JP2021184519A - Relay device for emergency calls - Google Patents

Abstract

To provide a suitable relay device for emergency calls for use when the emergency phone is installed in a remote place from a station exchange.SOLUTION: A relay device for emergency calls 401 is provided between a two line type first track 101 on a switchboard side of a telephone office and a two line type second track 111 to which one to a plurality of emergency phones are connected so as to extend the first track for making a telephone call of the emergency phone possible through the switchboard of the telephone office. The relay device for emergency calls includes: a first two lines-four lines conversion circuit 30 provided on the first track side; a second two lines-four lines conversion circuit 40 provided on the second track side; a transmission amplification circuit 50 provided in between the first two lines-four lines conversion circuit and the second two lines-four lines conversion circuit for amplifying transmission voice signals from the emergency phone; a receiver amplifying circuit 60 for amplifying a receiver sound signal to the emergency phone: and a power supply circuit 80 for carrying out power supply to one to plurality of emergency phones connected to the second line.SELECTED DRAWING: Figure 2

Description

The present invention relates to, for example, an emergency telephone relay device used when laying an emergency telephone arranged along an automobile road.

On highways and the like, a plurality of emergency telephones are installed at predetermined intervals on the side of the road. These multiple emergency telephones are connected in parallel to two lines of a dedicated emergency telephone line, and when any one of the emergency telephones is off-hooked, it is managed through the exchange of the central office. It is configured to be connected to the reception desk of the center by telephone so that a telephone call can be made (see, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2018-186441)).

Then, when a plurality of emergency telephones are installed at a predetermined distance from the exchange of the central office, the main unit is connected to the two lines of the emergency telephone line, and the main unit is to be installed. I am trying to connect multiple emergency phones.

FIG. 8 is a diagram for explaining a configuration example in which a plurality of emergency telephones are installed at a predetermined distance from the switchboard of the central office by using the main device.

In the example of FIG. 8, a two-line line 101 of an emergency telephone line is connected to a telephone office switchboard (hereinafter referred to as a station switchboard) 100, and the line 101 is separated from the station switchboard 100 by a predetermined distance. The main device 301 is connected to the above location.

In this case, the main device 301 is connected to the end of the two-line line 101 of the emergency telephone line connected to the station exchange 100. Then, a two-line line 111 different from the two-line line 101 is connected to the main device 301, and a plurality of emergency telephones 201 are connected to the line 111 at predetermined distance intervals.

Further, in the example of FIG. 8, the station exchange 100 is connected to the two-line line 102 of the emergency telephone line, which is different from the two-line line 101 of the emergency telephone line, and is connected to the line 102 of the separate line. Also, the main device 302 is connected to a place separated from the station exchange 100 by a predetermined distance. Then, a two-line line 121 different from the two-line line 102 is connected to the main device 302, and a plurality of emergency telephones 202 of another group are connected to the line 121 at predetermined distance intervals. Will be done.

Each of the main devices 301 and 302 includes a control unit including, for example, a microprocessor, has a function of managing and controlling each of a plurality of emergency telephones 201 and a plurality of emergency telephones 202, and has a function of managing and controlling each of the plurality of emergency telephones 201 and a plurality of emergency telephones 201. And a power supply circuit for supplying power to each of the plurality of emergency telephones 202.

Then, in the case of a plurality of emergency telephones 201 connected to the main device 301 connected to the two-line line 101 connected to the station exchange 100, when any of the emergency telephones 201 is off-hooked. , It is detected by the main device 301, and the call by the off-hook by the emergency telephone 201 is transmitted to the station exchange 100 by the control of the main device 301. The station exchange 100 receives this call to the management center (not shown), creates a communication path between the management center and the off-hook emergency telephone 201, and enables emergency telephone calls. Similarly, in the case of a plurality of emergency telephones 202 connected to the main unit 302, an emergency telephone call is made via the management control of the main unit 302.

Japanese Unexamined Patent Publication No. 2018-186441

As described above, in the conventional emergency telephone system, when the emergency telephone is installed at a predetermined distance from the station exchange 100, the ends of the two lines 101 and 102 connected to the station exchange 100 are used. Main devices 301 and 302 are provided in the section, and another two lines are arranged so as to extend each of the two lines 101 and 102 connected to the station switch 100. The lines 111 and 121 of the above are connected, and a plurality of emergency telephones 201 and 202 to be installed are connected to the lines 111 and 121 of the other two lines. Then, the emergency telephone is configured to make an emergency telephone call via the management control of the main device 301 and the main device 302.

Therefore, the main devices 301 and 302 need to be provided with a control unit including, for example, a microprocessor for management control, which causes a problem that the configuration becomes complicated and the cost becomes high.

