Displacement detection device
US4966041A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 1988 |
| Grant date | Oct 30, 1990 |
| Priority date | — |
| Expiry date | Dec 16, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/145
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pair of permanent magnets adjoining each other and magnetized with opposite polarities are coupled with a movable object through a connecting shaft so that the pair of permanent magnets are aligned in a direction of displacement of the movable object. A first and a second Hall element is disposed stationary at a position opposing to the pair of permanent magnets and aligned also in the direction of displacement of the movable object with a predetermined space interval between the first and second Hall elements. When the movable object is displaced in one direction, and hence the pair of magnets are moved from a neutral position at which the boundary of the pair of magnets corresponds to the center of the interval of the first and second Hall elements, output voltages of different phases are respectively generated by the first and second Hall elements. An input current corresponding to a difference value between the output voltages is supplied to each of the first and second Hall elements to compensate for a change in characteristics of the permanent magnets and Hall elements due to a change in ambient temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.