Unit 10 (Electricity) – Supercharged Science

Electrolysis

Friday April 5, 2019

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 figure out electroplating.) They added energy in the form of an electric current into a cup of water and captured the bubbles forming into two separate cups, one for hydrogen and other for oxygen.

This experiment is not an easy one, so feel free to skip it if you need to. You don’t need to do this to get the concepts of this lesson but it’s such a neat and classical experiment (my students love it) so you can give it a try if you want to. The reason I like this is because what you are really doing in this experiment is ripping molecules apart and then later crashing them back together.

Have fun and please follow the directions carefully. This could be dangerous if you’re not careful. The image shown here is using graphite from two pencils sharpened on both ends, but the instructions below use wire. Feel free to try both to see which types of electrodes provide the best results.

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Advanced Static Lab

Friday April 5, 2019

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 up, wiggle and more using static electricity! Please login or register to read the rest of this content.

Electric Eye Sensor

Friday April 5, 2019

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 allow different amounts of current through depends on how much light it “sees”.

Photoresistors are very inexpensive light detectors, and you’ll find them in cameras, street lights, clock radios, robotics, and more. We’re going to play with one and find out how to detect light using a simple series circuit.

Materials:

AA battery case with batteries
one CdS cell
three alligator wires
LED (any color and type)

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Pressure Sensor

Wednesday April 15, 2015

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 control the flow of electricity through a circuit. There are different kinds of switches. NC (normally closed) switches keep the current flowing until you engage the switch. The SPST and DPDT switches are NO (normally open) switches.

The pressure sensor we’re building is small, and it requires a fair amount of pressure to activate. Pressure is force (like weight) over a given area (like a footprint). If you weighed 200 pounds, and your footprint averaged 10” long and 2” wide, you’d exert about 5 psi (pounds per square inch) per foot.

However, if you walked around on stilts indeed of feet, and the ‘footprint’ of each stilt averaged 1” on each side, you’d now exert 100 psi per foot. Why such a difference?

The secret is in the area of the footprint. In our example, your foot is about 20 square inches, but the area of each stilt was only 1 square inch. Since you haven’t changed your weight, you’re still pushing down with 200 pounds, only in the second case, you’re pressing the same weight into a much smaller spot… and hence the pressure applied to the smaller area shoots up by a factor of 20.

So how do we use pressure in this experiment? When you squeeze the foam, the light bulb lights up! It’s ideal for under a doormat or carpet rug where lots of weight will trigger it.

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Electroscope

Wednesday November 5, 2014

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 own electroscope with this video!

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Special Science Teleclass: Robotics

Monday November 3, 2014

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!

Spark together electric motors, build homemade burglar alarms, wire up circuits and build your own robot from junk! Create your own whizzing, hopping, dancing, screeching, swimming, crawling, wheeling, robot during class. We'll cover hot topics in electricity, magnetism, electrical charges, robot construction, sensors and more.

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Special Science Teleclass: Electricity

Monday October 13, 2014

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 attract. After you’ve completed this teleclass, be sure to hop on over the teleclass in Robotics!

Electrons are strange and unusual little fellows. Strange things happen when too many or too few of the little fellows get together. Some things may be attracted to other things or some things may push other things away. Occasionally you may see a spark of light and sound. The light and sound may be quite small or may be as large as a bolt of lightning. When electrons gather, strange things happen. Those strange things are static electricity.

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Cosmic Ray Detector

Thursday August 1, 2013

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Amphibious Robot

Tuesday June 14, 2011

Amphibious vehicles is a craft which travels on both land and water. And it doesn't need to be limited to just cars. There are amphibious bicycles, buses, and RVs. Hovercraft are amphibious, too!

Amphibious crafts started back in the 1800s as steam-powered barges. In the 1950s, the German Schimmwagen was a small jeep that could travel in water as well as on land. The most popular amphibious vehicle on the market is the 1960 Amphibicar (photo shown left) and later the Gibbs Aquada.

The secret to making an amphibious vehicle is this: it must be designed so it floats in water (it must be watertight and buoyant) and robust enough to travel on land. Many amphibious creations either leaked, sank, or never made it off the drawing board. But that's what being a scientist is all about: coming up with an overall goal and figuring out a way to overcome the problems faced along the way.

