Abstract: The method of operating a windshield wiper intermittently requires an apparatus including a rain sensor (12), which generates a signal (S) depending on an amount of rain on the windshield, and a signal processing device (13), e.g.a microprocessor with internal A/D and D/A converters, connected to the sensor (12) to receive the signal (S) and, a control unit connected to the signal processing device (13), and, advantageously, a device for measuring a wiping process duration (T) and inputting the duration to the microprocessor and a drive for the windshield wiper connected to the signal processing device (13). According to the method, the windshield wiper is operated by the signal processing device at least partially according to the signals (S) from the sensor so that the time interval (I) between successive current wiping processes, depends, in part, on a duration (T.sub.-1, T.sub.-2, . . . T.sub.-n) of at least one past wiping process (W.sub.-1, W.sub.-2, . . . W.sub.

Abstract: A gas sensor device has a carrier plate of ceramic or glass. The carrier has apertures which leave only strips in a spiral configuration connecting a middle region of the carrier to the outer region thereof. The apertures may be mere slits separating the connection strips or they may be apertures providing larger air gaps. On each middle region so provided on the carrier a sensor element is located that has two electrodes and a sensitive layer which establishes a conducting connection between the electrodes. The electrodes and the sensitive layer are directly applied to the upper surface of the middle region. The two electrodes are comb shaped and are placed in inter-digital configuration to define a meandering gap between them. On the underside of the middle region of the carrier a heating element for the sensor element is provided and, if desired, also a temperature measuring resistance for regulating the temperature produced by a heating resistor.

Abstract: A device for engine cooling includes at least one mechanical coolant pump driven by the engine to be cooled and at least one electric coolant pump controlled by an electronic switching device being provided in at least one cooling circuit of an engine to be cooled. The conveying capacity of the electric pump is set as a function of operating variables of the engine to be cooled and of further variables, while the mechanical pump is designed for a basic conveying capacity. In the coolant circuit a heat exchanger which is operated as a radiator, the cooling capacity of which can be altered with the aid of a radiator blind and of a fan, is arranged in a first coolant path. An additional heat exchanger, the waste heat of which is used for heating purposes or for further engine cooling, is arranged in an additional coolant path or in a separate coolant circuit.

Abstract: A thermal radiation sensor is suggested which comprises two receiver surfaces exposed to the radiation, one receiver surface (1) having a high absorption capacity with respect to the thermal radiation, the other (2) having a low absorption capacity, the two receiver surfaces (1) and (2) consist of a NTC resistance material and are combined in a bridge circuit together with two temperature-independent cermet resistors (3) and (4). In order to prevent a dependency of the measurements of such a sensor on the ambient temperature, the NTC resistors (1) and (2) comprise underlying heating layers (6) and (7) which keep the two NTC resistors at a constant temperature. Insulating layers (8) and (9) are provided between the NTC resistors (1) and (2) and the heating layers (6) and (7). The heating layers (6) and (7) consist of a cermet thick film with platinum or of a platinum thick film and have the shape of a meander. The insulating layers (8) and ( 9) preferably consist of a crystallizing glass.

Abstract: A method of controlling climate in an interior of a vehicle, which method comprises the steps of measuring air temperature in the vehicle interior and outside of the vehicle, measuring relative humidity in the vehicle interior and outside of the vehicle, and controlling air flow from outside of the vehicle into the vehicle interior in accordance with the measured temperatures and humidities.

Abstract: A heat and/or air conditioning apparatus for a motor vehicle comprising control means and a first humidity sensor located in the interior of the motor vehicle, a second temperature sensor and a second humidity sensor located outside of the vehicle, intake duct means for supplying outside air to the vehicle interior, at least two discharge ducts located in the vehicle interior and of which at least one opens in the vicinity of a vehicle window, and a blower.

Abstract: An arrangement for polarization control for an optical heterodyne or homodyne receiver wherein the state of polarization of the optical signal of the local oscillator of a heterodyne or homodyne receiver and the optical signal supplied to the receiver can be transformed so that both signals can be adjusted to the same identical state of polarization. A phase modulator PM1 and a following polarization converter PK1 are arranged onto an optical waveguide WL1 which receives at an input e.sub.1 an optical wave from a subscriber and another polarization converter PK2 and a following phase modulator PM2 are arranged onto another optical waveguide WL2 which has an input e.sub.2 for coupling in the local oscillator signal. The arrangement can be controlled such that the signals fed in have the same state of polarization at the output for superposition and IF generation.

