SU965012A1 - Device for detecting telegraphic signal - Google Patents

Description

The invention relates to telecommunications and can be used in voice control devices for switching the transmission direction of simplex communication channels using telephone (voice) signals.

A speech detector device is known comprising a input amplifier connected in series, a rectifier, a speech signal envelope selector, an averaging circuit, a comparator, a first delay element, a pause / element delay element, and a high-pass filter connected to the input of a peak detector, the output of which is connected to the second input of the comparator, the second delay element, the input of which is combined with the input of the first element and the output of the comparator, and the output connected to the second input of the electric ements OR tl.

However, the known device is characterized by a low accuracy of detecting a telephone signal and insufficient protection from impulse noise in transmission pauses.

The aim of the invention is to improve the accuracy, speed of detection

signal and increase the security of the device from impulse noise in the pauses of the telephone signal transmission.

The goal is achieved in that a telephone signal detection device comprising a serially connected input amplifier, a syllable envelope selector. A telephone signal, a first comparator, as well as

10, the first and second delay elements, the inputs of which are combined, a rectifier whose input is connected to the output of the input amplifier, the source of the reference voltage and the delay element

15 pauses, the output of which is connected to the first input of the first element OR, introduced a second comparator, a second element OR, the first and second elements I. At the same time, the inverting input of the second

