Sensor circuit with diagnostic capability
US6025711A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1997 |
| Grant date | Feb 15, 2000 |
| Priority date | — |
| Expiry date | Mar 10, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D3/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A proximity sensing circuit is provided with various attributes, including the connection of a proximity sensor coil in a feedback loop of an amplifier, the frequency hopping technique that periodically changes the two frequencies used by its proximity sensor circuit to avoid deleterious interference by constant frequency EMI sources and the provision of a self diagnosis technique. The connection of the proximity sensor coil in the feedback loop of an amplifier results in several advantages including the connection of the coil to a virtually infinite impedance, the reduction of the number of components needed in the proximity sensing circuit and decreased temperature sensitivity of the overall circuit. The frequency hopping technique that periodically changes the two frequencies used by the proximity sensor significantly decreases the likelihood that a constant frequency EMI source in the vicinity of the circuit will have a continually adverse affect on its accuracy and reliability. In applications that require a large number of sensors, the circuit uses a multiplexer with a plurality of sensors and a single filtering network to decrease the necessary number of components in the pr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.