An impedance measurement circuit for determining a complex impedance of a capacitive sensor that is configured for employing at least one electric heater member as an electrode to be operated in loading mode. The measurement circuit includes: a signal generating unit for providing an electric measurement signal; a signal sensing circuit measuring current through the at least one electric heater member; an electric heater member connection circuit comprising a plurality of MOSFETs for selectively electrically connecting the electric heater member either to the signal sensing circuit for complex impedance measurement or to a DC electric power unit for heating purposes; and a control and evaluation unit that is configured for controlling a switching status of the plurality of MOSFETs according to a predefined sequence, and for determining a complex impedance from the determined currents with reference to a complex reference potential during predefined stages of the predefined sequence.


    Access

    Download


    Export, share and cite



    Title :

    Low-cost, protected capacitive sensing circuit for loading mode operation of capacitive sensors employing heater members


    Contributors:

    Publication date :

    2024-10-29


    Type of media :

    Patent


    Type of material :

    Electronic Resource


    Language :

    English


    Classification :

    IPC:    H03K PULSE TECHNIQUE , Impulstechnik / B60N SEATS SPECIALLY ADAPTED FOR VEHICLES , Sitze besonders für Fahrzeuge ausgebildet / B60R Fahrzeuge, Fahrzeugausstattung oder Fahrzeugteile, soweit nicht anderweitig vorgesehen , VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR



    LOW-COST, PROTECTED CAPACITIVE SENSING CIRCUIT FOR LOADING MODE OPERATION OF CAPACITIVE SENSORS EMPLOYING HEATER MEMBERS

    LAMESCH LAURENT / JUSTINGER TOBIAS / PUETZ MICHAEL et al. | European Patent Office | 2022

    Free access

    LOW-COST, PROTECTED CAPACITIVE SENSING CIRCUIT FOR LOADING MODE OPERATION OF CAPACITIVE SENSORS EMPLOYING HEATER MEMBERS

    LAMESCH LAURENT / JUSTINGER TOBIAS / PUETZ MICHAEL et al. | European Patent Office | 2024

    Free access

    LOW-COST, HIGH MEASUREMENT SPEED CAPACITIVE SENSING CIRCUIT FOR LOADING MODE OPERATION OF CAPACITIVE SENSORS

    LAMESCH LAURENT / JUSTINGER TOBIAS / PÜTZ MICHAEL et al. | European Patent Office | 2024

    Free access

    HEATER IN-CIRCUIT CAPACITIVE MEASUREMENT

    BOELKE JOEL | European Patent Office | 2020

    Free access

    HEATER IN-CIRCUIT CAPACITIVE MEASUREMENT

    BOELKE JOEL | European Patent Office | 2022

    Free access