The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 16, 2020
Filed:
Sep. 14, 2016
Ifm Electronic Gmbh, Essen, DE;
Jörg Schulz, Tettnang, DE;
IFM ELECTRONIC GMBH, Essen, DE;
Abstract
An evaluation circuit for a capacitive sensor for detecting the distance, speed, or position of an object, comprises a reference capacitance and a measuring capacitance. A square wave voltage is applied to the reference capacitance and the measuring capacitance via a resistor, and a pulse which has a variable duration is obtained with the aid of a logic linking unit. The reference capacitance is connected to a first switching stage and the measuring capacitance is connected to a further switching stage. A single measuring capacitance has a capacitive coupling to an auxiliary electrode, and the switching stages are part of a logic linking unit. An output of the logic linking unit is connected to an integration stage. A charging capacitor (Ca) is charged or discharged via an output of the integration stage.