SU1363287A1 - Apparatus for selecting the telemetering frequency signals - Google Patents

Abstract

The invention relates to telemechanics, in particular to devices for selecting frequency-manipulated signals, and can be used in industrial enterprises, in power engineering, in urban economy and in transport. The purpose of the invention is to increase the reliability and simplify the manufacture and configuration of the device. The device contains first and second filters, first, second, third, fourth, fifth and sixth load elements, first, second, third, fourth and fifth restrictive elements, first, second, third and fourth matching elements, first and second reverse elements. communications, the first and second amplifiers, the first, second and third separation elements, the first, second, third and fourth switched filters, the first and second elements NOT, the first and second controlled oscillators switching: x signals. The comment filter contains a counter, a multiplexer, accumulative elements, a restriction element. The introduction of switched filters into the device will reduce the number of labor-intensive in the manufacture and configuration, and not enough reliable RC-filters. The group tuning method using frequency dividers with a variable division factor in controlled switching signal generators simplifies the setup process of the device. The use of control oscillators of the switching oscillator with a quartz frequency stabilization in controllers provides high reliability of the device, while reducing the reliability requirements of RC filters. 2 Il. (WITH .

Description

The invention relates to telemechanics, in particular, to devices for selecting frequency-manipulated signals, and can be used in industrial enterprises, in power engineering, in urban areas and in transport.

The purpose of the invention is to increase the reliability and simplify the manufacture and configuration of the device.

Fig, 1 shows a functional diagram of the device; 2, time diagrams of the device operation.

The device contains the first 1 and second 2 filters, the first 3, second 4, third 5, fourth 6, fifth 7 and sixth 8 load elements, first 9, second 10, third 11, fourth 12 and fifth 13 restrictive elements, first 14 , second 15, third 16 and fourth 17 matching elements first 18 and second 19 feedback elements, first 20 and second 21 amplifiers first 22, second 23 and third 24 separation elements, first 25, second 26, third 27 and fourth 28 switched filters, the first 29 and the second 30 elements are NOT, the first 31 and the second 32 are controlled generators of commuting signals that

The switched filter contains a counter 33, a multiplexer 34, accumulation elements, a restriction element 36,

The device works as follows

Frequency-manipulated telemechanic signal with frequencies f - L f and. from the device's input through the active RC-filter 1 is fed to the combined inputs of the switched filters 25 and 26, one of them from a controlled generator of switching signals receives a sequence of pulses with a frequency, the other with a frequency of fp + 4f. When the frequency at the input of the device coincides with the filter switching frequency, a step signal of the same frequency appears at the output of the filter, approximating a sinusoid. When the frequency of a frequency-manipulated signal changes, a similar step signal appears at the output of another switched link filter. With a serial connection of a sufficient number of links, an optional

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The slope of the amplitude-frequency characteristic (AFC) of the device and sufficient attenuation for the signals of adjacent channels go. From the output of the second amplifier, the step signal goes to another active RC filter 2, from three outputs of which through the load elements 6-8 (resistors) to the output of the device sine wave signal. The resonant frequency of the switched filter is determined by the switching frequency of the integrating elements. By using a generator of switching signals as a controlled oscillator with a quartz frequency stabilization followed by dividing with tunable dividers, it is possible to ensure high reliability and accuracy of tuning by the frequency of switched filters and the entire device. This allows a large number of channels to be formed in the tonal frequency range. This simplifies the adjustment of the device, which reduces to the selection of the frequency division factors of an amplifier that commutes a group of filters. However, a combed frequency response of the switched filter makes it difficult to use it directly to select the frequency signals of the telemechanic. It transmits not only the main frequency band, but also multiple frequencies, as well as the frequency band near zero (Fig. 2). Therefore, additional analog filtering is required at the input and output of the device. In this case, the analog filter at the device input imposes high demands, since it must supply a frequency band near zero and signals of multiple frequencies at the input of switched filters, which, due to the ambiguity of the transfer of the switched filter, create interference at the main frequency. Such a device is obtained with: the gun, and the number of active links in it almost does not decrease.

In the proposed device for analog filtering, single-link low-Q units are used at the input and output. The formation of its frequency response is illustrated in FIG. 2, in which reference numerals 37-40 denote a comb.

