JPH0870365A - Private branch exchange - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a private branch exchange that can effectively use a high-voltage power supply, can reduce the power supply capacity, and therefore generate less heat and can be downsized. [Composition] A private branch exchange having a plurality of subscriber circuits for interfacing with an analog extension terminal and sending a high voltage signal as a call signal to the analog extension terminal when calling the analog extension terminal The power supply HVSa for signal generation has multiple types of timing phases so that the timings do not overlap, and when there are multiple analog extension terminals that call at the same time, the analog extension terminal that is the target of the call The control means 18 for sequentially allocating the above-mentioned timing phases and supplying the high-voltage signal from the power supply for generating the high-voltage signal to the analog extension terminal making the call at the timing of the allocated phase.
Configure with a and.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a plurality of subscriber circuits for interfacing with an analog extension terminal and sends a call signal to the analog extension terminal when the analog extension terminal is called. It relates to a private branch exchange (PBX).

[0002]

2. Description of the Related Art A digital exchange is controlled by software using a CPU (processor) at the center of control.
It has evolved into a highly intelligent system with various functions added in addition to the original circuit switching connection function. A private branch exchange to which a digital exchange is applied is generally a subscriber circuit that is an interface for an extension for connecting a telephone or the like, a time division switch that connects the subscriber circuits to each other, and a station line that is an interface that connects the office lines. It is composed of a trunk circuit and a control circuit for controlling these to realize various functions as an exchange such as circuit switching.

This digital exchange digitizes a call signal (voice signal, etc.) from a subscriber circuit and a call signal (voice signal, etc.) from a station trunk circuit, and digitizes the digitized PCM (Pulse Code Modulation: pulse signal). The signal is code-modulated and distributed by a time-division switch so as to correspond to the other party of the call, converted into an analog signal again, and then sent to the other party's line so that the call can be exchanged and used for the call.

That is, in the digital exchange, the exchange operation by the time division switch is performed using the time slot determined with the connected party, so that the call signal is transmitted in the time slot corresponding to the subscriber circuit or the trunk circuit of the called party. You can talk by inserting and removing (voice signal etc.).

FIG. 6 shows an example of an exchange system using a digital exchange. In the figure, 10 is a digital exchange, 11 and 12 are extension telephones accommodated in the digital exchange 10, and 13 and 14 are subscriber circuits provided in the digital exchange 10.

The subscriber circuits 13 and 14 convert a voice (analog) signal from the telephone into a PCM signal and, at the same time, send it through the time divisional switch 15 to P.
It has a function of converting a CM signal into a voice (analog) signal.

The time divisional switch 15 connects a plurality of subscriber circuits to form a PCM communication path. A trunk circuit 16 serves as an interface between the office line and the time divisional switch 15. Reference numeral 17 denotes a station line connection terminal, and the station line is connected to the station line trunk circuit 16 via the station line connection terminal 17. A control circuit 18 controls the operations of the subscriber circuits 13 and 14, the time division switch 15 and the office line trunk circuit 16.

FIG. 7 schematically shows the construction of the subscriber circuits 13 and 14. In the figure, 71 is a hybrid transformer, and this hybrid transformer 71
Converts the communication path to 2 lines / 4 lines. This 2 lines / 4
Two windings L1 and L2 are wound around one side of the hybrid transformer 71 that performs line conversion, and a winding L3 with an intermediate tap TP is wound around the other side.
Then, the two windings of L1 and L2 are converted into 2 wire / 4 wire conversion
It is used as the wire conversion side, and the winding L3 is used as the 4-wire conversion side.

One end of the winding L3 on the 4-wire conversion side is grounded via the matching load circuit 72a, and
It is connected to an analog / digital (A / D) converter 74 of a CODEC via a low pass filter 73. The other end of the 4-wire conversion side winding L3 is connected to a digital / analog (D / A) converter 76 of a CODEC via a series circuit of a matching load circuit 72b and a low pass filter 75. ing.

The intermediate tap TP of the winding L3 on the 4-wire conversion side of the hybrid transformer 71 is a load circuit 7 for matching.
It is grounded via 2c. The low-pass filters 73 and 75 are for removing high frequency components of the audio signal.

The A / D converter 74 is for converting a voice (analog) signal into a PCM signal and sending it to the time division switch 15, and the D / A converter 76 is sent from the time division switch 15. The PCM signal is converted into a voice (analog) signal and sent to the hybrid transformer 71 side.

Reference numerals 77 and 78 are telephone connection terminals, and 79 and 80 are time-division switch connection terminals. One end side of the two-wire conversion side winding L1 of the hybrid transformer 71 is connected to the telephone connection terminal 78, and one end side of the two-wire conversion side winding L2 of the hybrid transformer 71 is connected to the telephone connection terminal 78. . The output side of the A / D converter 74 is connected to the connection terminal 79 for the time division switch, and the input side of the D / A converter 76 is connected to the connection terminal 80 for the time division switch.

Reference numeral 81 is a constant voltage source, which is connected to the other end side of the winding L1 and the other end side of L2 of the hybrid transformer 71, respectively, and supplies electric power to the telephone sets 11 and 12.

Next, the concept of operation in the conventional apparatus having such a configuration will be described below. Now, for example, it is assumed that the user of the extension telephone set 11 takes the telephone set 11 off hook to make a call. Then, on the side of the private branch exchange 10, a signal indicating that the telephone 11 is off-hook is sent from the subscriber circuit 13 to which the telephone 11 is connected to the control circuit 18 in the private branch exchange 10. Control circuit 18
Receives the off-hook signal, the time division switch 15
To connect the time division switch 15 to the subscriber circuit 13.

