Patent ID: 6175456
Filing Date: 2001-01-16
Classification: G11B

Abstract:
A circuit for controlling a write current employed in a magnetic disk recording apparatus, said circuit comprising:a write unit delivering said write current to a plurality of magnetic heads to enable writing of data by said magnetic heads on surfaces of magnetic disks each characterized by a major surface exhibiting a plurality of recording zones formed on each said major surface, with each of said heads exhibiting a minimal number of errors at corresponding particular values of said write current, said write current exhibiting a first magnitude that varies in dependence upon a second magnitude exhibited by a driving current provided to a write current control terminal of said write unit;a control unit separately generating pulse width modulated signals each having duty cycles corresponding to respective said particular values for individual ones of said plurality of magnetic heads, to indicate said write current; anda write current adjusting unit receiving said pulse width modulated signals and delivering said driving current to said write current control terminal of said write unit, said write current adjusting unit applying said driving current to said control terminal to provide to selected individual ones of said heads corresponding said particular values by adjusting the second magnitude exhibited by said driving current in dependence upon said duty cycles of said pulse width modulated signals.