Cover: Electronics For Dummies, 3rd Edition by Cathleen Shamieh

Title Page

Electronics For Dummies®

To view this book's Cheat Sheet, simply go to and search for “Electronics For Dummies Cheat Sheet” in the Search box.


Are you curious to know what makes your iPhone tick? How about your tablet, stereo system, GPS device, HDTV — well, just about every other electronic thing you use to entertain yourself and enrich your life?

Or have you wondered how resistors, diodes, transistors, capacitors, and other building blocks of electronics work? Been tempted to try building your own electronic devices? Well, you’ve come to the right place!

Electronics For Dummies, 3rd Edition, is your entrée into the exciting world of modern electronics. Loaded with illustrations and plain-English explanations, this book enables you to understand, create, and troubleshoot your own electronic devices.

About This Book

All too often, electronics seems like a mystery because it involves controlling something you can’t see — electric current — which you’ve been warned repeatedly not to touch. That’s enough to scare away most people. But as you continue to experience the daily benefits of electronics, you may begin to wonder how it’s possible to make so many incredible things happen in such small spaces.

This book offers you a chance to satisfy your curiosity about electronics while having a lot of fun along the way. You get a basic understanding of exactly what electronics is, down-to-earth explanations (and gobs of illustrations) of how major electronic components — and the rules that govern them — work, and step-by-step instructions for building and testing working electronic circuits and projects. Although this book doesn’t pretend to answer all your questions about electronics, it gives you a good grounding in the essentials and prepares you to dig deeper into the world of electronic circuits.

I assume that you may want to jump around this book a bit, diving deep into a topic that holds special interest for you and possibly skimming through other topics. For this reason, I provide loads of chapter cross-references to point you to information that can fill in any gaps or refresh your memory on a topic.

The table of contents at the front of this book provides an excellent resource that you can use to quickly locate exactly what you’re looking for. You’ll also find the glossary useful when you get stuck on a particular term and need to review its definition. Finally, the folks at Wiley have thoughtfully provided a thorough index at the back of the book to assist you in narrowing your reading to specific pages.

It is my hope that when you’re finished with this book, you realize that electronics isn’t as complicated as you may have once thought. And, it is my intent to arm you with the knowledge and confidence you need to charge ahead in the exciting field of electronics.

Foolish Assumptions

In writing this book, I made a few assumptions about the skill level and interests of you and other readers when it comes to the field of electronics. I tailored the book based on the following assumptions:

  • You don’t know much — if anything — about electronics.
  • You aren’t necessarily well versed in physics or mathematics, but you’re at least moderately comfortable with introductory high school algebra.
  • You want to find out how resistors, capacitors, diodes, transistors, and other electronic components actually work.
  • You want to see for yourself — in simple circuits you can build — how each component does its job.
  • You're interested in building — and understanding the operation of — circuits that actually accomplish something useful.
  • You have a pioneering spirit — that is, a willingness to experiment, accept periodic setbacks, and tackle any problems that may crop up — tempered by an interest in your personal safety.

I start from scratch — explaining what electric current is and why circuits are necessary for current to flow — and build from there. You find easy-to-understand descriptions of how each electronic component works supported by lots of illustrative photographs and diagrams. In 9 of the first 11 chapters, you find one or more mini projects you can build in 15 minutes or so; each is designed to showcase how a particular component works.

Later in the book, I provide several fun projects you can build in an hour or less, and I explain the workings of each one in detail. By building these projects, you get to see firsthand how various components work together to make something cool — sometimes even useful — happen.

As you embark on this electronics tour, expect to make some mistakes along the way. Mistakes are fine; they help enhance your understanding of and appreciation for electronics. Keep in mind: no pain, no gain. (Or should I say, no transistor, no gain?)

Icons Used in This Book

Tip Tips alert you to information that can truly save you time, headaches, or money (or all three!). You’ll find that if you use my tips, your electronics experience will be that much more enjoyable.

Remember This icon reminds you of important ideas or facts that you should keep in mind while exploring the fascinating world of electronics.

Technical Stuff Even though this entire book is about technical stuff, I flag certain topics to alert you to deeper technical information that might require a little more brain power to digest. If you choose to skip this information, that’s okay — you can still follow along just fine.

Warning When you tinker with electronics, you’re bound to encounter situations that call for extreme caution. Enter the Warning icon, a not-so-gentle reminder to take extra precautions to avoid personal injury or prevent damage to your tools, components, circuits — or your pocketbook.

Beyond the Book

I have written a lot of extra content that you won’t find in this book. Go online to find the following:

  • Cheat sheet ( Here you’ll find important formulas and other information you may want to refer to quickly and easily when you’re working with a circuit.
  • Online articles covering additional topics ( Discover how semiconductors conduct, find out what an oscilloscope is and how it is used, and get more information designed to enhance your knowledge and use of electronics.
  • Updates ( Go to this link to find any significate updates or corrections to the material in this book. (My editor made me add the part about corrections, but since I dun’t maek mistacks, they’re wont be any errata posted. By the weigh, do you want too by a bridge?)

Where to Go from Here

You can use this book in a number of ways. If you start at the beginning (a good place to start), you discover the basics of electronics, add to your knowledge one component at a time, and then put it all together by building projects in your fully outfitted electronics lab.

Or, if you’ve always been curious about, say, how transistors work, you can jump right into Chapter 10, find out about those amazing little three-legged components, and build a couple of transistor circuits. With a chapter each focused on resistors, capacitors, inductors, diodes, transistors, and integrated circuits (ICs), you can direct your energy to a single chapter to master the component of your choice.

This book also serves as a useful reference, so when you start creating your own circuits, you can go back into the book to refresh your memory on a particular component or rule that governs circuits.

Here are my recommendations for good places to start in this book:

  • Chapter 1: Start here if you want to get introduced to three of the most important concepts in electronics: current, voltage, and power.
  • Chapter 3: Jump straight to this chapter if you’re anxious to build your first circuit, examine voltages and currents with your multimeter, and make power calculations.
  • Chapter 13: If you know you’ll be addicted to your electronics habit, start with Chapter 13 to find out how to set up your mad-scientist electronics lab, and then go back to the earlier chapters to find out how all the stuff you just bought works.

I hope you thoroughly enjoy the journey you are about to begin. Now, go forth, and explore!

Part 1

Fathoming the Fundamentals of Electronics


Discovering what makes electronics so fascinating

Shopping for circuit components and tools

Experimenting with series and parallel circuits