JPH0636527B2 - Audio signal distribution system and audio signal synthesis system - Google Patents

Description

DETAILED DESCRIPTION [Outline] An output of the first device for transmitting a voice signal between a single first device and a plurality of second devices via a trunk of an exchange and a network. Or a single input or output of the electrical matching means is connected to the input, and a required number of lossless compensating means are cascaded to the single output or input of the electrical matching means, and the electrical matching means Single output, or a single input of the input and the single output or the first lossless compensating means cascaded to the input, or a connection point with the output, a single output / input of the lossless compensating means An electrical matching branching means for matching impedance matching and signal level between the connection point between them and the output of the last lossless compensating means, or the input of the first lossless compensating means and the corresponding trunk of the exchange, or electrical The physical matching synthesis means is connected.

[Industrial application field]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice signal distribution system, and more specifically, it performs impedance matching and level matching for connection to each receiving device, and distributes a voice signal by providing a level compensating amplifier at a branch point. The present invention relates to an audio signal distribution system with improved quality and the like.

In the exchange system, there are cases where it is desired to simultaneously distribute the voice signals of the same content to a plurality of recipients at the same voice level. For example, there is a case where a user wants to send a fire-fighting-related message to a plurality of locations via an exchange.

Since the distribution of such audio signals has a variable distribution number, it is possible to eliminate problems caused by this as much as possible, and open up a system configuration that can easily cope with the increase in the number. There is a demand for technical means that can be used.

[Conventional technology]

A conventional system for sending the same content by voice from a command device on the transmitting side to a plurality of commanded devices on the receiving side is configured as shown in FIG. That is, the notification voice signal from the command device 31 passes through the hybrid circuit 32 of the command device 31 and is converted into two lines and four lines, amplified by the amplifier 33, and then connected to the trunk ODT (Out).
Each line is exchange-connected via a band dial trunk) 34 by a network 35 of an exchange, and is transmitted to a commanded device 37 via each subscriber circuit 36. The amplifier 33 of this system is constructed to present a sufficiently low output impedance to the extent possible to allow multiple connections. The same applies to the amplifier 38 on the receiving side.

[Problems to be solved by the invention]

As described above, in the conventional system, the voice signal is distributed to the commanded device 37 through the plurality of trunk ODTs 34 and the exchange 35 by the single amplifier 33, so that the single amplifier 33 and the plurality of trunk ODTs 34 are provided. In some cases, impedance matching cannot be obtained between the target device and the target device 37, and audio signals cannot be supplied to the commanded devices 37 at the same audio level.
For example, when the number of the trunk ODT 34 has changed. That is, normally, impedance matching is performed by interposing a coupling trunk or the like between one amplifier 33 and a predetermined number of trunk ODTs 34. In this impedance matching, the number of trunk ODTs 34 is usually predetermined. When it was configured to
If you change the number, depending on the number, the trunk ODT
This is when the combined impedance of the whole 34 becomes different and the difference becomes such a value as to hinder the intended purpose.

Therefore, if it is desired to change the number, the coupling trunk is replaced with one that fits the above number, or a number that allows for the change is set and the trunk ODT 34 is changed to that number.
It is necessary to take measures such as connecting a dummy resistor capable of impedance matching in parallel with the trunk ODT 34 to achieve impedance matching when the number of the impedances has not reached.

The present invention has been made in view of the above technical problems, and an audio signal distribution system capable of distributing an audio signal of the same audio level to a receiving device regardless of the number of receptions and fluctuations in the number of receptions. The purpose is to provide.

[Means for solving problems]

 FIG. 1 shows the basic circuit system of the present invention.

In this figure, 1 is a transmission / reception device such as a command device, and 2 is 2
It is a hybrid circuit that performs line-to-line conversion. The hybrid circuit 2 connects the 2-wire transmission / reception circuit 3 of the transmission / reception device 1 to the 4-wire transmission / reception path 4. It is connected to the 4-wire transmission / reception path 4. Downlink 5 of the 4-wire transmission / reception path 4
Is connected to a single input of an electrical matching means 6 for impedance matching and level matching with the transmitting / receiving device 1 (first device) side.

