Abstract: A method for operating devices on wheels having pneumatic tires to signal the tire pressure, i.e. the air pressure in the pneumatic tire, in which a pressure sensor measures the tire pressure at regular intervals, and an analysis circuit compares the tire pressure readings with a reference pressure and, in the event of deviations of the tire pressure reading from the reference pressure which exceed a threshold value .DELTA.p, transmits by radio, to an indicating device arranged separately from the wheel, a signal reporting the deviation, such that the device meets its energy needs from an electrical battery. Radio operation is discontinued as long as the pressure measured by the pressure sensor is below a preselected second pressure threshold, in particular a preselected absolute pressure value.

Abstract: Electric low current signals are transmitted through two-wire circuits having coaxial connectors which are closed by windings that are coupled transformer-like to the coaxial connectors. This arrangement allows transmission of control signals for electric power consuming devices within automobile doors, low frequency audio signals, and electrical power to power the electric consumers. All signals are transmitted on a common data cable. Control signals are in binary coded form, modulated onto a carrier signal, as are modulated, low frequency audio signals. The signals are demodulated in a door module and separated according to frequency. The low frequency audio signals are amplified and transmitted to a loudspeaker. The control signals are processed by a microprocessor controller in conjunction with switching units that create corrective actions for the power consuming devices located in the door.

Abstract: Control signals for electric consumers in vehicle doors and l.f. signals for loudspeakers in vehicle doors are transferred from a control apparatus (1) provided outside of the door over a common data line (42, 43) to a door module (20, 30). For this purpose, in the control apparatus (1) the control signals are modulated in binary-coded form onto a carrier signal and onto the same carrier signal there is also modulated the l.f. audio signal. In the door module 30) the signals are demodulated and separated according to frequency. The l.f. signals are amplified and fed to a loudspeaker (4, 5). The control signals are evaluated by a micro-controller (24, 34) and they control over switching stages (23, 33), setting elements (6, 7) provided in the door. Conversely there is also possible a data transfer from the door module (2, 3) to the control apparatus (1).

Abstract: A reader for a disk-shaped carrier with Wiegand wires is described which manages with only two permanent magnets (1, 2). the variation of the magnetic field needed for detecting the Wiegand wires is effected by flux concentrating pieces (3, 4, 7) attached to the permanent magnets (1, 2). In order to be able to read the carrier with the Wiegand wires without change when it is inserted into the reader rotated by 180.degree. round its longitudinal axis coinciding with the direction of insertion (14), the flux concentrating pieces (3, 4, 7) are arranged symmetrically with respect to the longitudinal axis (14) which is a two-fold axis of symmetry. To pick-up the Wiegand pulses, two E-shaped soft magnetic cores (9) are provided which carry on their center leg an electrical sensor winding (17). The free ends of the legs of the E-shaped cores (9) face one another and are also arranged symmetrically with respect to the longitudinal axis (14).

Abstract: A reader for a disk-shaped carrier with Wiegand wires is described which manages with only two permanent magnets (1, 2). The variation of the magnetic field needed for detecting the Wiegand wires is effected by flux concentrating pieces (3, 4, 7) attached to the permanent magnets (1, 2). In order to be able to read the carrier with the Wiegand wires without change when it is inserted into the reader rotated by 180.degree. round its longitudinal axis coinciding with the direction of insertion (14), the flux concentrating pieces (3, 4, 7) are arranged symmetrically with respect to the longitudinal axis (14) which is a two-fold axis of symmetry. To pick-up the Wiegand pulses, two E-shaped soft magnetic cores (9) are provided which carry on their center leg an electrical sensor winding (17). The free ends of the legs of the E-shaped cores (9) face one another and are also arranged symmetrically with respect to the longitudinal axis (14).

Abstract: The magnetic field sensor comprises a bundle consisting of a plurality of identical parallel bistable magnetic elements, which are surrounded by respective electrical windings, which are all wound in the same sense and are electrically connected in parallel.

Abstract: The reading head comprises a core, which carries an electric detector winding and which may be E-shaped for reading two rows of Wiegand wires or U-shaped for reading one row of Wiegand wires. Two platelike permanent magnets are spaced from the outer legs of the core. One pole face of each permanent magnet is covered by a low-reluctance element, which terminates close to the core in a top plan view on the reading surface. The core and the magnets include such an oblique angle that in the reading surface of the reading head each low-reluctance element is spaced in the reading direction from the adjacent free leg end of the core. This arrangement ensures that during the reading operation each Wiegand wire will first enter the relatively extensive magnetic field established between those pole faces which are not covered by low-reluctance elements. Thereafter, the Wiegand wire is trigger and then enters the region between the low-reluctance elements and is saturated in that region.