Magnetic disk drive and voice coil motor drive circuit
US6611118B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 2001 |
| Grant date | Aug 26, 2003 |
| Priority date | — |
| Expiry date | Sep 18, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/5547
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic disk drive uses a back electromotive force sensor that detects the back electromotive force produced in a VCM actuator without being affected by fast changes of current during a high-speed control sampling cycle, and that enables configuration of a fast, high-band speed control system. A back electromotive force sensor for disk drives has a first circuit that detests the coil terminal voltage of a voice coil motor and outputs that value as a band limited signal that is a constant multiple-of that value, a second circuit that detects a drive current in the voice coil motor and outputs a voltage signal proportional to that drive current, and a computation circuit that takes the difference between the output of said first circuit and the output of said second circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.