How to use this invisible earphones?
First you need to put a tiny magnet in one of your ears or put two in both of your ears. Then you need to wear a coil necklace which is connected with an amplifier. Next connect your mp3 player to the amplifier. Cover the coil necklace and the amplifier properly with your clothes.Turn it on. Now you can enjoy music without being noticed by other people. You can use another small magnet to get it out. This sort of Invisible headphones is sold on ebay.
(Warning : Don't put the magnet deeply in your ear. Although there is no medical proof that says magnets will cause trouble to your ear , it's better not to use this device for a long time. Magnetic fields can disrupt the operation of some internal medical devices such as pacemakers.Neodymium magnets are made with special powders and coatings, so they are very fragile. They are often plated with a metal such as nickel. The magnets can fracture at temperatures over 150 °C, or under impact as a result of their own acceleration. When this happens, in some cases the magnets may break apart so suddenly that flying pieces can cause injury.
Make sure that there are no magnets around you, when you use this device. These magnets can move with surprising force when exposed to another magnet or magnetic field.)
If you don't know what you can do with this device. please watch this video. (Just for Fun
Step 1: How Invisible Earphones Work
Step 2: Find the Proper Magnet for Your Project
Step 3: How to Make the Coil Necklace Part.1
2.enamelled wire ( Length=50meters Diameter=0.25millimeter )
Enamelled wire is a kind copper wire which is coated with Polyurethane. I use a cardboard to wind the coil necklace. Make sure the diameter of this coil necklace is larger than the diameter of your head. The resistance of the coil I made is about 23ohm.
Step 4: How to Make the Coil Necklace Part.2
Step 5: The Amplifier
Component List :
Capacitors 220uF X 1
10uF X 1
100nF X 1
47nF X 1
resistors 10 ohm X 1
1k ohm X 1
LM386 X 1
9 volts battery X 2
Step 6: Final Assembly
If you succeed in making this device , you can send me a e-mail with the picture of your work. I'll put the picture at the end of this tutorial.