A comparator 20 is connected to the non-inverting input 1 of the first comparator, and the non-inverting input of the second comparator and the reference voltage source are connected to the inverting input of the first comparator, the output of which is connected to the first input of the second OR element, the second input of which is connected to the output of the second comparator, and the output of the second element OR is connected to the first inputs of the first and second elements AND, the second outputs of which are connected respectively to the outputs of the first and second delay elements whose inputs are connected to the output of the rectifier, while the output of the first element and is connected to the input of the delayed pause element, and the output of the second element AND is connected to the second input of the first element OR. Figure 1 shows the functional diagram of the device; figure 2 - the timing diagram of his work. The device consists of an input amplifier 1, a selector 2 by the syllable envelope of the telephone signal, the first comparator 3, the second element OR 4, the first element AND 5, the delay element of the pauses 6, the first element IL 7, the second comparator 8, the source of the reference voltage 9, rectifier mittel 10, the first and second, elements 11 and 12 of the delay, the second element And 13. In the drawing, the input 14 of the input amplifier 1, the output 15 of the element OR 4, the output of the 16 element 12 of the delay 12, the output 17 of the delay element 11, the output 18 of the pause delay 6, output of 19 elements OR. 7.. The device operates in the following way: The telephone signal from the input through the input amplifier 1 enters the selector 2 of the syllable envelope, in which the infra-low-frequency envelope of the syllables and sounds of the voice telephone signal is extracted from this signal. Infrared-frequency signals of the right envelope by means of comparators 3 and 8 are converted without integration into a unipolar voltage. At the same time, the voltage of the telephone signal is released by rectifier 10 and fed to the inputs of the first .11 and second 12 delay elements. Further operation of the device depends on the duration of the signals or interference acting on it. During the action (in the transmission pause), the input of the interference device, whose pulse duration, for example, in the tg-t interval (Fig. 2a) does not exceed the allowable amount of detection of the telephone signal, at the output of the OR 4 element, a signal,; equal to the duration ,, but offset from the input signal by the time tQ-t of the delay in the selector filter 2 syllable envelope. Since the duration of the interference pulse does not exceed the delay time of the first 11 and second 12 delay elements, the interference from the output of the rectifiers of the bodies 10 does not pass fta enter respectively the first 5 and second 13 elements AND, therefore no control signal is generated at the device output. If in the transmission pause to the input of the device, an interference occurs, the pulse duration of which, for example, tg-tg (Fig. 25) exceeds the maximum permissible delay of detection of the telephone signal and, accordingly, the delay of the second 12 delay elements, then this interference generates false signals at the output element OR 4 and the output of the second. 12 delay element, creates through the second element And 13 and through the element OR 7 a short-term (for a period) false signal at the output of the device, which disappears at the moment ok (the action of the input pulse does not interfere. The duration of such a false signal does not lengthen, lagging it for a time, in the selector 2, the syllable envelope, and is reduced by the delay tg-t of the second delay element 12. When a device receives a signal corresponding to a separate sound or syllable of a telephone signal, for example, measures on the interval tQ-tg (figv), at the output of the element OR 4 there appears a lagging unipolar voltage with respect to the input on the interval t, -tg, which is fed to the first inputs of the first 5 and the second 13 elements I. At the second input of the second element AND 13, the signal appears with a delay of time tQ-t generated by the second element of delay 12. Accordingly, at the output of the second element And 13, the signal also appears with a delay of time. This signal through the element OR 7 enters the output of the device, thereby fixing the detection of the input signal in The time element is 14. At the second input of the first element AND 5, the signal from the output of the first delay element 11 appears delayed by the time tQ-t-, created by the delay element 11. The coincidence of the signals at the inputs of the first element And 5 causes a tj the appearance of the signal at the input of the element 6 delay pauses. In this case, the signal from the moment of time t comes from the output of the pause delay element 6 through one of the inputs of the element OR 7 to the output of the device, confirming the detection of the telephone signal. At the moment tg. Of the end of the input signal simultaneously and without delay, the signals at the inputs of the first 5 and second 13 elements disappear. However, the signal at the output of the device is saved for the first period tg-t, the value of which is chosen to be somewhat longer than the maximum pause duration t barely background noise. Such a delay (memorization) of the output signal in speech pauses is provided by the pause delay element 6 in order to eliminate unwanted shutdowns of the control signal at the device output in the pauses between words of one phrase. The use of the device, for example, to switch the direction of transmission of simplex technological communication channels makes it possible to significantly increase the stability of the speech-controlled simplex channels of the radio telephone and telephone communication by increasing the detection accuracy of the telephone signal and significantly reducing the operation of the device by impulse noise. Formula of the Invention A device for detecting a telephone signal comprising successively connected an input amplifier, a selector of the syllable envelope of a telephone signal, a first comparator, and also the first and second delay elements, whose inputs are combined, a rectifier, whose output is below the keys to the input booster. the source of the reference voltage and the element of pauses, the output of which is connected to the first input of the first element OR, differs in that, in order to improve the accuracy of detecting the telephone signal, a second comparator, a second element OR, the first and second elements AND, and the inverting input of the second the comparator is connected to the non-inverting input of the first comparator, and the non-inverting input of the second comparator and the source of the reference voltage are connected to the inverting input of the first comparator, the output of which is connected to the first th input of the second element OR, the second input of which is connected to the output of the second comparator, and the output of the second element OR is connected to the first inputs of the first and second elements AND, the second outputs of which are connected respectively to the outputs of the first and second delay elements, input of which are connected to the output of the rectifier , while the output of the first element And is connected to the input of the element of the delay of pauses, and the output of the second element And is connected to the second input of the first element OR. Sources of information taken into account in the examination 1. P. Patent SIL No. 4.187.396, cl. 179/1, 1980 (prototype).

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Claims (1)

Claim A device for detecting a telephone signal comprising a series-connected input amplifier, a syllable envelope separator for a telephone signal, a first comparator, as well as first and second delay elements whose inputs are combined, a rectifier whose output is connected to the output of the input amplifier, a reference voltage source and a pause delay element the output of which is connected to the first input of the first OR element, characterized in that, in order to improve the detection accuracy of the telephone signal, a second comparator is introduced, the second OR element, the first and second AND elements, wherein the inverting input of the second comparator is connected to the non-inverting input of the first comparator, and the non-inverting input of the second comparator and the reference voltage source are connected to the inverting input of the first comparator, the output of which is connected to the first input of the second OR element, the second input which is connected to the output of the second comparator, and the output of the second OR element is connected to the first inputs of the first and second AND elements, the second outputs of which are connected respectively to the outputs odes of the first and second delay elements, the input of which is connected to the output of the rectifier, while the output of the first element And is connected to the input of the delay element of pauses, and the output of the second element And is connected to the second input of the first OR element.