Patent ID: 8830614
Filing Date: 2014-09-09
Classification: G11B

Abstract:
1. A hard-disk drive, comprising: a head slider comprising a single resistive temperature detector (RTD); a magnetic-recording disk rotatably mounted on a spindle; a voice coil motor configured to move the head slider to access portions of said magnetic-recording disk; a read/write integrated circuit (IC) comprising a balance resistor that possesses the same resistance as the single RTD when the head slider is not in physical contact with the magnetic-recording disk, wherein the single RTD and the balance resistor are arranged in a circuit which causes the same amount of current to flow through both (a) a first arm of the circuit that includes the single RTD and (b) a second arm of the circuit that includes the balance resistor except when the head slider is in physical contact with the magnetic-recording disk, wherein a first voltage level associated with ground at the head slider is at a higher voltage level than a second voltage level associated with ground at the magnetic-recording disk, wherein the read/write IC comprises a plurality of resistors, and wherein electrical switches within the read/write IC are configured to place a portion of the plurality of resistors in series to form the balance resistor so that the portion of the plurality of resistors collectively have the same resistance as the single RTD when the head slider is not in physical contact with the magnetic-recording disk; and a mechanism for (a) detecting a change in altitude, pressure, or ambient temperature and (b) recalibrating the balance resistor upon detecting a change in altitude, pressure, or ambient temperature that exceeds a certain threshold.