SU1706009A1 - Automatic controller for acoustic signal level - Google Patents

Abstract

The invention relates to radio engineering and can be used in digital studio sound equipment of radio tele-centers. The aim of the invention is to reduce the distortion of the audio signal. In an automatic audio level controller containing delay 1, multiplier 2, pico detector 3, permanent memory 4, functional converter 5, made as an additional multiplier 6, first adder 7 of the exponential 8. of the second adder 9, the additional delay element 10 and the voltage divider 11, and the threshold unit 12, a smooth static response is formed, which allows to reduce the distortion of the sound system drove. 1 il. (Ls

Description

The invention relates to radio engineering and can be used in the digital studio sound equipment of radio television stations.

The aim of the invention is to reduce distortion of the audio signal.

The drawing shows a structural electrical circuit for the automatic level control of the audio signal.

The automatic sound level regulator contains a delay element 1. multiplier 2, peak detector 3, memory block 4, functional transducer 5, which implements a conversion of e / 3-ahove, of the form HuPr n -g; -f-i-- and

made, for example, in the form of an additional multiplier 6, the first adder 7, the exponential 8, the second adder 9, the additional delay element 10 and the divider 11, and the threshold unit 12.

The input signal Х0г п -ХНес п, where the envelope or signal level;

The X carrier signal is fed to the input of the delay element 1 and the input of the peak detector 3. The coefficients e, b are fed to the input of the control of the response time of the peak detector 3, one from the outputs of the fixed memory unit 4. defining dynamic characteristics of the device - time triggered and

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recovery time. Peak detector 3 extracts the envelope samples of the input audio signal, which are fed to the input of the additional delay element 10, the input of the threshold unit 12 and one of the inputs of the additional multiplier 6. The other input of the additional multiplier 6 receives the factor from one of the outputs of the memory block 4 -but. From the output of the additional multiplier 6, the result of multiplying a) 4g p is fed to the input of the first adder 7, to the second input of which the coefficient of one of the outputs of the memory block 4 is applied. The excluder 8 connected to the output of the first adder 7 converts the signal to exp (/ 3 - a hog n). This signal is fed to the input of the second adder 9, to another input of which from one of the outputs of the memory block 4 a factor A is applied. The second adder 9 operates in the subtraction mode. Difference

A - e No. and Hog No. from the output of the second adder 9 is fed to the first input of the divider 11. To the second input of the divider 11c, the output of the additional delay element 3 is delayed by time t count X0r {n. The delay time tj differs in the time it takes to calculate the signals in blocks 6,7,8,9. From the output of the peak detector 3, the signal enters a threshold unit 12, which compares this signal with the selected threshold values. Depending on the results of the comparison, 4 fixed dynamic parameters are selected from the fixed memory block. Formed in this way sigA e / 3-ahog pal hupr n --- yyr --- from the output

Log P

Function converter 5 is supplied to another input of multiplier 2. The output signal of the device is determined by

the output of the multiplier 2 by the following ratio

Yfnl - X | n Xynpln, where-held input sound

signal

 function converter output 5.

Thus, a smooth static characteristic is formed in the device.

which reduces distortion of the sound signal.

Claims (1)

Claims of the Invention An automatic audio signal level regulator comprising a series-connected delay element, the input of which is an input of the device, and a multiplier, serially connected peak detector and function transducer, connected between the input of the device and other multiplier inputs, as well as a fixed memory unit and a threshold unit, the output of which is connected to the address input of the permanent memory unit, inputs for setting the constant values of the function converter and the input controlling the response time of the peak detector are connected to the corresponding outputs of the unit fixed memory, characterized in that, in order to reduce the distortion of the audio signal, the input of the threshold unit is connected to the output of the peak detector, and the functional converter implemented to implement the transformation of the form And gp-gx0r n XvnP h --- WM --- where is the signal at the output of the peak detector;  - signal at the output of the functional converter; A, ft and a-values of constant coefficients. MIND fnj L L Hu / 7 / // # five