Capacitive sensing system able of using heating element as antenna electrode

US9000331B2 · kind B2 · utility

Assignee

• IEE INTERNATIONAL ELECTRONICS & ENGINEERING S.A. · LU

Inventors

• Michael Virnich · Korlingen, DE
• David Hoyer · Ayl, DE
• Martin Thinnes · Trier, DE
• Michael Puetz · Trier, DE
• Thomas Meyers · Fremont, US
• Laurent Lamesch · Reichlange, LU

Key dates

• Filing date: Sep 20, 2012
• Grant date: Apr 7, 2015
• Expiry date: Sep 6, 2033

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60N2210/12
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A capacitive sensing system for being connected to a heating element comprises a capacitive detector connectable to the heating element and a common mode choke for essentially preventing alternating current from flowing from the heating element to the heating current supply. The capacitive detector is configured for driving an alternating current into the heating element and for producing an output indicative of capacitance based upon the alternating current. The choke has a first and a second winding for connecting the heating element with the heating current supply. The choke comprises a third winding connected in parallel of the first and/or second winding. The capacitive detector is configured for measuring a portion of the alternating current flowing across the third winding and for taking into account the measured portion of alternating current when producing the output.