Further, in the conventional emergency telephone system configuration, the main devices 301 and 302 are connected to the ends of the two-line lines 101 and 102 connected to the station exchange 100, and are connected to the main devices 301 and 302. The configuration is such that the main devices 301 and 302 manage and control a plurality of emergency telephones 201 and 202 on different two-line lines 111 and 121, respectively, and a configuration in which the two-line lines 111 and 121 are further extended is not considered. rice field.

An object of the present invention is to provide an emergency telephone relay device capable of solving the above problems.

In order to solve the above problems, the present invention
A two-wire first line on the exchange side of the telephone office and a two-wire second line provided so as to extend the first line and to which one to a plurality of emergency telephones are connected. It is an emergency telephone relay device provided between the telephone offices to enable emergency telephone calls through the exchange of the telephone office.
The first 2-wire-4-wire conversion circuit provided on the first line side, and
The second 2-wire-4-wire conversion circuit provided on the second line side, and
A transmission amplifier circuit and an emergency transmission amplifier circuit provided between the first 2-wire to 4-wire conversion circuit and the second 2-wire to 4-wire conversion circuit to amplify a transmission audio signal from the emergency telephone. A receiver amplifier circuit that amplifies the received audio signal to the telephone,
A power supply circuit that supplies power to one or more emergency telephones connected to the second line, and
Provided is an emergency telephone relay device characterized by being provided with.

In the emergency telephone relay device according to the present invention having the above configuration, the first 2-wire-4 wire conversion circuit is provided on the first line side, and the second 2-wire-4 wire is provided on the second line side. Since a conversion circuit is provided, between the first 2-wire / 4-wire conversion circuit and the second 2-wire / 4-wire conversion circuit, there is a 2-wire transmission path and 2 when viewed from the emergency telephone side. A wire reception path is formed, a transmission voice amplification circuit is provided in the transmission path, and a reception voice amplification circuit is provided in the reception path. Therefore, even when the second line is far from the exchange of the central office, the transmitted voice from the emergency telephone connected to the second line is amplified and sent to the management center, and also. The received voice from the management center is amplified and sent to the emergency telephone, and good call voice can be obtained.

Then, since power is supplied to one or more emergency telephones connected to the second line from the power supply circuit of the emergency telephone relay device, when the second line is far from the exchange of the central office. Also, the emergency telephone connected to the second line is surely supplied with power.

Further, the invention of claim 2 is the relay device for emergency telephone of the invention of claim 1.
A loop control and polarity detection circuit provided between the first 2-wire / 4-wire conversion circuit and the first line,
A loop detection and polarity control circuit provided between the second 2-wire / 4-wire conversion circuit and the second line,
Equipped with
The loop control and polarity detection circuit receives the first control signal from the loop detection and polarity control circuit, transmits the loop closing by the off-hook of the emergency telephone to the first line side, and the first line side. The polarity of the line 1 is detected, and a second control signal for controlling the polarity of the power supply to the emergency telephone by the power supply circuit is generated according to the detection result.
The loop detection and polarity control circuit detects loop closure due to the off-hook of the emergency telephone to generate the first control signal, and receives the second control signal to receive the polarity of the power supply by the power supply circuit. It is characterized by controlling.

In the invention of claim 2, the loop detection and polarity control circuit detects the loop closure due to the off-hook of the emergency telephone and transmits it to the exchange of the central office. The exchange of the central office receives a call to the management center, and when the management center answers, the polarity of the first line connected to the exchange side of the central office is reversed accordingly. When the loop control and polarity detection circuit detects the polarity reversal of the first line, the polarity of the second line correspondingly reverses, enabling a call between the emergency telephone and the management center.

Further, the invention of claim 3 is the invention of claim 2.
The loop control and polarity detection circuit is directly connected to the first 2-wire-4-wire conversion circuit without an isolated circuit.
The loop detection and polarity control circuit and the feeding circuit are connected to the second 2-wire-4 wire conversion circuit via an insulation circuit.

According to the third aspect of the present invention, the configuration eliminates the need for insulation from the side to which the first line connected to the exchange side of the telephone office is connected, so that an insulating transformer or the like becomes unnecessary. , The configuration can be simplified.

Further, the invention of claim 4 is the invention of claims 1 to 3.
First, the line length from the own device to the off-hooked emergency telephone among the one or more emergency telephones is detected by the line voltage between the two lines of the second line at the time of loop formation by the off-hook. A second line length detection circuit that detects the line length detection circuit and the line length from the telephone office switch to the own device by the line voltage between the two lines on the first line side when the loop is formed by the off-hook. And one or both
Based on the detection result of the first line length detection circuit, the impedance on the second line side is variably controlled in order to reduce the echo of the received voice.
It is characterized in that the impedance on the first line side is variably controlled in order to reduce the echo of the transmitted voice based on the detection result of the second line length detection circuit.

