| 摘要 |
PROBLEM TO BE SOLVED: To provide a disk drive of small heat generation which can realize rotation drive with less jitters, without the use of a position detecting element. SOLUTION: A field effect power transistor of a power supplying section 20 forms a three-phase current path to coils 11 to 13 during high-frequency switching operation, in order to drive a disk 1 to rotate. A voltage-detecting section 23 compares direct terminal voltage pulses V1, V2, V3 with the common voltage Vc, to output a detection pulse signal. A power feed control section 32 controls the field effect power transistor to execute the high-frequency on/off switching operation, in response to the switching pulse signal of the switching control section 22. A resistor connection circuit 51 of the power supply section connects a necessary connection resistor between the power supply terminal of coil and output terminal of voltage supply section, in response to an output signal of a state transition section, in order to prevent erroneous detection of the voltage detecting section 23 due to switching noise. |