Here, the operator of the telephone 11 is the telephone 1
It is assumed that the dial key 1 is operated to dial the telephone number (extension number) assigned to the telephone 12. Then, the dial signal is sent to the control circuit 18. Receiving this, the control circuit 18 recognizes the telephone number from the dial signal and sends a calling signal to the corresponding subscriber circuit 14.

The call signal causes the telephone 12 to ring to notify of the incoming call. Then, when the telephone 12 responds (off-hook), the subscriber circuit 14 notifies the control circuit 18 of the incoming response, whereby the control circuit 18 knows the incoming response and sends a command to the time division switch to perform time division. The subscriber circuit 13 and the subscriber circuit 14 are connected via the switch 15 to secure a communication path. Then, the telephones 11 and 12 can communicate with each other.

By the way, in this way, the subscriber circuit 1
When a PCM communication path is formed by the time division switch 15 between the subscriber circuit 13 and the subscriber circuit 14, the voice signal transmitted from the telephone 11 is passed through the hybrid transformer 71 of the subscriber circuit 13 to the low-pass filter 73. Then, the low-pass filter 73 removes high-frequency components in the signal.

That is, the voice signal from the transmitter (microphone) of the telephone 11 is the hybrid transformer 71.
Is sent from the 2-wire side to the 4-wire side, reaches the low-pass filter 73 from the winding L3 on the 4-wire side, and the low-pass filter 73 removes high-frequency components in the signal.

The audio signal from which the high-frequency component has been removed by the low-pass filter 73 is further sent to the A / D converter 74, where it is converted into a PCM signal and sent to the time divisional switch 15 via the terminal 79. The time division switch 15 sends the sent PCM signal to the subscriber circuit 14 through the PCM communication path.

The PCM signal thus sent to the subscriber circuit 14 enters the D / A converter 76 from the terminal 80 in the subscriber circuit 14 and is reconverted into an analog signal from the PCM signal. Further, the re-converted analog signal is waveform-shaped by the low-pass filter 75 in the subscriber circuit 14, and is input to the 4-wire conversion side in the hybrid transformer 71 in the subscriber circuit 14. Then, it is output from the two-line conversion side of the hybrid transformer 71 and is output as voice from the receiver (speaker) of the telephone 12.

The voice signal of the subscriber using the telephone 12 is also output from the telephone 11 through the same process, and the telephone conversation between the telephone 11 and the telephone 12 becomes possible. When the telephone 11 (or telephone 12) is operated on-hook after the call ends, a signal indicating that the telephone is on-hook is sent from the subscriber circuit 13 (or subscriber circuit 14) to the control circuit 18
Sent to As a result, the control circuit 18 sends a disconnection command to the time divisional switch 15 upon knowing the end of the call. Then, by receiving this command, the time divisional switch 15 disconnects the speech path formed between itself and the subscriber circuit 13 and the subscriber circuit 14. In this way, the speech path formed between the subscriber circuit 13 and the subscriber circuit 14 is disconnected.

The above is the control in the communication between extension lines. Next, a call from an extension line to an outside line (station line) will be described. For example, it is assumed that the operator of the telephone 11 goes off-hook to make a call to the telephone 11, and further operates the dial key of the telephone 11 to dial the telephone number assigned to the outside line.

Then, the dial signal is transmitted to the control circuit 18
The control circuit 18 which has been sent to the telephone recognizes that the dial signal is an external line transmission, and the vacant trunk circuit 1
Find 6. When an empty trunk circuit is found, the time divisional switch 15 is controlled so as to secure a communication path between the trunk circuit 16 and the subscriber circuit 14 to which the telephone 11 is connected.

The dial tone is sent to the subscriber circuit 14
Send it to the side and inform that it is ready to dial. After the operator of the telephone 11 listens to this signal and operates the dial key of the telephone 11 to dial the subscriber number of the outside line, this dial signal is transmitted to the trunk circuit 1
It is sent to the central line via 6. Then, this is received by the central office side, a ringing signal is sent to the other party's office line of the subscriber number, and the incoming call is notified to the other party's telephone.

When the other party responds (off-hook) to this incoming call, the local exchange side secures a communication path with the trunk circuit 16 of the private branch exchange 10 and enables a communication. Then, this enables a telephone call between the telephone 11 and the outside party.

When either the telephone 11 or the other party on the outside line goes on-hook, the call is terminated, whereby the control circuit 1
8 sends a command to the time-division switch 15, and the time-division switch 15 and the subscriber circuit 13 and the outside line partner (trunk circuit 16)
The call path formed between and is disconnected.

In addition, in response to an incoming call from an external line, the control circuit 18 on the private branch exchange 10 side detects this via the trunk circuit 16 to which the external line (station line) is connected. Responds to the incoming call from the outside line by sending a ringing signal to the connection subscriber circuit of the predetermined extension called destination and ringing the bell of the extension telephone connected to the subscriber circuit.

With this ringing, when the telephone responds, the control circuit 18 sends a command to the time divisional switch 15 to secure a communication path between the subscriber circuit and the connection trunk circuit of the incoming external line and to make a call. To

When either the telephone of the extension or the other party of the outside that was in the call state goes on hook, the call ends.
As a result, the control circuit 18 sends a command to the time divisional switch 15, and the time divisional switch 15 disconnects the communication path formed between the subscriber circuit 13 and the subscriber circuit 14.

In this way, the private branch exchange is
Exchange connections are made between internal and external lines and between external lines and internal lines to enable communication. By the way, in the telephone network, various signals are used to notify the status. Considering a call signal for notifying an incoming call, a call signal transmitting mechanism conventionally used in a subscriber circuit (line circuit) of a private branch exchange or the like. As a result, the following configuration was adopted.

