Abstract: An apparatus for optimizing the charging of a rechargeable battery includes, in parallel with the rechargeable battery, a series of diodes selected to exhibit an effective impedance that is the inverse of the impedance of the rechargeable battery regardless of the ambient temperature.

Abstract: A data transport system connects with a telephone system for communication of data via subscriber telephone lines to a provider of data services. Connection of multiplexing circuitry to a set of subscriber lines is accomplished at a main distribution frame by adapters or access blocks set between arc suppressors and a terminal block. The multiplexing circuitry is activated by signals of a line scan unit which, in turn, cooperates with a host computer associated with the provider of data services. This arrangement bypasses the central switching equipment. The data may be transmitted out of voice band, if desired, to enable simultaneous voice and data transmission. Passive, active and interactive data can be transmitted by the data transport system.

Abstract: An apparatus for collecting and forwarding encoded information includes a source of power maintained from the output port thereof to provide power to the source of encoded informations whereby a local subscriber is not required to supply power to such encoders via the AC mains to his premises.

Abstract: A communication subsystem includes a plurality of peripheral interface devices, one or more network interface devices and, optionally, one or more gateway interface devices. Each and every interface device includes a uniform data transport controller that autonomously controls data traffic across the device associated therewith and executes all requisite communication protocol conversions.

Abstract: A redundant clock combiner device includes a clock selecting latch that recovers a clock signal even if both externally supplied clocks fail. The clock selection occurs, and an output clock provided, even if the non-prioritized clock signal is restored before the prioritized clock signal.

Abstract: A substrate for mounting electronic devices is provided with a capacitive coupler as an interconnecting means. The coupler comprises two partially co-extensive conductors surrounded by a shield. The substrate is made from a plurality of superimposed layers, each layer consisting of a dielectric, or a conductive material, or strips of conductive material separated by the dielectric to form a preselected profile.

Abstract: A miniature microwave guide is provided in a substrate made of successive superimposed layers of conductive and/or dielectric materials. Probes are provided at the extreme ends of the guide for injecting and extracting signals.

Abstract: A test trunk access controller includes a test trunk interface controller accessed by a subscriber line assigned to a service provider, or other remote metering facility, and a test trunk interface device inter-connecting the test trunk controller with the test trunk device of a local telephone switch.

Abstract: An apparatus for providing masterless collision detection in a communication network includes a distinct data transmission bus and distinct collision detection reference bus. A voltage on the reference bus is monitored by each element to ascertain the existence of a change in the voltage which results in either the enabling or disabling of data transmission on the transmission bus by that element.

Abstract: A telecommunication switching system includes a number of control circuits each of which is common to a plurality of line circuits and is coupled through time division multiplex links with two processor controlled interface circuits which are further coupled to a switching network. Line scanning information is processed in the control circuits to reduce the work load of the processor controlled interface circuits. Said line scanning information is then transmitted in the TDM links to the processor controlled interface circuits. The transmission priority among the control circuits is determined by a priority arrangement established for the system. A channel assignment controls the allocation of channels of the TDM links leading to parts of the line circuits.

Abstract: An apparatus for establishing a plurality of communication paths includes a plurality of ports each having different data rates associated therewith and a means for establishing simultaneous paths among the plurality of ports according to instruction signals from terminals interfaced with the ports and carried on the same path as the information to be switched.

Abstract: An apparatus for providing masterless collision detection in a communication network includes a distinct data transmission bus and distinct collision detection reference bus. A voltage on the reference bus is monitored by each element to ascertain the existence of a change in the voltage which results in either the enabling or disabling of data transmission on the transmission bus by that element.

Abstract: A communication system includes a digital switching network, a first apparatus for establishing communication paths interconnected thereto via a terminal element and a second apparatus for establishing communication paths interconnected directly thereto. The second apparatus being dedicated to communicating with the network via packetized messages.

Abstract: A system is presented for accessing a plurality of central office lines, PBX, etc. by a plurality of stations and for exchanging signals between the stations. Each station is provided with a self-sufficient microprocessor which controls all the functions of the station. The microprocessors exchange control signals to indicate the status of each station and each line. A common intercom line is provided for both audio signals and control signals. Each station is assigned a unique address so that each station is able to dial up another station for intercom communication by generating the proper control signals.Each station is also provided with a switch matrix for selectively accessing any of the lines, line status indicating means, and line holding means which is automatically released when any station accesses the held line.

Abstract: There is disclosed a programmable keyboard apparatus for allowing a user to select any one of a predetermined number of different keyboard arrangements such as the Qwerty or the Dvorak arrangements. The keyboard contains a plurality of fixed input keys arranged in rows and columns and according to a standard typewriter keyboard format. Each key has positioned above the key an indicating area whereby the designation or symbol for the key is automatically changed by the apparatus each time a different format is selected. In this manner, the user can experiment with keyboard formats which enable more rapid typing with fewer errors. The construction is extremely economical, and therefore, in utilizing the apparatus a user will have access to different keyboard arrangements which will increase the users ability to type or enter data.

Abstract: A comprehensive automatic directory assistance apparatus includes a means for receiving information from a caller via a specified number of DTMF signals, means for identifying another subscriber from the signals, means for vocally conveying information relating to the other subscriber to the caller and means, selectable by said caller, for connecting the caller with the other subscriber.

Abstract: A dual voltage source feed circuit arrangement for a two-wire telephone line circuit includes an auxiliary voltage source placed across the two-wire line and switchably controlled to connect the voltage source across the line to thereby supply an additional current to the line which current provides a optimum value of talk current to the line.

Abstract: A system for transporting data between equipment connected to a subscriber telephone line and a provider of services connects with subscriber telephone lines at a central office of a telephone company. The system includes a set of first multiplexers which are coupled to individual ones of the subscriber lines at a point between the cross-switching of the central office and the subscriber premises. Output signals of the first multiplexers fan into a second multiplexer. Bidirectional communication is provided between each of the multiplexers and the subscriber equipment, and also between the second multiplexer and the service provider via a line scanner which generates command signals for the operation of the first and second multiplexers. The first multiplexers, the second multiplexer, the line scanner and a host computer of the service provider can be located at a distance from each other and may be coupled together by communication links which permit the bidirectional flow of data.

Abstract: A time-division multiplexed switching system is disclosed with a transmit, and a receive bus. Communication ports are provided for transfer and conversion of signals between the lines and the buses. A control microprocessor is used for assigning appropriate time slots and for strobing the communication ports at appropriate times. The time slot interchange between the two buses is provided by a half-frame delay network. The slots assigned to a particular interconnected pair of communication ports differ by a half-frame period to provide full duplex operation.

Abstract: An interface circuit for a subscriber line circuit employs a controllable amplifier including a switching converter. The switching converter includes a capacitor coupled across a two-wire subscriber line and supplies an auxiliary voltage to the line. The amplifier includes an input adder having an output coupled to the switching converter for controlling the magnitude of the auxiliary voltage with one input of the adder adapted to receive a feedback control signal which is developed by monitoring the voltage across the output. Another input to the adder receives line input signals for the line circuit. The amplifier is controlled in operation by an off hook detector which provides an output signal when the subscriber line goes off hook to cause the amplifier to operate and further includes ring control logic which is also coupled to the amplifier and activates the amplifier during the presence of a ring control signal.