CN111182157A

CN111182157A - Isolated four-wire call one-to-two circuit

Info

Publication number: CN111182157A
Application number: CN201911399417.9A
Authority: CN
Inventors: 孙奎
Original assignee: Trainfx Technology Anhui Co ltd
Current assignee: Trainfx Technology Anhui Co ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-05-19
Anticipated expiration: 2039-12-30
Also published as: CN111182157B

Abstract

The invention relates to subway communication, in particular to an isolated four-wire call one-to-two circuit, which comprises an audio input differential signal and an audio output differential signal, wherein an isolation module for isolation and a signal amplification module for amplifying the audio signal are connected between the audio input differential signal and the audio output differential signal; the technical scheme provided by the invention can effectively overcome the defects of complex circuit, higher cost, mutual crosstalk between equipment and poorer communication effect in the prior art.

Description

Isolated four-wire call one-to-two circuit

Technical Field

The invention relates to subway communication, in particular to an isolated four-wire call one-to-two circuit.

Background

Subway trips are the first choice of public transportation mode in many cities, especially big cities, and a large number of people flow through subway station halls and tunnels every day. The normal communication between the staff on the subway is ensured, and the subway traffic system can run more smoothly.

The prior similar technology is as follows:

2/4 conversion: the advantages are that full duplex can be realized, and a pair of signal lines is reduced; the disadvantages are that the circuit design is complex, the cost is very high, the conversation effect is poor, the circuit stability is not high, and the isolation between the devices is not easy to realize.

Two-line half duplex: the advantages are that a pair of signal lines is reduced, the circuit is easy to realize, and the cost is lower; the disadvantages are low efficiency of half-duplex multi-person conversation and complex operation.

Non-isolated: the method has the advantages of more realization modes and lower cost; the defect is that the devices are not isolated, the condition that one device is damaged to influence all other devices is easy to occur, and the external high voltage is easily transmitted into the devices to cause the damage of the devices.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects in the prior art, the invention provides an isolated four-wire call one-to-two circuit, which can effectively overcome the defects of complex circuit, higher cost, mutual crosstalk between devices and poorer call effect in the prior art.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme:

an isolated four-wire call one-to-two circuit comprises an audio input differential signal and an audio output differential signal, wherein an isolation module for isolation and a signal amplification module for amplifying the audio signal are connected between the audio input differential signal and the audio output differential signal.

Preferably, one path of the audio input differential signal is connected to an input end of a first isolation module, an output end of the first isolation module is divided into two paths, and the two paths of the audio input differential signal are connected to input ends of two second isolation modules through the signal amplification module, and output ends of the two second isolation modules respectively output audio output differential signals corresponding to the other two paths of the audio input differential signal.

Preferably, the audio input differential signals comprise three pairs of differential signals of TL3-DACU and TL4-DACU, TL3-UIC and TL4-UIC, TL3-TRAIN and TL4-TRAIN, and the audio output differential signals comprise three pairs of differential signals of TL5-DACU and TL6-DACU, TL5-UIC and TL6-UIC, TL5-TRAIN and TL 6-TRAIN.

Preferably, the first isolation module and the second isolation module are both isolation transformers, the first isolation module comprises an isolation transformer TR4, an isolation transformer TR6 and an isolation transformer TR8, and the second isolation module comprises an isolation transformer TR5, an isolation transformer TR7 and an isolation transformer TR 9.

Preferably, the input ends of the isolation transformer TR5, the isolation transformer TR7 and the isolation transformer TR9 are all connected to the output end signals of the two-way signal amplification module.

Preferably, the signal amplification modules are all operational amplifiers.

(III) advantageous effects

Compared with the prior art, the isolated four-wire call one-to-two circuit provided by the invention has the following beneficial effects:

1. as can be seen from the circuit diagram, fewer electric elements are needed, and passive conventional devices are used, so that the circuit is simple and the cost is low;

2. the transformer is adopted for isolation, so that the external high voltage can be prevented from being transmitted into the equipment through TL3/TL4 and TL5/TL6 signal wires, and the safety and reliability of the equipment are greatly improved; the devices are interconnected through the isolation transformer, direct charge conversion is avoided, mutual crosstalk among the devices is avoided, the problem that a single device cannot spread and other devices on a bus cannot be interfered to work is solved, and the reliability of the system is improved;