For example, the calling signal generating circuit is provided for each subscriber circuit provided for each line (extension). This is as shown in FIG. 8, and for each subscriber circuit 20-1, 20-2 ..., 20-n provided for each line (extension),
This is a configuration in which a call signal generation circuit is provided. Generally, the subscriber circuit and the ringing signal generating circuit have a unit configuration in which a plurality of lines are assembled as a unit on an interface board, and a common power source or the like is shared.

The one shown in FIG. 8 has such a common structure that each of the subscriber circuits 20-1 to 20-n is connected.
Is a circuit with BORSCHT function. Where BORSCHT
Function is an abbreviation for the following function.

That is, "B" is "Battery f
"eed (call current supply function)" is a function for supplying a current for communication to the telephone. "O" is "Ov".
"voltage protection function" is a function to protect internal electronic circuits from overvoltage such as external lightning surge. "S" is "Super".
"vision (monitoring function)", on-hook /
This function monitors calling / restoration by off-hook, dial pulse, hooking, etc. "R" means "R
"inging (calling signal sending function)" is a function of supplying an AC voltage for ringing a bell of a telephone.
“C” is “Coder / Decoder”, which is a function of encoding an analog voice signal of a telephone in PCM and vice versa. "H" means "Hybrid (2 lines
4 wire conversion function) ", which is a function of converting a 2-wire communication path of a telephone into a 4-wire communication path of a time division switch system. And" T "is" Test (test function) ". This is a function that separates the telephone side and the line side from each other and pulls them into the test circuit so that the test can be performed.

Further, in FIG. 8, HVS is a common high voltage signal source for the calling signal, and this high voltage signal source H
The VS is a power supply having a voltage of about 90 [V] AC and +48 [V] DC superimposed, and is used for ringing a bell of a terminal.

RT1 is a ring trip circuit for detecting the off-hook of the terminal in the high voltage signal transmission width, and when the off-hook is detected during the high voltage signal transmission, the trip detection signal is sent to the switch opening / closing control circuit (not shown). No.) and the control circuit 18.

Further, in FIG. 8, reference numerals 21-1 and 22-1 are connection terminals of terminals, respectively. This connection terminal 21-
1, 22-1 are switches rg1-1 and rg1-2.
Is connected to the subscriber circuit 20-1 via the
0-1 is further connected to the communication path highway 24 of the time division switch 15. The connection terminal 21-1 is a switch rg.
It is connected to the high voltage signal source HVS via 1-3.
The connection terminal 22-1 is connected to the ring trip circuit RT1 via the switches rg1-4.

Here, the switches rg1-1 and rg1
Reference numeral -2 is a switch that is turned off while the call signal is on, and switches rg1-3 and rg1-4 are switches that are turned on while the call signal is on.

The above is the configuration for one line, and a similar configuration is provided for n lines. In such a configuration, the operation at the time of incoming call will be described by taking the line connected to the subscriber circuit 20-1 as an example. Subscriber circuit 20
-1 and the connection terminals 21-1, 22-1, the switches rg1-1, rg1-2 are normally turned on, and the extension call signal from the private branch exchange 10 or the call signal from the station. While receiving, these switches rg1-1, r
g1-2 is off, and a switch r for supplying a high voltage signal from the high voltage signal source HVS to the subscriber circuit 20-1.
g1-3 and rg1-4 are turned on.

On the terminal side connected to the connection terminals 21-1 and 22-1, the high voltage signal source HVS is supplied while receiving the call signal.
By receiving the high voltage from the terminal, the bell rings at the terminal and the incoming call is notified. When the operator of the terminal which has received the incoming call off-hooks the terminal, a direct current flows into the line, which is applied to the ring trip circuit RT1 via the switches rg1-4 and the ring trip circuit R.
T1 works.

When the ring trip circuit RT1 operates, the switches rg1-3 are turned off and the high voltage from the high voltage signal source HVS supplied to the line is turned off. Further, the operation of the ring trip circuit RT1 brings the line into a DC loop state, and the monitoring function in the subscriber circuit 20-1 detects an off-hook by this DC loop and notifies the private branch exchange 10 side of the response. As a result, control is performed by the control circuit 18 of the private branch exchange 10 so as to enable a call.

The above is the outline of the operation of the interface board having the subscriber circuit and the call signal generation circuit. Here, the transmission timing of the calling signal to each line will be described. That is, the call signal transmission timing for each line is as shown in FIG. 9, for example. In the figure, IR
And SIR are transmission timings of the calling signal using the high voltage signal source HVS.

IR is the transmission timing of the call signal of the station, and is the transmission timing of the incoming call signal from the station,
This is a configuration in which the terminal rings when "on for 1 second" and "off for 2 seconds". Further, SIR is the transmission timing of the extension call signal to the accommodation extension in the private branch exchange,
"ON for 0.25 seconds", "OFF for 0.25 seconds", "0.
The terminal is made to ring at a 3-second cycle of "on for 25 seconds" and "off for 2.25 seconds".

Thus, the call from the outside line or the extension line is IR
Alternatively, they are distinguished by the SIR transmission timing. As described above, in the subscriber interface, the ringing signal control is performed for each line, and the ringing signal IR or SI is used.
The ring trip circuit RT for each line detects the off-hook state of each subscriber circuit connection terminal while the R high voltage signal is being transmitted.
1, RT2, ... RTn.

Ring trip circuits RT1, RT2, ... R
Tn has a structure as shown in FIG. 10, for example.
That is, when the bell ringing is performed by the high voltage signal supplied from the high voltage signal source HVS by the ringing signal, from the terminal connected to the connection terminals 22 (22-1, 22-2 ..., 22-n). The inflowing current IR is passed through the ringing signal current limiting resistor 91 and the ring trip detecting resistor 92,
As a result, the fluctuation of the current IR in the off-hook state during the transmission of the ringing signal is converted into a voltage by the ring trip detection resistor 92.

