Invention Grant
- Patent Title: Evaluation circuit for a capacitive sensor, capacitive sensor, and actuator in a motor vehicle
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Application No.: US16060663Application Date: 2016-09-14
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Publication No.: US10684142B2Publication Date: 2020-06-16
- Inventor: Jörg Schulz
- Applicant: IFM ELECTRONIC GMBH
- Applicant Address: DE Essen
- Assignee: IFM ELECTRONIC GMBH
- Current Assignee: IFM ELECTRONIC GMBH
- Current Assignee Address: DE Essen
- Agency: Harness, Dickey & Pierce, P.L.C.
- Priority: com.zzzhc.datahub.patent.etl.us.BibliographicData$PriorityClaim@358e4561
- International Application: PCT/EP2016/071610 WO 20160914
- International Announcement: WO2018/033223 WO 20180222
- Main IPC: G06F3/044
- IPC: G06F3/044 ; H03K17/96 ; G01D5/24 ; G01R27/26 ; H03K17/955

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.
Public/Granted literature
- US20180274950A1 EVALUATION CIRCUIT FOR A CAPACITIVE SENSOR, CAPACITIVE SENSOR, AND ACTUATOR IN A MOTOR VEHICLE Public/Granted day:2018-09-27
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