SU951749A2 - Device for automatic switching of electro-acoustic circuit transmitting branch by voice command - Google Patents

Description

(54) DEVICE FOR AUTOMATIC INCLUSION OF THE TRANSMITTING BRANCH OF THE ELECTRIC ACOUSTIC TRACT

one

The invention relates to telephony and is intended for telephone equipment used in objects with a high level of acoustic noise intensity.

According to the main author. St. j№ 620028, a device for automatically switching on the transmitting branch of the electroacoustic path from voice, containing successively connected amplifiers and rectifiers in the sound and speech paths, associated with a comparator connected to an electronic key, as well as a comparison circuit and an automatic gain control unit 1.

However, the known device does not exclude the loss of audio information in the on-off transmission but a simplex radio channel. ,

The purpose of the invention is to exclude the loss of audio information during the oncoming transmission by forcibly periodically switching the radio station from transmission to reception.

This goal is achieved by the fact that the unit of periodic switching of the radio station from the transfer from voice to the automatic switching on of the transmitting branch of the electroacoustic path from the voice

reception (BPP), receiver, tone generator, reset unit, information erasing unit and switching element, the input of the tone signal receiver is connected to the first input of the information erasing unit, the second input of which is connected to the additional output of the delay unit, the additional input is connected to the output of the reset unit, the input of which is connected to the output of the receiver of tone signals, an additional input of the first

10 of the switching unit and the output of the control unit whose input is connected to the first output of the switching element, the second output of which is connected to the output of the delay unit, and the input of the switching element is connected to the output of the tone generator.

The drawing shows a structural electrical circuit of the proposed device.

The automatic switching device 20 of the transmitting branch of the electroacoustic path from the voice contains the amplifier 1 of the voice path, the rectifier 2 of the speech path, the electronic switch 3, the comparator 4, the comparison circuit 5, the rectifier 6

path, noise path amplifier 7, noise path AGC block 8, first and second switching blocks 9 and 10, matching block 11, delay block 12, and also block 13 for periodically switching the radio station from transmission to reception (BPP), receiver 14 and tone generator signals 15, the reset unit 16, the erase information block 17 and the switching element 18.

The device works in the following way.

In the absence of transmission, the control potential of the comparator 4 and the corresponding input of the comparison circuit 5 is not received, with the result that the electronic key 3 is locked.

The device is designed in such a way that the voice and noise inputs of the comparison circuit 5 have a large time constant, so it responds only to slowly varying signal levels and is not sensitive to rapidly varying levels of the speech signal.

If the voltages due to acoustic noise on the speech and noise inputs of the comparator 4 have different values, then from the output of the comparison circuit 5 to the control input of the AGC block 8 voltage is applied, under the action of which this block provides potential equalization on the voice and noise inputs the comparator 4. As a result, the potential of the comparator is zero and the electronic switch 3 is locked, and the input of the matching unit 11 connected to the output of the first switching unit 9 is not controlled The present voltage.

From the beginning of the transmission, the speech signals arrive at the input of the comparator 4, to the corresponding input of the comparison circuit 5. Since these signals have a pulse structure, the comparison circuit 5 and the AGC block 8 do not have time to react to changes in their level. The potential at the speech input of the comparator 4, which has a slight inertia, increases and begins to prevail over the potential at its noise input. As a result, a control potential appears at the output of the comparator, which is also sufficient to unlock the electronic key 3 and to control the control unit of the radio station through the first switching unit 9 and the matching unit 11.

After unlocking the electronic key 3, a voice source is connected to the input of the sound source (telephone, loudspeaker), thanks to it, the subscriber is provided with listening to his own transmission, which is typical of voice communication paths operating under conditions of intense acoustic noise. At the same time, a delay unit 12 is connected to the output of the electronic switch 3 via the second switching unit 10.

This block provides analog-to-discrete-analog conversion of speech signals and their memorization in the discrete conversion link.

Listening to your own transmission through delay unit 12 is eliminated, as this creates a false impression of oncoming transmission.

Through the output of the matching unit 11 closes the switching circuit of the radio station

on the transfer. Since the transfer of the radio station to this mode occurs with a slowdown that is much higher than the allowable in voice control devices, to avoid loss of information, the delay unit 12 provides for the accumulation of voice

signals on an interval equal to or slightly longer than the time of switching the radio station to transmission.

After the termination of the transmission of speech signals, the prohibition is lifted;

From the output of the electronic key 3 to the first input of the erasure unit 17 and from the output of the delay unit 12 through the second input of the erasure unit 17, its output through the matching unit 11 continues to flow to the control unit of the radio station, whereby it is held in transmission mode until full clearing the delay unit 12 from the information accumulated therein.

In the case when the correspondent with whom the connection is established wants to interrupt the master transmission, it acts on the switching element 18 (button, toggle switch, tangent or key). Through the contacts of the aforementioned switching element, the output of the tone signal generator 15 is connected to the input of the radio transmitter and the potential for prohibiting the control input of the PPO 13 is supplied.

At the other end of the radio path on the length of time when the output potential of the block 13 receives the control potential, switching

0, periodically, the radio station on reception, from the signal recorded by the receiver 14 of the tone signal, locks the first switching unit 9 and the radio station is forcedly held at the reception. Simultaneously, the potential from the output of the receiver 14

The 5 tone signal affects the control input of the reset unit 16, under the action of which the delay unit 12 is cleared of the information accumulated in it.

Received from the output of the radio

the tone and then the speech signals are heard by the correspondent, who previously conducted the transmission, through the sound emitter of the electroacoustic path. 55 In the described device, during periodic forced switching of the radio station to receive, there is also a delay in the information in block 12, to which the inhibit potential enters during this period.

As a result, there may be an increase in the information delay in block 12 during the negotiation process, which may be excluded from CibiTb, provided that the information delay time in block 12 is shorter than the pause time of the speech signal.

If it is assumed that the transmission time in each of the cycles is 950 ms, and the forced retention time is 50 ms, then the pause time is approximately 5% of the total transmission time. Therefore, under these conditions, the delay time in block 13 does not increase during the negotiation process. The switching time of the radio station from transmission to reception and back should not exceed 100-200 minutes.

Claims (1)

Invention Formula The device automatically turn on the transmitting branch of the electro-acoustic path from the voice on author. St. No. 620028, different -i & M, which, in order to exclude . loss of sound information during counter transmission by forcing periodically switching a radio station from transmission to reception; a block of periodic switching of a radio station from transmission to reception (BPP), a tone receiver, a tone generator, a reset unit, an information erasure unit and a switching element are introduced, and the receiver input tones are connected to the first input of the erase unit, the second input of which is connected to the additional output of the delay unit, the additional input of which Dinen with the output of the reset unit, the input of which is connected to the output of the receiver of tone signals, an additional input of the first switching unit and the output of the PPO, whose input is connected to the first output of the switching element, the second output of which is connected to the bypass of the delay unit, and the input of the switching element is connected to the generator output tones. Sources of information taken into account during the examination 1 USSR Author's Certificate No. 620028, cl. H 04 M 9/08. 1976.