The inventor of the telephone was Bell. It was March 10, 1876, when American inventor Bell invented the world's first telephone and was granted a telephone patent by the U.S. Patent Office. On the evening of June 2, 1875, Bell and electrical engineer Watson used the principle of electromagnetic induction to trial-produce the world's first machine for transmitting sound, a magnetoelectric telephone.
The principle of the magnetoelectric telephone is exactly the application Bell originally envisioned for the telephone: speaking into the microphone causes the metal diaphragm at the bottom of the microphone to vibrate with the sound, and the vibration of the diaphragm drives a magnetic spring. The diaphragm vibrates accordingly, and an induced current is generated in the electromagnetic coil. The current is transmitted to the receiver through the wire, causing the diaphragm on the receiver to vibrate accordingly and restore the voice.
Bell's main achievement:
Bell's main achievement was the invention of the telephone. In addition, he also manufactured hearing aids; improved the phonograph invented by Edison; he made a great contribution to the invention of deaf-mute languages; he wrote more than 100 articles and pamphlets. In 1881, he designed a metal inspection device to discover the bullet in the body of U.S. President James Garfield, which became the predecessor of the X-ray machine. He also founded the British Association for the Advancement of Education for the Deaf.