Dickon Ross
Editor-in-Chief, Electronics & Technology
Magazine
Cathleen Shamieh
Gordon McComb
Electronics experts
Learn to:
• Get to grips with electronics theory
• Start working with electrical parts
and equipment
• Read schematics and build simple
circuits
• Create your own projects, from flashing
lights to infrared detectors
Electronics
Making Everything Easier!
™
UK Edition
C1
C2
R5
IC-1
555
timer
470
D1-6
LED 1-7
2
6
14
3

• Key tools and equipment for your
workbench
• How to create solderless and
soldered breadboards
• Ways to measure your circuits with
multimeters and oscilloscopes
• Key safety information
• Top tips to help you succeed
Dickon Ross is the Editor-in-Chief of Electronics & Technology Magazine,
published by the IET. He is also the launch Editor of Flipside, a science,
engineering and technology magazine aimed at teenagers. Cathleen
Shamieh is a technology writer with extensive engineering and consulting
experience. Gordon McComb is an electronics author and consultant.
£16.99 UK / $24.99 US
ISBN 978-0-470-68178-7
Electronics
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Covering everything from the low-down on the science and
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and running in no time. So get reading and start putting
the electricity into electronics!
• Understand the basics – learn about electrons and find out about
resistors, capacitors, inductors, conductors and more

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Electronics
FOR
DUMmIES
‰
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by Dickon Ross, Cathleen Shamieh,
and Gordon McComb
Electronics
FOR
DUMmIES
‰
A John Wiley and Sons, Ltd, Publication
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Electronics For Dummies
®
Published by
John Wiley & Sons, Ltd

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About the Authors
Dickon Ross, adapting author of the UK edition, has been a science and
technology journalist for 20 years, working on titles ranging from Electronics
Times to Focus. Dickon is now Editor-in-Chief of Engineering & Technology
magazine and Flipside – the magazine he launched for teenagers – for the
Institution of Engineering and Technology.
Cathleen Shamieh is a writer with an engineering background who spe-
cialises in creating communication materials focused on technology and
its business bene ts. She received an outstanding education in electrical
engineering at Manhattan College and MIT, and enjoyed working as an engi-

and gentle reminders, and to Kirk Kleinschmidt for his intense technical scru-
tiny of the material. She is also grateful to Linda Hammer and Ken Donoghue,
who kindly recommended her work to Wiley. Finally, Cathleen thanks her
family and friends, whose support, assistance, and understanding helped
make her goal of becoming a Dummies author a reality.
Gordon McComb gives heartfelt thanks to Wiley and the hard-working edi-
tors at Wiley, especially Katie Feldman, Nancy Stevenson, Carol Sheehan,
Laura Miller and Amanda Foxworth. Many thanks also to Ward Silver, for
his excellent and thorough technical review, and Matt Wagner at Waterside
Productions for always having a positive outlook. Gordon also wishes to
thank his family, who once again put their lives on hold while he  nished
another book.
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Publisher’s Acknowledgements
We’re proud of this book; please send us your comments through our Dummies online registration
form located at
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Some of the people who helped bring this book to market include the following:
Commissioning, Editorial, and
Media Development
Project Editor: Steve Edwards
Content Editor: Jo Theedom
Commissioning Editor: Nicole Hermitage
Assistant Editor: Jennifer Prytherch
Development Editor: Andy Finch
Copy Editor: Anne O’Rorke
Technical Editor: Roger Dettmer
Proofreader: Kelly Cattermole
Production Manager: Daniel Mersey
Cover Photos: © Tombaky/Fotolia

Chapter 14: Great Projects You Can Build in 30 Minutes or Less 305
Part IV: The Part of Tens 329
Chapter 15: Ten Exciting Electronics Extras 331
Chapter 16: Ten Great Sources for Electronics Parts 341
Appendix: Internet Resources 345
Index 349
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Table of Contents
Introduction 1
Why Buy This Book? 1
Why Electronics? 2
Foolish Assumptions 3
Safety Is Number 1 3
How This Book Is Organised 4
Part I: Understanding the Fundamentals of Electronics 4
Part II: Getting Your Hands Dirty 5
Part III: Putting Theory into Practice 5
Part IV: The Part of Tens 5
Icons Used in This Book 6
Part I: Understanding the Fundamentals of Electronics 7
Chapter 1: What Is Electronics and What Can It Do for You? . . . . . . . .9
Just What Is Electronics? 9
Understanding Electric Current 10
Getting a charge out of electrons 10
Moving electrons in conductors 11
Harnessing Electricity to Do Work 12
Where Electrical Energy Comes From 12
Tapping into electrical energy 12
Giving electrons a nudge 13
Using conductors to make the circuit 13

