SU1078590A1 - Device for adjusting signal level - Google Patents

Abstract

A DEVICE FOR SIGNAL LEVEL REGULATORS, containing a source of information audio signals in digital form, the first multiplying digital-to-analog converter, a reference voltage source connected in series and an adjustable voltage divider, so as to reduce nonlinear distortions and expansion dynamic range of regulation, between the output of the source of information audio signals in digital form and the analog input of the first multiplying digital-analog conversion The bodies are connected in series by a higher-order module selector, a second multiplying digital-to-analog converter, an integrator, an attenuator and an adder, and a delay line is inserted between the source of informational audio signals in digital form and the digital input of the first digital-to-analog digital-to-analog converter. to the analog input of the second multiplying digital-to-analog converter and to another input of the adder.

Description

The invention relates to radio engineering and, can be used in digital radio receiving devices to provide for adjusting the level of the audio signal.

A device for adjusting the dynamic range is known by changing the gain depending on the change in volume {ij.

The disadvantage is that, in known devices, the adjustment always takes place with a delay, as a result of which either an excessive increase — a cry or a volume dips — will be heard. In addition, to ensure automatic control, these devices are provided with adjustable non-linear resistance, which introduces non-linear distortion.

The closest to the present invention is a device for adjusting the signal level, containing a source of informational audio signals. In digital form, a first digital-to-analog converter, a reference voltage source and an adjustable voltage divider 2

The disadvantage of this device when used in digital broadcasting systems is the appearance of distortions that occur when listening to various programs in various conditions and due to the large dynamic range of transmitted signals. The dynamic range of digital systems is approximately b. and dB, where n is the number of bits. Usually in digital systems and is 14 - 16, therefore, the dynamic range is 84 - 96 dB. In such a range, the listener will sit down and turn down the volume, he will not hear soft sounds, especially if the programs you are listening to occur in a room with increased noise, for example, in a car.

The purpose of the invention is to reduce non-linear distortions and to expand the dynamic range of the adjustment.

. The goal is achieved in that the device for adjusting the signal level, containing a source of information audio signals in digital form, the first multiplying digital-to-analog converter, serially connected source of reference voltage, and an adjustable voltage divider, between the output of the source of audio information signals in the digital The input and analog input of the first multiplying digital-to-analog converter are entered in series by the selector module of the highest order, second peremnozhakschy second digital to analog converter, an integrator, and an adder attenuator between the sound source output signals infogadatsionnyh tsifro10 tion and a digital input of a multiplying DAC first introduced delay line, the output of the adjustable voltage divider is connected

15 to the analog input of the second multiplying digital-to-analog converter and to another input of the adder.

The drawing shows the structural scheme of the proposed device.

The device contains a source of 1 sound information signals in digital form, the first multiplying digital-to-analog converter 2, the source 3 of the reference voltage, an adjustable voltage divider 4, the adder 5, the delay line 6, the selector 7 of the high-resolution module, the second multiplying digital-analog converter 8, integrator 9 and attenuator 10. The device works as follows.

If the regulator (not shown) of the attribute5 of the nuator 10 is on average

position, then at one input of the adder 5, the voltage is O. In this case, in accordance with the first multiplying digital-to-analogue converter .2 arriving at the digital input, the informational audio signal in digital form, arriving with a delay t, at its output passes part of It arrives at the analog input, the value of which is regulated by changing the division factor of the regulated voltage divider 4. Thus, the volume is adjusted to Q. At offset

attenuator regulator 10 relative to the average position from the output

the attenuator 10 to the input of the adder 5 receives the voltage, the absolute

5 the value of which corresponds to: the average volume level for the period of delay D, This happens as follows. The high-order modulo selector 7 provides 3–4 high-order bits, not the significant ones, that are needed to calculate the average value. In integrator 9, the constant rise time may differ from the constant recession time in accordance with the law, sound broadcasting. Line 6 of the delay makes the delay by the time g / c-de ijj - low frequency of the audio range. a large input signal level (when units arrive at the input of the second multiplying digital-analog converter 8) corresponds to a large output voltage level) and a small input level of the input signal of the second multiplying digital-analog converter (zeros) corresponds to a small output voltage. These instantaneous values of voltages, which carry information about the volume level during time t, are sent to the integrator 9, at the output of which the voltage corresponds to the average value of the volume level during time C. At the same time, the voltage supplied from the output of the attenuator 10 to the input of the adder 5 is positive in one direction of the bias of the attenuator regulator 10 and negative when the other. This is provided by applying to the regulator an attenuator 10 of the antiphase voltage (for example, using an inverter which is not shown in the diagram). Thus, with one direction of the attenuator regulator bias 10, the volume level (the voltage value at the analog input of the first multiplying digital-analog converter (2) increases, and when ohm - decreases. Moreover, the change in the volume level is greater, the greater the average volume level during the delay time, Thus the dync range is adjusted (in the first case it expands and in the second it is narrowed.) The change in dynamic range does not depend on the position of the controller. a torus (not shown) of an adjustable voltage divider 4, since the reference voltages for the first and second multiplying digital-to-analog converters are removed from the output of this regulator of an adjustable divider 4 voltage When the attenuator controller 10 is set to a position other than the average, the dynamic range is adjusted automatically. This reduces the non-linear distortion. All this makes it possible to achieve better reproduced programs, i.e. improve consumer qualities of digital radio equipment.

Claims (1)

DEVICE FOR REGULATING A SIGNAL LEVEL, containing a source of informational sound. signals in digital form, the first multiplying digital-to-analog converter, a series-connected source of reference voltage and an adjustable voltage divider, characterized in that, in order to reduce non-linear distortion and expand the dynamic range of regulation, between the output of the source of information audio signals in digital form and The analog input of the first multiplying digital-to-analog converter is used to connect the high-order module selector in series, the second multiplying the first digital-to-analog converter, integrator, attenuator, and adder, and a delay line is introduced between the output of the information audio signal source in digital form and the digital input of the first multiplying digital-to-analog converter, while the output of the adjustable voltage divider is connected to the analog input of the second multiplying digital-to-analog converter and to the other input of the adder .