Sensorless closed-loop actuator unlatch
US5600219A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1994 |
| Grant date | Feb 4, 1997 |
| Priority date | — |
| Expiry date | Jun 29, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/91
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A first method for detecting movement of an actuator includes supplying a demand current to a voice coil motor of the actuator (A.sub.1), sampling a voice coil motor voltage (B.sub.1), performing a slope detection of a voice coil motor voltage function (C.sub.1) and extrapolating the voice coil motor function (D.sub.1) to identify a change in slope of the voice coil motor function. A second method for detecting movement of an actuator includes supplying a continuously increasing current ramp to the voice coil motor of an actuator (A.sub.2), measuring a back e.m.f. voltage of the voice coil motor (B.sub.2), performing a change in slope detection of a back e.m.f. voltage function (C.sub.2) and integrating the back e.m.f. voltage function (D.sub.2) to determine movement of the actuator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.