A tape head is a type of transducer used in tape recorders to convert electrical signals to magnetic fluctuations and vice versa. They can also be used to read credit/debit/gift cards because the strip of magnetic tape on the back of a credit card stores data the same way that other magnetic tapes do. Cassettes, reel-to-reel tapes, 8-tracks, VHS tapes, and even floppy disks and early hard drive disks all use the same principle of physics to store and read back information. The medium is magnetized in a pattern. It then moves at a constant speed over an electromagnet. Since the moving tape is carrying a changing magnetic field with it, it induces a varying voltage across the head. That voltage can then be amplified and connected to speakers in the case of audio, or measured and sorted into ones and zeroes in the case of digital data.
Tape head assembly from a compact cassette deck. The compact cassette uses four tracks, two for each side; visible are two heads (the silver rectangles inside the black rectangle) for playing one side of the tape at a time.
Erase head
D6 HDTV VTR Scanner and video head, removed
Inside a D6 HDTV VTR Tape Deck, VTR Scanner and video head in place.
A transducer is a device that converts energy from one form to another. Usually a transducer converts a signal in one form of energy to a signal in another.
Transducers are often employed at the boundaries of automation, measurement, and control systems, where electrical signals are converted to and from other physical quantities. The process of converting one form of energy to another is known as transduction.
Mechanical transducer
