The Basics of Circuit Making

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.

But as the complexity of the electronics increases, so does the need to place all or most of the components in one handy spot. This is the job of the circuit board. Some types of circuit boards don’t require soldering, and some do. The most commonly used circuit board–making techniques are outlined here; each is detailed more fully in Chapters 32 and 33.

Solderless Breadboards

Solderless breadboards allow you to quickly build and test a circuit, without the trouble of soldering. Then, when you are assured that the circuit works—and only if you want to—you may commit the design permanently using one of the other construction techniques.

I urge you to first test all the circuits you build on a solderless breadboard. You’ll find that you can often improve the performance of the circuit just by changing a few component values. These changes are easier to make when you can simply remove one component and exchange it for another.

Permanent Circuits on Solderboards

The soldered breadboard (also called a universal solderboard or experimenter’s PC board) allows you to make permanent any design you create on a solderless breadboard. This board comes pre-etched with the same electrical connection points as the solderless breadboard just described. You simply solder the components into place, using jumper wires to connect components that can’t be directly tied together.

Find out more about soldered breadboards in Chapter 33, “Making Circuit Boards.”

Point-topoint Perforated Boards

Point-to-point “perf” board construction refers to the process of mounting the components on predrilled circuit board material and connecting the various components together directly, with wire and solder.

There are many different designs of point-to-point boards, so you can match the best board to your project. Read more about perf boards in Chapter 33, “Making Circuit Boards.”

Wire Wrapping

Wire wrapping is a process of using a special tool to connect thin insulated wires from one component to another in order to complete the circuit. Wire wrapping is considered a permanent construction technique because once (properly) wrapped, the wires do not come off.

However, because the wrapped wires aren’t typically soldered in, wire-wrapped projects can be redone and reworked. This is one of their chief advantages, though in this age of simplified circuits through the use of microcontrollers, wire wrapping is seeing less use. Read more about wire wrapping in Chapter 33, “Making Circuit Boards.”

Custom Printed Circuit Boards

A printed circuit board is the ultimate in soldered electronic circuits, and with time and some skill, you can make your own. It’s a “printed” circuit board because the interconnections of the circuit are part of the copper metal bonded to the board. Wires are only sometimes used to connect components together.

You have the option of creating a custom printed circuit board (PCB) entirely at home, though this does require the use of some nasty (and potentially harmful) chemicals. Or you can prepare the layout of your PCB and submit it to one of many online services that will produce the finished board for you.