DE1096425B - Device for level regulation for carrier frequency long-distance systems - Google Patents

Description

The invention relates to a device for level regulation for carrier frequency wide area systems, in particular for multi-channel systems that work purely electronically according to the reverse control principle by a control network inserted into the transmission path depending on the level deviation of a pilot voltage is influenced with reference to a target value.

There are already various mechanically operating devices for level regulation in carrier frequency long-haul systems known. However, these devices occur as well as a known electronic Arrangement for level regulation under certain circumstances disturbing control oscillations. The well-known electronic Arrangement that works without storage has the further disadvantage that when suddenly occurring Pilot failure the current control status is not maintained.

In order to avoid these disadvantages, the device for level regulation according to the invention is so designed that an electronic memory is provided, the information content of which is continuously working interrogator changed the control network proportionally and that a differential encoder for evaluation the difference voltage between the pilot amplitude and a setpoint value the electronic memory in such a way controls that the pulses continuously emitted by a pulse generator are activated by a pulse input get to the memory and thereby its information content depending on the direction of the level deviation increase or decrease until the differential voltage in the differential encoder is below a specified value Value goes down. Through these measures, a purely electronically working device is created, the opposite previously known electronically operating devices has a number of significant advantages. For example, in the event of a sudden pilot failure, the current control status is maintained. The control speed is proportional to the rate of change of the deviation of the pilot amplitude. Further are control oscillations, as they are with previously known-40-electronically working facilities are avoided.

In a further embodiment of the invention, an over- and an under-level indicator are provided, which after exceeding block the pulse inputs of a specified differential voltage of the differential encoder. Furthermore can also a limiter arrangement for limiting the information content of the memory to a specific one minimum and maximum value can be provided.

The invention is based on the exemplary embodiment shown schematically in FIG. 1 and on the basis of the diagram of FIG. 2 explained in more detail.

In contrast to short-haul systems, an automatic level control for long-distance overhead line equipment must be used for level control
for carrier frequency long-haul systems

Applicant:
Siemens & Halske Aktiengesellschaft,

Berlin and Munich,
Munich 2, Witteisbacherplatz 2

Dipl.-Ing. Friedemann Vollnhals, Hofheim (Taunus),
has been named as the inventor

systems meet the requirement to store the instantaneous value of the pilot amplitude in order to ensure the stability of the The route must be safely preserved in the event of attenuation drops in the overhead line and certain periodic fluctuations. The use of storage also enables very short settling times for the system after eliminating Line interruptions, which is particularly important in multi-channel systems. As a memory was previously a small DC motor is used, which controls the damping control network via a high reduction gear steered. The motor was driven by a differential voltage or current transmitter with positive or negative values if the pilot amplitude deviates from the setpoint. If level jumps occurred, the motor was switched off, so that the last set attenuation of the control network was retained.

The purely electronic device for level regulation, which is shown schematically in FIG. 1 and operates with storage, allows large attenuation differences in the line to be compensated for. The control network 3 is inserted in the line between the input level f _e and the constant output level fi _a. It is usually designed as an NTC thermistor control network. It denotes 1 an electronic memory, 2 an interrogation device, 4 a differential transmitter, 5 a device for determining the setpoint, 6 a pulse transmitter and 7 a pulse input device. A threshold 8 for over- or under-level and a response threshold 9 are inserted between the difference transmitter 4 and the pulse input device 7.

A digital counter consisting of a sequence of flip-flop stages with direct pulse increment is used as memory 1. The number of stages η required results from the maximum attenuation difference to be compensated for on line AA and the maximum permissible

009 697/372

Claims (3)

Damping step difference ^ d «, assuming a linear relationship between damping and pulse steps to Δα. By means of the interrogation device 2, a voltage (or a current) is obtained which is proportional to the value entered into the memory 1. This voltage controls the thermistor network 3, which causes the change in attenuation. The instantaneous value of the pilot amplitude is saved as follows: If the target value deviates by a defined amount (response threshold), the differential encoder enables the input of pulses to the memory. The pulse repetition frequency f of the pulse generator 6 itself is constant. Its maximum value results from the condition that the rate of change of the damping network is small compared to the sampling frequency for the alternating current telegraphy, its minimum value due to the greatest rate of change VA-j of the line attenuation VL ^ s ^ f Δφ Δα Δα allow higher pulse repetition rate. Despite the constant pulse repetition frequency of the pulse generator 6, as a result of the response threshold 9 (or 9 'in Fig. 2) according to the selection of the largest permissible damping step difference Δα in the difference encoder 4, a change rate of the damping control network proportional to the line attenuation occurs 2 for different rates of change - the line attenuation at constant pulse repetition frequency 8 'also means a threshold for over-level ^> «or under-level j> u. Reverses the change in attenuation of the line, e.g. B. from increasing to decreasing attenuation, the switching device 1Ö for the counting direction of the memory switches a counter of z. B. “subtract” into “add”. Between the sign of the change in line attenuation "positive" or "negative", represented by pos. 11 in FIG. 1, and the counting direction of the memory, there is thus a forced linkage. The memory 1 also includes a device 12 which, when “memory full” or “memory empty”, blocks the pulse input 7 according to the maximum and minimum attenuation of the control network 3 and only releases it again when the sign of the difference transmitter 4 changes. So that the last saved value is retained in the event of a sudden pilot failure or a sudden line interruption, the differential sensor has the second level threshold for over- and under-level of the multiple of the value Δα, ζ. B. ± 0.2 N, which also blocks the pulse input 7 when it is exceeded. The states »storage empty and full« as well as over- and under-level can be alarmed. If it is to be avoided that the stored value is lost in the event of a short-term power failure, it is advisable to buffer the memory with interrogation device and attenuation control network against the network, e.g. B. by gas-tight collectors. The electronic device for level regulation according to the invention requires about 450 cm3 of space in the printed circuit. The power consumption is around 1 to 1.5 W constant, including the thermistor current. The constant requirement for a battery voltage of 24 V is only ± 10 ° / 0 with a control error of <0.01 N. • Patent claims: 1. Device for level regulation for long-distance carrier frequency systems, especially for multi-channel systems that are purely electronic according to the principle the backward regulation works by depending on a regulation network inserted in the transmission path is influenced by the level deviation of a pilot voltage with respect to a target value, thereby characterized in that an electronic memory (1) is provided, the information content of which has a continuously working interrogator (2) the control network (3) proportionally changed, and that a Differential encoder (4) for evaluating the differential voltage between the pilot amplitude and a target value (5) the electronic memory (1) in such a way controls that the pulses continuously emitted by a pulse generator (6) for so long by a pulse input (7) get to the memory (1) and thereby its information content depending on the Increase or decrease the direction of the level deviation until the differential voltage in the differential encoder (4) drops below a specified value. 2. Device for level regulation according to claim 1, characterized in that an over and an under-level indicator are provided, which after exceeding a predetermined differential voltage of the Block the pulse inputs with the differential encoder. 3. Device for level regulation according to one of claims 1 and 2, characterized in that a Limiter arrangement for limiting the information content of the memory to a certain minimum and maximum value is provided. 1 sheet of drawings © 009 697/372 12. 60