The ring trip detection resistor 9
The voltage obtained at 2 is amplified by the amplifier 93 and then given to the inverting side input terminal of the comparator 94. To the non-inverting input terminal of the comparator 94, a reference voltage setting circuit composed of a resistor 95 and a resistor 96 that are connected in series to divide the 5V DC power source is connected, and the resistor 95 and the resistor 96 are connected to each other. The ring trip detection voltage of the reference voltage setting circuit that supplies the ring trip detection voltage with the voltage divided by is supplied.

Therefore, the comparator 94 compares the ring trip detection voltage set by the reference voltage setting circuit with the output of the amplifier 93 and generates an output when the output of the amplifier 93 exceeds the reference value of the ring trip detection voltage. . This output is output through the buffer circuit 97 to the output terminal 23 (23-1, 23
-2 ..., 23-n) is output to the control circuit 18 as a trip detection signal.

The ring trip circuit is connected to the connection terminal 22 (22) when the ringing of the bell is performed by the high voltage signal supplied from the high voltage signal source HVS by the ringing signal.
-1, 22-2 ..., 22-n) causes a current flowing from a terminal connected to the ringing signal current limiting resistor 91 and the ring trip detecting resistor 92 to thereby reduce the off-hook current during ringing signal transmission. The fluctuation is converted into a voltage by the ring trip detection resistor 92, amplified by an amplifier 93, then compared in level by a comparator 94, and when a predetermined level is exceeded, it is output as a ring trip detection voltage corresponding to the line. The configuration is such that it is provided to the control circuit 18.

However, in the case of the configuration of this conventional example,
The call signal is sent out at the same timing for all lines. That is, the ringing signal is transmitted at the same timing on all the lines. Then, sending the ringing signal to each line at the same timing causes intensive power consumption, and therefore, the high-voltage signal source requires a large current capacity at the peak of its output, which increases space and cost. There is a problem.

As a countermeasure against this, the call signal transmission timing may be divided into phases so as to eliminate the concentration of power consumption. By distributing this power consumption, it is possible to reduce the current capacity scale of the high-voltage signal source and solve the problem of space and cost.

[0050]

By the way, in the private branch exchange, a circuit interface board for a dedicated line, a digital extension interface, an ISDN interface board, etc. can be accommodated in addition to the line / trunk circuit configured as described above. , We are able to provide various services.

For example, in a private branch exchange capable of accommodating about 400 extension lines, various interface boards have a maximum of two.
If the structure is such that four boards can be accommodated, not all the twenty-four interface boards that are accommodated are analog extension (subscriber circuit) interface boards, but a local line interface board, a digital extension interface board,
And various interface boards such as the ISDN interface board are accommodated according to the service scale of the user.

Also, for example, the maximum number of interface boards is 2.
In a private branch exchange capable of accommodating four boards, if the accommodation position for each type of interface board is not specified and various interface boards can be accommodated arbitrarily, an analog extension interface that requires a high-voltage signal source is required in which slot. In this case, if the call signal is phase-divided for each slot and the call signal is transmitted, the control is most easily performed.

However, in recent years, in the private branch exchange in the enterprise, the function of multimedia services such as the digital extension interface board and the interface board for ISDN is progressing, and the tendency to use these interface boards is increasing, while the analog service is increasing. The usage rate of extension interfaces is decreasing.

Therefore, even if the call signal is sent out by phase-dividing the call signal for each slot or line, it is not possible to use an analog extension interface board with a built-in high voltage signal source. Considering the fact that the demand for the extension interface board is lower than that of other interface boards, the following problems remain.

That is, the high voltage signal source has a high voltage power source and is a large heat source. Since there are a plurality of lines accommodated in one analog extension interface board, even if the method of transmitting the ringing signal by phase-dividing each slot or line is adopted, the ringing signal is in-phase. Is transmitted to some extent. If the calling signal from the high-voltage signal source has no probability that the calling signal is transmitted in the same phase, the high-voltage power source must have a current capacity equivalent to that, so the amount of heat generation also increases. .

Conventionally, although a method has been adopted in which all the call signals are not overlapped at the same time by transmitting the call signals by phase division, but it is not evenly distributed. In consideration of the maximum number of lines in which the timing of sending a calling signal may overlap at the same time, a high voltage power supply with a capacity added to this has been prepared.

However, the call signal is about 15% of the whole line from the call volume (about 60 lines in the case of the structure of about 400 lines).
It is necessary to provide a high-voltage power supply with a power supply capacity that can send the power. Further, the power supply capacity required to cover the ringing signal for about 60 lines is quite large, and therefore there is a problem that it hinders downsizing of the device and reduction of the device cost.

Further, since the heat generated from the high voltage power source is not small, the heat generation amount of the high voltage power source having a power source capacity necessary to cover a ringing signal for about 60 lines becomes considerably large, and moreover, the private branch exchange. Since it is housed and used in the inside, there is a problem that heat causes deterioration of electronic components constituting the private branch exchange, which leads to deterioration in quality.

The present invention has been made in consideration of such circumstances, and an object of the present invention is to make it possible to effectively use a high-voltage power supply and to significantly reduce the capacity of the high-voltage power supply. Therefore, it is an object of the present invention to provide a private branch exchange which generates little heat, can prevent deterioration of electronic components constituting the private branch exchange, and can significantly improve the space factor.

[0060]

In order to achieve the above object, the present invention has a plurality of subscriber circuits for interfacing with an analog extension terminal, and when calling the analog extension terminal, the corresponding analog extension terminal is used. In a private branch exchange that sends a high voltage signal to a terminal as a ringing signal, an analog extension terminal that has multiple types of timing phases so that the timings do not overlap with the power supply for generating the high voltage signal, and that calls at the same time When there are a plurality of calls, the timing phases are sequentially assigned to the analog extension terminal to be called, and at the timing of the assigned phase, the high-voltage signal generating power supply is turned on to the analog extension terminal to be called. And a control means for controlling to supply a voltage signal.

