Unit 10 Module 1: Circuits – Supercharged Science

What IS electricity, anyway? You can’t see it, but you can certainly detect its effects. Blenders, washing machines, vacuum cleaners, airplanes – all of these use electricity. While you don’t need to understand electricity to turn on a light, you do need to cover the basics in order to make the burglar alarms, remote controls, and robot projects in this unit! I’ll show you how to convert your kitchen table into a real Electric Lab. Are you ready?

Why study electricity? While it’s true that you don’t need to know how electricity works in order to flip on a light switch, but you do need to know a thing or two about circuits before you start wiring up your own robot. Electricity is all around you from the tiny subatomic level of the electron to the gigantic solar storms from the sun. When you’re done with this lesson, you’ll know how to wire up circuits for underwater vehicles, create your own robotics sensors, extract energy from fruit, split a water molecule, and really make sparks fly. Are you ready? This video will get you started on the right foot for your study into electricity:

You can get started by watching this video, and afterward either read more about it or start your experiments!

Scientific Concepts:

The proton has a positive charge, the neutron has no charge (neutron, neutral get it?) and the electron has a negative charge.
These charges repel and attract one another kind of like magnets repel or attract. Like charges repel (push away) one another and unlike charges attract one another.
Generally things are neutrally charged. They aren’t very positive or negative, rather have a balance of both.
Objects that are electrically charged can create a temporary charge on another object.
The triboelectric series is a list that ranks different materials according to how they lose or gain electrons.
LED stands for “Light Emitting Diode”. Diodes are one-way streets for electricity – they allow electrons to flow one way but not the other.
When electric current passes through a material, it does it by electrical conduction.
There are different kinds of conduction, such as metallic conduction, where electrons flow through a conductor (like metal) and electrolysis, where charged atoms (called ions) flow through liquids.
Metals are conductors not because electricity passes through them, but because they contain electrons that can move.

