Electricity for Technicians

520 Pages·1975·61.076 MB·English

by  Abraham Marcus, Charles M. Thomson

ELECTROTY
TECHMOANS
FOR
Abraham Marcus /' Charles M. Thomson
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SECOND
EDITION
ELECTRICITY
FOR
TECHNICIANS
ABRAHAM MARCUS
CHARLES M.THOMSON
PRENTICE-HALL, INC.. ENGLEWOOD CLIFFS, NEWJERSEY
Marcus, Abraham
Electricity for technicians, 2nd ed.
1. Electronics. I. Thomson,CharlesM.
jointauthor. II. Title
74-29477
ISBN: 0-13-248658-X
® 1975 by Rebecca B. Marcus and Charles M. Thomson;
(c) 1968 by Abraham Marcus. All rights reserved.
No part ofthis book may be reproduced in any
form or by any means without permission in
writing from the authors and the publisher.
Current printing:
10 9 8
Printed in the United States ofAmerica
I
Prentice-Hall International, Inc., London
Prentice-Hall ofAustralia, Pty. Ltd., Sydney
Prentice-Hall ofCanada, Ltd., Toronto
Prentice-Hall ofIndia Private Limited, New Delhi
Prentice-Hall ofJapan, Inc., Tokyo
CONTENTS
Preface ix
Prologue 1
I
Introduction 5
1 WHAT IS ELECTRICITY? 7
A. Early theories 7
B. The structure ofmatter 8
c. The electric field 17
2 STATIC ELECTRICITY 23
A. Electrical pressure 23
B. Electricity and lightning 24
c. Practical applications ofstatic electricity 27
MAGNETISM
3 33
A. The magnetic field 35
B. Theories ofmagnetism 38
c. Magnetic units and terms 42
D. Practical applications ofpermanent magnets 47
ui
iv Contents
I
II
Direct Current Electricity 57
4 THE ELECTRIC CURRENT 53
A. Current carriers 53
B. Three factors ofan electric current 54
c. Units ofmeasurement 57
D. Ohm's law 62
5 HOW CURRENT FLOWS THROUGH A CIRCUIT 65
A. The electric current in solids 65
B. The electric current in liquids 66
c. The electric current in gases 67
D. The electric current in a vacuum 68
E. Types ofcircuits 69
6 EFFECTS OF ELECTRIC CURRENT 89
A. Thermal effect 89
B. Luminous effect 91
c. Chemical effect 93
D. Magnetic effect 93
7 D-C MEASURING INSTRUMENTS 98
A. Measurement based upon the
chemical effect ofelectric current 98
B. Measurement based upon the
thermal effect ofelectric current 99
c. Measurement based upon the
magnetic effect ofelectric current JOO
D. Types ofmeters 107
E. Miscellaneous notes 122
III
Alternating Current Electricity 127
8 INDUCED EMF AND THE A-C CYCLE 129
A. Induced electromotive force 129
B. The simple generator 133
c. The alternating-current cycle 135
Contents v
\
9 CHARACTERISTICS OF
ALTERNATING CURRENT 143
A. Impedance 143
B. Phase relationships J44
c. Power in a-c circuits J48
D. Vectors 152
E. Waveforms 154
10 FACTORS AFFECTING
ALTERNATING CURRENT J60
A. Resistance 160
B. Inductance 161
c. Capacitance 169
11 CIRCUITS CONTAINING RESISTANCE,
INDUCTANCE, AND CAPACITANCE 182
A. Circuits containing resistance and inductance 183
B. Circuits containing resistance and capacitance 188
c. Circuits containing resistance, inductance,
and capacitance 190
D. Filters 198
E. Coupled circuits 202
12 A-C MEASURING INSTRUMENTS 215
A. Metermovementsthatmay beused for
a-cord-c measurement 215
B. Adapting the d'Arsonval-type moving-coil movement
to a-c measurement 217
c. The a-c watthour meter 227
D. The frequency meter 227
E. Bridges 229
IV
Sources of Electrical Energy 237
13 MECHANICAL GENERATORS 237
A. Alternating-current generators 239
B. Direct-current generators 249
c. Efficiency and regulation ofgenerators 267
D. Control ofgenerators 269
vi Contents
I
14 OTHER SOURCES OF ELECTRICAL ENERGY 278
A. Chemical cells 278
B. The solar cell 302
c. The atomic cell 304
D. Miscellaneous sources ofelectric energy 305
Transmission and Control of Electric Power 319
15 TRANSMISSION OF ELECTRIC POWER 321
A, Single-phase alternating current 321
B. Polyphase alternating current 328
c. Long-distance transmission ofelectric power 336
16 CONTROL OF ELECTRIC POWER 340
A. Variable resistors and transformers 341
B. The saturable reactor 343
c. The amplidyne 348
VI
Practical Applications of Electricity 353
17 APPLICATIONS DEPENDING UPON THE
THERMAL EFFECT 355
A. Devices employing heating elements 356
B. Fuses and circuit breakers 363
c. The infrared lamp 366
D. Welding 367
E. Electric ovens and furnaces 370
F. Induction and dielectric heating 371
18 APPLICATIONS DEPENDING UPON THE
LUMINOUS EFFECT 379
A. Incandescent-filament lamp 379
B. Arc lamp 382
c. Vapor lamp 383