Planar coil apparatus employing a stationary and a movable board
US4425511A · kind A · utility
Inventor
Key dates
| Filing date | Feb 9, 1981 |
| Grant date | Jan 10, 1984 |
| Priority date | — |
| Expiry date | Feb 9, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2017/9713
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A planar coil apparatus is disclosed for providing an output signal indicative of a movement between at least a first and a second position. A first stationary planar member has disposed on a surface, a first flat coil configuration which is emplaced thereon by a printed circuit or similar technique. Located adjacent to this coil on the board is a second coil of similar configuration. A drive signal such as that obtained from an AC or pulse source is applied to the input terminals of one of the coils which constitutes the drive coil. A second planar board is positioned relatively congruent and above the first board and has located thereon a closed coil configuration which constitutes a closed coil loop. As this movable board is brought into proximity with the stationary board, magnetic flux is coupled via the loop from the drive coil to the second coil which serves as the sense coil. By monitoring the output of the sense coil, an AC signal can be detected when the movable board is within a predetermined range of distances from the stationary board. The detection of the AC signal indicates a change of position or state. Various other arrangements employ a movable board configuration…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.