[0061]

In the private branch exchange thus constructed, the control means is provided with a timing control function by a plurality of types of timing phases so that the timings do not overlap each other.
When there are a plurality of analog extension terminals calling at the same time, the control means sequentially allocates the timing phases to the analog extension terminals to be called, and generates the high voltage signal at the timing of the allocated phase. The power supply for use is controlled to supply a high voltage signal to the analog extension terminal making the call.

In this way, the transmission timing by phase division of the ringing signal is controlled, and when there are a plurality of analog extension terminals making a call at the same time, the timing phase is set to the analog extension terminal to be called. Allocate in order,
As a result of controlling to supply a high voltage signal from the power supply for generating the high voltage signal to the analog extension terminal making the call at the timing of the allocated phase, the number of in-phase outputs of the call signal is evenly distributed, and the high voltage signal is output. The power supply capacity for supply can be reduced. Moreover, since the number of in-phase outputs of the ringing signal is evenly distributed, the power supply can be used with a uniform utilization rate and minimized.

In particular, by taking such a means, even if the ringing signal is conventionally phase-divided, the ringing signal is about 15% of the entire line from the call volume (about 60 lines in the configuration of about 400 lines). ) Is required, but by performing the above-mentioned control for reducing the phase division of the ringing signal and the in-phase output (for example, when three phase divisions are performed, Ringing signal is about 5% of the whole line (about 20 lines in the case of about 400 lines)
Is possible with a high-voltage power supply having a power supply capacity to send out, and can suppress the amount of heat generation to promote miniaturization of the device, and by suppressing the amount of heat generation, deterioration due to heat of the exchange housing parts can be suppressed, and It is possible to reduce the device cost due to the downsizing of the device.

[0064]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same components as those of the conventional technique will be described with the same reference numerals. FIG. 1 is a block diagram showing an example of an exchange system using a private branch exchange according to the present invention. In the figure, 10a is a digital exchange as a private branch exchange, 11 and 12 are telephones accommodated in the digital exchange 10a, 13a and 14a are subscriber circuits provided in the digital exchange 10a, and an HV.
Sa is a common high voltage power supply for supplying the ringing signal to the subscriber circuits 13a and 14a.

The subscriber circuits 13a and 14a convert a voice (analog) signal from the telephone into a PCM signal, and at the same time, convert a PCM signal sent through the time division switch 15a into a voice (analog) signal. It has the function of.

The time divisional switch 15a connects a plurality of subscriber circuits to form a PCM communication path. A trunk circuit 16a serves as an interface between the office line and the time divisional switch 15a. Reference numeral 17a denotes a station line connection terminal, and the station line is connected to the station line trunk circuit 16a via the station line connection terminal 17a. A control circuit 18a controls the operations of the subscriber circuits 13a and 14a, the time divisional switch 15a and the office line trunk circuit 16a.

FIG. 2 shows the digital exchange 10a of this embodiment.
3 is a circuit diagram showing a specific configuration of a call sending mechanism in FIG. Note that, here, description will be made assuming that 384 lines from L1 to L384 are accommodated as extension lines.

First, each of the call signaling mechanisms has 16
Blocks are divided into 24 units UN1 to UN24 accommodating lines, and these 24 units UN1
A line-related mechanism corresponding to each of UN 24 is provided. A high voltage power supply HVSa is provided in addition to the units UN1 to UN24.

The unit UN1 is provided with components for 16 lines. That is, 16 subscriber circuits 20-1, 20-2, to 20-16, 16 connection terminals 21-1 to 21-16, 16 connection terminals 22-1,
22-2 to 22-16, 16 switch opening / closing control circuits 25-1, 25-2 to 25-16, 16 terminals 2
6-1, 26-2, to 26-16, 16 terminals 27-
1, 27-2 to 27-16, 16 switches rg1
-1, rg2-1, to rg16-1, 16 switches rg1-2, rg2-2 to rg16-2, 16 switches rg1-3, rg2-3 to rg16-3, 16
Number of switches rg1-4, rg2-4, ~ rg16-
4, 16 ring trip circuits RT1 to RT16 are provided.

Each of the subscriber circuits 20-1 to 20-16 is a circuit having a BORSCHT function and executes an interface operation with a terminal. Connection terminal 21
Reference numerals -1, 22-1 are terminals for connecting a terminal to the line L1, and the connection terminal 21-1 is connected to the subscriber circuit 20-1 via the switch rg1-1, and the connection terminal 22-.
1 is connected to the subscriber circuit 20-1 via the switch rg1-2. Then, the subscriber circuit 20-1 is further connected to the communication path highway 24 of the time divisional switch 15a.

The connection terminal 21-1 has a switch rg.
It is connected to the high voltage signal source HVSa via 1-3. The connection terminal 22-1 is connected to the switches rg1-4.
Is connected to the ring trip circuit RT1 via.

The connection terminals 21-16 and 22-16 are connected to the line L.
16 is for connecting a terminal, and a connection terminal 21
-16 is a subscriber circuit 20 via the switch rg16-1
-16, the connection terminal 22-16 is a switch rg.
It is connected to the subscriber circuit body 20-16 via 16-2. The subscriber circuit 20-16 is further connected to the communication path highway 24 of the time divisional switch 15a.

The connection terminal 21-16 is connected to the switch r.
It is connected to the high voltage signal source HVSa via g1-3. The connection terminal 22-16 is connected to the switch rg16.
-4 is connected to the ring trip circuit RT16.

