Amphibionics P2

Amphibionics quick-setting epoxy (T) to secure parts. Safety glasses (U) should be worn at all times when cutting and drilling metal or soldering. Test Equipment To calibrate and troubleshoot the electronics, you will need a dig-ital multimeter with frequency counting capabilities, similar to the Fluke 87 multimeter (Figure 1.14, left). When working with elec-tronic circuits, a good multimeter is invaluable. The second multi-meter in Figure 1.14 (right) is manufactured by Circuit Test and measures capacitance, resistance, and inductance. It is nice to be able to measure the exact values of components when working on precise circuits, but in most cases, this is not necessary. If you are winding your own transformers or chokes, the ability to measure inductance will be helpful. The specific use of the multimeter will be explained during the construction of the robot’s electronics in later chapters. FIGURE 1.14 Fluke and Circuit Test multimeters. 10 Chapter 1 / Tools, Test Equipment, and Materials If you are really serious about electronics, then an oscilloscope, like the one pictured in Figure 1.15, is a great investment. This is the Tektronix TDS 210 dual channel, digital real-time oscilloscope, with a 60-MHz bandwidth. The TDS 210 on my bench also has the RS-232, GPIB, and centronics port module added, so that a hard copy of waveforms can be output. The great advantage to using an oscilloscope is the ability to visualize what is happening with a circuit. The new digital oscilloscopes also automatically calculate the frequency, period, mean, peak to peak, and true RMS of a waveform. You will probably need to use a regulated direct current (DC) power supply and a function generator quite often as well. None of the equipment shown in Figure 1.15 is required when building the robots in this book, but it will make your life as an FIGURE 1.15 Oscilloscope, regulated DC power supply, and function generator. 11 Amphibionics electronics experimenter much easier. There is nothing more frustrating than finding out that a circuit you are working on is malfunctioning because of a dead battery or an oscillator cali-brated to the wrong frequency. If you use a good power supply and oscilloscope when building and testing a circuit, the chance of these kinds of problems surfacing is much lower. I have always found that if I am working late at night and start to encounter a lot of small problems and make mistakes, the best thing to do is to shut my equipment down and get a good night’s sleep. Sometimes the difference between frying an expensive chip or the circuit’s working perfectly on the first try is just one mis-placed component. Construction Materials The robots in this book are constructed using aluminum and fas-teners that are readily available at most hardware stores. Five sizes of aluminum will be used. The first stock measures 1/2-inch wide by 1/8-inch thick, and is usually bought in lengths of 4 feet or longer. Many of the robot parts are constructed from aluminum, with the dimensions as shown in Figure 1.16. FIGURE 1.16 1/2-inch by 1/8-inch aluminum stock. 12 Chapter 1 / Tools, Test Equipment, and Materials FIGURE 1.17 Aluminum stock with 1/4-inch by 1/4-inch dimensions. The second type of aluminum stock that will be used measures 1/4-inch 1/4-inch, and is shown in Figure 1.17. It is usually bought in lengths of 4 feet or longer as well. The third kind of aluminum stock is 1/2-inch 1/2-inch angle aluminum, and is 1/16-inch thick, as shown in Figure 1.18. The fourth type is 1/16-inch thick flat aluminum, as shown in Figure 1.19, and it is usually bought in larger sheets. However, most metal suppliers will cut it down for you. This thickness of aluminum is great for cutting out custom parts and it is easy to FIGURE 1.18 1/2-inch angle aluminum. 13 Amphibionics FIGURE 1.19 1/16-inch thick flat aluminum. bend, making it ideal for the hobbyist experimenter. I buy all of my metal from a company called The Metal Supermarket (www.metalsupermarkets.com) because its prices are much lower than buying metal at a hardware store. Their friendly staff is always helpful, and will cut the stock to whatever size you require. I usually ask them to cut the raw stock in half so that it will fit into the back seat of my car. The fifth type of stock that will be needed is 3/4-inch 3/4-inch angle aluminum. The fasteners that will be used are 6/32-inch diameter machine screws, nuts, lock washers, locking nuts, and nylon washers, as shown in Figure 1.20. Three different lengths of machine screws will be used: 1-inch, 3/4-inch, and 1/2-inch. 14 ... - tailieumienphi.vn