR circuit 139 ix
143. Transistor NOT circuit 139 144. Transistor NOR circuit 140 145. Exclusive OR circuit 140 146. An npn transistor flip-flop circuit 141 147. Flip-flop with 3-trigger inputs 142 148. Frequency dividing flip-flops 143 149. A latch circuit and logic diagram 144 150. Schmidt trigger circuit and waveform 146 151. Differentiating circuit and waveform 146 152. Diode pulse selection technique 147 153. Binary counter using flip-flops and gates 147 154. Logic gates forming a half adder 148 155. A full adder gate arrangement 149 156. An adder used to add 4-digit binary numbers 149 157. Diagram of an encoder 150 158. A decoder for convening binary numbers to decimal digits 151 159. Simple electroscope 153 160. Example of a d Arsonval meter movement 154 161. A simple single-scale voltmeter 155 162. An analog voltmeter with selector switch for choosing any of five voltage ranges 155 163. Analog current meter circuit 155 164. An ammeter arrangement with five ranges 156 165. A simple form of ohmmeter 157 166. A multi-range ohmmeter 157 167. AC voltmeter with rectifiers and range switch 158 168. Sine wave after full-wave rectification 158 169. Sine wave after half-wave rectification 158 170. Arrangement for measuring alternating current 159 171. Analog multimeter 159 172. Testing field-effect transistor (FET) circuits with a VOM 159 173. Digital multimeter 160 174. Digital multimeter displays 160 175. Dual-channel oscilloscope 161 176. Principal parts of a typical cathode ray tube 162 177. Positioning controls for an oscilloscope 163 178. Minimum number of special circuits in an oscilloscope 164 179. A sawtooth wave of the sort used to drive the horizontal deflection amplifier 165 180. Pattern of sine wave on oscilloscope screen 166 181. Sine wave of 15 volts value 167 182. Sawtooth pulse 168 183. Dual-trace scope-meter 169 184. Typical screen display of dual-trace scope-meter 169 185. Connecting scope-meter to computer 169 186. Digital current meter 170 187. Circuit diagram of a type 741 op amp with a typical package format 173 188. A 1950s-era modular device. Note the vacuum tubes and large relays. 174 189. Printed circuit card containing integrated circuits and numerous discrete components 174 190. Manufacturer s instruction manuals 175 191. A troubleshooting chart 176 192. A step-by-step troubleshooting table 177 193. Diagram of test points 178 194. Flow diagram for troubleshooting generator controls 179 x
Tables 1. Numbers Arranged in Vertical Columns of Hundreds, Tens, and Ones 1 2. Decimal and Binary Equivalent Numbers 8 3. Binary Number in Groups of Three (Top) and Decimal Equivalents (Bottom) 8 4. Hexadecimal and Binary Equivalent Numbers and Letters 9 5. BCD, Binary, and Decimal Equivalent Numbers 9 6. ASCII Characters and the Equivalent Binary Numbers 10 7. Gray Code Numbers with Equivalent Binary Numbers 10 8. Current-Carrying Capacity of Copper Wire 29 9. Resistivities of Conductors (per mil-foot at 200 C) 30 10. Temperature Coefficients of Conductors (per mil-foot at 20 C or 68 F) 30 11. Characteristics of Standard-Gauge Copper Wire Conductor 31 12. Preferred Values of Resistors 60 13. Prefixes for SI Units 61 14. Dielectric Constants 71 15. Dielectric Strengths 71 16. NEMA Specified Motor Torque Values 95 17. Trigonometric Functions 99 18. Truth Table for C = AB 134 19. Truth Table for D = ABC 134 20. Truth Table for D = A + B + C 135 21. Buffer Gate 135 22. AND Gate 135 23. OR Gate 137 24. Inverter (NOT) Gate 137 25. NAND Gate 137 26. NOR Gate 137 27. Flip-Flop Truth Table 143 28. Body Response to Various Current Levels 184 29. Arc Flash Energy 185 xi