Electromagnetic drive apparatus having a flat coil
US4951023A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 1985 |
| Grant date | Aug 21, 1990 |
| Priority date | — |
| Expiry date | Jul 15, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R9/047
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electromagnetic drive apparatus for undertaking linear or circular movements as a flat coil disposed within a magnetic circuit, which may be formed by a iron core having one or more permanent magnets. The magnetic circuit includes at least one plate or coating of electrically conductive material which is spaced from the coil and coextensive with the area of movement of the coil within the magnetic circuit. The electrically conductive material promotes rapid change of the coil current due to induced eddy currents and thus contributes to a low response time, or alternatively to a high response speed, of the drive apparatus, particularly with the use of a pulsed drive signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.