In this blog, we are going to know about the Block Diagram of Magnetic Tape Recording System. Welcome to Poly Notes Hub, a leading solution for Engineering Notes.
Author Name: Arun Paul.
What is Magnetic Tape Recording System?
A Magnetic Tape Recording System is a system that stores and plays back audio or video recordings. It operates by recording data on a magnetic tape using magnetic impulses. These impulses constitute audio or video signals, which may be read back by running the tape over a magnetic playback head.
Magnetic recording is the storage of sound pressure fluctuations using primary magnets whose length and intensity are determined by audio signals. Poulsen from Denmark discovered it in 1998.
Magnetic recording works on the idea that when certain materials (such as iron oxide) are exposed to a magnetic field, they become magnetized and keep their magnetism indefinitely unless altered. The many steps of magnetic recording are outlined here.
Block Diagram of Magnetic Tape Recording System
A microphone converts changes in sound pressure into electrical fluctuations. The microphone’s audio output is amplified and fed into the coil of an electromagnet. The electromagnet contains a small gap through which magnetic lines of force cannot easily flow due to the high resistance of air. When a magnetic material-coated tape is used to bridge the gap, the lines of force have an easy passage through the iron oxide, which is converted into elementary magnets. The magnetic strength of the electromagnet, and hence the gap covered by the tape’s iron oxide, is dependent on the audio current.
Thus, the iron oxide layer on the tape is magnetized in response to the audio current and, as a result, to fluctuations in sound pressure. Iron oxide has the ability to retain magnetism for an extended period of time. This means that sound was recorded as a fluctuating magnetic field.
When recreating the recorded sound, the tape passes through a similar gap, causing a shift in the lines of force across the coil. This induces emf in the coil, which is proportional to the rate of change of magnetic flux in the tape. The induced emf is amplified and directed to a loudspeaker, which turns the audio signal into sound.