According to the fourth aspect of the present invention, the line length from the own device to the off-hooked emergency telephone is detected by the first line length detection circuit, and the detection result is used to reduce the echo of the received voice. The impedance on the line side of 2 is variably controlled. In addition, the line length from the switchboard of the central office to the own device is detected by the second line length detection circuit, and the impedance on the first line side is variable in order to reduce the echo of the transmitted voice based on the detection result. Be controlled. As a result, a call voice with reduced echo can be obtained.

Further, the invention of claim 5 is the invention of claims 1 to 4.
First, the line length from the own device to the off-hooked emergency telephone among the one or more emergency telephones is detected by the line voltage between the two lines of the second line at the time of loop formation by the off-hook. A second line length detection circuit that detects the line length detection circuit and the line length from the telephone office switch to the own device by the line voltage between the two lines on the first line side when the loop is formed by the off-hook. And one or both
The amplification factor of the receiver amplifier circuit is controlled by the detection result of the first line length detection circuit.
It is characterized in that the amplification factor of the transmission amplification circuit is controlled by the detection result of the second line length detection circuit.

In the invention of claim 5, the line length from the own device to the off-hooked emergency telephone is detected by the first line length detection circuit, and the amplification factor of the receiver amplifier circuit is controlled by the detection result. Further, the line length from the switchboard of the central office to the own device is detected by the second line length detection circuit, and the amplification factor of the transmission amplifier circuit is controlled by the detection result. This makes it possible to reduce the volume reduction of the call voice.

Further, the invention of claim 6 is the invention of claims 1 to 4.
First, the line length from the own device to the off-hooked emergency telephone among the one or more emergency telephones is detected by the line voltage between the two lines of the second line at the time of loop formation by the off-hook. A second line length detection circuit that detects the line length detection circuit and the line length from the telephone office switch to the own device by the line voltage between the two lines on the first line side when the loop is formed by the off-hook. And with
Controlling The amplification factor of the receiver amplifier circuit and the amplification factor of the transmission amplifier circuit are controlled based on the detection result of the first line length detection circuit and the detection result of the second line length detection circuit. It is characterized by doing.

In the invention of claim 6, the first line length detection circuit detects the line length from the own device to the off-hook emergency telephone, and the second line length detection circuit detects the line length from the telephone office switchboard. The line length to the own device is detected. Then, based on the detection result of the first line length detection circuit and the detection result of the second line length detection circuit, that is, the line length from the own device to the off-hooked emergency telephone and the line length from the telephone office switch to the own device. The amplification factor of the receiver amplifier circuit and the amplification factor of the transmission amplifier circuit are controlled based on the line lengths up to. This makes it possible to reduce the volume reduction of the call voice.

According to the present invention, the emergency telephone provided farther than the switchboard of the central office can be provided via the emergency telephone relay device according to the present invention, so that the emergency telephone can make an emergency telephone call to the management center without any trouble. .. Moreover, the emergency telephone relay device according to the present invention extends the two-wire line connected to another emergency telephone relay device connected to the exchange side of the central office and the two-wire line. It can be further provided between the line and another two-wire line arranged in such a manner. Therefore, by sequentially connecting one emergency telephone line connected to the switchboard of the central office to the emergency telephone relay device according to the present invention via another two-line line, the emergency telephone can be used. It has the effect that it can be extended in sequence according to the number of relay devices installed.

It is a figure which shows the system configuration example of the emergency telephone using the relay device for emergency telephone by this invention. It is a block diagram which shows the structural example of the embodiment of the relay device for an emergency telephone by this invention. It is a figure which shows the circuit configuration example of the main part of the embodiment of the relay device for emergency telephones by this invention. It is a figure which shows the circuit configuration example of the embodiment of the relay device for an emergency telephone by this invention. It is a figure which shows the other circuit configuration example of the embodiment of the relay device for an emergency telephone by this invention. It is a figure which shows the circuit example which is a part of the circuit configuration example of FIG. It is a figure used for the explanation of a part of the circuit examples of the circuit configuration example of FIG. It is a figure which shows the system configuration example of the conventional emergency telephone using the main apparatus.

Hereinafter, embodiments of the emergency telephone relay device according to the present invention will be described with reference to the drawings.

[Example of emergency telephone system configuration using the emergency telephone relay device according to the present invention]
FIG. 1 is a diagram showing an example of a system configuration of an emergency telephone using the emergency telephone relay device according to the present invention. In FIG. 1, the same reference numbers are assigned to the same parts as those in the system configuration diagram of FIG. 8 described above.

