Method and apparatus for measuring displacement of a moveable member of an electromagnetic device by using perturbations in the device's energizing current
US4907901A · kind A · utility
14Cited by
13References
19Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 24, 1986 |
| Grant date | Mar 13, 1990 |
| Priority date | — |
| Expiry date | Dec 24, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/12
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus including a circuit for measuring the displacement of an electromagnetic device wherein the measuring is effected by utilizing the perturbations which occur in the energizing current of the device when the moveable member contacts a second member during a "gap" measurement, for example. The circuit includes circuitry for obtaining a first derivative signal having indicator portions corresponding to the perturbations. An apparatus including a test block is used for testing center-to-center distances.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.