Magnetic head

A magnetic head is a component that is used to write, read and / or erase magnetic storage media / data carriers.

Close up of a magnetic head from a hard drive. The coil and the air gap directed downwards to the magnetic medium are centered .

When writing to the storage medium (e.g. audio tape , video tape , hard disk ), the magnetic head works as an electromagnet and magnetizes the hard magnetic layer material (small-grained parts) in the rhythm of the information. When reading, this magnetization in turn induces a small voltage in the magnetic head, which is converted into electrical signals and passed on. For erasing analog media (tape, video recorder), a separate erasing head is used, which is only used to generate a high-frequency alternating field that demagnetizes the magnetic layer of the medium. Hard disks, for their part, do not have an erase header; the erasure occurs here by overwriting the data to be deleted with new data. Read and write heads for analog sound recording ( tape heads ) consist of a laminated, highly permeable toroidal core wound with enamelled copper wire, which has a taper and a gap at one point. Erasing heads and the magnetic heads of video recorders, hard drives and floppy - drives the other hand, are made of ferrite .

CD-ROM media work on a different principle.

See also

• Perpendicular recording
• Longitudinal recording

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• Something about sound heads and tapes for analog magnetic sound recording ( Memento from September 3, 2013 in the Internet Archive ) (PDF file; 1.03 MB)
• Sybex Hardware Manual