First, the production method
1, two paper cups, with a needle at the center of the bottom of the paper tube for the thread to pass through.
2. Thread both ends of cotton thread into two small holes of two paper tubes.
3. Remove the ignited gunpowder from the match, leaving the match stalk.
4. Pull out the cotton thread inserted in the paper cup and tie the matchstick with cotton thread from the center of the matchstick.
5. Fix the matchstick: gently pull the cotton thread to the bottom of the paper cup, let the matchstick stick stick to the bottom of the cup, then add 520 glue, fix the matchstick to the bottom of the cup, and wait to dry. That is, successfully making local calls.
6, audition, pull a straight line, talk to the paper cup to hear the sound.
The earth phone is an ancient practical entertainment tool, which was first invented by China people and is the original prototype of the telephone. It has made great contributions to the communication and entertainment between people. The telephone is simple to make, and it can be easily made with two round cartons, a cotton thread and two sticks. In ancient times, it was called a megaphone.
Homemade telephone can be said to be the embryonic form of modern telephone. The ancestors of China people learned to make earthen telephones very early, which can be said to be the inventors of the rudiments of telephones. Homemade telephones are easy to make. Use two bamboo tubes or paper cups, kraft paper and a thread. One end of a bamboo tube or paper cup sealed with kraft paper is open, and cotton threads are connected through holes. The wire end is fixed at the center of the bottom of kraft paper or paper cup of microphone.
Two people each take a microphone and straighten the cotton thread, so they can talk, and it can be effective within 100 meters. One person speaks at the microphone, and the other person listens with his ears at the microphone. Sound can travel far through the vibration of cotton thread. Some experts have suggested that China declare local telephones as world intangible cultural heritage.
The home-made telephone consists of two cylinders with paper at the bottom. A line is pierced on the paper film to connect the two cylinders. Straightening both sides of this line can make you speak intelligently.
Second, principles.
It is the sound wave that makes the paper film vibrate, and the vibration wave is transmitted to another paper film through the connecting wire to make it vibrate. When the other party hears the sound, it belongs to the mechanical vibration transmission of sound wave and has nothing to do with electricity.