摘要:
For a dial pulsing telephone set it is desirable to have a low voltage drop across the pulsing switch 4, and a control voltage of the pulsing switch situated between the voltages of the leads 2-1 and 2-2. These demands can be met by selecting for a switching element a bipolar transistor of such a conductive type that the emitter is connected to the subscriber line. To keep this switching transistor constantly in the saturated state irrespective of the magnitude of the line current, this transistor is driven via a current source 14 supplying a current linearly related to the line current. In order to prevent the control circuit from causing too large a voltage drop for this current source, consequently leaving too little voltage for the remaining circuits of the telephone set, this current source is designed as a voltagecurrent source. Driving this current source can be realised by means of a voltage linearly related to the line current. Such a voltage can easily be obtained without too large a voltage drop arising across this element.
摘要:
The values of the samples to be restored can be estimated in a simple and time-saving manner by determining, first of all, a quantity which represents a number of samples and is a measure of the periodicity of an environment of the valid samples, located at an interval containing invalid samples. Using a quantity thus determined it is possible to form a simple system of equations containing the values to be estimated as unknown quantities, it being possible to solve these unknown quantities on the basis of «real time» and using simple means. The proposed technique can advantageously be applied to the restoration of a speech signal in which intervals up to approximately 12 msec containing invalid samples may occur. It has been found that then unvoided speech can be restored in the same way as voiced speech.
摘要:
The invention relates to a control arrangement for an internal transport system. The transport system comprises a conveyor arrangement carrying the products, work stations and transport stations. The task of the work stations is not only processing the product but also routing and controlling the transport system whilst the transport stations carry out routing and control tasks only. A modular system of work and transport stations is suggested whilst different control and routing functions are each accommodated in one module and the modules can communicate with each other both via an electronic data communication channel and via a physical channel namely by appending information labels to the products.
摘要:
A modular coupling unit which functions as an interface between a communication unit or peripheral apparatus and the communication network includes a code word signal generator for generating a unique address code which is representative of the geographical location in which the relevant coupling unit is "permanently" included in the communication network. This signal generator is and continuous to be energized as soon as and for so long as a communication unit or peripheral apparatus is and has been connected to the coupling unit. The address codes generated in bursts by such a generator are transferred via a connecting cable between the relevant communication unit and the coupling unit to this communication unit. The relevant address code is stored there. On request and within the time regime holding for the communication network, the address code is read and transferred to a diagnostic module via the communication network. Thus a geographical survey of the communication network with the peripheral apparatus connected thereto can be obtained. The geographical address of the communication unit in which a disturbance has occurred can thus be determined, using an error search algorithm.
摘要:
The invention relates to a time switching stage for exchanging data words. In switching systems for communication systems the need is sometimes felt for switching what are commonly referred to as multi-slot connections. To enable this, the memory capacity of the time switching stage must be doubled. The invention provides a method and an arrangement with which multi-slot connections are realized without extanding the memory capacity. This accomplished by using an appropriate interleaving of a shift register and a memory.
摘要:
The invention relates to a receiving arrangement 4-1 for SHF signals, comprising a rectangular waveguide filter 5 formed from resonators 10-1 to 10-4 arranged in cascade, a SHF signal arrangement 6 containing a microstrip circuit and a microstrip to waveguide filter transition connection to this circuit. Generally, such a receiving arrangement is not suitable for use in radiators comprising a partly shown polarization converter 3 with two such receiving arrangement 4-1 each receiving one of two mutually orthogonally polarized signals. When the prior art receiving arrangements are used in these radiators, the channel separation is inadequate. According to the invention, an adequate channel separation is obtained by providing the microstrip to waveguide filter transition in the waveguide filter and matching the filter 5 thereto. As a result thereof, the receiving arrangement 4-1 becomes more compact and has a very low reflection and, in addition, it is no longer necessary to adjust the transition to the waveguide filter 5. Preferably, dimensioning is realized by the choice of the size in the axial direction of the end resonator 10-4 and/or the choice of the dimensions of the coupling aperture which connects the end resonator 10-4 to the adjacent resonator 10-3.
摘要:
FSK data receiver which comprises a mixer stage (2) with a mixer signal which is frequency-shifted through a fixed distance relative to the carrier signal, the receiver comprising an AFC control loop and having a high selectivity. Such receivers have the disadvantage that they are not so suitable for production in integrated circuit technique and that for small received signals the AFC control loop has a small pull-in range and can be locked on a plurality of frequencies. According to the invention, this is obviated in that the receiver comprises means which emphasises the energy content of signals located at the ends of the passband of the receiver over signals located in the centre of the band and that the AFC control loop comprises an integrator (16).
摘要:
A Costas loop for recovering the carrier signal from a carrier signal which is continuously phase-modulated by a data signal. So as to increase the stability of the Costas loop the loop comprises a clock signal generator-controlled sample-and-hold circuit for applying as a control signal tq the voltage-controlled oscillator a square-wave signal which is obtained by instantaneously sampling the control signal generated in the Costas loop at a predetermined fixed instant per bit period.
摘要:
The invention relates to a device for eliminating stray pulses occuring on the output of a digital-to-analogue converter DA. The pulses may be caused by, for example, insufficient synchronism in the input data bits and may be predicted in time. According to the invention an inductor L is arranged between the output of the digital-to-analogue converter and a following circuit F, for example a deflecting amplifier for random scan displays, and a switch S2 is arranged between the said output and ground which switch when a pulse is predicted to occur shortcircuits the output of the digital-to-analogue converter to ground. Hereby an eliminating device of simple and cheap construction is obtained operating at high frequencies.