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CHAPTER 8. ABOUT THIS BOOK
under copyright is whimsically termed copyleft. Anyone can "copyleft" their creative work simply
by appending a notice to that effect on their work, but several Licenses already exist, covering the
fine legal points in great detail.
The first such License I applied to my work was the GPL General Public License of the
Free Software Foundation (GNU). The GPL, however, is intended to copyleft works of computer
software, and although its introductory language is broad enough to cover works of text, its wording
is not as clear as it could be for that application. When other, less specific copyleft Licenses began
appearing within the free software community, I chose one of them (the Design Science License, or
DSL) as the official notice for my project.
In "copylefting" this text, I guaranteed that no instructor would be limited by a text insufficient
for their needs, as I had been with error-ridden textbooks from major publishers. I'm sure this book
in its initial form will not satisfy everyone, but anyone has the freedom to change it, leveraging my
efforts to suit variant and individual requirements. For the beginning student of electronics, learn
what you can from this book, editing it as you feel necessary if you come across a useful piece of
information. Then, if you pass it on to someone else, you will be giving them something better than
what you received. For the instructor or electronics professional, feel free to use this as a reference
manual, adding or editing to your heart's content. The only "catch" is this: if you plan to distribute
your modified version of this text, you must give credit where credit is due (to me, the original
author, and anyone else whose modifications are contained in your version), and you must ensure
that whoever you give the text to is aware of their freedom to similarly share and edit the text. The
next chapter covers this process in more detail.
It must be mentioned that although I strive to maintain technical accuracy in all of this book's
content, the subject matter is broad and harbors many potential dangers. Electricity maims and
kills without provocation, and deserves the utmost respect. I strongly encourage experimentation
on the part of the reader, but only with circuits powered by small batteries where there is no risk of
electric shock, fire, explosion, etc. High-power electric circuits should be left to the care of trained
professionals! The Design Science License clearly states that neither I nor any contributors to this
book bear any liability for what is done with its contents.
8.2
The use of SPICE
One of the best ways to learn how things work is to follow the inductive approach: to observe
specific instances of things working and derive general conclusions from those observations. In
science education, labwork is the traditionally accepted venue for this type of learning, although
in many cases labs are designed by educators to reinforce principles previously learned through
lecture or textbook reading, rather than to allow the student to learn on their own through a truly
exploratory process.
Having taught myself most of the electronics that I know, I appreciate the sense of frustration
students may have in teaching themselves from books. Although electronic components are typically
inexpensive, not everyone has the means or opportunity to set up a laboratory in their own homes,
and when things go wrong there's no one to ask for help. Most textbooks seem to approach the task
of education from a deductive perspective: tell the student how things are supposed to work, then
apply those principles to specific instances that the student may or may not be able to explore by
themselves. The inductive approach, as useful as it is, is hard to find in the pages of a book.
However, textbooks don't have to be this way. I discovered this when I started to learn a