Process for operating a capacitive switch and a circuit of a capacitive switch
US6225710A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1999 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | Mar 25, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/955
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A capacitive switch is presented including an oscillator, with a gauge length and an evaluation circuit. The oscillator delivers a measurement signal and the gauge length has at least one sensor with a sending electrode and a measurement electrode. The switch has a low noise emission and is especially invulnerable to incident noise due to the fact that there is a noise source and two correlators. In the first correlator, frequency-spreading of the measurement signal takes place. The frequency-spreading measurement signal is connected to the second input of the second correlator and to the sending electrode. The measurement electrode is connected to the first input of the second correlator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.