Authors: Charles Platt
Learning by Discovery
with photographs and illustrations by the author
Beijing • Cambridge • Farnham • Köln • Sebastopol • Taipei • Tokyo
by Charles Platt
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For my dearest Erico
How to Have Fun with This Book
Everyone uses electronic devices, but most of us don’t really know what goes on inside them.
Of course, you may feel that you don’t need to know. If you can drive a car without understanding the workings of an internal combustion engine, presumably you can use an iPod without knowing anything about integrated circuits. However, understanding some basics about electricity and electronics can be worthwhile for three reasons:
Learning by Discovery
Most introductory guides begin with definitions and facts, and gradually get to the point where you can follow instructions to build a simple circuit.
This book works the other way around. I want you to start putting components together right away. After you see what happens, you’ll figure out what’s going on. I believe this process of
learning by discovery
creates a more powerful and lasting experience.
Learning by discovery occurs in serious research, when scientists notice an unusual phenomenon that cannot be explained by current theory, and they start to investigate it in an effort to explain it. This may ultimately lead to a better understanding of the world.
We’re going to be doing the same thing, although obviously on a much less ambitious level.
Along the way, you will make some mistakes. This is good. Mistakes are the best of all learning processes. I want you to burn things out and mess things up, because this is how you learn the limits of components and materials. Since we’ll be using low voltages, there’ll be no chance of electrocution, and so long as you limit the flow of current in the ways I’ll describe, there will be no risk of burning your fingers or starting fires.
Stay Within the Limits!
Although I believe that everything suggested in this book is safe, I’m assuming that you will stay within the limits that I suggest. Please always follow the instructions and pay attention to the warnings, denoted by the icon you see here. If you go beyond the limits, you will expose yourself to unnecessary risks.
Learning by discovery allows you to start building simple circuits right away, using a handful of cheap components, a few batteries, and some alligator clips.
How Hard Will It Be?
I assume that you’re beginning with no prior knowledge of electronics. So, the first few experiments will be ultra-simple, and you won’t even use solder or prototyping boards to build a circuit. You’ll be holding wires together with alligator clips.
Very quickly, though, you’ll be experimenting with transistors, and by the end of Chapter 2, you will have a working circuit that has useful applications.
I don’t believe that hobby electronics has to be difficult to understand. Of course, if you want to study electronics more formally and do your own circuit design, this can be challenging. But in this book, the tools and supplies will be inexpensive, the objectives will be clearly defined, and the only math you’ll need will be addition, subtraction, multiplication, division, and the ability to move decimal points from one position to another.
Moving Through This Book
Basically there are two ways to present information in a book of this kind: in tutorials and in reference sections. I’m going to use both of these methods. You’ll find the tutorials in sections headed as follows:
You’ll find reference sections under the following headings:
How you use the sections is up to you. You can skip many of the reference sections and come back to them later. But if you skip many of the tutorials, this book won’t be of much use to you. Learning by discovery means that you absolutely, positively have to do some hands-on work, and this in turn means that you have to buy some basic components and play with them. You will gain very little by merely imagining that you are doing this.
It’s easy and inexpensive to buy what you need. In almost any urban or suburban area in the United States, chances are you live near a store that sells electronic components and some basic tools to work with them. I am referring, of course, to RadioShack franchises. Some Shacks have more components than others, but almost all of them have the basics that you’ll need.
You can also visit auto supply stores such as AutoZone and Pep Boys for basics such as hookup wire, fuses, and switches, while stores such as Ace Hardware, Home Depot, and Lowe’s will sell you tools.
If you prefer to buy via mail order, you can easily find everything you need by searching online. In each section of the book, I’ll include the URLs of the most popular supply sources, and you’ll find a complete list of URLs in the appendix.
Mail-ordering components and tools
Here are the primary mail-order sources that I use myself online:
RadioShack, a.k.a. The Shack.
For tools and components. Not always the cheapest, but the site is easy and convenient, and some of the tools are exactly what you need.
Mouser, Digi-Key, and Newark are all good sources for components, usually requiring no minimum quantities.
All Electronics Corporation. A narrower range of components, but specifically aimed at the hobbyist, with kits available.
You can find surplus parts and bargains here, but you may have to try several eBay Stores to get what you want. Those based in Hong Kong are often very cheap, and I’ve found that they are reliable.
McMaster-Carr. Especially useful for high-quality tools.
Lowe’s and Home Depot also allow you to shop online.
You’ll find no shortage of parts, tools, kits, and gadgets online.
Maker Shed (
) offers a number of
companion kits, both toolkits and bundles of the various components used in the book’s experiments. This is a simple, convenient, and cost-effective way of getting all the tools and materials you need to do the projects in this book.
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