Method and apparatus for sensing armature position in direct current solenoid actuators
US5942892A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 6, 1997 |
| Grant date | Aug 24, 1999 |
| Priority date | — |
| Expiry date | Oct 6, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8242
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus detects a position of an armature within a solenoid coil by superimposing a fixed frequency sensing signal onto the coil driver signal. The combined signal is applied to the solenoid coil and an alternating current component varies with changes in inductance of the solenoid coil that result from position changes of the armature. A current sensor produces an output signal indicating a level of current flowing through the solenoid coil and a filter extracts the alternating component of that output signal that results from the sensing signal. A position circuit determines the position of the armature from an output from the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.