Proximity sensor combining impedance, frequency and decay constant information
US7173410B1 · kind B1 · utility
25Cited by
6References
22Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 28, 2004 |
| Grant date | Feb 6, 2007 |
| Priority date | — |
| Expiry date | Aug 3, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/9502
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Systems and methods are disclosed that compensate for temperature drift in a proximity sensor, such as an extended range inductive proximity sensor. Voltage measurement can be taken before, and during damped oscillatory decay of a voltage in a resonant circuit in the proximity sensor to determine a value, γ, associated with an inductive time constant for the resonant circuit. A target-induced inductance value can be isolated, via manipulation of the gamma value, and compared to a predetermined threshold value to determine whether the target has been sensed by the proximity sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.