Then, impedance matching and level matching branching means (electrical matching branching means) 8 for connecting the trunk ODT 10 corresponding to a single output of the electrical matching means 6 is connected and, if necessary, electrical A single input is connected to the output of the physical matching means 6, and the required number of lossless compensating means 9 having outputs that want to output the same input level are cascaded.

A single input of one electrically matching branching means 8 is connected to a connection point between a single input and output of the lossless compensating means 9. The single output of the electrical matching branching means 8 is connected to the network NW of the exchange via the trunk ODT 10 and to the plurality of transceivers 7 via the line 11.

Further, as shown in FIG. 1, the same means as the down line 5 is provided to the up line 13 to the hybrid circuit 1 as shown in FIG. Corresponding components are indicated by reference numbers with a dash.

[Operation] The electrical matching means 6 is provided in the downlink 5 of the 4-wire transmission / reception path 4 of the transmission / reception device 1. As a result, impedance matching with the 4-wire transmission / reception path 4 is obtained, and the signal levels are matched. An electrical matching branching means 8 for connecting a single output of the electrical matching means 6 to the trunk ODT 10 is connected. As a result, impedance matching is obtained between the single output of the electrical matching means 6 and the input of the trunk ODT 10, and the signal levels are matched. Also, if necessary, the upstream line 14 is also connected with similar components 8 ', 9', 6 '.

Then, as many loss-free compensating means 9 as necessary are provided.
Are directly cascaded to the electrical matching means 6, and the electrical matching branching means 8 is connected to the connection point between the single input and output of each lossless compensating means 9. The lossless compensating means 9 outputs a signal having the same level as the input signal. Then, the electrical matching branching means 8 causes a trunk OD corresponding to the output.
Impedance matching between the input of T10 and the signal level is adjusted.

Therefore, the audio signal of the transmitter / receiver 2 is distributed to each of the plurality of transmitter / receivers 7 at the same audio signal level.

In addition, the ODT 10 is formed by cascading the electric matching unit 6 and the required number of lossless compensating units 9 as a unit.
Can be easily accommodated.

〔Example〕

FIG. 2 shows an embodiment of the present invention. In this example,
The electrical matching means 6 of FIG. 1 comprises a trunk 20 and a buffer amplifier 21. The trunk 20 connected to the downlink 5 shown in FIG. 1 has a one-to-one configuration of primary windings and secondary windings as in the conventional case. The buffer amplifier 21 includes a resistor 32 and a lossless amplifier 33. The resistor 32 is an impedance matching resistor having a resistance value of 600Ω. Resistance 32 600Ω
Is selected because the characteristic impedance of the line system of the exchange is 600Ω.

The trunk 20 and the buffer amplifier 21 perform impedance matching and signal level matching with the transmission / reception device side such as a command device.

The electrically matching branching means 8 in FIG. 1 is composed of an amplifier 22 and a trunk 23. The amplifier 22 is composed of a lossless amplifier 34 and a resistor 35, and the lossless amplifier 34
Generates from the output a signal having the same signal level as the signal level of the input signal. The resistor 35 is a resistor for impedance matching, and its resistance value is 600Ω as described above.
Is.

The amplifier 22 and the trunk 23 are connected to the electrical matching means 6 and the lossless compensating means 9 or the connecting point between the input and output of the lossless compensating means 9 and the trunk ODT 10 (see FIG. 1).
The impedance is matched with the input of and the signal level is adjusted.

The lossless compensating means 9 shown in FIG. 1 is composed of an amplifier 24 and generates the same signal level as the signal level of the input signal supplied to its input as an output signal.

The components provided in the upstream line 13 are similarly configured,
Corresponding components are referenced by reference numbers with a tash.

