Electronics for Beginners: A Practical Introduction to Schematics, Circuits, and Microcontrollers

Book Preface

Welcome to the world of electronics! In the modern world, electronic  devices are everywhere, but fewer and fewer people seem to understand  how they work or how to put them together. At the same time, it has never  been easier to do so as an individual. The availability of training, tools,  parts, instructions, videos, and tutorials for the home experimenter has  grown enormously, and the costs for equipment have dropped to almost nothing.

However, what has been lacking is a good guide to bring students from  wanting to know how electronic circuits work to actually understanding  them and being able to develop their own. For the hobbyist, there are  many guides that show you how to do individual projects, but they often  fail to provide enough information for their readers to be able to build  projects of their own. There is plenty of information on the physics of  electricity in physics books, but they fail to make the information practical.  One exception to this is Horowitz and Hill’s The Art of Electronics. This  book is a wonderful reference guide for practical circuit design. However,  its target audience is largely electrical engineers or other very advanced  circuit designers. Not only that, the book itself is prohibitively expensive. What has been needed for a long time is a book that takes you from  knowing nothing about electronics to being able to build real circuits  that you design yourself. This book combines theory, practice, projects,  and design patterns in order to enable you to build your own circuits  from scratch. Additionally, this book is designed entirely around safe, low-current DC (direct current) power. We stay far away from the wall  outlet in this book to be sure that you have a fun and largely worry-free experience with electronics.

This book is written with two groups of people in mind. First, this book  can be used as a guide for hobbyists (or wannabe hobbyists) to learn on  their own. It has lots of projects to work on and experiment with. Second,  this book can also be used in electronics classes for high school and  college students. It has problems to be worked, activities to do, and reviews  at the end of each chapter.

The needs of these groups are not so different from each other. In fact,  even if you are a hobbyist and plan on using this book to learn on your  own, I suggest that not only do you read the main parts of the chapter  but that you also do the activities and homework as well. The goal of the  homework is to train your mind to think like a circuit designer. If you work  through the example problems, it will make analyzing and designing  circuits simply a matter of habit.

Working the Examples
In this book, all examples should be worked out using decimals, not  fractions. This is an engineering course, not a math course, so feel free to  use a calculator. However, you will often wind up with very long strings  of decimals on some of the answers. Feel free to round your answers, but  always include at least a single decimal point. So, for instance, if I divide  5 by 3 on my calculator, it tells me 1.66666667. However, I can just give  the final answer as 1.7. This only applies to the final answer. You need to maintain your decimals while you do your computations.

Also, if your answer is a decimal number that begins with a zero, then  you should round your answer to include the first two to four nonzero  digits. So, if I have an answer of 0.0000033333333, I can round that to  0.00000333. If you want to be precise about the proper way to round results, see the section on significant figures in the next chapter.

For beginners and hobbyists, this is less of a concern, and we will generally  be in a hobbyist mindset for the book.

In short, as engineers, we wind up being, at minimum, as precise as  we need to be or, at maximum, as precise as we can be. The amount of  precision we need will vary from project to project, and the amount of  precision that we can be will depend on our tools, our components, and  other things we interact with. Therefore, there is not a lot of focus on this  book on how many decimals exactly to use. You can get more detailed  descriptions in other science books for dealing with significant figures. In  the problems in the chapters, if you are off by a single digit due to rounding errors, don’t worry about it