Capacitive displacement sensing circuit with a guard voltage source
US9826308B2 · kind B2 · utility
0Cited by
4References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 28, 2015 |
| Grant date | Nov 21, 2017 |
| Priority date | — |
| Expiry date | Jan 21, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R9/06
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A common plate is formed in a moveable element of a device, the device having an actuator coupled to drive the moveable element. A first plate and the common plate together form a first capacitance, while a second plate and the common plate together form a second capacitance, both of which varies as a function of displacement of the moveable element. A measurement circuit has an input coupled to the first plate, while an excitation voltage source has an output coupled to the second plate. A guard voltage source has an output coupled to a conductive portion of the device. Other embodiments are also described and claimed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.