Non-contact proximity switch and method for programming it
US5818129A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1996 |
| Grant date | Oct 6, 1998 |
| Priority date | — |
| Expiry date | Jul 24, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/94021
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In order to improve a non-contact proximity switch, and a method for programming it, with an resonant circuit that can be influenced by objects approaching from outside and an evaluation circuit to generate an output signal as a function of an output voltage of the resonant circuit that exceeds a predefined threshold value, and with standard terminals, in such a way that the proximity switch can be used at different temperatures and operates accurately independently of the ambient temperature and independently of other trouble influences, it is proposed that a temperature sensor be arranged in the vicinity of the resonant circuit; and that a compensation circuit comprise a circuit unit, downstream from the temperature sensor, which outputs a compensation quantity, dependent on the sensed temperature, that is delivered to a comparator to be compared with the output voltage of the oscillator circuit and, when identity exists, to enable the output signal; and that the compensation magnitude for compensating for the temperature dependence and for other influences be capable of being repeatedly modified in temperature-dependent fashion from outside using the "teach-in" method by means o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.