With such a configuration, when performing broadcast communication from one 2-wire type transmitting / receiving circuit 3 to a plurality of transmitting / receiving devices 7 (see FIG. 1), the electrical matching means 6 performs impedance matching at 600Ω. While being taken, the audio signal output with the signal level adjusted is supplied to the electrical matching branching means 8 directly or through one or more lossless compensating means 9 and the electrical matching branching means. In 8 as well, the signal level is adjusted while being impedance-matched at 600Ω and output to the trunk ODT 7 (see FIG. 1). Therefore, the two-wire type transceiver circuit 3
The voice signal broadcast from the plurality of transmitting / receiving devices 7 is subjected to signal level matching while impedance matching is performed at 600Ω in any of the reporting lines. Therefore, an audio signal of the same audio level is supplied to each transmitting / receiving device.

The effect is that even if the number of transmitting / receiving devices 7 connected via the exchange network changes, the amplifiers 24 and the amplifiers 22 and the trunks 23 are simply added in accordance with the number.
Alternatively, since it may be separated, it is possible to easily cope with a change in the number of transmitting / receiving devices 7. The addition or disconnection does not affect the circuit system at all.

Also, regarding the up line 13, the down line 5 as described above.
The notification voice signal from the plurality of transmitting / receiving devices 7 to the two-wire type transmitting / receiving circuit 3 can be transmitted with the same voice level. This effect can be enjoyed without depending on the number of transmitting / receiving devices 7. It is possible to easily cope with a change in the number of the transmitting / receiving devices 7.

〔The invention's effect〕

As described above, according to the present invention, the number of transmission / reception devices that are built into the system and are simultaneously connected in connection with one transmission / reception device such as a command device and a plurality of transmission / reception devices such as commanded devices. Even if there is a change in the audio signal, the audio signal is distributed to each transmitting / receiving device at the same audio level, and it is possible to easily deal with the case where the number of devices receiving the simultaneous command etc. incorporated in the system is changed. Signal transmission from the sender to the sender can be guaranteed as well. Further, as shown in FIG. 1, for example, multiple connections with impedance matching can be easily performed by simply connecting three lines as one block (circuit) in cascade.

[Brief description of drawings]

FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a diagram showing a main part configuration of an embodiment of the present invention, and FIG. 3 is a diagram showing a conventional example.
In FIG. 1 and FIG. 2, 1 is a transmitter / receiver on the transmitting side, 4 is a transmission / reception line, 5 is a down line, 6, 6 ′, 8,
8'is an electrical matching means, 9, 9'is a lossless compensating branching means, 10 and 10 'is an ODT, 11 is a line circuit, 7 is a transmitter / receiver on the receiving side, and 13 is an uplink.

Claims (2)

[Claims] 1. A first device and a plurality of trunks of an exchange,
A system for transmitting an audio signal to and from a plurality of second devices via a network, comprising: a single input and an output; connecting the single input to an output of the first device; An electrical matching means 6 for matching the impedance matching and the signal level with, and a direct cascade connection to a single output of the electrical matching means 6,
A required number of lossless compensating means 9 having a single output for outputting an output signal at the same level as the input level, and a first lossless compensating means 9 cascade-connected to the single output of the electrical matching means 6. Of the lossless compensating means 9, and the impedance matching between the output of the last lossless compensating means 9 and the corresponding trunk of the exchange. And an electrical matching branching means 8 for adjusting the signal levels. 2. A first device and a plurality of trunks of an exchange,
A system for transmitting an audio signal to and from a plurality of second devices via a network, comprising: a single input and an output; connecting the single output to an input of the first device; And an electrical matching means 6'for matching the impedance level with the signal level and a single input of the electrical matching means 6'is directly connected in series and outputs an output signal at the same level as the input level. A required number of lossless compensating means 9'having outputs, connection points between a single input of said electrical matching means 6'and a single output of the last cascaded lossless compensating means 9 ', each Electrical connection to match the impedance and signal level between the single input and output of the lossless compensating means 9'and between the input of the first lossless compensating means 9'and the corresponding trunk of the exchange. That the synthesizing means 8'is provided. Audio signal synthesis method in which the butterflies.