Connection end pieces 21-2 to 21-15, 22-2
22 to 15 are terminals for connecting to the terminals of the lines L2 to L15, and have the same connection configuration as the above. Each of the ring trip circuits RT1 to RT16 is a circuit for detecting an off-hook in the high voltage signal, and is a circuit which outputs a trip detection signal when the off-hook in the transmission of the high voltage is detected. The circuit has the same configuration as that of. 23 is this ring trip circuit RT
1 to RT16 output terminals.

Here, the ring trip circuits RT1, RT
2, ... Review RTn. The ring trip circuits RT1, RT2, ... RTn, as described with reference to FIG. 10 as an example, are connected to the connection terminal 22 (when the bell ringing is performed by the high voltage signal supplied from the high voltage signal source HVS by the ringing signal. 22-1, 22-2 ..., 22-n)
The current IR flowing from the terminal connected to the ring signal is passed through the ringing signal current limiting resistor 91 and the ring trip detecting resistor 92, so that the fluctuation of the current IR off-hook during the ringing signal transmission is detected by the ring trip detecting resistor 9
Turn to voltage at 2.

The ring trip detection resistor 9
The voltage obtained at 2 is amplified by the amplifier 93 and then given to the inverting side input terminal of the comparator 94. To the non-inverting input terminal of the comparator 94, a reference voltage setting circuit composed of a resistor 95 and a resistor 96 that are connected in series to divide the 5V DC power source is connected, and the resistor 95 and the resistor 96 are connected to each other. The ring trip detection voltage of the reference voltage setting circuit that supplies the ring trip detection voltage with the voltage divided by is supplied.

Therefore, the comparator 94 compares the ring trip detection voltage set by the reference voltage setting circuit with the output of the amplifier 93, and generates an output when the output of the amplifier 93 exceeds the reference value of the ring trip detection voltage. . This output is output through the buffer circuit 97 to the output terminal 23 (23-1, 23
-2 ..., 23-n) is output to the control circuit 18a as a trip detection signal.

In the present embodiment, the trip detection signal for each line is also given to the switch opening / closing control circuit for that line. That is, in the line L1, the switch opening / closing control circuit 25-1 in the line L1, the line L2 in the switch opening / closing control circuit 25-2 in the line L2, ... And in the line L16, the switch opening / closing in the line L16. Control circuit 2
It is 5-16.

Switches rg1-1, rg2-1, ... rg
16-1, rg1-2, rg2-2, to rg16-2
Is a switch that is turned off while the ringing signal is on. Switches rg1-3, rg2-3 to rg16-
3, rg1-4, rg2-4 to rg16-4 are switches that are turned on while the ringing signal is on.

Switch open / close control circuits 25-1 to 25-1
6 is from the control circuit 18a to the terminals 26-1 to 26-16.
27-1 to 27-16 and their corresponding ring trip signal circuits RT1 to RT1
The switches rg1-1, rg2-1, ...
g16-1, switches rg1-2, rg2-2, to rg
16-2, switches rg1-3, rg2-3, to rg1
6-3, switches rg1-4, rg2-4 to rg16
-4 is controlled to open and close.

That is, the switch opening / closing control circuit 25-1 includes the switches rg1-1, rg1-2, rg1-3, rg1.
-4 is controlled to open / close, and the switch open / close control circuit 25-2 controls the switches rg2-1, rg2-2, rg2-3, rg2-.
4 is controlled to open and close, ..., Similarly, the switch opening and closing control circuit 25
-16 is a switch rg16-1, rg16-2, r
That is, g16-3 and rg16-4 are controlled to be opened and closed.

On the other hand, each of the units UN2 to UN24 has the same structure as that of the unit UN1 and the lines L15 to L384 can be connected. The units UN2 to UN24 are also configured to be supplied with power from the above-described high-voltage power supply HVSa.

The above-mentioned high-voltage power supply HVSa is a common high-voltage signal source for calling signals, and the high-voltage power supply HVSa is used.
Is a power supply to the extent that a direct current of −48 [V] is superimposed on an alternating current of 90 [V] and is used for ringing the bell of a terminal.

In this system, when the control circuit 18a receives a call signal transmission instruction from an extension or a station, the control circuit 18a outputs the call signals to the destination line in three different phases so as not to overlap each other in timing. It is assigned to one and controlled to be performed at that timing. That is, the timing of sending the calling signal is time-sequentially divided into three time axes, and one is sequentially assigned to each of the lines to which the calling signal is to be sent at that time. , The number of lines to which a call signal is transmitted at the same timing is evenly distributed.

Further, in this system, the maximum number of lines from which call signals are transmitted at the same time is 15 in total.
The high voltage power supply HVS
Design the power capacity of a. In this example, since the number of lines in the analog system is 384, the capacity necessary to cover one-third of the 15% of the lines is set.

That is, in this system, the control circuit 18
By adopting a configuration in which a performs such control, it is possible to increase the power supply capacity necessary for sending a calling signal to one-third of the number of lines that are instructed to send a calling signal at the same time. The power supply capacity of the voltage power supply HVSa can be suppressed.

FIG. 3 shows a switch opening / closing control circuit 25 (25-
1 to 25-16) is a circuit diagram showing a detailed configuration. As shown in the figure, the switch opening / closing control circuit 25 includes a flip-flop FF, a driver DR, a photocoupler PC, and an exciting coil RG.

Of these, the flip-flop FF is
Control circuit 1 via terminals 26 (26-1 to 26-16)
The control signal supplied from 8a is input to the set terminal S, and the trip detection signals output from the ring trip circuits RT1 to RT16 are input to the reset terminal R, respectively.

The output of this flip-flop FF is input to the driver DR. When the flip-flop FF is in the set state, the driver DR grounds the cathode of the photodiode pd, which is a light emitting element in the photocoupler PC, and the photodiode p in the photocoupler PC.
The photodiode pd is energized by a DC power source of +5 [V] connected to the anode of d.

