SU1239889A1 - Loud-speaking communication device - Google Patents

Abstract

The invention relates to communication technology. Noise immunity increases. The device contains a power-matching junction block 1, two rectifiers with a delay (c) 2, 9, comparator. (K) 3, matching unit 4, three keys (C) 5, 6, 8, control unit 7, filter 10 ,. the allocation unit max, signal 11, two controlled amplifiers 12 and 13, the device is made so that the time delay B 2 is significantly less than the delay time B 9. Under the influence of the speech signal, the potential at the 1st input K 3 quickly increases, the potential at the 2nd its input is the same as when exposed to acoustic i-Tv-j L 8 0

Description

noise, The accumulation of energy in the circuit of the 2nd input of K 3 is prevented by CL 5. At the output of de K 3, a control potential appears at the 1st input. C 6 and the input of block 7. C 5 is unlocked, through its input the energy accumulated at the 2nd input K 3 occurs. The voltage supplied to the input of block 7 is inverted and the input of K, 8 receives a zero potential. KP 8

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The invention relates to a communication technique, in particular to a hands-free telephone communication.

The purpose of the invention is to improve noise immunity.

The drawing is an electrical block diagram of a speakerphone device.

The loudspeaker device contains: an amplifier / divider unit 1, the first rectifier 2 with a delay, comparator 3 ,, matching unit A, the first key 5, the second switch 6, the control unit 7, the third switch 8, the second rectifier 9 with delay , filter 10, block 11 for maximal signal, first controlled amplifier 12, second controlled amplifier 13.

The speakerphone device operates as follows.

When the transmission is not conducted, the second key 6 is locked and the third key 8 is open. If there is acoustic noise in the room, the voltage of the amplifying-separating unit 1 is supplied by the voltage, caused by the action of this noise on the sound receiver (microphones. Laryngophones) of the electroacoustic path. From the output of the amplifier-divider block I, the noise voltage is fed to the input of the maximum signal extraction unit 11 and the input of the filter 10. The filter 10 is an adjustable band-pass filter tuned to the frequency band of the voice signal of a particular operator, the unit 11 for the maximum signal passes the signal 35-45 dB, t “e. higher speech signal and converts

239889

locked between inlets and outlets

- the receiving path introduces a large attenuation determined by the resistance of CL 8. C 6 opens a speech signal in the transmission path from amplifier 12, depending on the noise (where the transmission is transmitted) and exceeding its level by 5-7 dB. The goal is achieved by the introduction of filter 10, AND block, amplifiers 12 and 13. 1 Il.

its control signal to the controlled amplifiers 2 and 13. From the output of the filter 10, the noise voltage goes to the first rectifier 2 with a delay

and then to the first input of the comparator 3, at the same time, this voltage is fed to the input of the second rectifier 9 with a delay and then to the second input of the comparator 3. The passage of the noise signal through the filter 10 causes it to be limited by the frequency spectrum intended to skip the speech spectrum signal. For a given operator using a device

5, the setting of the filter 10 is made in advance and manually. At the same time, the filter 10 causes the impulse noise signal to be limited in amplitude in a frequency band other than the band,

0 filter noise transmission 10.

The transmission coefficient of the second rectifier 9 with a delay is slightly higher than the transmission ratio of the circuit of the first rectifier 2 with a delay. Due to this, the noise voltage acting on the second input of the comparator 3 in the absence of speech transmission prevails over the noise voltage acting on the first input of the comparator 3. As a result, in the absence of speech transmission, the output of the comparator 3 has a zero potential and the second key 6 is locked as a result of the inversion

5, in the control unit 7, a zero voltage is applied to the first input of the third key 8 and it turns out to be open.

When a speech signal

0 to receive and no noise path c.

In the premises, the speech signal is amplified to the level of normal audibility. If there is noise in the room that exceeds a certain level, the control input of the second controllable amplifier t3 of the reception path receives a signal that causes the amplification of the speech signal of the reception path to the level of 5-7 dB above the noise level in the room. With the beginning of the transmission, the speech signal enters through the amplifier-separating unit 1, filter 10 and then through the first and second, inters - mixers 2 and 9 with a delay on the first and second inputs of the comparator 3. The device is designed in such a way that the delay of the first A delay 2 is significantly shorter than the delay of the second rectifier 9 and a delay 9. Therefore, under the influence of a speech signal, the potential at the first input of the comparator 3 quickly increases, while the potential at its second input remains approximately the same ashe would have been at the action of acoustic noise. The accumulation of energy in the second input circuit of the comparator 3 during transmission control is prevented by the first key 5; Due to this construction of the device with the beginning of the transfer, the potential at the first input of the comparator 3 begins to prevail over the potential at its second input. As a result, at the output of the comparator 3, a control potential appears at the first input of the second switch 6, as well as at the input of the control unit 7. The first switch 5 is unlocked and through its output occurs

the discharge of the energy accumulated on the second .j | C by the selection unit of the maximum signal output of the comparator 3. The voltage input to the control unit 7 is inverted, with the result that the third input of the third key 8 goes to the left and left potential and this key is recorded . Between the inputs and the output of the receiving-path, a large stroke is inserted.

: The input is connected to the first inputs of the first and second controlled amplifiers, the second input of the first amplifier is connected to the output of the filter, and the output of the second amplifier is connected to the second input of the third key.

Editor A. Sabo

Compiled by A. Levitska

Tehred O. Sopko Proofreader V. But

Order 3411/58 Circulation 624 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

j 10 15 0 5 0

five

The second key 6 is open, so a speech signal comes to the transmission path from the first controlled amplifier 12, the value of which depends on the noise level from which the transmission is transmitted and exceeds its level by 5-7 dB.

Claims (1)

Invention Formula A loudspeaker device containing a serially connected unit or a dividing unit, a first rectifier with a delay, a comparator, the second input of which is connected to the input of the matching unit, the output of which is connected to the first input of the First Key, and the second input of which is connected to the output of the Omster , the first input of the second key, the input of the control unit, the output of which is connected to the first input of the third key, and the input of the amplifier-dividing unit - to the second input of the second key, and also the second rectifier with delay oh, the input of which is connected to the input of the first rectifier with a delay, and the output of the second rectifier with a delay - with the second input of the comparator, which is equal to the fact that, in order to increase the noise immunity, a filter for extracting the maximum signal was inserted into it , the first and second controlled amplifiers, with the output of the amplifier-dividing unit connected to the input of the first rectifier with a delay through a filter, the input of which is connected : The input is connected to the first inputs of the first and second controlled amplifiers, the second input of the first amplifier is connected to the output of the filter, and the output of the second amplifier is connected to the second input of the third key.