Abstract: A method and apparatus is provided for communicating information in the form of plural items of data between a first station and a rail vehicle by transmission of pulses at predetermined repetition rates along railway tracks including a transmitting station for generating the information pulses having control apparatus receiving a particular data item as an input for selecting a repetition rate to represent the data item for transmission and generating apparatus connected to the control apparatus for generating the information pulses. The information pulses are coupled to railway tracks which transmit the generated information. A receiving station receives the information pulses from the tracks and includes sensing apparatus for sensing the information pulses and apparatus for removing interference signals received along with the information pulses, the interference signals being attributable to a number of causes which include unbalanced traction return currents and/or transmission interference.

Abstract: Method and apparatus for use in telephone exchanges, such as time division multiplex exchanges, for eliminating the side tone of a telephone station by interruption of a restored input signal to a hybrid circuit thereof. A sampled signal is provided to a storage means having an output signal. The storage means output signal is filtered for reconstruction prior to connection to a reception line on the four-wire side of a hybrid circuit. The restored signal is interrupted during moments wherein a transmission signal, output on the four-wire side of the hybrid circuit, is sampled.

Abstract: An adjustable current input inverter-induction motor drive using a commutation bridge associated with a common commutating capacitor and four commutating thyristors. Capacitive means is provided for transferring energy during commutation from one main thyristor branch to the next in sequence through the inverter, and a capacitor inputting in a transformer and full wave rectifier bridge is provided coupled to said capacitive means for recuperating excess energy and for restitution thereof into the DC link of the inverter.

Abstract: Procedure and system for driving a vehicle required to travel repeatedly over the same path, in which procedure at least some elements of the vehicle are operated in accordance with prerecorded information.According to the invention, the information relates to the operations to be performed on or by such elements in relation to the position of the vehicle on its path; and the elements are operated on the basis of such information in the light of the vehicle's instantaneous position with a correction for instantaneous vehicle speed and the response time of the elements.

Abstract: A telephone junctor for interconnecting an electromechanical and an electronic automatic exchange, the latter using tone signaling and capable of operating in time-division-multiplex. The junctor permits direct inward dialing of a subscriber on the electromechanical exchange by a subscriber of the electronic exchange.

Abstract: A power semiconductor assembly in which two metallic heat sinks with inner planar surfaces clamp between these surfaces a housing of a power semiconductor therein at a set clamping pressure. The casing has planar surfaces against which the inner planar surfaces of the heat sinks are clamped. Three threaded rod assemblies are assembled in three sets of recesses on the heat sinks controlling the pressure applied to the semiconductor assembly. Each heat sink has three recesses communicating with outer surfaces thereof aligned axially with corresponding similar recesses of the other heat sink. The rod assemblies each have a pair of threaded rods joined coaxially by a molded element made of, for example, porcelain, or a resin epoxy such as "Araldite", or a mica-glass composition. Nuts are threaded on the two rods and a calibrated elastic washer on one rod hold the entire assembly at the desired clamping pressure.

Abstract: An electronic replacement for a telephone transformer for connecting a two-wire circuit to a four-wire circuit comprises a first differential amplifier having a constant gain feedback loop. The feedback loop comprises an opto-electronic coupler and a second differential amplifier. A DC source connected to the first differential amplifier by a switch produces biasing current for a photo transistor in the opto-electronic coupler. A DC supply to the line on the two-wire side is provided by a source connected to the wires by transistor circuits connected as active reactances.

Abstract: A method of and apparatus for fast digital multiplication wherein the lowest-weight digits and the high-weight digits which are equal to zero and whose weight is greater than the first high-weight digit equal to 1 are removed. The apparatus and method may be utilized in digital frequency filters.

Abstract: A d.c. power supply circuit for a telephone line which utilizes transistor circuits having an active reactance to replace the telephone transformer. The transistor circuits each transform a capacitor into an effectively inductive reactance, thus resulting in a cost and space savings.

Abstract: A method and apparatus applicable with transformers having a magnetic circuit which is supported horizontally within a tank or shell made up of upper and lower parts, wherein a two-piece bar-like member assembly supported at its extremities on edges of the lower part of the tank, along with a conventional T-shaped beam support member is utilized to support the core laminations in such a manner that wedges used to fix in place the windings of the circuit can be readily adjusted beneath the area of the T-shaped beam. The bars are tensioned in place by adjustment of the wedges between the lower area of the windings and the tank sidewalls. The beam is then placed on the edges and anchored thereon.

Abstract: Electronic time switching telephone system so that the operator can listen in, with the ability to break-in and talk to the correspondents connected to the corresponding exchange, the system comprises an interface modem between the operator's line transformer and the connection network.