That is, in the system configuration example of FIG. 1, a two-line emergency telephone line 101 is connected to the station exchange 100, and a plurality of emergency telephones 201 of the first group are connected to the line 101 at predetermined intervals. It is connected. Then, the emergency telephone relay device 401 according to the present invention is connected to the end of the two-line line 101 of the emergency telephone line connected to the station exchange 100. Then, another two-line line 111 is connected to the emergency telephone relay device 401 so as to extend the two-line line 101, and a plurality of emergency lines of the second group are connected to the line 111 at predetermined intervals. The telephone 202 is connected.

Further, in the system configuration example of FIG. 1, another emergency telephone relay device 402 according to the present invention is connected to the end of the line 111 to which the plurality of emergency telephones 202 of the second group are connected. .. Then, another two-line line 112 is connected to the emergency telephone relay device 402 so as to extend the two-line line 111, and a plurality of other groups are connected to the line 112 at predetermined intervals. The emergency telephone 205 is connected.

In the system configuration example of FIG. 1, the emergency telephone relay device 401 is arranged at a position separated by the distance D1 of the length of the line 101 from the station switch 100, and is the length of the line 101 from the station switch 100. The emergency telephone relay device 402 is arranged at a position separated by a distance D2 of the sum of the lengths of the lines 111. That is, in the emergency telephone system using the emergency telephone relay device according to the present invention, another two lines are connected to one emergency telephone telephone line via the emergency telephone relay device according to the present invention. Further, it can be configured to connect another two lines to the other line via an emergency telephone relay device.

Another emergency telephone relay device is connected to the two-line line 112 connected to the emergency telephone relay device 402, and the two-line line is connected to the other emergency telephone relay device. A plurality of emergency telephones can be connected to the line at predetermined intervals to further extend the line.

Although detailed illustration is omitted in FIG. 1, when the station switch 100 is connected to the two-line line 102 of the emergency telephone line, which is a separate line from the two-line line 101 of the emergency telephone line, Similar to the line 101, the line can be sequentially extended by using an emergency telephone relay device.

[Embodiment of an emergency telephone relay device according to the present invention]
Hereinafter, embodiments of the emergency telephone relay device according to the present invention will be described with reference to the drawings. The emergency telephone relay device of this embodiment is provided with respect to the emergency telephone relay device so as to extend a two-wire type first line connected to the station exchange 100 side and the first line. The internal configuration is exactly the same, except that the second line of the two-wire system connected to the side opposite to the station exchange 100 side to which one to a plurality of emergency telephones are connected is different.

That is, in the emergency telephone relay device 401 in the system configuration example of FIG. 1, the first line is the line 101, the second line is the line 111, and a plurality of emergency lines connected to the second line 111. It enables an emergency telephone call through the station switch 100 by the telephone 202. Further, in the emergency telephone relay device 402, the first line is the line 111, the second line is the line 112, and the station switch 100 by the plurality of emergency telephones 205 connected to the second line 112. It enables emergency telephone calls through. Therefore, the emergency telephone relay device 401 and the emergency telephone relay device 402 have the same configuration.

The emergency telephone relay device of this embodiment is used for off-hook operation by any emergency telephone in the plurality of emergency telephones without performing exchange management control for each of the plurality of emergency telephones connected to the second line. It is provided with a configuration that enables emergency telephone calls through a station exchange. In the following description, an embodiment of the emergency telephone relay device according to the present invention will be described by taking the case of the emergency telephone relay device 401 as an example.

FIG. 2 is a block diagram showing a configuration example of an embodiment of the emergency telephone relay device according to the present invention, taking the case of the emergency telephone relay device 401 as an example.

As shown in FIG. 2, in the emergency telephone relay device 401 of this embodiment, the loop control / polarity detection circuit 10 is connected to the first line of the two-wire system on the station exchange 100 side, in this example, the line 101. Further, the loop detection / polarity control circuit 20 is connected to the second line of the two-wire system opposite to the station switch 100 side, in this example, the line 111.

Then, the loop control / polarity detection circuit 10 is connected to the 2-wire-4-wire conversion circuit 30 constituting the first 2-wire-4-wire conversion circuit, and the loop detection / polarity control circuit 20 is connected to the second 2-wire conversion circuit 20. It is connected to the 2-wire / 4-wire conversion circuit 40 that constitutes the 4-wire conversion circuit.

The 2-wire-4-wire conversion circuit 30 converts the 2-wire on the loop control / polarity detection circuit 10 side into a 4-wire consisting of a 2-wire transmission path and a 2-wire receiver path. Further, the 2-wire-4-wire conversion circuit 40 converts the 2-wire on the loop detection / polarity control circuit 20 side into a 4-wire consisting of a 2-wire transmission path and a 2-wire receiver path. In the description of this specification, the transmission and reception are the concepts when viewed from the emergency telephone 202 side connected to the second line connected to the emergency telephone relay device 401.

