Experiment 1: Taste the Power!

Chapter Experiment 1: Taste the Power!

Make Electronics Book Learning by Discovery
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Make Electronics Book Learning by Discovery

  • Experiencing Electricity5Experiment 1: Taste the Power!Experiment 1: Taste the Power!Can you taste electricity? Maybe not, but it feels as if you can.You will need:• 9-volt battery• Snap connector for battery terminals • MultimeterProcedureMoisten your tongue and touch the tip of it to the metal terminals of a 9-volt battery. The sudden sharp tingle that you feel is caused by electricity flowing from one terminal of the battery (Figure 1-16), through the moisture on and in your tongue, to the other terminal. Because the skin of your tongue is very thin (it’s actually a mucus membrane) and the nerves are close to the surface, you can feel the electricity very easily.Now stick out your tongue, dry the tip of it very thoroughly with a tissue, and repeat the experiment without allowing your tongue to become moist again. You should feel less of a tingle. What’s happening here? We’re going to need a meter to find out. ToolsSettingupyourmeterCheck the instructions that came with the meter to find out whether you have to install a battery in it, or whether a battery is preinstalled.Most meters have removable wires, known as leads (pronounced “leeds”). Most meters also have three sockets on the front, the leftmost one usually be-ing reserved to measure high electrical currents (flows of electricity). We can ignore that one for now.The leads will probably be black and red. The black wire plugs into a socket labeled “COM” or “Common.” Plug the red one into the socket labeled “V” or “volts.” See Figures 1-17 through 1-20.The other ends of the leads terminate in metal spikes known as probes, which you will be touching to components when you want to make electrical mea-surements. The probes detect electricity; they don’t emit it in significant quan-tities. Therefore, they cannot hurt you unless you poke yourself with their sharp ends.If your meter doesn’t do autoranging, each position on the dial will have a number beside it. This number means “no higher than.” For instance if you want to check a 6-volt battery, and one position on the voltage section of the dial is numbered 2 and the next position is numbered 20, position 2 means “no higher than 2 volts.” You have to go to the next position, which means “no higher than 20 volts.” No More Than 9 VoltsA 9-volt battery won’t hurt you. But do not try this experiment with a higher-voltage battery or a larger battery that can deliver more cur-rent. Also, if you have metal braces on your teeth, be very careful not to touch them with the battery.Figure 1-16. Step 1 in the process of learn-ing by discovery: the 9-volt tongue test.Figure 1-17. The black lead plugs into the Common (COM) socket, and the red lead plugs into the red socket that’s almost always on the righthand side of a multimeter.