Electricity from Sound
Can you turn your voice into electricity?
Maybe you can, maybe you cant, but you'll never know until you build this Project!
This circuit is simple to build. Once you are finished, try talking into the Speaker as loudly as you can. Does the Meter pointer move?
If not, try speaking louder or even yelling. You might also try putting the speaker of a portable radio up against the Speaker in your Kit. Can you get the Meter pointer to move?
At best you probably only got a very small movement from the Meter pointer. But can you guess why the Meter pointer would even move at all?
Speaker operation is based upon electromagnetism as well. When the coil of wire in a speaker carries electricity, it moves a paper cone back and forth to produce sound waves you can hear. The coil is able to move because a speaker also has a permanent magnet. The electromagnet and the permanent magnet take turns attracting and repelling each other when current flows through the electromagnet.
In this Project, sound waves striking the Speaker's paper cone causes the coil of wire (attached to the cone) to move as well. The coil of wire moves back and forth across the permanent magnet, making the magnetic field seem to "move." And, you guessed it, this causes electricity to flow in the moving coil.
This is the same principle used in microphones. Since the Speaker in your Kit is not designed to pick up sounds and convert them Into electricity, the Speaker doesn't work as well as a true microphone.