Then, as shown in FIG. 2, in the transmission path of two wires out of the four wires between the two-wire-four-wire conversion circuit 30 and the two-wire-four-wire conversion circuit 40, a transmission voice amplifier circuit is used. 50 is provided, and a received voice amplifier circuit 60 is provided in the receiving path of two lines.

The emergency telephone relay device 401 of this embodiment is provided with an AC / DC conversion circuit 70 that converts a commercial AC power supply voltage into a DC voltage in order to generate a power supply voltage of the internal circuit. An AC plug 71 inserted into an AC outlet is connected to the AC / DC conversion circuit 70. Although not shown, the AC / DC conversion circuit 70 includes a transformer, a commercial AC voltage is connected to the primary winding of the transformer, and a rectifier circuit is provided in the secondary winding. The DC power supply voltage of the emergency telephone relay device 401 of this embodiment is generated.

The DC power supply voltage from the AC / DC conversion circuit 70 is supplied to the power supply circuit 80 and also to each part of the emergency telephone relay device 401. The power supply circuit 80 supplies power to the emergency telephone 202 connected to the two-line line 111 connected to the loop detection / polarity control circuit 20 through the two-line line 111.

The operation of the emergency telephone in the emergency telephone relay device 401 of this embodiment configured as described above will be described.

When an off-hook operation is performed on any of the plurality of emergency telephones 202 connected to the two-line line 111 as the second line to form a closed loop for the two-line line 111, the emergency telephone relay device is used. In 401, the loop detection / polarity control circuit 20 detects the formation of the closed loop, and the detection result is sent to the loop control / polarity detection circuit 10. The loop control / polarity detection circuit 10 forms a closed loop between the two lines 101 based on the detection result of the closed loop formation from the loop detection / polarity control circuit 20, and transmits the closed loop to the station exchange 100.

The station exchange 100 detects the off-hook of one of the emergency telephones by forming this closed loop, and causes the management center (not shown) to receive a call by the emergency telephone. Then, when the management center responds, the station exchange 100 reverses the polarity of the two-line line 101.

The loop control / polarity detection circuit 10 of the emergency telephone relay device 401 detects the polarity reversal of the line 101 of the two lines, and the detection result is sent to the loop detection / polarity control circuit 20. The loop detection / polarity control circuit 20 inverts the polarity of the two-line line 111 based on the detection result of the polarity inversion from the loop control / polarity detection circuit 20.

By the above operation, a communication path is generated between the off-hook emergency telephone 202 and the management center via the emergency telephone relay device 401, and an emergency telephone call is made. At this time, the transmitted voice from the emergency telephone 202 is amplified by the transmitted voice amplification circuit 50 of the emergency telephone relay device 401 and sent to the management center, and the received voice from the management center is the emergency telephone relay device 401. Since it is amplified by the received voice amplifier circuit 60 and sent to the emergency telephone 202, even if the emergency telephone 202 is far from the station switch 100, a call is made with a good call voice volume.

Then, when the emergency telephone 202 is turned on-hook for the end of the call and the loop of the two-line line 111 is opened, the loop detection / polarity control circuit 20 of the emergency telephone relay device 401 detects the loop opening. , The detection result is sent to the loop control / polarity detection circuit 10. The loop control / polarity detection circuit 10 transmits the loop opening to the station switch 100. This completes the end of the call.

When an off-hook operation is performed on any of the plurality of emergency telephones 205 connected to the two-line line 112 of the emergency telephone relay device 402 to form a closed loop for the two-line line 112, the above-mentioned description is made. Similarly, the formation of the closed loop is detected by the loop detection / polarity control circuit 20 of the emergency telephone relay device 402, the detection result is sent to the loop control / polarity detection circuit 10, and the loop control / polarity detection is performed. A closed loop is formed between the two lines 111 in the circuit 10 and transmitted to the emergency telephone relay device 401.

In the emergency telephone relay device 401, the formation of the closed loop is detected by the loop detection / polarity control circuit 20 in the same manner as when off-hooked by any of the emergency telephones 202 described above, and the detection result is the loop control / polarity. It is sent to the detection circuit 10, and the loop control / polarity detection circuit 10 forms a closed loop between the two lines 101 and transmits it to the station exchange 100.

Then, the station exchange 100 detects the off-hook of one of the emergency telephones by forming this closed loop in the same manner as when the emergency telephone 202 described above is off-hooked, and causes the management center to receive a call by the emergency telephone. When the management center responds, the station exchange 100 reverses the polarity of the two-line line 101.

The loop control / polarity detection circuit 10 of the emergency telephone relay device 401 detects the polarity reversal of the two-line line 101, and sends the detection result to the loop detection / polarity control circuit 20. The loop detection / polarity control circuit 20 of the emergency telephone relay device 401 reverses the polarity of the two-wire line 111 based on the detection result of the polarity reversal from the loop control / polarity detection circuit 20.

