Magnetic disk storage apparatus
US6801382B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 17, 2002 |
| Grant date | Oct 5, 2004 |
| Priority date | — |
| Expiry date | Feb 10, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/28
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Currents of sine waveforms can be fed through coils by a relatively small-sized circuit, and thereby, highly dense magnetic storage can be realized with less rotation variations and a driving control circuit of a motor rotating at a low noise level can be provided. A coil of one phase of a three-phase brushless motor is driven with full amplitude at which an applied voltage becomes equal to a source voltage, and a coil of one of other phases is driven with gradually changing voltages so that a current of sine waveform is delivered, and a coil of the remaining phase is driven by feedback control so that a total current flowing through all coils becomes a predetermined current value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.