2-90 Phaser 6180MFP Multifunction Printer Service ManualTheory of OperationFax SystemTelephone System OverviewConverting and Sending Voice in the Form of Electrical SignalsThe human voice is a sound wave; in other words, air vibrations. Conversationbetween two people results when such vibrations travel through the air andreach each other’s ears. A string telephone transmits the sound wavegenerated between two people along a string stretched tight, thus allowingconversation over a distance. In this system, a paper cup at one end of thestring receives the sound wave, which are then transmitted along the string. Apaper cup at the other end of the string transmits them back to the air, so thatthey again become audible sound waves.A telephone is a device that replaces the vibrations transmitted by string withelectrical signals. The two paper cups correspond to microphone, speaker,and the string to the telephone line. Because electrical signals travel over thetelephone line at a high speed with minimal attenuation, the telephoneenables conversation over great distances.Voice is changed into electrical signals using electromagnetic induction, aprocess by which electrical signals are generated by vibrating a coil in amagnetic field. Both the microphone and speaker utilize this process. Themicrophone transduces sound into electrical signals using electromagneticinduction that occurs as a moving coil coupled to a diaphragm picking upsound wave.
