A capacitive occupancy or proximity detector includes a heating circuit, an impedance measurement circuit connected to the heating element, and a diagnostic circuit configured for determining integrity of the heater element. The heating circuit includes a heating element, a heating current source and a common mode choke having a first and a second winding, the heating element being connectable to the heating current source via the first and second windings. The diagnostic circuit includes at least one controllable switching element coupled across the second winding, circuitry for injecting a DC current into a series connection formed by the first winding the heating element and a parallel connection of the second winding and the at least one controllable switching element, and at least one detection circuit for detecting a voltage variation across the second winding.
Capacitive occupancy or proximity detector
2018-11-13
Patent
Elektronische Ressource
Englisch
IPC: | G01D MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE , Anzeigen oder Aufzeichnen in Verbindung mit Messen allgemein / 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 / B62D MOTOR VEHICLES , Motorfahrzeuge / G01R Messen elektrischer Größen , MEASURING ELECTRIC VARIABLES |
Diagnostic capacitive occupancy or proximity detector
Europäisches Patentamt | 2017
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