Apparatus for positioning a magnetic head

摘要

An apparatus, primarily for use in battery-powered floppy disk drives, for moving a magnetic head radially toward a reference track in accordance with a direction signal from a disk controller. The apparatus comprises a track position sensor for sensing the track position of the magnetic head. The track sensor outputs a signal indicating whether the magnetic head is positioned radially inward or outward of track positions within a predetermined vicinity of a magnetic disk reference track. The apparatus has a reset circuit for generating a set signal when a power is applied to the reset circuit, and a logic circuit responsive to the track sensor output and set signal for providing a first binary control signal for use in selecting the direction of movement of said magnetic head. A second logic circuit utilizes the first binary control signal and the direction signal from the disk controller to provide a second binary control signal operative to set the direction of movement of the magnetic head. The direction of movement is set in accordance with the direction signal when the first binary control signal is in a first state and in accordance with a predetermined direction when the first binary control signal is in a second state. A moving mechanism moves the magnetic head in accordance with the second binary control signal.