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	Special Science Teleclass: Electricity This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn, too! We’re going to study electrons and static charge. Kids will build simple electrostatic motor to help them understand how like charges repel and opposites … Continue reading "Special Science Teleclass: Electricity"
	Basic Circuits An electrical circuit is like a raceway or running track at school. The electrons (racecars) zip around the race loop (wire circuit) superfast to make stuff happen. Although you can’t see the electrons zipping around the circuit, you can see the effects: lighting up LEDs, sounding buzzers, clicking relays, etc. There are many different electrical … Continue reading "Basic Circuits"
	Electrical Safety – Best Batteries to Use Before you reach for the pack of Duracells, watch our video on the best batteries to use when starting out with your electricity experiments. (The answer is much cheaper than you think.) Here’s what you need to know:
	Conductivity Testers Make yourself a grab bag of fun things to test: copper pieces (nails or pipe pieces), zinc washers, pipe cleaners, Mylar, aluminum foil, pennies, nickels, keys, film canisters, paper clips, load stones (magnetic rock), other rocks, and just about anything else in the back of your desk drawer. Certain materials conduct electricity better than others. … Continue reading "Conductivity Testers"
	Simple Switches When you turn on a switch, it’s difficult to really see what’s going on… which is why we make our own from paperclips, brass fasteners, and index cards. Kids can see the circuit on both sides of the card, so it makes sense why it works (especially after doing ‘Conductivity Testers’). SPST stands for Single … Continue reading "Simple Switches"
	Wiring Up Motors Imagine you have two magnets. Glue one magnet on an imaginary record player (or a ‘lazy susan’ turntable) and hold the other magnet in your hand. What happens when you bring your hand close to the turntable magnet and bring the north sides together? The magnet should repel and move, and since it’s on a … Continue reading "Wiring Up Motors"
	Dimmers and Motor Speed Controllers So now you know how to hook up a motor, and even wire it up to a switch so that it goes in forward and reverse. But what if you want to change speeds? This nifty electrical component will help you do just that. Once you understand how to use this potentiometer in a circuit, … Continue reading "Dimmers and Motor Speed Controllers"
	Forward and Reverse Motor Control Once you’ve made a a simple switch, you’re ready to use more advanced electrical components, such as the DPDT switch you picked up from an electronics store (refer to shopping list for this section). When you wire up this nifty device, you’ll be able to get your motors to go forward, reverse, and stop… all with … Continue reading "Forward and Reverse Motor Control"
	Electric Eye Sensor This is a super-cool and ultra-simple circuit experiment that shows you how a CdS (cadmium sulfide cell) works. A CdS cell is a special kind of resistor called a photoresistor, which is sensitive to light. A resistor limits the amount of current (electricity) that flows through it, and since this one is light-sensitive, it will … Continue reading "Electric Eye Sensor"
	Trip Wire Burglar Alarm Burglar alarms not only protect your stuff, they put the intruder into a panic while they attempt to disarm the triggered noisemaker. Our burglar alarms are basically switches which utilize the circuitry from Basic Circuits and clever tricks in conductivity. A complete and exhaustive description of electronics would jump into the physics of solid state … Continue reading "Trip Wire Burglar Alarm"
	Pressure Sensor By controlling how and when a circuit is triggered, you can easily turn a simple circuit into a burglar alarm – something that alerts you when something happens. By sensing light, movement, weight, liquids, even electric fields, you can trigger LEDs to light and buzzers to sound. Your room will never be the same. Switches … Continue reading "Pressure Sensor"
	More Sensors If you want your robot to detect when it’s flipped sideways, this is the sensor you need. It’s ridiculously simple to make, and works great as long as the metal makes good contact. I’ve also included instructions for making a motion sensor as well, just in case you need to detect motion or acceleration.
	Latching Circuit Once you’ve made the Pressure Sensor burglar alarm, you might be wondering how to make the alarm stay on after it has been triggered, the way the Trip Wire Sensor does. The reason this isn’t as simple as it seems is that the trip wire is a normally closed (NC) switch while the pressure sensor … Continue reading "Latching Circuit"
	Nerve Tester Electrical circuits are used for all kinds of applications, from blenders to hair dryers to cars. And games! Here’s a quick and easy game using the principles of conductivity. This experiment is a test of your nerves and skill to see if you can complete the roller coaster circuit and make it from one end … Continue reading "Nerve Tester"
	How to use a Digital MultiMeter One of the most useful tools a scientist can have! A digital multimeter can quickly help you discover where the trouble is in your electrical circuits and eliminate the hassle of guesswork. When you have the right tool for the job, it makes your work a lot easier (think of trying to hammer nails with … Continue reading "How to use a Digital MultiMeter"
	Electroscope When high energy radiation strikes the Earth from space, it’s called cosmic rays. To be accurate, a cosmic ray is not like a ray of sunshine, but rather is a super-fast particle slinging through space. Think of throwing a grain of sand at a 100 mph… and that’s what we call a ‘cosmic ray’. Build your … Continue reading "Electroscope"
	Cosmic Ray Detector When high energy radiation strikes the Earth from space, it’s called cosmic rays. To be accurate, a cosmic ray is not like a ray of sunshine, but rather is a super-fast particle slinging through space. Think of throwing a grain of sand at a 100 mph… and that’s what we call a ‘cosmic ray’.
	Ten Static Electricity Experiments to Mystify Your Kids The smallest thing around is the atom, which has three main parts – the core (nucleus) houses the protons and neutrons, and the electron zips around in a cloud around the nucleus. The proton has a positive charge, and the electron has a negative charge. In the hydrogen atom, which has one proton and one … Continue reading "Ten Static Electricity Experiments to Mystify Your Kids"
	Seeing Electric Fields Using Your Spice Rack Have you wrapped your mind around static electricity yet? You should understand by now how scuffing along a carpet in socks builds up electrons, which eventually jump off in a flurry known as a spark. And you also probably know a bit about magnets and how magnets have north and south poles AND a magnetic … Continue reading "Seeing Electric Fields Using Your Spice Rack"
	Advanced Static Electricity Experiments You can use the idea that like charges repel (like two electrons) and opposites attract to move stuff around, stick to walls, float, spin, and roll. Make sure you do this experiment first. I’ve got two different videos that use positive and negative charges to make things rotate, the first of which is more of … Continue reading "Advanced Static Electricity Experiments"
	Advanced Static Lab If you have a Fun Fly Stick, then pull it out and watch the video below. If not, don't worry - you can do most of these experiments with a charged balloon (one that you've rubbed on your hair). Let' play with a more static electricity experiments, including making things move, roll, spin, chime, light … Continue reading "Advanced Static Lab"
	Alien Detector (Advanced) This simple FET circuit is really an electronic version of the electroscope. This “Alien Detector” is a super-sensitive static charge detector made from a few electronics parts. I originally made a few of these and placed them in soap boxes and nailed the lids shut and asked kids how they worked. (I did place a … Continue reading "Alien Detector (Advanced)"
	Electrolytes When an atom (like hydrogen) or molecule (like water) loses an electron (negative charge), it becomes an ion and takes on a positive charge. When an atom (or molecule) gains an electron, it becomes a negative ion. An electrolyte is any substance (like salt) that becomes a conductor of electricity when dissolved in a solvent … Continue reading "Electrolytes"
	Electrolysis This experiment is just for advanced students. If you guessed that this has to do with electricity and chemistry, you’re right! But you might wonder how they work together. Back in 1800, William Nicholson and Johann Ritter were the first ones to split water into hydrogen and oxygen using electrolysis. (Soon afterward, Ritter went on to … Continue reading "Electrolysis"
	Electroplating If you don’t have equipment lying around for this experiment, wait until you complete Unit 10 (Electricity) and then come back to complete this experiment. It’s definitely worth it! Electroplating was first figured out by Michael Faraday. The copper dissolves and shoots over to the key and gets stuck as a thin layer onto the … Continue reading "Electroplating"
	Fruit Battery This experiment shows how a battery works using electrochemistry. The copper electrons are chemically reacting with the lemon juice, which is a weak acid, to form copper ions (cathode, or positive electrode) and bubbles of hydrogen. These copper ions interact with the zinc electrode (negative electrode, or anode) to form zinc ions. The difference in … Continue reading "Fruit Battery"
	Salty Battery Using ocean water (or make your own with salt and water), you can generate enough power to light up your LEDs, sound your buzzers, and turn a motor shaft. We’ll be testing out a number of different materials such as copper, aluminum, brass, iron, silver, zinc, and graphite to find out which works best for … Continue reading "Salty Battery"
	Silver Battery Never polish your tarnished silver-plated silverware again! Instead, set up a ‘silverware carwash’ where you earn a nickel for every piece you clean. (Just don’t let grandma in on your little secret!) We’ll be using chemistry and electricity together (electrochemistry) to make a battery that reverses the chemical reaction that puts tarnish on grandma’s good … Continue reading "Silver Battery"
	Air Battery It’s easy to use chemistry to generate electricity, once you understand the basics. With this experiment, you’ll use aluminum foil, salt, air, and a chemical from an aquarium to create an air battery. This experiment is for advanced students.

Scientific Concepts:

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