Method and apparatus for dynamic low voltage spindle motor operation
US5633568A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 6, 1995 |
| Grant date | May 27, 1997 |
| Priority date | — |
| Expiry date | Jun 6, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B19/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A spindle motor operates dynamically in one of two modes for a disc drive. During power-up, the disc drive electronics are configured to operate the motor in a line-to-line configuration, thus assuring generation of adequate torque. An operating condition circuit senses when the motor has attained substantially the desired running velocity .omega., after which, the drive electronics are dynamically reconfigured to operate the spindle motor in a line-to-neutral mode. A power interruption circuit senses when the source power supply V.sub.cc voltage level is too low or turned off, thereafter initiating a reconfiguration back to line-to-line mode, wherein the highest voltage pair of motor windings are electrically held across the source power supply V.sub.cc lines. Simultaneously, a switching circuit electrically connects the V.sub.cc lines across the transducer positioning voice coil motor in the disc drive, thereby delivering current from the spindle motor to the voice coil. Because only one spindle motor winding is powered during normal operation, a back EMF voltage may be developed in a single winding to a level to just below the source power supply V.sub.cc level while still able …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.