Then, the loop control / polarity detection circuit 10 of the emergency telephone relay device 402 detects the polarity reversal of the two-line line 111 and sends the detection result to the loop detection / polarity control circuit 20. The loop detection / polarity control circuit 20 of the device 402 inverts the polarity of the two-wire line 112.

By the above operation, a communication path is generated between the off-hook emergency telephone 205 and the management center via the emergency telephone relay device 401 and the emergency telephone relay device 402, and an emergency telephone call is made. At this time, the transmitted voice from the emergency telephone 205 is amplified by the transmitted voice amplification circuit 50 of the emergency telephone relay device 402 and the transmitted voice amplification circuit 50 of the emergency telephone relay device 401 and sent to the management center. Further, the received voice from the management center is amplified by the received voice amplifier circuit 60 of the emergency telephone relay device 401 and the received voice amplification circuit 60 of the emergency telephone relay device 402 and sent to the emergency telephone 205. Even if is far from the station switch 100, a call is made with a good call voice volume.

Then, when the emergency telephone 205 is turned on-hook for the end of the call and the loop of the line 112 of the two lines is released, the emergency telephone relay device 402 and the emergency telephone relay device 402 are similarly to the case of the off-hook on the emergency telephone 205 described above. The emergency telephone relay device 401 and the emergency telephone relay device 401 perform the above-mentioned operation during the on-hook operation of the emergency telephone to end the call.

[Specific circuit configuration example of emergency telephone relay device]
[First example]
The emergency telephone relay device needs to be insulated so as not to affect the DC voltage with respect to the station switch 100. Therefore, in FIG. 2, the portion surrounded by the dotted line is configured to be electrically insulated from the station exchange 100.

FIG. 3 is a specific circuit configuration example in the case of considering the insulation of the portion surrounded by the dotted line in the emergency telephone relay device 401. In this example, a transformer is used to insulate between the loop control / polarity detection circuit 10 and the 2-wire / 4-wire conversion circuit and between the loop detection / polarity control circuit 20 and the 2-wire / 4-wire conversion circuit 40. Has been made.

That is, as shown in FIG. 3, the 2-wire-4 wire conversion circuit 30 includes a transformer 31, and one end and the other end of one winding 31a of the transformer 31 are passed through a loop control / polarity detection circuit 10. It is connected to one and the other of the two lines 101. Further, one end of the other winding 31b of the transformer 31 is grounded via the resistor 32, and the other end is grounded via the series circuit of the impedance matching circuit 34 and the resistor 33. It should be noted that the impedance matching circuit and the resistor may be grounded via a parallel circuit.

Although not shown here, the impedance matching circuit 34 is composed of, for example, a series circuit of a capacitor and a resistor, and is for echo reduction of the received sound. The impedance matching circuit 34 can also be configured as a parallel circuit of a capacitor and a resistor.

Then, the connection point between one end of the winding 31b and the resistor 32 and the connection point between the resistor 33 and the impedance matching circuit 34 are connected to the input end of the earpiece audio amplifier circuit 60. Further, the output end of the transmission sound amplifier circuit 50 is connected to the connection point between the other end of the winding 31b of the transformer 31 and the impedance matching circuit 34.

Further, the 2-wire-4-wire conversion circuit 40 includes a transformer 41, and one end and the other end of one winding 41a of the transformer 41 are one of the two-wire lines 111 through the loop detection / polarity control circuit 20. And is connected to the other. Further, one end of the other winding 41b of the transformer 41 is grounded via the resistor 42, and the other end is grounded via the series circuit of the impedance matching circuit 44 and the resistor 43. It should be noted that the impedance matching circuit and the resistor may be grounded via a parallel circuit.

Although not shown here, the impedance matching circuit 44 is composed of, for example, a series circuit of a capacitor and a resistor, and is for echo reduction of the transmitted sound. The impedance matching circuit 44 can also be configured as a parallel circuit of a capacitor and a resistor.

Then, the connection point between one end of the winding 41b of the transformer 41 and the resistor 42, and the connection point between the resistor 43 and the impedance matching circuit 44 are connected to the input end of the transmission voice amplifier circuit 50. Further, the output end of the received voice amplifier circuit 50 is connected to the connection point between the other end of the winding 41b of the transformer 41 and the impedance matching circuit 44.

Then, as shown in FIG. 3, in this example, one end of the winding 41a of the transformer 41 connected to one of the two-wire lines 111 through the loop detection / polarity control circuit 20 is a diode whose anode is grounded. The other end of the winding 41a of the transformer 41 connected to the cathode of the 82 and connected to the other of the two-wire line 111 is connected to the anode of the diode 81. The cathode of the diode 81 is connected to the feeding circuit 80.

