Record and playback heads

Tape drives of the various types all use a record and playback head which uses the technique of electro-magnetic induction described above. In this case there is only one winding and the magnetic material is shaped to concentrate the lines of magnetic flux at one point. This point is in contact with the tape/ disc. When recording, the current through the winding changes the amount magnetic flux in sympathy with the signal being recorded -voice, music, video or digital.

This is passed to the tape/ disc, which stores the magnetism as very tiny magnets made up of the magnetic material. The playback process is a straight reversal - the stored magnetism on the tape is transferred to the magnetic material in the head, which induces a current into the winding. The resultant signal is processed by electronic circuitry to produce the original signal. The size of heads vary and is consistent with the signal being recorded, video heads for example are tiny.