We're going to build our own version using items like foam blocks and hobby motors. Are you ready?
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Propeller Car

Monday May 31, 2010

The great news is that many of the problematic airplane troubles were figured out a long time ago by two amazing people: the Wright brothers.

The Wright brothers also took an airfoil (a fancy word for “airplane wing”), turned it sideways, and rotated it around quickly to produce the first real propeller that could generate an efficient amount of thrust to fly an aircraft.

Before the Wright brothers perfected the airfoil, people had been using the same “screw” design created by Archimedes in 250 BC. This twist in the propeller was such a superior design that modern propellers are only 5% more efficient than those created a hundred years ago by the two brilliant Wright brothers.

We’re going to use a propeller on our basic race car chassis (frame) to see how much thrust we’d need to make it move. If you don’t want to make the fancy triangle-shaped body frame, you can substitute a foam block or two (which will make your car able to go in water, too!)

Are you ready?
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Bristle Brush Bot

Saturday May 1, 2010

This is the simplest robot you can make… out of old parts from around the house. While this little robot doesn’t use energy from the sun or wind, we’ve placed it here with other alternative energy projects because the parts come from the trash bin.

This project is an extension of the Jigglebot robot from Unit 10.

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Electrical Circuits & Components Exercises

Sunday March 7, 2010

Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.

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Robotics Exercises

Sunday March 7, 2010

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Answers to Robotics Exercises

Sunday March 7, 2010

Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!

Here’s printer-friendly versions of the exercises and answers for you to print out: Simply click here for printable questions and answers.

Answers:
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Answers to Electricity Exercises

Sunday March 7, 2010

Here’s printer-friendly versions of the exercises and answers for you to print out: Simply click here for printable questions and answers.

Answers:
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Basic Circuits

Sunday March 7, 2010

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 components that make the electrons react in different ways, such as resistors (limit current), capacitors (collect a charge), transistors (gate for electrons), relays (electricity itself activates a switch), diodes (one-way street for electrons), solenoids (electrical magnet), switches (stoplight for electrons), and more. We’re going to use a combination diode-light-bulb (LED), buzzers, and motors in our circuits right now.

A CIRCUIT looks like a CIRCLE. When you connect the batteries to the LED with wire and make a circle, the LED lights up. If you break open the circle, electricity (current) doesn’t flow and the LED turns dark.

LED stands for “Light Emitting Diode”. Diodes are one-way streets for electricity – they allow electrons to flow one way but not the other.

Remember when you scuffed along the carpet? You gathered up an electric charge in your body. That charge was static until you zapped someone else. The movement of electric charge is called electric current, and is measured in amperes (A). 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.

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Waterbots

Sunday March 7, 2010

ROV stands for Remotely Operated Vehicle. These robots are used by scientists to explore the waters both offshore and in the deep sea, and often bring back samples and/or take video of their underwater findings. ROVs usually have a tether from the vehicle to the boat, which lightens up the load quite a bit (as it no longer needs to carry its own power or data storage). Powerful motors, such as bilge pumps or 24VDC motors, enable this robot to move in all six directions. ROVs are designed to be slightly positive in buoyancy, so they can surface automatically during power failures.

Of the robots we’re going to build, waterbots have the highest instant-success rate. You basically attach a motor to a piece of foam, stick it in the water, and it either floats and zips around, or capsizes and acts like an odd submarine. Either way, kids shriek with delight that their creation actually moves.

We’re going to use foam to create a waterbot, which will be powered by a simple electrical circuit. The hardest part of this activity will actually be building it stable enough so it doesn’t capsize. Boats are always built in a way so they don’t get pushed or flipped over easily by carrying a ballast, or extra weight, at the lowest part of the boat. You’ll need to figure out where to out your motor and batteries (which weigh a lot compared to a foam block) in order to balance your boat.

One of the biggest hurdles to overcome when building junkyard robots is friction. Since the motors have high speed and low torque, they can be difficult to use without a gearbox (which is both hard to find and out of the scope of this class). Since water has little friction, the robot will move about quite easily in the wet environment. We offer kids waterproof materials to build their robots with so that in the event their invention has trouble moving, we usually toss it in the pool to see if it can swim… which sparks another avenue of creativity and another round of improvements. Just be sure to keep the batteries out of the water. Are you ready?

