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: An arrangement for determining the axial play between the stator and the rotor of an electric motor, especially of a small-size electric motor, includes resilient elements which mount the respective electric motor on a stationary support for oscillatory movement relative thereto, an electromagnet which causes the electric motor to oscillate in a predetermined path at such a frequency and amplitude that, so long as there is an axial play between the rotor and axial bearings thereof, the rotor will conduct movement not only with, but also relative to, the stator, which results in axial impacts between the rotor and the axial bearing and in a complex motion of the stator which has the effect of the impacts superimposed on the basic motion. The arrangement further includes a sensor which detects the complex motion and generates an electric signal representative thereof.

Abstract: A strip of recording paper on which a metallization is formed on a paper substrate, which metallization is burned off under the influence of an electrical discharge is passed beneath a recording head. In one embodiment, the recording head is moved transversely across the recording paper, while in engagement with a group of contact tracks which are, selectively, energized in accordance with the desired alphanumeric output. The recording head is formed with point contact electrodes and line-contact electrodes. The alphanumeric output is displayed on the instrument in segmental form and when a segment is to be printed in the direction transverse to the relative direction of movement of the head and the paper, the line-contact electrode is momentarily energized to cause printing of a line; if a segment is to be printed which extends in the direction of relative movement of the head and the paper, a point contact segment is energized for a distance corresponding to the distance of the segment to be formed.

Abstract: A thin sheet of metal is first etched in accordance with similar patterns after exposure through masks, from both sides, to form parallel strips which, preferably, extend to integral connecting elements and may, also, include printed circuit connections or components; one of the sides of the strips, additionally, includes transverse cross connections to provide for mechanical attachment of the parallel strips, permitting application of the parallel strips to a substrate, for subsequent removal, so that the resulting electrode will be a plurality of closely spaced parallel strips applied, for example by an adhesive, on a substrate, integral with connecting portions for a printed circuit.