Exploring Electricity Marquette Engineering Outreach

Today’s Schedule: Learn what "current" is Learn about Tesla Coils, courtesy of Mr. Collin Learn about conductors and insulators Test materials for conductivity Learn about and build circuits Create a game using “file folder circuits.” Play our games!

What is Electrical Current? Current is created when charges MOVE. Remember… Static electricity does NOT move. Current is carried by moving electrons, the way that water carries waves Two types of current: Direct Current (DC) from batteries Alternating Current (AC) from a wall outlet

Alternating vs. Direct Current DC is usually generated by batteries. It involves the flow of electricity in ONE direction AC is made by electrical generators. It involves the flow of electricity BACK and FORTH Changes direction 60 times per second Frequency = 60 Hz

Nicola Tesla and the Tesla Coil Who was Nicola Tesla? What is a Tesla Coil? What can Tesla Coils be used for? See one in action! Collin Matthews Electrical Engineer, GE Healthcare Bachelor’s Degree in Electrical Engineering, minors in Math and Physics Mentor for FIRST Robotics Team 1714 in South Milwaukee

Conductors and Insulators A conductor is a material that allows electricity to flow through it Conductors have chemical structures where electrons can move easily An insulator is a material that restricts or stops the flow of electricity Insulators have chemical structures where electrons are not easily moved

Conductors and Insulators Copper Silver Gold Insulators Glass Plastic Rubber

Testing Conductivity Using a light bulb, a battery, and two Alligator clips, you can test items to see if they conduct electricity Test the following items: A ruler (note the material of your ruler) A dry paper towel A wet paper towel A pencil – HINT: Your pencil has conductors AND insulators. You should be able to identify TWO pencil components of each type! ?

BREAK! Stretch! Restroom! Water fountain!

What is a circuit? A circuit is a closed pathway of conductive material where electricity can run. Electricity will not run unless it can get from the power source and then back to the power source

Two kinds of circuits Series – items are placed one after another Parallel – items are placed like the rungs of a ladder Stringing more than 1 battery together will burn out the light bulb. Stringing more than 2 light bulbs together in parallel can lead to excessive heat. BUILD THESE! (AS SHOWN) Observe the light bulbs in each kind of circuit Warning!

Water… Conductor or not? Question: Is water a conductor? Answer: In its purest form, NO. Water: Salt Water:

Test it! Set up a simple circuit using distilled water, an LED, and a 9-Volt battery, as shown: Add salt to the water. What happens? LED= Light-Emitting Diode LEDs only emit light when electricity is flowing through them in the right direction! Hint: Tape or hold this connection If the LED doesn’t light up at all, flip it around so the other “leg” is in the water.

Short Circuits If you provide an extra path for electricity to travel along, it might skip the place you want it to go. Short circuits usually are made of wires which have no resistors (light bulbs, motors, etc.) attached They can get very HOT!

The Circuit “Game Show!” Using a file folder, aluminum foil, and tape, create a game board Think of 4 questions and 4 answers Your final result will look something like this: A B C D Apple Bear Cat Doll

How to make your circuit: Cut 4 slots in the fold of your file-folder. Make sure they are 2-½ inches apart! Punch 4 holes opposite your slots. ONLY punch through the cover of the folder. Open the folder. Using a piece of Aluminum foil, on the INSIDE COVER of the folder, connect one slot to one hole. Completely cover the foil with tape, from start to end. Repeat until you have each slot attached to one hole. On the cover, place labels so the questions match the answers.

Folder Example:

Playing The Custom Circuit Game The game-testing board is a parallel circuit When you touch the question, only ONE leg of the circuit is complete. The correct answer lights up! A B C D Apple Bear Cat Doll