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Jigglebots

Sunday March 7, 2010

Ever wonder how a cell phone vibrates? What mechanism could be in such a tiny space to make the entire phone jiggle around? Well, there’s a tiny motor inside with an off-center weight on the shaft, called an eccentric drive.

You can still see eccentric drive mechanisms in older steam engines where the rotational motion is converted to liner? movement. Eccentrics are also found on tandem bicycles with timing chains.

Kids can make this robot in less than five minutes, but it will take hours to get all their modifications and adjustments just right. This robot works by wobbling, and the sloppier the kids are in their construction, the better the robot dances around. Play with the placement of the weight (battery pack) and the legs. Add more skewers, adjust their position and angle until you get it dancing without toppling over.

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Conductivity Testers

Sunday March 7, 2010

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. Silver, for example, is one of the best electrical conductors on the planet, followed closely by copper and gold. Most scientists use gold contacts because, unlike silver and copper, gold does not tarnish (oxidize) as easily. Gold is a soft metal and wears away much more easily than others, but since most circuits are built for the short term (less than 50 years of use), the loss of material is unnoticeable.
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Simple Switches

Sunday March 7, 2010

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 Pole, Single Throw, which means that the switch turns on only one circuit at a time. This is a great switch for one of the robots we’ll be making soon, as it only needs one motor to turn on and off.
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How to use a Digital MultiMeter

Sunday March 7, 2010

meter 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 your shoe).

We'll show you how to get the most out of this versatile tool that we're sure you're going to use all the way through college. This project is for advanced students.

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BumperBot

Sunday March 7, 2010

If you have a pet, they’ll be sure to get a great workout chasing this nifty little robot. If you can, I totally encourage you to make two or more and have a contest!

This BumperBot is one of the simplest robots you can make that uses a touch sensor, tricycle gear, and simple parts from around the house. (And there’s no computer programming required.) Using a switch that reverses direction upon impact, this robot will have your kid’s mind-wheels spinning. Be sure to follow the wiring directions EXACTLY as shown or it won’t work right!

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Race Cars

Sunday March 7, 2010

Racerbots can steer, unlike the Jigglebot. If you have more than one motor on your robot frame, you can turn either left, right, or spin on command. Wired remote control instructions follow this project.

These racerbots are the toughest of these robots to build. The wheels need to be squarely set on their shafts, all wheels need to be parallel, long wires out of the way, the motors spinning in the right direction, the battery pack in the right position… does this sound like a headache yet? Pay attention to construction details in the video and you’ll have less to fix later on.

Construction Tip: Cut the dowels in half to use for the axles and use the milk jug lids or film canister tops for wheels (you can also rip small, lightweight wheels off an old toy if they are about the size of a quarter). You may need to sand the dowels slightly if they are hard to fit into the wheels.

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Wiring Up Motors

Sunday March 7, 2010

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 turntable, it will circle out of the way. Now flip your hand over so you have the south facing the turntable. Notice how the turntable magnet is attracted to yours and rotates toward your hand. Just as it reaches your hand, flip it again to reveal the north side. Now the glued turntable magnet pushes away into another circle as you flip your magnet over again to attract it back to you. Imagine if you could time this well enough to get the turntable magnet to make a complete circle over and over again… that’s how a motor works!

After you get the buzzer and the light or LED to work, try spinning a DC motor:

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Superfast Bug Bot

Sunday March 7, 2010

This project is advanced students. If you like tiny robots, then this one is for you! Powered by cheap hobby motors, this fast little robot zips ’round and avoids obstacles using momentary switches and an idler wheel for a tail.

I recommend watching the entire video first, then rewind and watch again, this time building as you go. Make sure you have all your parts laid out ahead of time, or you’ll get frustrated partway through if you have to stop. You will need a soldering iron to make this project.

Here’s what you do:
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Underwater R.O.V. Robot

Sunday March 7, 2010

This project is for advanced students.

Up until 200 years ago, people thought the oceans were bottomless. The diving bell was one of the first recorded attempts at undersea exploration, and was simply a five-foot inverted cup with viewing holes on a platform that lowered into the water, which allowed people to breathe the trapped air inside… until they ran out of air. Leonardo da Vinci draw several sketches of underwater submersibles, and in the 1700s, John Lethbridge invented a long wooden cylinder with glass ends as one of the first diving units to reach 60 feet.

