Ke Kommunikations-elektronik Gmbh & Co.

Kabelmetal Electro Gesellschaft MIT Beschrankter Haftung

Ke Kommunikations Elektronik

Kabelmetal Electro Gmbh

Ke Kommunications Elektronik Gmbh & Co.

Ke Kommunications Elektronik

Martin Brahms

Ziaedin Chahabadi

Andreas Hennig

Andreas Timmermann

Werner Klamt

Christian Prenner

Johannes Ocker

Olaf Wittur

Jurgen Schroder

Wolfgang Fritz

A switching device is presented for the transmission of telecommunication signals between a telephone network exchange and at least one subscriber connected thereto, where the exchange is able to transmit metering pulses, in addition to the voice signal. The signals are transmitted as digital signals between the exchange and the subscriber via a two-wire line, Which is connected with the exchange through a hybrid switching unit. To prevent the metering pulses from interfering with the voice signals, a parallel resonant circuit consisting of an inductance and a capacitor is connected to the two-wire system of the hybrid switching unit, and the receiving branch of the hybrid switching unit has an active and a passive filter connected in series. The passive filter is adjusted for the metering pulse frequency, and a filter that is tuned to the passive filter is used as the active filter, which compensates for a decrease in the NF (low frequency) level caused by the passive filter, with a corresponding increase.

Switching device for transmitting telecommunication signals

A process is indicated for the bidirectional transmission of digital data through a glass fiber, whereby the bits from data to be transmitted are compressed by a factor &gt;2 into bursts, in packages of equal quantities, without changing the transmission rate. The bursts in one direction of the transmission are sent by an emitter station through a glass fiber to the other station, during the pauses between the bursts in the other transmission direction. Independent external pulse generators are used at both ends of a glass fiber to determine the transmission rates of the stations. If the frequencies of the two pulse generators deviate from each other, the bursts of the data flowing at the lower transmission rate are displaced with respect to the bursts of the other flow of data, by the width of one bit of the pertinent continuous flow of data. The displacement of the bursts is communicated to the respective receiver by at least one information bit corresponding to the burst preceding the first burst to be displaced.

Process for bidirectional transmission of data

A connecting line is provided between a switching center and a subscriber for transmission of telecommunication signals. At the subscriber's end of the connecting line, there is located a device which, in addition to other passive and active units, includes a transformer, whose output winding is subdivided into two partial windings of identical size. A first capacitor, a switch and a second capacitor are connected in series between the partial windings. To prevent distortions of the dial pulses, a connecting line between the switch and the second capacitor is connected with a reference potential of the circuit arrangement.

Circuit arrangement for the transmission of telecommunication signals

In a system wherein a main channel of data is transmitted between two stations by means of an optical waveguide, an additional optical channel may be transmitted. Bits of the additional optical channel are inserted into the main channel at a transcoder in the transmitting station in place of bits of the main channel at defined spacings, known to the transcoder of the receiving station, with a bit rate lower than that of the main channel. The inserted bits are removed from the optical main channel at the receiving station. The bits of the additional optical channel inserted into the main channel are double bits that are identical to a forbidden bit combination that results during the recoding of an electrical AMI code into an optical CMI code. In the receiving station, the double bits of the main channel replaced by the bits of the additional optical channel are recovered by using sequential logic and memory to apply the fixed rules of the electrical AMI code.

Method for the transmission of data between two stations by means of

A controllable amplifier, which has two symmetrical outputs, at which two output signals mirror-symmetrical with respect to each other are present, is used for amplification of a burst signal. To achieve the largest possible eye opening of the signals to be fed to a comparator, a predetermined d.c. voltage difference for the formation of matched signals is adjusted for both output signals. After this, the arithmetic mean values of the two matched signals are formed and are fed to a second comparator. The output value of the second comparator is fed to an integrator, to which a reference voltage is also fed. In case of a deviation of the mean values of the two matched signals from each other, the amplifier is adjusted in a compensating direction by the integrator.

Procedure and apparatus for amplification of a burst signal

For controlling the level of electrical signals a circuit arrangement is formed with two series connected amplifiers. A first amplifier containing a first variable resistor, operates at maximum amplification when a low input signal level is received. A second amplifier comprises a series connection of a second variable resistor and a current-controlled voltage source with two complementary outputs. The outputs of the voltage source are connected to a comparator and a controller with two separate outputs. One of the controller outputs transmits a control signal while the other output simultaneously transmits a blocking signal. A first output of the controller is connected with the first variable resistor, while a second output of the controller is connected to the second variable resistor.

Circuit arrangement for controlling the level of electrical signals

Apparatus for bidirectional transmission of optical signals between two stations connected by a light transmission path of optical fibers, each station including a laser module comprised of a laser diode and an adjacent monitor diode, the latter performing the dual functions of detecting light emitted by such laser diode in its transmission mode, and for detecting light transmitted from the other station when such adjacent laser diode is not in its transmission mode.

Apparatus for bidirectional transmission of optical signals

There is disclosed an improved method and apparatus for operating an electric power station including a cycled transformer having a primary winding and a plurality of secondary windings, in a manner that includes the changing of the current permeability of a variable load component connected in parallel to one of the secondary windings for preventing the current flowing within the circuitry thereof from decreasing below a predetermined value during a no-load condition at the output terminal of such secondary winding, thus assuring that the widths of the direct current pulses admitted into the primary winding are maintained above a predetermined value and that the energy transfer to each of the secondary windings is sufficient.

Having a plurality of secondary windings

A circuit for protecting electronic devices which are fed from a source of dc voltage and to which a subscriber's line (ASL) is connected. In order to limit the current in the event of an overload on the subscriber's line (ASL), a MOSFET (T1) is provided as current-limiting component. The MOSFET (T1) is disconnected and re-connected periodically by means of a relaxation generator (K) when the MOSFET is in its current-limiting condition. Upon the normal operation of the circuit, the relaxation generator (K) does not operate. By proper dimensioning thereof, the time for which the MOSFET (T1) is blocked can be roughly adjusted as compared with the time in which it acts as current limiter. In this way, too great a heating of the MOSFET (T1) is avoided.

Circuit for protecting electronic devices against overload

A circuit is described for producing an alternating voltage in an electronic device which is remotely fed over a digital transmission path. By the pulses of a clock (8) two capacitors, C1, C2 are charged via a transistor (T1) and a transformer (10), one of them (C2) being discharged over a parallel resistor (R2). A coupling capacitor (CK) which is charged by the other capacitor (C1) is discharged alternately by the influence of the dischargeable capacitor (C2) over a transistor (T2).

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Hanover, Germany

Martin Brahms