Telephone is a kind of remote communication equipment that can send and receive sound. As early as the18th century, there was a word "telephone" in Europe, which was used to refer to microphones strung together with wires (cups strung together with wires). The telephone was attributed to Alexander Graham Bell. The principle of early telephone is that sound is a compound vibration in the air, which can be transmitted to solids and to conductive metals through electric pulses. Bell applied for the telephone patent in March 1876.
principle of operation
Telephone communication is a communication technology that uses electricity as the medium and transmits language through the mutual conversion of acoustic energy and electric energy. The simplest way for two users to communicate is to connect two phones with a pair of wires.
When the speaker picks up the phone and speaks into the microphone, the vibration of the vocal cords excites the air to vibrate, forming sound waves.
Sound waves act on the microphone to generate current, which is called speech current.
Voice current is transmitted along the line to the receiver of the other party's phone.
A receiver is just the opposite of a microphone-it converts current into sound waves, which are transmitted to people's ears through the air.
In this way, the simplest call process is completed.