sells 5 mm LEDs for $0.03 each in green (#A-1553), red (#A-1554), and yellow (#A-1555), as well as other colors and sizes for a few pennies each. (I suggest you buy ten red, ten yellow, and ten green.)
• Eight ultrabright clear LEDs, 5 mm, white. Tayda Electronics #A-408 ($0.05 each).
• Ten 1N4148 or 1N914 small signal diodes. Tayda Electronics #A-157 ($0.01 each) or #A-615 ($0.03 each).
• One 1N34/1N34A germanium diode. Tayda Electronics #A-1716 ($0.24).
✓ Transistors: Buy one or two more than the minimum specified quantity of each type, just in case you fry one. They cost pennies each online, or $1.49 each in RadioShack stores.
• Two 2N3904 general-purpose NPN bipolar transistors. Tayda Electronics #A-111 ($0.02).
• One 2N3906 general-purpose PNP bipolar transistor. Tayda Electronics #A-117 ($0.02).
✓ Integrated circuits (ICs):
• Two 555 timers (8-pin DIP). Splurge and buy four or five! Tayda Electronics #A-249 ($0.13 each).
• One LM386 audio power amplifier (8-pin DIP). Get two because they’re so cheap. Tayda Electronics #A-206 ($0.23).
• One 4017 CMOS decade counter. Buy at least two because these chips are sensitive to static discharge. Tayda Electronics #A-020 ($0.30 each).
✓ Miscellaneous:
• One 8 Ω, 0.5 W speaker. Tayda Electronics #A-4140 ($1.28), RadioShack #2730092 ($3.99), or similar.
• One or more light-dependent resistor (LDR, or photoresistor). (any value). Tayda Electronics #A-1528 ($0.24) or similar.
• One spool (at least 50 feet) of 24 gauge (AWG) magnet wire. You need this expensive item if you choose to build the radio in Project 14. Temco #MW0190 or similar. ($6.00–$15.00 online at Amazon or eBay.)
• (Optional) One cheap ($10.00 or less) 3.5 mm audio headset. This headset is optional for Project 14. Check Walmart or your local dollar or other discount store.
You need the following hand tools and other supplies to help you build your projects:
✓ 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