The photocoupler PC is composed of this photodiode pd which is a light emitting element and a phototransistor tr which is a light receiving element. The collector of the phototransistor tr is connected to one end of the exciting coil RG, and the emitter is grounded. ing. The other end of the exciting coil RG is +12
A DC power supply of [V] is connected.

Next, the operation of the exchange system configured as above will be described. Since the unit UN1 and the units UN2 to UN16 operate in the same manner, the operation of the unit UN1 will be mainly described here.

First, in the normal state and in the state where the call signal transmission instruction is not received, the control circuit 18a sets all the flip-flops FF of the switch opening / closing control circuits 25 (25-1 to 25-16) to the reset state. There is. Switch open / close control circuit 25 (25-1 to 25-1
In 6), when the flip-flop FF is in the reset state, the driver DR is inoperative and therefore the photodiode pd is not energized. Therefore, the photodiode pd does not emit light, the phototransistor tr is off, and the exciting coil RG is not energized.

Here, the switches rg1-1 to rg1-4 are the exciting coils RG of the switch opening / closing control circuit 28-1, and the switches rg2-1 to rg2-4 are the switch opening / closing control circuit 2.
8-2 Excitation coil RG ..., Switch rg16-1.
rg16-4 are respectively driven by the exciting coil RG of the switch opening / closing control circuit 28-16, and the switches rg1-1 to rg16-1, rg1-2 to rg1.
6-2 is a normally closed contact, and switches rg1-3 to rg16-
3, rg1-4 to rg16-4 are normally open contacts.

Thus, in the state where the call signal transmission instruction is not received, the switches rg1-1 to rg16-1, rg
1-2 to rg16-2 are in the ON state, the subscriber circuit 20-1 is connected to the line L1, the subscriber circuit 20-2 is connected to the line L2, and the subscriber circuit 20-16 is connected to the line L16. Has been done.

From this state, it is assumed that the control circuit 18a receives a call signal transmission instruction to any one of the lines (here, the line L1) from the extension or station. Then
The control circuit 18a gives a set signal to the switch opening / closing control circuit 25-1 via the terminal 26-1 in the time slot for the line L1.

In order to prevent the call signal transmission timings from overlapping in time, phase division is performed as shown in FIG.
Switch control is performed at this timing. That is, as shown in FIG. 4, the transmission timing of the calling signal is time-sequentially divided into three time axes, and one of them is assigned to each line. Then, the phase P1 and the phase P
Either 2 or phase P3 is assigned to each line.

In this embodiment, the total number of lines is 384. Therefore, consider the total number of lines to be 384. In this case, generally speaking, the maximum number of lines in which a ringing signal is transmitted at the same time from the call volume is 15% of the total.
This is about 15% of the 384 lines are 57.6.
Therefore, the maximum number of lines that call signals are transmitted at the same time is about 58 lines, and these 58 lines are the call signal transmission lines in this system.

In this system, when the control circuit 18a receives a call signal transmission instruction from an extension or a station, the control circuit 18a outputs the call signals to the destination line in three different phases so as not to overlap each other in timing. It is configured to be assigned to one and controlled to be performed at that timing. That is, the timing of sending the calling signal is time-sequentially divided into three time axes, and one is sequentially assigned to each of the lines to which the calling signal is to be sent at that time. , The number of lines to which a call signal is transmitted at the same timing is evenly distributed.

For example, as shown in FIG. In this example, a ringing signal is transmitted to a total of 58 lines from line L1 to line L58. In this case, line L1
.., L58 to phase P1, lines L2, L5, L8 ..., L56 to phase P2, and lines L3, L6. L9 ..., L57
Is assigned to the phase P3.

That is, when the call signal transmission request is issued to the control circuit 18a in this order from the line L1 to the line L58, the control circuit 18a has three phases P1 to P3.
Are assigned in descending order from the line L1 to the line L58 so that the calling signal transmission timing is any one of the phases P1 to P3, and the number of allocated lines for each phase is even in each phase. Assign to be distributed.

In this way, the lines L1 to L5
In the state that the ringing signal is sent to 58 lines up to 8,
If the line L1 stops sending the calling signal and then the line L59 requests the sending of the calling signal, in this case, the line L59.
Sends a call signal at the call sending timing of phase P1. That is, the line L58 transmits the ringing signal at the ringing timing of the phase P3, and the line L58 is followed by the line L5.
Since the order is 9, the call sending timing of the phase P1 is allocated, so that the line L59 sends the call signal at the call sending timing of the phase P1.

In this state, when a request for sending a ringing signal to the line L1 is made again, the phase L of the line L59 becomes P.
1 is assigned to the call transmission timing, and the line L1
The order of is similar to that of the line L59, and since the call sending timing of the phase P1 is assigned to the line L59, the call sending timing of the phase P2 is assigned to the line L1.

Therefore, the ringing signal is transmitted to the line L1 at the phase P2 ringing timing. Thus, depending on the state, the call signal may be sent at a call signal sending timing phase different from the previous one.

As described above, the control circuit 18a always recognizes and manages the calling signal transmission of the entire line, and controls so that the calling signal transmission timing phase is not biased. Thus, according to this embodiment, assuming that the total number of system lines is 384,
From the fact that the maximum number of lines that call signals are sent from is about 15% of the total, about 58 lines are the maximum call signal sending lines in this system, and the call signals of the entire line are always sent. At the same time one third
Since the control circuit 18a manages the call signal so that the call signal sending timings are evenly distributed to the three groups, the call signal sending timings of the three groups are shifted from each other. The high-voltage signal source, which is a signal source, is sufficient for the power supply capacity of 20 lines, which is 1/3 of about 58 lines of the maximum ringing signal transmission line in this system. Therefore, the high-voltage power supply HVSa itself, which is a high-voltage signal source, can be made much smaller than the conventional one, and the amount of heat generated by the power supply can be greatly reduced.