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the frequency response of the filter switched with the frequency f.-uf., the positions 41–44 are the combed frequency response of the filter switched with the frequency fo + 4f; positions 453, 1363287

- Frequency response of the switched filter, position 51 - Frequency response of the active link with transmission zero at channel frequency 35, position - Frequency response of the device for electing

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by 37 and 44 frequency response in the frequency band near zero transmitted by the switched filter, 38, 42, 45, 46 and 52, first frequency resonance frequency response, 39, 43, 47 and 48 frequency response, second frequency response, 40 , 44, 49 and 50 - frequency response of the third resonance of switched filters.

The low-frequency noise signals transmitted by the switched filters (AFC 37-41) are mutually compensated in the operational amplifiers. To compensate for interference at the output of switched filters from a signal whose frequency is close to double switching frequency (frequency response 39, 43, 47 and 48), filters operating at the same frequency are switched by pulsed signals shifted in phase by switching on elements (FIG. 1). Interference suppression from signals with a triple and larger frequency ratio (Fig. 2, frequency response 40, 44, 49 and 50) is performed by the input active link, for which the transmission zero of this link is set to triple channel frequency (Fig. 2, pos. 51) . For signals that form higher-order resonances, the input active CS-link represents a rather large attenuation, and their amplitude at the output of the switched filter decreases strongly with increasing frequency.

The active link at the output of the device converts the stepped signal into a sinusoidal signal and introduces additional attenuation for the signals of adjacent channels. The transmission zero of this link is also tuned to a triple channel frequency.

When the device frequency response is misaligned due to adjustment errors and the variation of parameters of individual units, it is typed by changing the resistance of the second 10 and third 11 restrictive elements (Fig. 1).

The use of switched filters in the proposed device makes it possible to reduce the number of labor-intensive RC-filters that are laborious in manufacturing and tuning. Group configuration method using de0

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Variable division frequency models further simplify device setup.

The use of a master oscillator with a quartz frequency stabilization in controlled oscillators of switching signals ensures high reliability of the entire device, while reducing the reliability requirements of active QC filters.

Claims (1)

Invention Formula A device for selecting telemechanical frequency signals comprising a first filter, the input of which is connected to the first output of the first limiting element, the second output of which is the input of the device, the first second and third outputs of the first filter through the first, second and third load elements, respectively, are combined and connected to the first .the output of the first separating element, the second filter, the first, second and third outputs of which through the quarter, fifth and sixth load elements are respectively combined and are the output of the device, the first amplifier, whose output through the first feedback element is connected to its first input and to the first output of the first matching element, the first output of the second limiting element connected to the zero potential bus, characterized in that, c. the purpose of increasing reliability and simplifying the manufacture and tuning of the device, the third, quarter and fifth are introduced. Restrictive elements, second, third and fourth matching elements, second feedback element, second amplifier, second and third separation elements, first, second, the third and fourth switched filters, the first and second elements And, the first and second controlled generators of switching signals, the second output of the first separating element is connected to the first inputs of the first and second switched the output of the first switched filter is connected to the second terminals of the first matching element and the second limiting element, the output of the second switched filter is connected to the first terminals of the second matching element and the third restrictive element, the second output of the second matching element is connected to the second input of the first amplifier and the first terminal of the fourth The limiting element, the output of the first amplifier through the second separating element is connected to the first inputs of the third and fourth comm filters that are connected to the first terminals of the third and fourth matching elements, the second terminal of the third matching element is connected to the first output of the second feedback element and to the first input of the second amplifier, the output of which is connected to the second output of the second feedback element and through the third dividing the element is connected to the input of the second filter, the second output of the fourth matching element is connected to the first output of the fifth limiting element and the second input of the second amplifier S, the second outputs of the third, fourth and fifth restrictive elements are connected to the zero potential bus, the output of the first controlled switching signal generator to the second input of the first switched filter and through the first element to the second input of the third the switched filter, the output of the second controlled generator of switching signals is connected to the second input of the second switched filter and through the second element NOT to the second input of the fourth switched filter. b figure 1 38 33 A to o And / 2lf, -4f) ) Uxcpz 3 K / I / o  I / o ZM) 2fo J / o  fo fo- i Editor E. Kopcha Compiled by I. Kuznetsov Tehred L. Oliynyk Order 6366/44 Circulation 544Subscribe VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 FIG. 2 Corrector; S. Shekmar