Resisting the Flow of Current 37
Resistors: Passive Yet Powerful 39
Discovering the usefulness of resistors 39
Choosing a type:  xed or variable 40
Decoding  xed resistors 42
Dialling with potentiometers 44
Rating resistors according to power 45
Combining Resistors 47
Using resistors in series 47
Employing resistors in parallel 48
Combining series and parallel resistors 50
Obeying Ohm’s Law 51
Driving current through a resistance 51
Understanding a relationship that’s constantly proportional! 52
Working with one law, three equations 53
Using Ohm’s Law to Analyse Circuits 54
Calculating current through a component 54
Working out voltage across a component 55
Determining an unknown resistance 56
What is Ohm’s Law Really Good For? 56
Analysing complex circuits 57
Designing and altering circuits 58
The Power of Joule’s Law 60
Using Joule’s Law to choose components 60
Going perfectly together: Joule and Ohm 60
Trying Your Hand at Circuits with Resistors 61
Chapter 4: Getting a Charge Out of Capacitors. . . . . . . . . . . . . . . . . . . .63
Reservoirs for Electrical Energy 63
Charging and discharging 64
Opposing voltage change 65

Looking at low-pass  lters 85
Encountering high-pass  lters 86
Cutting off frequencies at the knees 87
Filtering frequency bands 88
Trying Out Simple Capacitive Circuits 88
Chapter 5: Curling Up with Coils and Crystals . . . . . . . . . . . . . . . . . . . .89
Working Both Ways: Magnetism and Electricity 90
Drawing the ( ux) lines with magnets 90
Producing a magnetic  eld with electricity 91
Inducing current with a magnet 92
Introducing the Inductor: A Coil with a Magnetic Personality 93
Measuring inductance 93
Opposing current changes 94
Alternating current gets nowhere fast 95
Understanding Inductive Reactance 96
Using Ohm’s Law for inductive reactance 97
Discovering that behaviour depends on frequency (again!) 97
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Table of Contents
Using Inductors in Circuits 98
Insulating and shielding inductors 98
Reading inductance values 98
Combining shielded inductors 99
Filtering signals with inductors 99
Calculating the RL time constant 100
Now Introducing Impedance! 101
Tuning in to Radio Broadcasts 102
Resonating with RLC circuits 102
Ensuring crystal-clear resonance 104

Turning it up 133
Turning it to your needs 134
Switching Signals with a Transistor 135
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Electronics For Dummies
xiv
Choosing Transistors 135
Tackling transistor ratings 136
Identifying transistors 136
Recognising transistors 137
Integrating Components 138
Chapter 7: Cramming Components into Chips. . . . . . . . . . . . . . . . . . . .139
Discovering Integrated Circuits 140
Linear, Digital or Both? 141
Making Decisions with Logic 141
Beginning with bits 142
Processing data with gates 144
Telling the truth 146
Understanding How to Use ICs 147
Identifying ICs with part numbers 147
Packaging is everything 147
Understanding IC pinouts 149
Relying on IC datasheets 150
Meeting Some Top Chips 151
Sounding out operational ampli ers 151
Playing with the IC time machine: the 555 timer 153
Counting on the 4017 decade counter 159
Expanding Your IC Horizons 161
Chapter 8: Rounding Out Your Parts List . . . . . . . . . . . . . . . . . . . . . . . .163
Making Connections 163

Collecting cloths and cleaners 197
Oiling the wheels 198
Sticking with it 198
Selecting other tools and supplies 199
Picking up Parts 200
Practising with solderless breadboards 200
Building a circuit-building starter kit 202
Adding up the extras 203
Organising all your parts 204
Protecting You and Your Electronics 204
Accepting that electricity can really hurt 205
Soldering safely 208
Avoiding static like the plague 209
Staying Safe: Safety Checklist 211
Chapter 10: Sussing out Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . .213
Approaching Schematics 213
Seeing the Big Picture 214
Following connections 215
Looking at a simple battery circuit 216
Recognising Symbols of Power 217
Showing where the power is 218
Marking your ground 220
Labelling Circuit Components 223
Analogue electronic components 224
Digital logic and IC components 226
Odds and ends 228
Exploring a Schematic 229
Alternative Schematic Drawing Styles 231
Chapter 11: Constructing Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .233
Taking a Look at Solderless Breadboards 234

Setting Up Your Multimeter 263
Operating Your Multimeter 264
Measuring voltage 265
Measuring current 266
Measuring resistance 268
Running other multimeter tests 273
Using a Multimeter to Check Your Circuits 274
Introducing Logic Probes and Oscilloscopes 275
Probing the depths of logic 275
Scoping out signals with an oscilloscope 276
Part III: Putting Theory into Practice 279
Chapter 13: Exploring Some Simple Circuits . . . . . . . . . . . . . . . . . . . .281
Getting Equipped 281
Seeing Is Believing: Ohm’s Law Really Works! 283
Analysing a series circuit 284
Dividing up voltage 287
Parallel parking resistors 289
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Table of Contents
Charging and Discharging a Capacitor 291
Watching your charges go up and down 291
Varying the RC time constant 293
Dropping Voltages across Diodes 294
Turning on an LED 294
Clipping voltages 296
Gaining Experience with Transistors 298
Amplifying current 298
Measuring tiny currents 300
Creating light at your  ngertip 300

