| 摘要 |
PROBLEM TO BE SOLVED: To easily detect the failure in a spindle motor by monitoring a motor current that is supplied to the fluid bearing spindle motor. SOLUTION: A current sensor 17 detects a current supplied from a driver IC 12 to the fluid bearing spindle motor 13. A CPU 11 periodically reads an ambient temperature, that is detected by a temperature sensor 14 via an A/D converter 111 and refers to a temperature table 110a, thus acquiring a reference voltage value that is equivalent to the current, that is supplied to the motor 13 at the ambient temperature and when the spindle motor 13 is normal. The CPU 11 generates the reference voltage of the reference voltage value by a reference voltage generating circuit 15. A comparator 16 compares the detection value of a current sensor 17 with a reference voltage, that is generated by the reference voltage generating circuit 15. A controller 18 interrupts the CPU 11, when a failure in the spindle motor 13 is decided from the comparison result of the comparator 16. |
