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370 BUILDING ROBOT ELECTRONICS— THE BASICS

Always wear eye protection when using flush wire cutters or, for that matter, any wire- cutting
tool. It’s quite common for wires to literally shoot out at high velocity when cut. You don’t want
anything flying into your eyes.

Making Electronic Circuits— the Basics

You have at your disposal numerous ways to construct the electronic circuits for your robots.
Those designs involving only switches and batteries and motors can simply be wired together,
one to the other, and there is no need to centralize the components in a single place. Options
include:

• Solderless breadboard. Quickly and easily construct circuits by plugging components into
sockets on a plastic board. No soldering necessary. See Chapter 32, “Using Solderless
Breadboards” for more information.
• Permanent circuit board. Select from among several methods for soldering parts to build
a permanent circuit. You can use generic boards that accept common components, or
design your own printed circuit board (PCB). See Chapter 33, “Making Circuit Boards” for
details.
• Wire wrapping. Use a low- cost tool to interconnect electronic components with very fine
wire. See how in Chapter 33.

Understanding Wires and Wiring

Almost every electronic circuit uses wire of one kind or another. Wiring is a science all to itself,
but we’ll concentrate just on three main aspects: insulation, gauge, and conductor type.

INSULATION

Most of the wire used in building robot electronics is insulated with a plastic covering. This
keeps one wire from touching another and causing a short circuit. Apart from esoteric aspects
about insulation, the most important is its color. Get into the habit of using different- color
wiring to denote what it’s being used for in your circuit. For example, red wire is often used
for the + (positive) battery connection; black wire for the (negative) connection.

GAUGE

The thickness, or gauge, of the wire determines its current- carrying capabilities. Generally,
the larger the wire, the more current it can pass without overheating and burning up.
See Appendix D, “Electronic Reference,” for common wire gauges and the maximum
accepted current capacity, assuming reasonable wire lengths of 5 feet or less. When you are
constructing circuits that carry high currents, be sure to use the proper gauge of wire. Con-
versely, there’s no need to use wires that are way too large for their job. That just makes
things bulkier and harder to solder together.

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