Abstract: In an electrical drive system an increased electromagnetic compatibility is achieved by used of AC rotating motors having no commutator and no slip rings as driving motors, whereby a simplified structure of the drive system and of the control of the drive is achieved in that, particularly plural phased stator windings of the AC motors are pulsewise controlled by use of plural channel control whereby the rotation speed of the respective rotating magnetic field of the AC motors is controlled.

Abstract: In an electrical model railway set, increased electromagnetic compatibility is achieved by using AC motors without commutator and slip ring as drive motors for the model vehicles, wherein a simple structure of drive and drive control is attained by performing pulse control of polyphase stator windings of the AC motors of the model vehicles while employing the multi-channel control which is moreover customary in model railway sets.

Abstract: The invention concerns a process and a circuit arrangment to transmit digital control data, preferably between a central station and individual locomotives of a model railway. In order to make possible an association between transmitters and receivers with strongly dispersed frequencies, the receiver frequency is to be adapted to the transmitter frequency. The step width of the adaptation and therefore of the synchronization is to be determined differently.

Abstract: A circuit arrangement is provided for completely testing the operability of a data transmission facility which has a four-wire connected to a two-wire line via a hybrid and in which an echo compensation circuit is connected between the data signal output line and the data signal receiving line of the circuit arrangement. The data signals appearing on the data signal output line are supplied to the hybrid without delay as well as delayed by a fixed time interval which is selected to exceed the longest time leading to a correlation between delayed and undelayed data signals. The echo compensation circuit is driven only with the delayed data signals.

Abstract: In order to control the transmission capacity of the receiving branch of a transmission system comprising this receiving branch as well as a transmitting branch with an echo compensation network, the system generates a level-indicating signal, which indicates, at an output of an amplifier (Am), the signal level contained in the receiving branch, plus a level change-indicating signal, which indicates level changes in this branch. These two signals are linked logically to one another in such manner that the output circuit of the amplifier (Am) is enabled for signal transmission only upon simultaneous occurrence of a level-indicating signal which indicates the presence of a prescribed level and a level change-indicating signal which indicates that a prescribed level change has not been exceeded.

Abstract: A data modulated carrier is branched into two orthogonal components and as a result of correlation with a difference signal supplied to a receiver, first and second regulating signals are produced. The first and second regulating signals each regulate a base band simulation stage to produce respective dummy signals, taking into account the two orthogonal signal components, and form components of a compensation signal which is used to suppress a cross-talk signal which is superimposed on a signal received from a remote station.

Abstract: Automatic digital simulation of a two-wire line is provided for the transmission of data in full duplex operation. Coefficients which signal the influence of ternary values on a received signal are stored in a plurality of sub-intervals of the individual ternary values and information are stored which signal the ternary values assigned to the coefficients. After a comparison of the received signal with the simulated signal, the coefficients are continuously corrected and the simulated signal is obtained by summing the coefficients.

Abstract: A circuit arrangement for automatic distortion correction of a signal transmitted over a line having low-pass filter characteristics, employs a distortion corrector having a controllable high-pass filter and a controllable-gain amplifier. The distortion corrector includes the high-pass filter with a predetermined frequency characteristic and a first attenuator connected in series therewith in a first branch, and a two-terminal network of a predetermined frequency characteristic in a second branch. The controlled-gain amplifier includes a second attenuator and an amplifier connected in series therewith which effects a predetermined amplification. The current/voltage characteristics of the first and second attenuators are substantially identical and their attenuation depends on a signal which is derived from the distortion-correct signal by means of rectification and smoothing.

Abstract: In a two-wire, full duplex data transmission system a circuit arrangement is described for carrying out an automatic adjustment of the value of the current flowing from the transmitter in a given station to a receiver therein relative to the value of the current supplied to that receiver from another station over a transmission line. A balancing circuit receives the station transmitter current and divides it into a plurality of sub-currents which are subsequently recombined and conducted to the station's receiver. The station transmitter current and the received current values are compared, and a voltage proportional to the difference is produced. That voltage is utilized by a regulating stage to produce a number of regulating voltages corresponding to the number of sub-current carrying branches in the balancing circuit for regulating the amplification of the sub-currents.

Abstract: Apparatus is described for balancing a two wire, full duplex data transmission system. In the described system a transmitter and receiver in one station are connected to a transmitter and receiver in another station by means of two lines. The two lines carry transmitted data signals, and the transmitters in each station are connected to the receiver in the same station by a dummy circuit. The balancing operation is performed in a dummy circuit comprising a plurality of parallel-connected current paths, each path including a series combination of a time stage and an amplitude stage for adjusting the amplitude and phase relation to the data signal of subsidiary current flowing therethrough. The sum of the subsidiary currents flowing through the parallel paths from the transmitter via the dummy circuit to the receiver in the same station is adjusted to be equal to the current flowing from the transmitter via the lines to the receiver in the same station.

Abstract: A method and apparatus for transmitting data so as to reduce the effects of signal distortions caused by the transmission medium are described. The data signal is encoded and formed into a combination of wide rectangular pulses and narrow rectangular pulses having a width equal to half that of the wide pulses. The wide pulse portion of the encoded signal is preliminarily distorted, and a combination of the distorted wide pulses and the narrow pulses is transmitted.

Abstract: A circuit arrangement for providing full duplex data communication over two wires is described. Each station connected to the two wires contains a transmitter and receiver. The receivers are connected across the two lines; a balancing resistor connects one of the two lines to each receiver. The balancing resistors are adapted so that transmitter operation in a given station does not interfere with reception. The receivers produce measuring signals for aiding in the reception of data from other stations. The measuring signals are equal in value to the difference between two currents; the first current is that which flows through a transmitter and the two lines in a given station, and the second current is that which flows through the transmitter and the balancing resistor in a given station.

Abstract: A circuit arrangement for facilitating the determination of a wire break in a line interconnecting a plurality of subscriber stations in a direct current, keyed data transmission system. Each subscriber station is equipped with a bridge circuit containing a balancing resistance, bridge resistances and a fourth arm formed by the transmission line. A transmitter is connected in one diagonal of the bridge, and the receiver in another. An operational amplifier forms a first voltage source connected in the line circuit and a second voltage source connected in the balancing arm generates a monitoring current flow. The two operational amplifiers forming these voltage sources function as differential amplifiers, and the voltages are adjusted to the same value by a single balancing operation.