DEVICE AND METHOD FOR CONTROLING BIAS CURRENT FOR MAGNETO-RESISTANCE EFFECT TYPE MAGNETIC HEAD, AND MAGNETIC STORAGE DEVICE

摘要

PROBLEM TO BE SOLVED: To improve a utilization factor by making an investigation current flow through a magneto-resistance effect type magnetic head for calculating a resistance of the head from the current and a terminal voltage, determining a tolerance range of the bias current based on a pre-investigated relationship between the life and resistance, and setting an optimal bias current within the range. ;SOLUTION: A current control circuit 21b supplies a bias current to a magneto-resistance effect type magnetic head 10. A voltage detector 21c detects a voltage across both terminals of the magnetic head 10 then. A host system 50 works out a resistance of the magnetic head 10 from the bias current value and the voltage across the terminal. The host system 50 stores life data representing a relationship among resistance, bias current value, and life beforehand, and sets a tolerance of the bias current level referring to the relationship. And, the bias current is determined according to a prescribed optimal bias current setting procedure and also within a tolerance of the bias current.;COPYRIGHT: (C)1998,JPO