In 1930, two explorers used the bathysphere (a giant ball with windows) reached 1,428 feet below the surface, which was later followed by the bathyscape (deep diving vessel) that reached the deepest part of the Pacific Ocean, the Marianas Trench, at 35,800 feet in 1960.

The ROVs first made their appearance in the late 1960s, when military and offshore drilling required deeper dives. In the late 1980s, scientists needed a way to explore the remains of the Titanic, and a lower-cost, lighter weight version design was developed. ROVs are designed to be remote extensions of the operator.

One of the biggest challenges with deep-diving underwater vessels is keeping the tremendous pressure from crumpling the frame. The project we’re going to design is meant for swimming pools and smaller lakes. When designing your underwater vehicle, you’ll need to pay close attention to the finer details such as waterproofing the electrical motors and maintaining proper balance so that your robot doesn’t flip over or swim in circles.

Learn about thruster motors, create the chassis, and build the controller for these super-popular underwater robots that really swim in water! A fantastic project for parents and kids to work together on. Your underwater robot will move in all six directions and utilizes a 12V power source.

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Pressure Sensor Burglar Alarm

Sunday March 7, 2010

However, if you walked around on stilts indeed of feet, and the ‘footprint’ of each stilt averaged 1” on each side, you’d now exert 100 psi per foot. Why such a difference?

So how do we use pressure in this experiment? When you squeeze the foam, the light bulb lights up! It’s ideal for under a doormat or carpet rug where lots of weight will trigger it.

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Latching Circuit

Sunday March 7, 2010

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 is a normally open (NO) switch. This means that the trip wire is designed to allow current to flow through the tacks when there’s no paper insulating them, while the pressure sensor stops current flowing in it’s un-squished state. It’s just the nature of the two different types of switches.

However, we can build a circuit using a relay which will ‘latch on’ when activated and remain on until you reset the system (by cutting off the power). This super-cool latching circuit video will show you everything you need to know.
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Trip Wire Burglar Alarm

Sunday March 7, 2010

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 electronics, which is covered in undergraduate university courses. Instead, here is a quick description based on the fluid analogy for electric charge:

The movement of electric charge is called electric current, and is measured in amperes (A, or amps). When electric current passes through a material, it does so by electrical conduction, but 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).

Why does metal conduct electricity? Metals are conductors not because electricity passes through them, but because they contain electrons that can move. Think of the metal wire like a hose full of water. The water can move through the hose. An insulator would be like a hose full of cement – no charge can move through it.

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Dimmers and Motor Speed Controllers

Sunday March 7, 2010

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, you’ll be able to control the speed of your laser light show motors as well as the motors and lights on your robots. Ready?

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Forward and Reverse Motor Control

Sunday March 7, 2010

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 the flip of a switch.

You can use this component along with a potentiometer so you can not only control the direction but also the speed of a motor, like in a robot or laser light show. And don’t feel limited on using this switch just with motors – it works with bi-polar LEDs and other things as well. For example, you can hook this up so that when it’s in the UP position, the buzzer sounds, and the DOWN position makes the headlights go on. Are you ready to learn how to wire this one up?

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Salty Battery

Sunday March 7, 2010

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 your solution.

This project builds on the fruit battery we made in Unit 8. This experiment is for advanced students.

The basic idea of electrochemistry is that charged atoms (ions) can be electrically directed from one place to the other. If we have a glass of water and dump in a handful of salt, the NaCl (salt) molecule dissociates into the ions Na+ and Cl-.

When we plunk in one positive electrode and one negative electrode and crank up the power, we find that opposites attract: Na+ zooms over to the negative electrode and Cl- zips over to the positive. The ions are attracted (directed) to the opposite electrode and there is current in the solution.

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Seeing Electric Fields Using Your Spice Rack

Sunday March 7, 2010

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 field (more on this later). Did you also know that electrical charges have an electrical field, just like magnets do?

It’s easy to visualize a magnetic field, because you’ve seen the iron filings line up from pole to pole. But did you know that you can do a similar experiment with electric fields?

Here’s what you need:

dried dill (spice)
vegetable or mineral oil
2 alligator wires
static electricity source (watch video first!)

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Silver Battery

Sunday March 7, 2010

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 silver. It’s safe, simple, and just needs a grown-up to help with the stove.

