3x Paper plates
1x sheet of paper
20" of 26 gage wire (found at radioshack)
1x hot glue gun
1x scary magnet of the neodymium kind
2x alligator clips
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Cut two pieces of paper so that they’re about 3cm taller than the magnet. This does not have to be exact.
Wrap first piece of paper around magnet tightly then wrap the second piece of paper around the first.
Tape the second piece of paper so that it stays in a circle. Then, remove the first piece of paper. This will leave a very small amount of room between the magnet and the paper so that the paper can move.
Glue the magnet to the center of one of the paper plates.
Glue the circle of paper to the center of the second paper plate
Wrap the wire very tightly around the circle of paper. Leave approximately 10 cm of wire from each end hanging loose off of the coil.
Cut a 13cm by 10cm rectangle out of the third paper plate.
Fold the rectangle accordion style so that the folds are parallel with the 10cm side. Cut it in half the long way so there are two 13cm by 5cm accordion folded rectangles.
Glue the ends of the accordion pieces to the paper plates. Glue them so that the faces of the rectangles are facing towards the magnet and coil. Glue them about 5cm away from the magnet on opposite sides from each other.
Burn the enamel off the ends of the wire hanging off of the coil.
Attach the audio jack to the ends of the coil using alligator clips. DO NOT attach anything to the white wire on the audio jack. It is useless. It does not matter which end of the coil is attached to which wire on the audio jack.
Step 12: Easy Mistake
Creating a speaker requires many steps, and it is easy to make mistakes. One mistake that is easy to make can happen when hooking up the audio jack to the coil. The white wire on the audio jack is useless to this project and doesn't need to be used at all. Placing one of the audio jacks on this wire will cause the speaker not to work. One easy way to avoid this problem is by simply cutting the white wire off, that way there is no need to worry about putting anything on it by accident. Also, make sure all of the contact in your jack are properly attached to the jack so that it works, and you don't spend hours trying to figure out what is wrong with your coil even though its a jack issue.
Step 13: Why This Works(sciencey Bit)
This speaker works by utilizing a magnet’s ability to apply a force on a wire via its magnetic field. When a current is put through a wire, a magnetic field is created around the wire. When this wire is put into another magnetic field, the two magnetic fields interact with each other and a force is applied to the wire (I mean there’s also a force on the magnet because Newton’s 3rd law but we can safely assume that there isn’t enough force to also move the magnet at all). Because of this fact, we can use the audio jack to put electrical current through the wire in such a pattern so that it move up and down very quickly. When it vibrates, it also vibrates the plate that it is attached to. This rapid movement of the plate disturbs particles in the air, causing them to vibrate as well. These vibrations, or sound waves, travel through the air until they reach the listener’s ears. The vibrating air travels into the ear of the listener and interacts with it somehow, then the ear tells the brain that there is sound and the brain interprets it. I’m sure a biologist could tell you how that process works. A biology student told me to use the phrase “action potential”. I’m not entirely sure what that means but it makes me feel smarter.