When you've finished building a circuit, the fun is often just beginning! As you build more and more circuits, you'll find that your experience lets you work with equipment of all sorts. In this part, we touch on techniques for maintenance and troubleshooting that you'll find very handy in the days of circuitbuilding that lie ahead for you.

Chapter 15 is devoted to that ubiquitous energy source, the battery. With so many types and styles available, how do you choose just one — and why do they perform the way they do? Read and behold the secrets revealed!

Electronics are seemingly everywhere and that extends to vehicles. Your car is full of electronics and opportunities abound for adding more. The automotive environment presents its own special challenges, so we'll review the basics of mobile installation. With electronics cropping up everywhere, all that equipment and all those gadgets may interact in ways not intended by their designers! Chapter 17 presents some techniques for dealing with noise to (and from!) your circuits.