Abstract: A switching arrangement for activating a plurality of electrical devices connected to a communication line. The switching arrangement monitors the communication line for the reception of activation signals, and also transmits activation signals to the communication line. The switching arrangement activates an electrical device (from the plurality of electrical devices) connected to the communication line, in response to the detection of the an activation signal, to shift the electrical device from a dormant state (in which electrical consumption by the electrical device is minimized) to a normal, functional operational state (in which a maximum electrical consumption of the electrical device occurs) only when the electrical device is actually being operated. By switching the electrical device between a dormant state and an operational state, the amount of electrical power required to operate the plurality of electrical devices is reduced.

Abstract: A method for correction errors in radar systems that operate using a crossfeed principle (CFR), in which echo signals are directly received from flying objects, such as an aircraft. In particular, the present invention is used in connection with low-flying objects, in which radar signals are indirectly reflected from the surface of the earth to an antenna of the radar system. Correction terms are determined and weighted, using correction factors, so as to improve the capability of the crossfeed radar system to accurately determine the exact elevation of the flying object. The correction factors that are used to improve the accuracy of the radar system are based upon sea state numbers, or Beaufort numbers, which vary in relation to the shape and/or structure of the reflecting surface.

Abstract: A method and apparatus for conducting a conference call among a plurality of subscriber stations. Each subscriber station contains a transmitter, a receiver, and an auxiliary receiver. An output of the auxiliary receiver can be selectively connected to an adding member that is located between a microphone and an input of the transmitter. The subscriber stations establishing the conference call connection form a transmission chain. Each subscriber station involved in the conference call, with the exception of the first subscriber station on the transmission chain, receive a user signal of a preceding subscriber station. The user signal of the preceding subscriber station is added to its own user signal to produce a compound signal that is transmitted to the next subscriber station on the transmission chain. A compound signal created in the last subscriber station of the transmission chain is supplied to the receiver of all the subscriber stations on the transmission chain.

Abstract: An attenuation network comprises a T or a .pi. network and first and second regulating circuits for controlling it. The T or .pi. network has at least two variable resistances. A switch S1 permits selection of a desired attenuation value which is set through the operation of the second regulating circuit on the T or .pi. network, while the first regulating circuit acts on the T or .pi. network such that its input and output resistances are kept constant.

Abstract: An expander system for pulse signals with enhanced output power level is disclosed. The expander system, which comprises an expander filter and subsequently connected amplifier means, is provided with a supplementary 180 degree phase modulator connected in front of the expander filter. The phase modulator is switched on and off by a control signal delivered from a control stage in such a manner that, during the duration of a pulse signal, the phase modulator produces at least two phase shifts of approximately 180 degrees.

Abstract: During the pre-soldering or tinning of printed circuit boards, as a rule, also the drill holes or bores and, in particular, the through-metallized drill holes are filled in an undesirable manner with solder. This solder must be removed before mounting the electrical components or elements upon the printed circuit boards. A simple apparatus is disclosed for this purpose, affording a faultless de-soldering of the drill holes, without deleteriously affecting the properties of the solder material. The printed circuit boards, in a condition where the solder applied during the pre-soldering operation is still molten, are accelerated at least once and thereafter suddenly brought to standstill in such a fashion that the excess solder is knocked or propelled out of the drill holes.

Abstract: A surface acoustic wave (SAW) filter features a ground lead in a transducer that has an aperiodic meander structure. This arrangement permits the self-capacitance and inherent resistance of the transducer to be utilized in forming the RC networks of a phase shifter associated with the transponder.

Abstract: An oscillating device has an electro-mechanical drive, a pivotal or oscillating armature and a regulating circuit, wherein a capacitor, the capacitance of which varies with oscillation of the armature is used as a displacement transducer or pickup. A signal generated by a signal generator is conducted by way of the series-connection of the displacement transducer, a rectifier and a filter to an amplifier circuit, the frequency of said signal being much greater than the natural resonant frequency of oscillation of the electro-mechanical drive. An output voltage which is substantially in phase with the angular movements of the armature i.e. angle-proportional thereto, appears at the output of the amplifier circuit and is supplied to a set value input of a differential amplifier contained in the regulating circuit.

Abstract: A data exchange system permits data transfers where both the length of the data words, and the speed of change of the information represented by the data, can both vary considerably. A central station is connected to an interface circuit, which in turn is radially connected by four-wire conductors or lines to a number of sub-units. Each sub-unit is in turn connected by a bus to a number of modules or sub-assemblies. The interface circuit contains a microcomputer and a coupler circuit. Each sub-unit contains a switching stage, a control logic circuit, and a number of shift registers.

Abstract: The arrangement comprises a support at which there is mounted an induction loop through which flows a high-frequency alternating current. By displacing the support or the circuit board possessing the contact pins which are to be soldered, a multiplicity of contact pins at which contact is to be made are simultaneously brought together with the solder material and the solder eyelets of the contact locations into the range of influence of the magnetic alternating field. By appropriately constructing the induction loop there is obtained a simultaneous uniform heating of the contact pins and the contact locations. The arrangement thus renders possible a simultaneous faultless soldering of the contact pins of one or a number of pin rows of multipoint connectors mounted at the circuit boards.

Abstract: A multi-channel amplifier apparatus for oscillation or pulse packets wherein there is provided an amplifier having an input connected by a number of input time-delay lines with a respective input channel, each of which is correlated to an oscillation or pulse packet. The output of the amplifier is connected by means of respective series circuits of an output time-delay line and an output switch connected thereafter with a respective output channel correlated to the corresponding oscillation packet.

Abstract: A radar transmitter apparatus comprising a radar transmitter equipped with a modulator arranged in an oil-filled housing, the modulator being held in spaced relationship with respect to the inner walls of the housing in order to form an intermediate space for the convection flow of the oil. The housing is substantially trough or vat-shaped and covered by a trough or vat-shaped cover member. In the internal chamber or space between the cover member and the modulator, which internal space is wetted by the oil, there is arranged, on the one hand, a magnetron attached at the cover member and, on the other hand, a thyratron which is mounted directly below an opening at the cover member. This opening is closable by means of oil sealed throughpassage means.

Abstract: A synchronization arrangement for a TDM concentrator in which phase differences between the transmission line clock and the internal concentrator clock are compensated for by lengthening or shortening a signalling channel (Ksynch).