For better understanding, here are two videos describing about the principle of magnetic recording...
Compact Disks are optical media; they record information by burning pits in the disk and use a laser and optical sensor to detect whether a pit is present or not. A hard disk is a magnetic system - a recording head is moved close to the surface of the disk and used to read or write information. It is these different technologies that lead to the difference in abilities; CDs are more robust and cheaper, but slower - particularly...
1. Analog recording Analog recording is based on the fact that remnant magnetization of a given material depends on the magnitude of the applied field. The magnetic material is normally in the form of tape, with the tape in its blank form being initially demagnetized. When recording, the tape runs at a constant speed. The writing head magnetizes the tape with current proportional to the signal. A magnetization distribution is...
Oberlin Smith published a description of magnetic recording in Electrical World, Sep. 8, 1888, based on his visit to Edison's lab in 1878, using an electromagnet with a string covered with iron filings. He may have built a working model but no device has survived. Above is the "original drawing of Oberlin Smith (1840-1926) published in the Electrcial World of 8.9.1888. The spoken words are transformed by the telephone A into...
Have you ever wondered how a whole album of your favorite music got onto one of those little cassette tapes? Or, what about computer floppy disks; have you ever wondered how they can hold 180 or more pages of typed text? The answer to both of these questions is magnetic recordingMagnetic recording devices seldom get much attention until they fail to work. But without magnetic recording, recording your favorite television show...
1. The voice or music is fed into microphones 2. Converted to electrical current and amplified as with disc recording. 3. The signal is then fed into an electromagnet called the recording head. Electric current passes through the coil of a magnetic head.4. When the magnetic fields get to the head gap, some of them spread outside the core to form a fringing field.5. When a recording medium is passed through this fringing field,...
In order to see the magnetic recording works, we need three things: 1. An input signal.This input signal can come from microphone or from our original voice that is capable to produce a recordable signal.There are two types of input.First is the input signal that can be recorded simultaneously and second is the input signal that must be processed first (in case it is weak or out of frequency range) 2. Recording mediumA material that has...