Two-port electromagnetic drive for a double-ended tuning fork
US5501103A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 1994 |
| Grant date | Mar 26, 1996 |
| Priority date | — |
| Expiry date | Feb 15, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P2015/0828
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electromagnetically-excited silicon micromachined vibrating beam accelerometer includes a proof mass or pendulum attached to an outer casing by way of a pair of flexures defining a hinge axis HA. A double-ended tuning fork (DETF) is connected between the proof mass and the casing along an axis generally perpendicular to the hinge axis (HA) defining a sensitive axis SA such that forces applied along the hinge axis HA will cause the DETF to go into either compression or tension. Electromagnetic excitation causes the vibrating beams to vibrate at a resonant frequency when the proof mass is at rest. In response to a force along the sensitive axis SA, the vibrating beams go into either tension or compression resulting in a change in the resonant frequency which, in turn, is used as a measure of the force. The excitation includes a magnetic field B, applied in a direction generally perpendicular to the plane of the DETF and perpendicular to the sensitive axis SA. In order to eliminate the effects of variations in the resistance path of the vibrating beams due to either manufacturing tolerances and temperature, the DETF in accordance with the present invention is formed as a dual-port …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.