US Patent 11787265 Electrical heating device for motor vehicles

A radiant heating device for producing radiant heat in a passenger compartment of a motor vehicle includes a heating surface for emitting heat radiation, a heating element for providing heating power, a first temperature sensor for detecting a first temperature in a specific spot and for providing a corresponding first temperature indication, and a second temperature sensor for detecting a second temperature on the surface and for providing a corresponding second temperature indication. In order to detect a local over-heating of the heating surface, a difference between the two temperature indications is determined. In the event of a defect, a protective operating mode is then selected.