As described above, in the emergency telephone relay device 401 of the first example, the transformers 31 and 41 are connected to both the line 101 side of the first two lines on the station exchange 100 side and the plurality of emergency telephone 202 sides. By providing the above, insulation is realized. As described above, the AC / DC conversion circuit 70 is provided with a transformer inside, and insulation is realized by the transformer.

[Second example]
In this second example, the circuit of the loop control / polarity detection circuit 10 and the loop detection / polarity control circuit 20 is devised, and the transformer 31 on the line side of the first two lines on the station switchboard 100 side is omitted. This is an example in which the configuration of the emergency telephone relay device can be simplified.

FIG. 4 is a specific circuit configuration example of the second example in the case of the emergency telephone relay device 401. In FIG. 4, the same parts as those shown in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 4, in this example, the loop control / polarity detection circuit 10 includes a photocoupler 11 and a switch circuit 12. The photocoupler 11 includes a light emitting diode 11D and a phototransistor 11T. Then, the cathode of the light emitting diode 11D of the photocoupler 11 is connected to one line 101a of the two-line line 101 on the station switcher 100 side, and the anode is connected to the emergency telephone relay device of this example via the switch circuit 12. It is connected to the 2-wire-4-wire conversion circuit 30A of 401.

The 2-wire-4 wire conversion circuit 30A of the emergency telephone relay device 401 of this example does not include the transformer 31, and the anode of the light emitting diode 11D of the photocoupler 11 is one input end of the resistor 32 and the earpiece audio amplifier circuit 60. It is directly connected to the connection point with.

Then, the emitter of the phototransistor 11T of the photocoupler 11 is grounded, and the collector is connected to the control ends of the changeover switch circuits 22 and 23 of the loop detection / polarity control circuit 20 described later. The phototransistor 11T is turned on according to the light emission of the light emitting diode 11D, and is turned off when it is not emitting light. The changeover switch circuits 22 and 23 are switched and controlled by turning the phototransistor 11T on and off.

Then, in this example, the other line 101b of the two-line line 101 on the station switchboard 100 side is directly connected to the connection point between the impedance matching circuit 34 and the transmission sound amplifier circuit 50.

Further, the loop detection / polarity control circuit 20 is composed of a photocoupler 21 and two changeover switch circuits 22 and 23 in this example. The photocoupler 21 includes two light emitting diodes 21D1 and 21D2 connected in parallel in opposite directions to each other, and a phototransistor 21T.

The two light emitting diodes 21D1 and 21D2 of the photocoupler 21 are connected between one end of the winding 41a of the transformer 41 of the 2-wire-4 wire conversion circuit 40 and one line 111a of the 2-wire line 111. .. Then, in this example, the other line 111b of the two-line line 111 is connected to the other end of the winding 41a of the transformer 41 of the 2-wire-4 line conversion circuit 40.

Then, the emitter of the phototransistor 21T of the photocoupler 21 is grounded, and the collector is connected to the control end of the switch circuit 12 of the loop control / polarity detection circuit 10. The phototransistor 21T is turned on in response to the light emission of any of the two light emitting diodes 21D1 and 21D2, and is turned off when the two light emitting diodes 21D1 and 21D2 are not emitting light. The switch circuit 12 is controlled to be turned on and off by turning the phototransistor 21T on and off.

Then, in this example, in order to transmit the polarity reversal of the two-wire line 101 on the station switch 100 side, the two-wire line 111 from the feeding circuit 80 is between the feeding circuit 80 and the two-wire line 111. The changeover switch circuits 22 and 23 are provided in order to invert the polarity of the feeding voltage supplied to the device.

That is, the changeover switch circuit 22 is provided between the diode 81 and the two-wire line 111. Then, the movable terminal c of the changeover switch circuit 22 is connected to the anode of the diode 81, one fixed terminal a of the changeover switch circuit 22 is connected to one line 111a of the two-line line 111, and the other fixed terminal b. Is connected to the other line 111b of the two-line line 111.

Further, the changeover switch circuit 23 is provided between the diode 82 and the two-wire line 111. Then, the movable terminal c of the changeover switch circuit 23 is connected to the cathode of the diode 82, one fixed terminal a of the changeover switch circuit 23 is connected to one line 111a of the two-line line 111, and the other fixed terminal b. Is connected to the other line 111b of the two-line line 111.

Then, these changeover switch circuits 22 and 23 are interlocked with each other by turning on and off the phototransistor 11T of the photocoupler 11 of the loop control / polarity detection circuit 10, and one of the changeover switch circuits 22 and 23 is a fixed terminal a. When connected to the fixed terminal b, the other is connected to the fixed terminal b, and when one is connected to the fixed terminal b, the other is switched and controlled so as to be connected to the fixed terminal a.

