Electronics All-in-One For Dummies. Doug Lowe

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Chapter 4

      Staying Safe

      IN THIS CHAPTER

       Knowing the risks of working with electricity

       Protecting yourself from the perils of stray electricity

       Safeguarding your gear from static electricity

      When I was a kid, I helped a good friend named Barry who built a Tesla coil. By “helped,” I mean that I hung out in his garage and watched while he meticulously wrapped thousands of turns of bare copper wire around a huge glass milk bottle, painted it with dozens of coats of lacquer, and polished the brass ball that attached to the very top of the coil. I’m quite certain he couldn’t have done it without me.

      When it was done, we plugged it in and marveled at what it could do. Sparks flew at random a foot or two into the air from the ball at the top of the coil. If you held a crowbar in one hand, you could draw a spark several feet from the ball to the crowbar. The current coming off the ball flew through the air and into the crowbar, and then passed through our bodies and into the ground. You could also light up a fluorescent light tube simply by holding the tube in your hand within a few feet of the coil.

      To this day, I cannot believe Barry’s parents let him build it. I know my parents wouldn’t have let me build one. My mom was kind of like the mom in A Christmas Story, who wouldn’t let her son Ralphie have a Red Ryder BB gun (the one with a compass in the stock and this thing that tells time) because “you’ll shoot your eye out.”

      That was my mom. No Tesla coils for me. Too dangerous.

None of the electronic projects described in this book are anywhere near as dangerous as a Tesla coil. In fact, most of them pose no threat at all. That being said, it’s important to remember that whenever you’re working with electricity, you’re working with something that’s potentially very dangerous.

      The possibility of electric shock is always present whenever you work with electricity, but there are other potential dangers as well. You probably won’t shoot your eye out, but if you’re not careful, you might start a fire or otherwise injure yourself or someone else.

      The purpose of this chapter, then, is to keep you safe while you experiment with electronics. Please read it well, and please heed every bit of advice I give here.

Facing the Realities of Electrical Dangers

      There’s no escaping the simple fact that an electric shock, if strong enough, can kill you. So whenever you work with electricity, you must be sure to take every precaution you can to avoid being the recipient of a shock strong enough to do damage.

      In the United States, somewhere between 500 and 1,000 people die every year from accidental electrocutions. Many of those are industrial or weather-related accidents in which people come into contact with downed power lines. But many of them are completely avoidable accidents that happen in the home. In the sections that follow, I give you specific guidelines for avoiding accidental electrocution.

      Household electrical current can kill you!

      Too many people are under the false impression that the 120 volts of alternating current running through household electrical wires isn’t enough to kill. So let’s start by getting one fact straight:

       The electricity in your home wiring system is more than strong enough to kill you.

You’re exposed to household electrical current primarily in two places: in electrical outlets and in the lamp sockets within light fixtures. As a result, you should be extra careful whenever you plug or unplug something into or from an electrical outlet, and you should be careful whenever you change a light bulb. Specifically, you should follow these precautions: