Recording Characteristics on Pulse Train Write Current Waveform

A magnetic recording head using separate read and write elements can have a reduced number of write coil turns. This facilitates write element fabrication for this kind of thin film head. However, a large current is required, and more heat is generated, when a square-wave write current waveform is used with fewer coil turns. A pulse train write current waveform represents one solution to this problem, by reducing heat generation, cross feed and power dissipation. We discuss the possibility of high-density magnetic recording using pulse train recording. A write head with a two-turn coil and an MR read head were used in experiments. We found no significant difference in the write head characteristics over the characteristics for a conventional square-wave NRZI write current waveform. Double-density NRZI pulse train recording best minimized the bit error rate, and a recording density more than double that for NRZI recording was attained.