3. the electric elements in the circuit are all passive devices, audio fidelity is high, the problem of conversion distortion from sampling to restoration can not be caused in a countless analog-to-digital conversion process, and a full-duplex call is adopted, so that a plurality of people can talk and listen at the same time, and the call efficiency is greatly improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic diagram of the working circuit of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

An isolated four-wire call one-to-two circuit, as shown in fig. 1, includes an audio input differential signal, an audio output differential signal, and an isolation module for isolation and a signal amplification module for amplifying the audio signal are connected between the audio input differential signal and the audio output differential signal.

One path of audio input differential signal is connected to the input end of the first isolation module, the output end of the first isolation module is divided into two paths and is connected with the input ends of the two second isolation modules through the signal amplification module, and the output ends of the two second isolation modules respectively output audio output differential signals corresponding to the other two paths of audio input differential signals.

The audio input differential signals comprise three pairs of differential signals of TL3-DACU and TL4-DACU, TL3-UIC and TL4-UIC, TL3-TRAIN and TL4-TRAIN, and the audio output differential signals comprise three pairs of differential signals of TL5-DACU and TL6-DACU, TL5-UIC and TL6-UIC, TL5-TRAIN and TL 6-TRAIN.

The first isolation module and the second isolation module are isolation transformers, the first isolation module comprises an isolation transformer TR4, an isolation transformer TR6 and an isolation transformer TR8, and the second isolation module comprises an isolation transformer TR5, an isolation transformer TR7 and an isolation transformer TR 9.

The input ends of the isolation transformer TR5, the isolation transformer TR7 and the isolation transformer TR9 are all connected with the output end signals of the two signal amplification modules.

The signal amplification modules are operational amplifiers.

The audio input differential signals TL3-DACU and TL4-DACU of the DACU are transmitted to an operational amplifier N1A and an operational amplifier N4A in an isolation mode through an isolation transformer TR4, and transmitted to TL5/TL6 of TRAIN and TL5/TL6 of UIC through an operational amplifier N1A and an operational amplifier N4A respectively, so that audio is transmitted to audio output ends of the TRAIN and the UIC.

Similarly, the audio input differential signals TL3-UIC and TL4-UIC of the UIC are transmitted to TL5/TL6 of TRAIN and TL5/TL6 of DACU; the audio input differential signals TL3-TRAIN and TL4-TRAIN of TRAIN are transmitted to TL5/TL6 of UIC, TL5/TL6 of DACU.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims

1. An isolated four-wire call one-to-two circuit, comprising: the audio frequency differential signal and the audio frequency differential signal are connected with an isolation module for isolation and a signal amplification module for amplifying the audio frequency signal.

2. The isolated four-wire call one-to-two circuit of claim 1, wherein: one path of the audio input differential signal is connected to the input end of the first isolation module, the output end of the first isolation module is divided into two paths and is connected with the input ends of the two second isolation modules through the signal amplification module, and the output ends of the two second isolation modules respectively output the other two paths of audio output differential signals corresponding to the audio input differential signal.

3. The isolated four-wire call one-to-two circuit of claim 2, wherein: the audio input differential signals comprise three pairs of differential signals of TL3-DACU and TL4-DACU, TL3-UIC and TL4-UIC, TL3-TRAIN and TL4-TRAIN, and the audio output differential signals comprise three pairs of differential signals of TL5-DACU and TL6-DACU, TL5-UIC and TL6-UIC, TL5-TRAIN and TL 6-TRAIN.

4. The isolated four-wire call one-to-two circuit of claim 2, wherein: the first isolation module and the second isolation module are both isolation transformers, the first isolation module comprises an isolation transformer TR4, an isolation transformer TR6 and an isolation transformer TR8, and the second isolation module comprises an isolation transformer TR5, an isolation transformer TR7 and an isolation transformer TR 9.

5. The isolated four-wire call one-to-two circuit of claim 4, wherein: the input ends of the isolation transformer TR5, the isolation transformer TR7 and the isolation transformer TR9 are all connected with the output end signals of the two signal amplification modules.

6. The isolated four-wire call one-to-two circuit of claim 2, wherein: the signal amplification modules are operational amplifiers.