Chasing down the parts 327
Making an Electronic Die 327
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Electronics For Dummies
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Part IV: The Part of Tens 329
Chapter 15: Ten Exciting Electronics Extras. . . . . . . . . . . . . . . . . . . . .331
Trying Out Ready-Made Electronics Kits 331
Varying Your Voltage 332
Counting Up Those Megahertz 332
Generating All Kinds of Signals 334
Sweeping Frequencies Up and Down 334
Taking the Pulse 335
Analysing Your Logic 336
Simulating with Software 336
Buying Testing Tool Deals 338
Boxing Your Tricks – With Knobs On 339
Chapter 16: Ten Great Sources for Electronics Parts . . . . . . . . . . . . .341
Buying British: Suppliers within the UK 341
Maplin 341
RS Components 342
Farnell 342
RSH Electronics 342
Bitsbox 343
ESR Electronic Components 343
Ordering from across the Pond 343
Digikey 343
All Electronics 344
B.G. Micro 344
Mouser Electronics 344

This book is designed to explain electronics in ways you can relate to. It gives
you a basic understanding of exactly what electronics is, provides down-to-
earth explanations of how major electronic components work and gives you
just what you need to build and test working electronic circuits and projects.
Although this book doesn’t pretend to answer all your questions about elec-
tronics, it does give you a good grounding in the essentials.
We hope that when you’re done with this book, you’ll realise that electronics
isn’t as complicated as you may have thought. And we want to arm you with
the knowledge and confidence you need to go deeper into the exciting world
of electronics.
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2
Electronics For Dummies
Why Electronics?
Electronics is everywhere. You find electronics in your phones, audio and
video systems, and kitchen appliances. Electronic systems control traffic
lights, Internet commerce, medical devices – even many toys. You can’t see
most of them, but electronic systems also proliferate throughout your car.
Try for just one minute to imagine your life without electronics; you may as
well be living in the Dark Ages!
So what does all this mean to you as you peruse this book? After all, you
don’t expect to be able to design satellite communication systems after a sit-
down session with this humble For Dummies book.
Remember though that even the most complicated electronics systems con-
sist of no more than a handful of different electronic component types gov-
erned by the same set of rules that make simple circuits work. So if you want
to understand complex electronic systems, you start with the basics – just
like the designers of those systems did when they started out.
More importantly, understanding the basics of electronics can enable you to
create some really useful, albeit somewhat simple, electronic devices. You

you, distilling fairly technical information down into easy-to-understand con-
cepts. You don’t need to be well-versed in physics or mathematics to benefit
from reading this book, although a little bit of school algebra is helpful (but
we do our best to refresh that possibly painful memory).
We assume you may want to jump around this book a bit, diving deep into
a topic or two that holds special interest for you, and possibly skimming
through other topics. For this reason, we provide loads of chapter cross-
references to point you to information that can fill in any gaps or refresh your
memory on a topic. And although the first half of the book is devoted to how
electronic circuits and individual parts work, we include cross-references to
simple circuits and projects that appear later in the book. That way, as soon
as you find out about a component, you can jump ahead, if you like, and build
a circuit that uses that very component.
The table of contents at the front of the book provides an excellent resource
that you can use to find quickly exactly what you’re looking for. Finally, the
good people at Wiley have thoughtfully provided a thorough index at the
back of the book to help you find what you want fast.
Safety Is Number 1
Reading about electronics is pretty safe. About the worst that can happen is
that your eyes get tired from too many late nights with this book. But actually
building electronic projects is another matter. Lurking behind the fun of your
electronics hobby are high voltages that can electrocute you, soldering irons
that can burn you and little bits of wire that can fly into your eyes when you
snip them off with sharp cutters. Aaaagh!
Safety comes first in electronics. It’s so important, in fact, that we devote a
major section of Chapter 9 to it – and continually refer you to this section.
If you’re brand new to electronics, please be sure to read this section thor-
oughly. Don’t skip over it, even if you think you’re the safest person on earth.
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4

speakers, buzzers, switches, wires and connectors.
Throughout Part I, we point you to introductory circuits you can build in Part
III to see what each component does.
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5

Introduction
Part II: Getting Your Hands Dirty
Part II is all about tooling-up, constructing real circuits and probing around
working (and non-working) circuits – without electrocuting yourself.
In Chapter 9, you find out how to set up an electronics workbench, what
electronic components, tools and other supplies you need to build circuits,
and how to protect yourself and your electronic components as you work
on circuits. Chapter 10 explains how to interpret circuit diagrams (known as
schematics) so that you know how to connect components together when you
build a circuit.
You discover various methods of wiring up temporary and permanent cir-
cuits in Chapter 11, including how to solder. Finally, Chapter 12 explains how
to use the most important testing tool in electronics – the multimeter – to
explore and analyse your circuits. This chapter also introduces you very
briefly to two other tools: the logic probe and oscilloscope.
Part III: Putting Theory into Practice
If you’re anxious to wire up some circuits and get your electronic juices flow-
ing, Part III is the place to be.
Chapter 13 shows you some elementary circuits that you can build to dem-
onstrate the principles of electronics and observe specific electronic compo-
nents functioning as advertised. Turn to this chapter if you want to reinforce
your theoretical knowledge of electronics or gain experience building simple
circuits.
When you’re ready for more involved circuits, explore Chapter 14. Here, you