Abstract: In a method for controlling an air-conditioning unit, in which the incident solar radiation is captured by means of at least three spatially arranged sensors, the calculation of the incident solar radiation is performed on the basis of a vector representation of the incident solar radiation. In this way a particularly simple calculation method can be implemented, which requires a particularly small calculation effort.

Abstract: A method and a device detects the state of an air filter in an air conditioning system for the interior of a motor vehicle. Condensed water created at the evaporator is discharged and fed to a sensor, which determines a parameter of the condensed water, and which, from a change or a certain value of the measured parameter, draws a conclusion regarding a change of the state of the air filter.

Abstract: A sensor device is provided for generating an electrical output signal in dependence on the position of a light source in relation to the sensor device. The sensor device has a three-dimensional switch carrier with several adjacent faces oriented in different directions, on which faces at least two sensors are arranged. On the two sides of a central face, there is arranged in each case a face, with an infrared light (IR) photodetector in each case, oriented at an angle to the central face, whereby the faces on which the IR photodetectors are arranged are not directly adjacent to one another.

Abstract: A sensor arrangement for determining brightness, comprising a photosensor and a reflector. The photosensor and the reflector are positioned such that light reflected by the reflector reaches the photosensor; and the reflector is designed such that a visible fraction of the ambient light is reflected, and an infrared fraction of the ambient light is transmitted. In this way, a sensor arrangement is created which is modeled on the perception of the human eye and which is comparatively easy and economical to produce.

Abstract: A sensor device is provided for generating an electrical output signal in dependence on the position of a light source in relation to the sensor device. The sensor device has a three-dimensional switch carrier with several adjacent faces oriented in different directions, on which faces at least two sensors are arranged. On the two sides of a central face, there is arranged in each case a face, with an infrared light (IR) photodetector in each case, oriented at an angle to the central face, whereby the faces on which the IR photodetectors are arranged are not directly adjacent to one another.

Abstract: The invention is directed to a level control system for a motor vehicle wherein the controllable valves (8a to 8d and 10) are controlled by a first control unit (24). The first control unit (24) transmits a signal to a second control unit (36) at time intervals. If the second control unit (36) does not receive the signal expected from the first control unit, then the second control unit (36) assumes the control of the valves (8a to 8d and 10) in such a manner that the motor vehicle is transferred into a dynamically safe driving condition.