What kind of material is a general audio tape made of?
Magnetic material is widely used in electroacoustic, telecommunication, electric meter, motor, memory element, microwave component and so on. Magnetic tapes for recording language, music, image information, magnetic storage devices for computers, vouchers for passenger travel, magnetic cards for fare settlement, etc.. The following focuses on the magnetic materials used on tape and the principle of action.
During playback, the recorded tape is pressed close to the aperture of the playback head at the same speed as the recording. The head core is made of high permeability ferrite soft magnetic materials, its flux resistance is very small. Therefore, the audio residual magnetization recorded on the magnetic tape is easily formed through the magnetic head iron core. The residual flux in the magnetic tape induces an induction electromotive force that is the same as the remnant flux change in the playback head coil. After the amplifier is amplified, the loudspeaker is sent to push the loudspeaker, and the audio signal recorded on the tape is restored to the original sound.
As we know, hard magnetic materials are magnetized and leave residual magnetism. The strength and direction of residual magnetism depend on the strength and direction of magnetism at magnetization. A tape is composed of tape, binder, and magnetic powder. The base generally uses polycarbonate or vinyl chloride. Magnetic particles are R, Fe2O3 or CrO2 powders with strong residual magnetism. When recording, the current corresponding to the sound change is amplified and sent to the coil of the recording head to produce a concentrated magnetic field in the gap of the head magnet. As the coil current changes, the direction and intensity of the magnetic field changes accordingly. As the tape passes through the gap of the head evenly, the magnetic field passes through the tape and magnetized it. The polarity and intensity of the magnetic tape corresponding to the original sound due to the residual magnetism remaining after leaving the head of the tape. As the tape moves, the sound is constantly recorded on the tape.