Abstract: Apparatus for continuous reset-free polarization and phase control which includes an optical strip waveguide 10 in which two waves TE and TM mode are polarized orthogonally relative to each other and have mutually different propagation constants .beta..sub.1 and .beta..sub.2 and includes a plurality of N=4m equidistant electrodes (E.sub.i, where i=1, 2 . . . N) which are mounted successively along the strip waveguide 10 and where m is a whole number between 5 and 10 and wherein each electrode E.sub.i receives a voltageU.sub.i =U.sub.0 sin (.eta.+(i-1).multidot..pi..multidot..LAMBDA..sub.0 /2.multidot..LAMBDA..sub.1) with i=1, 2, . . . Nwherein .LAMBDA..sub.0 is the geometrical length fixed by four electrodes and .LAMBDA..sub.1 is the length defined by the operating wavelength .LAMBDA..sub.1 and .eta. is a variable control quantity between and 0 and 2.pi. and U.sub.0 is a variable maximum voltage.

Abstract: An ion conductive sensor is connected to a current source which, in order to prevent polarization effects, controls current flow through the sensor in spaced or polarity-alternating pulses. If the sensor is a humidity sensor, it is preferably constituted by Cr.sub.2 O.sub.3, V.sub.2 O.sub.5 and Na.sub.2 WO.sub.4 in a proportion, by weight, of preferably 2 to 2.5:1:1, sintered on a substrate which has comb electrodes applied thereto. The sensor is especially immune to noise or disturbance pulses from the current supply and is especially suitable for use as an ambient humidity sensor in an automotive vehicle (810).

Abstract: A heat radiation sensing device is provided, which comprises two receiver surfaces which are exposed to the radiation, one of which comprises a high absorption ability with respect to the heat radiation by means of a black coloring, while the other has a low absorption ability by means of a covering which reflects the heat radiation. These two receiver surfaces consist of NTC resistor material and are combined to form a bridge circuit with two cermet resistors which are independent of temperature. The four resistors are applied to a ceramic substrate and are connected with conductor path which, in turn, end in the four required connections. The ceramic substrate is fixed in a frame which carries a covering which is pervious to heat radiation to a great degree and which, in turn, carries a layer having a window over one of the two NTC resistors the layer is made of a material which reflects the heat radiation to a great degree.

Abstract: A humidity sensor, and particularly a sensor which can distinguish between low humidity values, for example below 60% humidity, and high humidity values, for example 90% humidity and thereover, and change the capacitance between output electrodes (5, 6) is formed by applying interdigited comb electrodes (1, 2) on a substrate (8) and applying over the substrate a ceramic mass formed of BaRuO.sub.3, V.sub.2 O.sub.5 and Na.sub.2 WO.sub.4, with a weight relationship of (1.+-.0.4):(1.+-.0.4):(0.6.+-.0.2) preferably 1:1:0.6. The sensor is made by first making a powder of the components, mixing it with a glass paste and, if necessary, a thinner, and applying the resulting paste by thick-film technology to a ceramic substrate on which the electrodes have been applied, and then firing the substrate at a temperature of between 550.degree. C. to 850.degree. C.

Abstract: An air blower sucks air from an area of an air heated compartment of a motor vehicle and blows out an air stream into a different area of the compartment. A temperature sensor is located in the air stream at a relatively large distance from the air blower so as to entrain ambient air from the compartment. Due to the mixing of the discharged air stream with the ambient stream, an information about the overall temperature in the compartment is detected by a single temperature sensor.

Abstract: A temperature-sensing module is described, including a measuring element sensitive to temperature, such as an NTC resistor. In order to reduce the thermal influence of the housing of the element and of the electrical connection, and also to improve the mechanical stability and resistance against vibrations, the connection wires of the element are attached to conductive webs formed side-by-side on a carrier plate of an electrically and thermally insulating material. The conductive webs at one end have enlarged areas which are connected to the connection wires of the sensitive element, and the connecting part of each web is relatively narrow in cross section and has a meander-like configuration. The transition between the enlarged part and the meander-like part is further restricted in cross section to reduce the thermal influence to a minimum.