Introduction to Electric Circuits

265 Pages·2007·7.68 MB·English

Introduction to Electric Circuits
To the memory of my mother and father with grateful thanks
Essential Electronics Series
Introduction to Electric Circuits
Eur Ing R G Poweli
Principal Lecturer
Department of Electrical and Electronic Engineering
Nottingham Trent University
ARNOLD
A member of tile Hodder Headline Group
LONDON (cid:12)9 SYDNEY (cid:12)9A UCKLAND
First published in Great Britain 1995 by
Arnold, a member of the Hodder Headline Group,
338 Euston Road, London NWl 3BH
(cid:14)9 1995 Ray Powell
All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any
means, electronically or mechanically, including photocopying, recording or any information storage or
retrieval system, without either prior permission in writing from the publisher or a licence permitting
restricted copying. In the United Kingdom such licences are issued by the Copyright Licensing Agency:
of 90 Tottenham Court Road, London WlP 9HE.
Whilst the advice and information in this book is believed to be true and accurate at the date of going to
press, neither the author[s] nor the publisher can accept any legal responsibility or liability for any errors
or omissions that may be made.
British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library
Library of Congress Cataloging-in-Publication Data
A catalog record for this book is available from the Library of Congress
ISBN 0340 63198 8
2345
Typeset in 10~/13(cid:1)89T imes by Wearset, Boldon, Tyne and Wear.
Printed and bound in Great Britain by J W Arrowsmith Ltd, Bristol.
Series Preface
In recent years there have been many changes in the structure of undergraduate
courses in engineering and the process is continuing. With the advent of
modularization, semesterization and the move towards student-centred learn-
ing as class contact time is reduced, students and teachers alike are having to
adjust to new methods of learning and teaching.
Essential Electronics is a series of textbooks intended for use by students on
degree and diploma level courses in electrical and electronic engineering and
related courses such as manufacturing, mechanical, civil and general engineer-
ing. Each text is complete in itself and is complementary to other books in the
series.
A feature of these books is the acknowledgement of the new culture outlined
above and of the fact that students entering higher education are now, through
no fault of their own, less well equipped in mathematics and physics than
students of ten or even five years ago. With numerous worked examples
throughout, and further problems with answers at the end of each chapter, the
texts are ideal for directed and independent learning.
The early books in the series cover topics normally found in the first and
second year curricula and assume virtually no previous knowledge, with
mathematics being kept to a minimum. Later ones are intended for study at
final year level.
The authors are all highly qualified chartered engineers with wide experience
in higher education and in industry.
R G Powell
Jan 1995
Nottingham Trent University
This Page Intentionally Left Blank
Contents
Preface xi
Acknowledgements xiii
Chapter 1 Units and dimensions
1.1 Introduction
1.2 The Syst~me International d'Unit~s
1.3 Dimensional analysis
1.4 Multiples and submultiples of units
1.5 Self-assessment test
1.6 Problems
Chapter 2 Electric circuit elements
2.1 Electricity 10
2.2 Electric circuits 11
2.3 Circuit elements 11
2.4 Lumped parameters 34
2.5 Energy stored in circuit elements 35
2.6 Power dissipated in circuit elements 36
2.7 Self-assessment test 37
2.8 Problems 38
Chapter 3 DC circuit analysis
3.1 Introduction 40
3.2 Definition of terms 40
3.3 Kirchhoff's current law 42
3.4 Kirchhoff's voltage law 42
3.5 The Principle of Superposition 45
3.6 Thevenin's theorem 48
3.7 Norton's theorem 52
3.8 The Maximum Power Transfer Theorem 54
3.9 Delta-star transformation 56
3.10 Star-delta transformation 59
3.11 Self-assessment test 61
3.12 Problems 62
Chapter 4 Single-phase a.c. circuits
4.1 Alternating quantities 66
viii Contents
4.2 Single-phase a.c. circuits in the steady state 72
4.3 Series a.c. circuits 77
4.4 Complex notation 82
4.5 Parallel a.c. circuits 91
4.6 Series-parallel a.c. circuits 95
4.7 Power in single-phase a.c. circuits 97
4.8 Self-assessment test 103
4.9 Problems 105
Chapter 5 Three-phase a.c. circuits
5.1 Introduction 107
5.2 Generation of three-phase voltage 107
5.3 Phase sequence 108
5.4 Balanced three-phase systems 109
5.5 Power in balanced three-phase circuits 115
5.6 Self-assessment test 120
5.7 Problems 122
Chapter 6 Resonance
6.1 Series resonance 123
6.2 Parallel resonance 133
6.3 Self-assessment test 137
6.4 Problems 138
Chapter 7 Nodal and mesh analysis
7.1 Introduction 141
7.2 Matrices 141
7.3 Nodal voltage analysis 147
7.4 Mesh current analysis 158
7.5 Self-assessment test 168
7.6 Problems 168
Chapter 8 Transient analysis
8.1 Introduction 172
8.2 Circuits containing resistance and inductance 172
8.3 Circuits containing resistance and capacitance 181
8.4 The Laplace transform 192
8.5 Self-assessment test 201
8.6 Problems 202
Chapter 9 Two-port networks
9.1 Introduction 205
9.2 The impedance or z-parameters 205
9.3 The admittance or y-parameters 208
Contents ix
9.4 The hybrid or h-parameters 210
9.5 The inverse hybrid or g-parameters 211
9.6 The transmission or ABCD-parameters 213
9.7 The inverse transmission parameters 214
9.8 Cascaded two-port networks 219
9.9 Characteristic impedance (Z0) 225
9.10 Image impedances 226
9.11 Insertion loss 227
9.12 Propagation coefficient (3') 229
9.13 Self-assessment test 230
9.14 Problems 231
Chapter 10 Duals and analogues
10.1 Duals of circuit elements 233
10.2 Dual circuits 234
10.3 Analogues 238
10.4 Self-assessment test 241
Answers to self-assessment tests and problems 242
Index 246