Abstract: A method for querying a measurement value, wherein the measurement value is converted into a modulation signal that influences the reflective properties of a sensor antenna. A signal is emitted via a query device, wherein the signal is returned in an altered fashion by the sensor antenna and then received again by the query device. The measurement value is determined from the altered signal received. According to at least one embodiment of the invention, a plurality of measurement values are detected by sensors and the query device is moved past a plurality of sensor antennas in a vehicle or by a person. Thus, a plurality of sensors detect measurement values on a railroad line, for example. The vehicle is, for example, a rail vehicle traveling on the track of the railroad line.

Abstract: A method is disclosed for querying a measurement value, wherein the measurement value is converted into a modulation signal that influences the reflective properties of a sensor antenna. A signal is emitted via a query device, wherein the signal is returned in an altered fashion by the sensor antenna and then received again by the query device. The measurement value is determined from the altered signal received. According to at least one embodiment of the invention, a plurality of measurement values are detected by sensors and the query device is moved past a plurality of sensor antennas in a vehicle or by a person. Thus, a plurality of sensors detect measurement values on a railroad line, for example. The vehicle is, for example, a rail vehicle traveling on the track of the railroad line.

Abstract: A method is for identifying risks as a result of stray currents which flow to ground from a rail which returns a traction current in a track with a DC power supply. In accordance with a first embodiment, in which the voltage between the rail and ground is measured and an increased risk as a result of stray currents is indicated if there is a discrepancy from a voltage reference value, provision is made for the voltage to be measured at a plurality of measurement points along the track and for the measurements to be evaluated in an evaluation center. In accordance with a second embodiment, provision is made for activating a short-circuiter to connect a parallel path to the rail for returning the traction current. The current level in the parallel path is then measured and an increased risk as a result of stray currents is indicated if there is a discrepancy from a current-level reference value.

Abstract: A method for transmitting data via a traction current conductor which simultaneously conducts drive current for a vehicle and in which an interruption in the data transmission by an arc cccurring between a vehicle-end drive current collector and the traction current conductor is reliably avoided. The method for trandsmitting data via a traction current conductor, in which at the transmitter end at least two data signals including in each case the data in an identical form are fed into the traction current conductor with different frequency channels. In the event of an arc occurring at the receive end, the received data of that data signal or those data signals whose amplitude does not drop below a ratio necessary for achieving a specific bit error probability with respect to the amplitude of the interference signal S(f), is selected for evaluation.

Abstract: A method is for identifying risks as a result of stray currents which flow to ground from a rail which returns a traction current in a track with a DC power supply. In accordance with a first embodiment, in which the voltage between the rail and ground is measured and an increased risk as a result of stray currents is indicated if there is a discrepancy from a voltage reference value, provision is made for the voltage to be measured at a plurality of measurement points along the track and for the measurements to be evaluated in an evaluation center. In accordance with a second embodiment, provision is made for activating a short-circuiter to connect a parallel path to the rail for returning the traction current. The current level in the parallel path is then measured and an increased risk as a result of stray currents is indicated if there is a discrepancy from a current-level reference value.

Abstract: In a device for the short-circuiting of a first electrical line (1) with a second electrical line (2) by at least one mechanical switching device (SM), at least one first electronic switching device (SE1) is arranged in parallel with the mechanical switching device (SM) and at least one second electronic switching device (SE2) is arranged reverse-connected in parallel with said first electronic switching device, by means of which a voltage difference that occurs between the first electrical line (1) and the second electrical line (2) can be bridged. Such a device is constructed in a simple manner and has short response times.

Abstract: The invention relates to a method for transmitting a control signal to a vehicle which is driven using an electrical drive current which is fed into a traction current conductor at a drive current feed point. In order to ensure that the transmission of the control signal is very largely unaffected by interference frequency components included in the drive current, according to the invention one current sensor, which is located outside the line section, is used to receive the control signal.