Disk drive motor position detection using mutual inductance zero crossing
US6555977B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 2000 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | Jul 27, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/18
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention includes a method and apparatus for detecting the position of an electric motor rotor by sensing the zero crossing or polarity change of a mutual inductance associated with the motor. The use of mutual inductance provides for consistent position detection unaffected by motor speed or winding current, thus providing significant advantages over traditional back emf zero crossing detection methods. The mutual inductance zero crossing may be detected by measuring a voltage signal in a floating phase of the motor, filtering back emf and excitation components out of the measured voltage signal, and detecting a polarity change or zero crossing in the resulting mutual inductance signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.