Method and arrangement for determining the position of an electromagnetic actuator
US6798635B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 30, 2001 |
| Grant date | Sep 28, 2004 |
| Priority date | — |
| Expiry date | Jun 18, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F2007/1866
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method for driving and measuring the position of an electromagnetic actuator that operates according to the voice coil principle. The coil thus moves within a magnetized gap relative to permanent magnet core. As the coil extends partially outside of the core, its inductance will change. The voice coil is connected to a controllable current source that can both generate and control an average current and an AC component through the voice coil. The frequency of the AC component is measured, and is a function of the instantaneous inductance of coil, which in turn is a function of the coil's position relative to the core. In an alternative embodiment, the phase shift between an AC current and an AC voltage through the coil is analyzed to determine the position of the coil, while simultaneously controlling the force.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.