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Air Battery

Sunday March 7, 2010

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.

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Nerve Tester

Sunday March 7, 2010

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 to the other. You can opt to make a noisy version (more fun) or a silent version (for stealth). Are you ready?

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Electrolytes

Sunday March 7, 2010

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 (like water).

This type of conductor is called an ‘ionic conductor’ because once the salt is in the water, it helps along the flow of electrons from one clip lead terminal to the other so that there is a continuous flow of electricity.

This experiment is an extension of the Conductivity Tester experiment, only in this case we’re using water as a holder for different substances, like sugar and salt. You can use orange juice, lemon juice, vinegar, baking powder, baking soda, spices, cornstarch, flour, oil, soap, shampoo, and anything else you have around. Don’t forget to test out plain water for your ‘control’ in the experiment!

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Advanced Static Electricity Experiments

Sunday March 7, 2010

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 a demonstration (unless you happen to have a 50,000 Volt electrostatic generator on hand), and the second is a homemade version on a smaller scale.

Did you know that you can make a motor turn using static electricity? Here’s how:

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Alien Detector (Advanced)

Sunday March 7, 2010

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 on/off switch poking through the box along with the LED so they would have ‘some’ control over the experiment.)

This detector is so sensitive that you can go around your house and find pockets of static charge… even from your own footprints! This is an advanced project for advanced students.

You will need to get:

9V battery clip (and a 9V battery)
MPF 102 (buy 2 – one for back up)
LED (any regular LED works fine)

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Remote Controls I

Sunday March 7, 2010

Radio control (RC) is a 100 year-old technology. RC requires both a transmitter and a receiver. The control box sends commands to the robot the same way you change channels on the TV with the remote.

The difference between RC (radio control) and IR (infrared control) is in the frequency of the signals. With the radio controller, the light waves that carry the command information are lower energy, lower frequency signals. The TV remote uses higher energy, higher frequency infrared signals called CIR (consumer infrared).

Both RC and CIR require circuit design at a college graduate level. However, wired remote controls are well within the reach of any young budding scientist.

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Remote Controls II

Sunday March 7, 2010

If you've made the waterbot, you can use this wired remove to make the motor turn both forward and reverse. All you need is an extra set of wires (telephone cable with two wires in it work great, or else twist two long wires together... they can be as long as you want.) Enclose the whole thing in a plastic box (I like to use tupperware or a soap box) and drill three holes in the top for the brass fasteners and one in the side for the wire and you're all set!

Materials:

your robot that you want to control (use any from this section)
index card
3 brass fasteners
1 paper clip
4 additional alligator clip lead wires
optional: plastic soap container
optional: drill with drill bits

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More Sensors

Sunday March 7, 2010

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.

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Unit 10: Electricity (Robotics) Video

Sunday March 7, 2010

Now that you’ve got a good handle on circuits and electrical components, it’s time to pull it together into something useful, like building robots and sensors. Are you ready? Then let’s put your new ideas and electrical circuit building skills to the test…

Unit 10: Electricity (Circuits & Components) Video

Sunday March 7, 2010

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:
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Electrical Safety – Best Batteries to Use

Wednesday February 3, 2010

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:

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Fruit Battery

Sunday January 10, 2010

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 electrical charge (potential) on these two plates causes a voltage.

Materials:

one zinc and copper strip
two alligator wires
digital multimeter
one fresh large lemon or other fruit

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Electroplating

Sunday January 10, 2010

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 metal key. During this process, hydrogen bubbles up and is released as a gas. People use this technique to add material to undersized parts, for place a protective layer of material on objects, to add aesthetic qualities to an object.

Materials:

one shiny metal key
2 alligator clips
9V battery clip
copper sulfate (MSDS)
one copper strip or shiny copper penny
one empty pickle jar
9V battery

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Ten Static Electricity Experiments to Mystify Your Kids

Saturday March 7, 2009

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 electron, the charges are balanced. If you steal the electron, you now have an unbalanced, positively charge atom and stuff really starts to happen. The flow of electrons is called electricity. We’re going to move electrons around and have them stick, not flow, so we call this ‘static electricity’.

These next experiments rely heavily on the idea that like charges repel and opposites attract. Your kids need to remember that these activities are all influenced by electrons, which are very small, easy to move around, and are invisible to the eye.
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