Method of Monitoring the Working Status of the Magnetic Head during High Speed Revolution of Hard Disk

doi:10.3901/JME.2018.05.228

Abstract

Abstract: With the gradual decrease of the effective clearance between the hard disk and the magnetic head, the head may work at three states-flying, surfing and sliding. In order to make the head stable working, the state of the head must be monitored and identified. A method is given to real-time monitor the state of the head by measuring the tribocurrent resulting from the friction between the disk and the head. A tribocurrent measurement system is constructed which includes air bearing motor, thermal-flight-height-control head, power loading control unit, electrometer, loading/unloading unit, electrostatic shielding box and so on. By applying the voltage to the thermal-flight-height-control head with the step of 0.1 V, the clearance between the hard disk and the head is gradually decreased, and the tribocurrent at different clearance was measured by the electrometer, and the current range of distinguishing three working states of the head is obtained. When the tribocurrent is below 10^-4 μA, the head works stably at the flying state. When the tribocurrent is at 6 μA-50 μA, it works at the surfing state. When the tribocurrent is more than 140 μA, it works at the sliding state.

Key words: hard disk, magnetic head, tribocurrent, working status

CLC Number:

TH12

SHI Dequan, KANG Kaijiao, GAO Guili. Method of Monitoring the Working Status of the Magnetic Head during High Speed Revolution of Hard Disk[J]. Journal of Mechanical Engineering, 2018, 54(5): 228-232.

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