Study Notes in Electrical Science

4 Alternating-current Theory 32 4.1 Basic Concepts 32 sinusoidal waveform, amplitude and 'angle of rotation'frequency-angular frequency-periodic time 4.2 Average Value and R.M.S. Value of an Alternating Waveform 33 average and r.m.s. values-form and peak factors Contents v 4.3 Phasors and Phase Relationships phasors-phase displacement-addition and subtraction of phasors 4.4 Complex Notation operator j-rectangular and polar components-complex conjugate-operations with complex quantities 5 Single-phase A.C. Circuits 5.1 Basic Circuits circuit containing R only-reactance-circuit containing L only-circuit containing C only 5.2 Series Circuits power factor-Rand Lin series-Rand C in series-R, L and C in series-series resonance 5.3 Parallel Circuits circuit containing R, L and C-parallel resonance 5.4 Complex Impedances reactance-impedance of series and parallel circuits 6 Tbree-pbase A.C. Circuits 54 6.1 Star-connected Systems voltage and current relationships 6.2 Mesh-connected or Delta-connected Systems current and voltage relationships-power consumed in a balanced load 7 Transformers 58 7.1 E.M.F. Equation 7.2 Basic Relationships in an Ideal Transformer 7.3 Transformer Efficiency copper and iron losses-condition for maximum efficiency 7.4 Phasor Diagrams 61 ideal and practical transformers with and without load 7.5 The Transformer as an Impedance-matching Device 63 8 Electrical Machines 64 8.1 Types of Electrical Machine 64 salient and cylindrical magnetic systems 8.2 Single-excited Machines 65 8.3 Double-excited Machines 66 8.4 Windings 66 concentrated and distributed windings vi Contents 8.5 D.C. Machines 68 e.m.f. equation-methods of connection 8.6 Characteristic Curves of D.C. Generators 68 separately excited, shunt-excited, series-excited and compound-wound generators 8.7 Power Required to Drive a D.C. Generator 71 8.8 D.C. Motors 72 torque equation-face-plate starter 8.9 Characteristic Curves of D.C. Motors shunt, series and compound-wound motors 8.10 Induction Motors principle-synchronous speed of the magnetic fieldfractional slip 8.11 Efficiency of Electrical Machines 73 76 77 9 Measurements 9.1 Analog and Digital Instruments 78 9.2 Effects Utilised in Measuring Instruments 78 9.3 Analog Indicating Instruments 78 controlling and damping forces-methods of supporting moving systems-instrument scales 9.4 Moving-coil Instruments or Galvanometers 81 construction and uses-extending the current and voltage ranges-the moving-coil instrument as an ohmmeterrectifier instruments 9.5 Moving-iron Instruments construction and use-ammeters-voltmeters 9.6 Electrodynamic Instruments 9.7 The D.C. Potentiometer 9.8 The Wheatstone Bridge 9.9 A.C. Bridges basic four-arm bridge-De Sauty's, Schering's, Maxwell's and Hay's bridges 9.10 The Cathode Ray Oscilloscope electron gun-electron lens system-deflection systemc.r.t. screen-principal controls 10 Rectifiers 10.1 Semiconductors i-type-n-type-p-type 10.2 Rectifiers diode characteristicsp-n junction, Zener and thermionic diodes Contents 10.3 Rectifier Circuits single-phase half-wave, full-wave and bridge circuitssmoothing circuit 11 Transistors, Triodes and Amplifiers Vll 100 102 11.1 Bipolar Junction Transistors 102 construction-basic configurations-common-emitter and common-base characteristics 11.2 Field-effect Transistors 104 junction-gate and insulated-gate FETs 11.3 Triodes 107 11.4 Amplifiers 108 classification-small-signal amplifiers with bipolar transistors -load line-small-signal common-cathode triode amplifier 11.5 Electronic-device Parameters and Equivalent Circuits 115 use of parameters-hybrid parameters-equivalent circuits Preface This book is a collection of notes and essential diagrams for the study of the subjects of electrical science and electrical principles in T.E.C. courses, City and Guilds of London Institute courses, O.N.C. and O.N.D. courses, and sciencebased 0-level and A-level subjects. The treatment is abbreviated and is produced in the most economical form possible. Present-day syllabuses place an immense burden on students, who have also to deal with advances in technology. This book provides the reader with a summary of the work in electrical science and principles, allowing him to streamline the activities that lead to his final goal. I should like to express my gratitude to my wife for the assistance she has given during the preparation of this book. Thanks are also due to the Macmillan production and editorial stafffor their guidance and help during the production of the book. Front Matter....Pages i-x Direct-current Circuits....Pages 1-10 Electromagnetism....Pages 11-23 Electrostatics....Pages 24-31 Alternating-current Theory....Pages 32-41 Single-phase A.C. Circuits....Pages 42-53 Three-phase A.C. Circuits....Pages 54-57 Transformers....Pages 58-63 Electrical Machines....Pages 64-77 Measurements....Pages 78-95 Rectifiers....Pages 96-101 Transistors, Triodes and Amplifiers....Pages 102-118