SU1282354A1 - Device for suppressing self-excited oscillations due to acoustical feedback - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to increase the degree of suppression of autogeneration and simplify the device by simplifying the signal suppressor. The device contains a block of 1 frequency shift, a suppressor of 2 reflected signals, consisting of two transducers 3 and 5 of the dynamic range, a selective u 4, a mapatopa 6, a large u 7, a multiplier 8 analog signals and a source tension The input signal is multiplied by a constant voltage, the value of which depends on whether or not the input signal beats. With the appearance of beats, a decrease in the coefficients occurs. transfer device. As soon as the amplitude of the signals reaches the value determined by the threshold of comparator 6, the coefficient will decrease. transmission, which will lead to the limitation of the SS-level of the parasitic modulation depth and, consequently, to an increase in the quality of sound amplification. I il. (L

Description

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The invention relates to the field of radio engineering and communications and can be used in devices amplifying electrical signals.

The aim of the invention is to increase the degree of autogeneration suppression and simplify the device by simplifying the reflection suppressor.

The drawing shows the structural electrical circuit of the autogeneration suppression device due to acoustic feedback.

The device contains a frequency shift unit 1, a return signal return feeder 2, comprising a first dynamic range converter 3, a selective amplifier 4, a second dynamic range converter 5, a compator 6, a large scale amplifier 7, a multiplier 8, analog signals and a reference voltage source 9, the Device suppressing autogeneration due to reverse acoustics

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large-scale amplifier 7. The output from the large-scale amplifier 7 is blunt on one of the inputs of multiples 8, on the other input of which the sound signal comes from the input of the device. The signal from the multiply 9 output is fed to block 1, where it is shifted along the frequency axis.

Thus, the input signal is multiplied by a constant voltage, the value of which depends on whether or not the input signal is beating, i.e., when a beating is detected, the transmission coefficient of the device decreases. Since the process of increasing the output voltage carries an inertial pattern, in order for a beat to occur, noticeable by ear, several cycles of signal reversal must occur through a feedback loop. this, as soon as the amplitude of the beats reaches a value determined by

connection, operates as follows by the operation of the comparator 6,

at once

In the first converter 3, suppressor 2, by means of the Hilbert transform, selects the envelope of the signal, which is the sum of direct and diffuse, frequency shifted by 5 Hz, sound signals. Summing such signals causes beats with a frequency of 2.5 Hz.

Thus, in the selected envelope there will be a variable component with a frequency of 2.5 Hz. This component is filtered in a selective amplifier 4, the output of which crawls a narrowband signal with a center frequency of 2.5 Hz. In the second transducer 5, completed in the form of a selector of the Hubert envelope, there is a positive voltage, which is the envelope of the said narrowband signal. This voltage, appearing only at a beat between the direct and frequency-shifted diffuse signals, arrives at the input of the comparator 6 and, if it exceeds the threshold value specified by source 9 (the threshold value is chosen so that the beats are not heard) a voltage appears at the output of the comparator 6, which decreases the magnitude of the output voltage

VNIIPI Order 7288/59

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Claims (1)

there will be a decrease in the transmission coefficient, which, in turn, will reduce the increase in the depth of the infield modulation and, consequently, increase the quality of the sound amplifier. The formula of the invention of the device for autogeny suppression caused by acoustic backbone, a block of frequencies and a suppressor of reflected signals, is characterized in that, in order to increase the degree of suppression of autogeneration and to simplify the device by simplifying the suppression of reflected signals, the suppressor of reflected The signals are switched on at the input of the frequency shift block, while the pressure suppressor of the reflected signals contains a serially connected fifth dynamic range converter, the second amplifier dynamic range, comparator, large-scale amplifier and analog signal multiplier, the second input of which is connected to the input of the first dynamic range transformer, the second input of the comparator is connected to the output of the reference voltage source, and the analog signal multiplier output is the output of the affected signals. Circulation 637 Subscription five 0 scale amplifier 7. The voltage from the output of the scale amplifier 7 is fed to one of the inputs of multiplier 8, to the other input of which a sound signal is received from the input of the device. The signal from the output of the multiplier 9 is fed to block 1, where it is shifted along the frequency axis. Thus, the input signal is multiplied by a constant voltage, the value of which depends on whether or not the input signal beats, i.e., when a beat appears, a decrease in the transmission coefficient of the device occurs. Since the process of increasing the output voltage is inertial in nature, in order for the beats to be noticeable by ear, several cycles of signal reversal must occur through the feedback loop. At the same time, as soon as the amplitude of the beats reaches a value determined by the trigger threshold of the comparator 6, thirty 35 40 45 50 55 there will be a decrease in the transmission coefficient, which, in turn, the prize goes to limit the increase in the depth of parasitic modulation, therefore, to an increase in the quality of the sound amplifier. The invention The autogeneration suppressor device due to acoustic feedback contains its frequency shift unit and the echo suppressor, characterized in that, in order to increase the autogeneration suppression degree and simplify the apparatus by simplifying the echo suppressor, the echo suppressor is enabled at the input block frequency shift, while the suppressor of reflected signals contains serially connected the first dynamic range converter, the selective amplifier , a second dynamic range converter, a comparator, a large-scale amplifier and an analog signal multiplier, the second input of which is connected to the input of the first dynamic range converter, the second comparator input is connected to the output of a reference voltage source, and the output of the analog signal multiplier. Circulation 637 Subscription