Accelerometers
US10161957B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 2015 |
| Grant date | Dec 25, 2018 |
| Priority date | — |
| Expiry date | May 10, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P2015/0814
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for closed loop operation of a capacitive accelerometer comprising: a proof mass; first and second sets of both fixed and moveable capacitive electrode fingers, interdigitated with each other; the method comprising: applying PWM drive signals to the fixed fingers; sensing displacement of the proof mass and changing the mark:space ratio of the PWM drive signals, to provide a restoring force on the proof mass that balances the inertial force of the applied acceleration and maintains the proof mass at a null position; detecting when the mark:space ratio for the null position is beyond a predetermined upper or lower threshold; and further modulating the PWM drive signals by extending or reducing x pulses in every y cycles, where x>1 and y>1, to provide an average mark:space ratio beyond the upper or lower threshold without further increasing or decreasing the mark length of the other pulses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.