Electronics, mechanics, robotics: Huh?
Do you dream of building elaborate Erector Set-types
of mechanical structures — perhaps a model of the Golden Gate Bridge
with pulleys and levers moving objects around? Is your goal to create a
robot butler with a programmed brain that enables it to serve your every
whim? Well, those aren’t exactly what we categorize as electronics
projects. Certainly, electronics projects are often combined with
mechanical structures that use motors, and a robot has electronic
components driven by microcontrollers and computer programs. In this
book, though, we focus on projects that use simple electronics
components to form a circuit that directs voltage to produce effects
such as motion, sound, or light. By keeping to this simple approach, you
can pick up all the basic skills and discover all the common components
and tools that you need to work on a wide variety of projects for years
to come. For these projects, you don’t have to become a mechanical or
programming whiz. An electronic circuit might run a motor, light an LED
display, or set off sounds through a speaker. It uses various components
to regulate the voltage, such as capacitors and resistors. A circuit can
also use integrated circuits (ICs), which are teeny, tiny circuits that
provide a portion of your circuit in a very compact way. This saves you
time micromanaging pieces of the project because somebody else has
already done that job for you, such as building a timer chip that sets
off a light intermittently.
Programmable versus nonprogrammable
ICs are preprogrammed or programmable. And that
brings us to our next distinction. Although we do use ICs in many of our
projects — for example, in the form of a sound chip that’s preprogrammed
with beeps and music — for the most part, we keep away from programmable
electronics. In order to work with programmable electronics, you have to
get your hands dirty with programming code and microcontrollers, and
that’s not what we’re about here. Instead, we focus on building
electronics gadgets that teach you about how electricity works and get
your mind stirring with ideas about what you can do by using
electronics, rather than computers. Don’t get us wrong: Microcontroller
projects can be a lot of fun.
Mixing and Matching Effects
The possibilities of what electronics projects can do
are probably endless; on a basic level, the projects in this book use
electricity to do a variety of things, from running a small cart around
the room to setting off a sequence of lights or sounds. Generally, most
electronics projects consist of four types of elements:
This sets off the
effect, such as a remote control device or a switch that you push.
An event and a sensor, such as a motion or light detector, can also
be used to activate an effect.
We typically use
batteries in these projects.
control the voltage — such as transistors, capacitors, amplifiers,
and resistors — are connected to each other and to the power source
by wires and make up the circuit.
This is what is
powered by the circuit to produce an effect, such as speaker
emitting sound, LED lights going off, or a motor that sets attached
Battery-powered versus 120 volts+
One other thing that we made a conscious decision
about when writing this book was that we didn’t want you tinkering with
high-voltage projects. Electricity can be dangerous! Keeping to about 6
volts keeps you reasonably safe whereas working with something that uses
120 volts — like the juice that comes out of your wall socket — can kill
you. While you’re discovering the basics of electronics, our advice is
that it’s better to be safe than sorry. When you get more comfortable
and more knowledgeable about tools and skills and safety measures (which
we put a lot of emphasis on, especially in "Avoiding shocks" section), you might explore
higher-voltage projects such as high-powered audio or ham radio
projects. In this book, we show you how to work with low-voltage
batteries and still have fun in the process.
What Can You Do with Electronics Projects?
You get to explore a number of variations in the
projects in this book. And sure, this stuff sounds like it might be
cool, but what’s in it for you? Electronics projects offer three
benefits (at least):
of making something work all by yourself
of useful knowledge