Automatic velocity calibrator for a velocity servo loop in a magnetic disk drive
US4480217A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 1982 |
| Grant date | Oct 30, 1984 |
| Priority date | — |
| Expiry date | Dec 14, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/5521
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An automatic velocity calibrator for a head positioning servo system in a magnetic disk drive performs a velocity calibration in a single pass over the magnetic disks by measuring actuator velocity and adjusting the gain of the velocity transducer in a series of successive approximations. Velocity is determined by turning a timer on in response to a track crossing and turning the timer off after at least two successive track crossings have been detected. A plurality of velocity measurements are stored and averaged. The average velocity is compared to a constant velocity command and an 8-bit latch is incremented or decremented in response to this comparison. A digital to analog converter produces a reference for an automatic gain control amplifier in the servo system which in turn adjusts the velocity transducer gain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.