✓ Solderless breadboard: You use a solderless (pronounced “sodd-er-less”) breadboard like the one shown in Figure 1-2 to build circuits. Purchase a breadboard that has at least 830 contact holes (also called tie points) and includes power rails (also called power lanes or bus lines), such as Tayda Electronics #A-2372 ($4.59) or RadioShack #2760001 ($22.00).
✓ Wire stripper/cutter: You use this tool to cut wires, trim component leads, and strip insulation from the end of wires. I recommend getting a gauged wire stripper/cutter (Figure 1-3, left), but you can use an adjustable wire stripper/cutter (Figure 1-3, right) instead. Make sure your wire stripper can be adjusted to strip 22-gauge (22 AWG) wire. ($7.00–$20.00 at RadioShack, hardware stores, or Walmart.)
✓ Needle-nose pliers: Pictured in Figure 1-4, needle-nose pliers help you bend leads and wire and make it easier to insert and remove components from your solderless breadboard. (Check your family’s toolbox or get a set of 5-inch pliers for $6.00–$12.00 at a hardware store or Walmart.)
✓ Antistatic wrist strap: You use a strap like the one in Figure 1-5 to prevent the charges that build up on your body from zapping – and potentially damaging – the static-sensitive 4017 integrated circuit (IC) (used in Projects 12 and 13) during handling. Buy RadioShack #2762395, Zitrade #S-W-S-1, or similar. ($9.00 in select RadioShack stores; $2.00–$12.00 on Amazon.com, Walmart.com, and Newark.com.)
✓ Safety glasses: Okay, so you risk looking a bit geeky wearing safety glasses like the ones shown in Figure 1-6 while you work on your electronics projects. But better to look geeky than to not be able to look at all because the wire that you just clipped went flying into your eye. (3M #11228-00000-100 is actually attractive and costs about $1.00 on Amazon.com.)
✓ Electrical tape: You need about 4–6 inches of 3/4-inch electrical tape, such as Scotch #4218-BA-40. ($2.00 per roll at Walmart or any hardware store.)
✓ Hot glue gun: This item is optional for Project 14. You can purchase one at any craft store.
✓ One 9-by-12-inch sheet of adhesive craft foam: Check your local craft store (roughly $1.00). (Amazon and Walmart sell multipacks for $12.00–$15.00.)
✓ One package of assorted grit sandpaper: If you don’t already have this, you can purchase it from any hardware store, Walmart, Amazon.com, and other suppliers ($5.00 or less).
✓ Assorted household items: One toilet paper roll, one paper towel roll, aluminum foil, one sheet of plain white paper, transparent tape, a ruler, a magnifying glass (optional), and one piece of cardboard or a plastic lid (optional).
Project 2
LED Flashlight
One of the many fun things you can do with electronics is control lights. You can turn lights on and off, have them turn on only when the room gets dark, make them blink, change their timing, and much more.
For your first circuit-building project, you make your own flashlight using a special kind of electronic light bulb known as an LED (which is short for light-emitting diode).
So let’s getting started making an LED flashlight!
The main ingredients of your LED flashlight are a battery, an LED, and a resistor. They are the components of your circuit. Each component is like a piece of a puzzle: It has a certain job to do and it works with the other components to form the completed circuit.
Using electrical tape and craft foam, you can transform your three-component circuit into a portable, brightly colored device that you can show off – maybe even sell – to your friends.
Check out Project 1 for where to buy parts, tools, and other supplies. Grab a pair of scissors and your needle-nose pliers, then gather the items in the following list (shown in Figure 2-1):
✓ One 9-volt battery
✓ One ultrabright clear 5 millimeter LED
✓ One 470 Ω resistor (look for a stripe pattern of yellow, violet, brown, and then any color stripe)
✓ A roll of 3/4-inch wide electrical tape (you need roughly 4 inches in length from this roll)
✓ One 9-by-12-inch sheet of adhesive-backed craft foam (any color)
Before you start building your flashlight, you should know a few things about the three main circuit components (the battery, LED, and resistor).
Chances are you’re familiar with 9-volt batteries like the one in Figure 2-1. The battery’s job is to provide the electrical energy needed to power the LED in your flashlight circuit.
Explore your battery
Every battery has two terminals, which are the metal pieces that stick out from the top of a 9-volt battery (see Figure 2-2) or the metal ends of an AA, AAA, C, or D battery. One terminal is positive and is labeled with a +. The other terminal is negative and isn’t labeled. Locate the positive and negative terminals on your 9-volt battery. Note that the two terminals look different.
When you connect your battery in a circuit, you connect the positive terminal to one part of the circuit and the negative terminal to another part of the circuit. The battery voltage is a form of energy (specifically, potential energy) that exists between the two terminals. Voltage is measured in volts, which is abbreviated V.
Voltage and current
When you connect a battery in a circuit, the battery’s voltage forces electrons to flow out of the battery, through the circuit, and then back into the battery. But what are electrons, you ask?
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