Thus, according to the present invention, downsizing of the device and reduction of the device cost can be realized. Also,
According to the present invention, heat generation by a high-voltage power supply is reduced, so that it is possible to suppress deterioration of electronic components used in a private branch exchange due to heat, and to suppress deterioration of quality.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the description has been made assuming that the total number of accommodated lines is 384. However, this may be arbitrary, and the number of phase divisions is not limited to 3 and is arbitrary. good.

Besides, various modifications can be made without departing from the scope of the present invention. As described above, the present invention provides a private branch exchange having a plurality of subscriber circuits for interfacing with an analog extension terminal and transmitting a high voltage signal as a call signal to the analog extension terminal when calling the analog extension terminal. , A power supply for high voltage signal generation,
Each has a plurality of types of timing phases so that the timings do not overlap, and when there are multiple analog extension terminals making a call at the same time, the timing phases are sequentially assigned to the analog extension terminals to be called,
And a control means for controlling to supply a high voltage signal from the power source for generating the high voltage signal to the analog extension terminal which makes the call at the timing of the allocated phase.

The private branch exchange having such a configuration is
The control means is provided with a timing control function by a plurality of types of timing phases so that the timings do not overlap, and the control means is a target for calling when there are a plurality of analog extension terminals calling at the same time. The above-mentioned timing phases are sequentially allocated to the analog extension terminals, and the high-voltage signal is controlled to be supplied from the power supply for generating the high-voltage signals to the analog extension terminals making the call at the timing of the allocated phases. .

In this way, the transmission timing by phase division of the ringing signal is controlled, and when there are a plurality of analog extension terminals making a call at the same time, the timing phase is set to the analog extension terminal to be called. Allocate in order,
As a result of controlling to supply a high voltage signal from the power supply for generating the high voltage signal to the analog extension terminal making the call at the timing of the allocated phase, the number of in-phase outputs of the call signal is evenly distributed, and the high voltage signal is output. The power supply capacity for supply can be reduced. Moreover, since the number of in-phase outputs of the ringing signal is evenly distributed, the power supply can be used with a uniform utilization rate and minimized.

In particular, by taking such a means, even if the ringing signal is conventionally phase-divided, the ringing signal is about 15% of the entire line from the call volume (about 60 lines in the case of the structure of about 400 lines). ) Is required, but by performing the above-mentioned control for reducing the phase division of the ringing signal and the in-phase output (for example, when three phase divisions are performed, Ringing signal is about 5% of the whole line (about 20 lines in the case of about 400 lines)
Is possible with a high-voltage power supply having a power supply capacity to send out, and can suppress the amount of heat generation to promote miniaturization of the device, and by suppressing the amount of heat generation, deterioration due to heat of the exchange housing parts can be suppressed, and It is possible to reduce the device cost due to the downsizing of the device.

[0111]

As described in detail above, according to the present invention,
By controlling the phase division of the ringing signal and reducing the in-phase output (for example, if three phase divisions are performed, about 5% of the ringing signal is sent out of the entire line (about 20 lines in the case of a structure of about 400 lines). It is possible to use a high-voltage power supply having a required power supply capacity, so that the device can be downsized and the device cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention,
1 is a block diagram showing an example of a switching system to which a private branch exchange according to an embodiment of the present invention is applied.

FIG. 2 is a diagram for explaining an embodiment of the present invention,
FIG. 2 is a circuit diagram showing a specific configuration example of a calling signal transmission mechanism in the digital exchange 10a in FIG.

FIG. 3 is a diagram for explaining an embodiment of the present invention,
The switch opening / closing control circuit 25 (25-1 to 25- in FIG.
FIG. 16) is a circuit diagram showing a detailed configuration of 16).

FIG. 4 is a diagram for explaining an embodiment of the present invention,
The figure which shows the example of the transmission timing of the calling signal in this invention system.

FIG. 5 is a diagram for explaining an embodiment of the present invention,
The timing chart which shows the concrete transmission timing of the calling signal concerning the Example of this invention.

FIG. 6 is a diagram for explaining a conventional example and is a block diagram showing an example of a conventional exchange system.

FIG. 7 is a diagram for explaining a conventional example and is a circuit diagram showing a configuration example of a conventional subscriber circuit.

FIG. 8 is a diagram for explaining a conventional example and is a circuit diagram showing a configuration example of a conventional call signal transmission mechanism.

FIG. 9 is a timing chart showing a pattern of a calling signal.

FIG. 10 is a circuit diagram showing a configuration of a ring trip circuit.

[Explanation of Codes] 10a ... Digital switch 11, 12 ... Telephone 13a, 14a ... Subscriber circuit 15a ... Time division switch 16a ... Trunk circuit 17a ... Station line connection terminal 18a ... Control circuit 20 (20-1 to 20-16) ) ... Subscriber circuit 25 (25-1 to 25-16) ... Switch opening / closing control circuit HVSa ... High voltage power source (high voltage signal source) RT1 to RT16 ... Ring trip circuit rg1-1 to rg16-1, rg1-2 rg16-
2, rg1-3 to rg16-3, rg1-4 to rg16
-4 ... switch.

Claims (1)

[Claims] 1. A private branch exchange which has a plurality of subscriber circuits for interfacing with an analog extension terminal and sends a high voltage signal as a call signal to the analog extension terminal when the analog extension terminal is called. When there are multiple analog extension terminals that call at the same time and that have multiple types of timing phases that do not overlap in timing with the power supply for high-voltage signal generation, the analog extension terminal that is the target of the call On the other hand, the above timing phases are assigned in order,
A private branch exchange comprising: control means for controlling to supply a high voltage signal from the power source for generating the high voltage signal to the analog extension terminal which makes the call at the timing of the allocated phase.