The operation of the loop control / polarity detection circuit 10 and the loop detection / polarity control circuit 20 of the emergency telephone relay device 401 will be described below. Before the off-hook is performed on any of the emergency telephones, the switch circuit 12 of the loop control / polarity detection circuit 10 is in the off state, and the changeover switch circuit 22 of the loop detection / polarity control circuit 20 has a fixed terminal b. The changeover switch circuit 23 is connected to the fixed terminal a.

When an off-hook operation is performed on any of the plurality of emergency telephones 202 connected to the two-line line 111 as the second line to form a closed loop for the two-line line 111, the emergency telephone relay device 401 Then, since the light emitting diode 21D2 of the photocoupler 21 of the loop detection / polarity control circuit 20 emits light, the phototransistor 21T is turned on, and the switch circuit 12 of the loop control / polarity detection circuit 10 is turned on. When the switch circuit 12 is turned on, the formation of a closed loop is transmitted to the station exchange 100 through the two-wire line 101.

As described above, the station exchange 100 causes the management center (not shown) to receive a call from the emergency telephone based on the detection of the formation of this closed loop. Then, when the management center responds, the station exchange 100 reverses the polarity of the two-line line 101.

Then, since the light emitting diode 11D of the photocoupler 11 of the loop control / polarity detection circuit 10 of the emergency telephone relay device 401 emits light, the phototransistor 11T is turned on, and the changeover switch circuits 22 and 23 of the loop detection / polarity control circuit 20 are turned on. Switch the switching state of. As a result, the polarity of the two-line line 111 of the power supply voltage by the power supply circuit 80 is reversed, and a communication path via the emergency telephone relay device 401 is generated between the off-hook emergency telephone 202 and the management center. Then, an emergency telephone call is made.

At this time, when the polarity of the two-wire line 111 of the feeding voltage from the feeding circuit 80 is reversed, the light emitting diode 21D1 emits light instead of the light emitting diode 21D2 of the photocoupler 21, so that the phototransistor 21T emits light. The ON state is maintained, and the switch circuit 12 of the loop control / polarity detection circuit 10 maintains the ON state.

Then, when the emergency telephone 202 is turned on-hook for the end of the call and the loop of the two-line line 111 is opened, the light emitting diode 21D1 of the photocoupler 21 of the loop detection / polarity control circuit 20 of the emergency telephone relay device 401 is opened. Since both 21D2 and 21D2 are in the non-light emitting state, the phototransistor 21T is turned off, so that the switch circuit 12 of the loop control / polarity detection circuit 10 is turned off, and the loop opening is transmitted to the station switch 100. This completes the end of the call.

Then, since the light emitting diode 11D of the photocoupler 11 of the loop control / polarity detection circuit 10 of the emergency telephone relay device 401 is in a non-light emitting state, the phototransistor 11T is turned off, whereby the loop detection / polarity control circuit 20 is turned off. The switching state of the changeover switch circuits 22 and 23 is returned to the initial state, and the polarity of the two-wire line 111 of the power supply voltage from the power supply circuit 80 is returned to the original state.

As described above, in the configuration of this second example, the DC voltage is not changed on the station switch 100 side. Therefore, in the first example, 2 on the station switch 100 side of the emergency telephone relay device 401. The transformer 31 provided for the line can be omitted, and the configuration can be simplified.

[Third example]
In the emergency telephone relay device of the above example, the transmitted voice amplifier circuit 50 and the received voice amplifier circuit 60 have a fixed amplification factor. Impedance matching circuits 34 and 44 are also set to fixed values.

However, the length of the second line connected to the side opposite to the station switch 100 side of the emergency telephone relay device is long, and the emergency telephone relay with each of the many emergency telephones connected to the second line. The distance to the device will be quite different. In the example of FIG. 1, the length of the two lines between each of the emergency telephones 202 connected to the second line 111 of the emergency telephone relay device 401 and the emergency telephone relay device 401 is, for example, , D11 = 500 meters, D12 = 1500 meters, ... D13 = 4500 meters.

Further, as shown in FIG. 1, the emergency telephone relay device can be connected to one emergency telephone line connected to the station exchange 100 so that a plurality of units are sequentially extended. Therefore, the lengths of the two lines from the station exchange 100 to the emergency telephone relay device are different, for example, D1 = 5000 meters, D2 = 10000 meters, and so on.

Therefore, when the amplification factors of the transmitted voice amplifier circuit 50 and the received voice amplifier circuit 60 are fixed, the transmitted voice sent from the emergency telephone to the management center may differ for each emergency telephone, or in each of the emergency telephones. There is a risk that the earpiece volume will be different. In addition, the emergency telephone may make it inappropriate to reduce echoes for transmitted and received voices.

The third example is an example of solving the above problems. FIG. 5 is a specific circuit configuration example showing a third example in the case of the emergency telephone relay device 401. In FIG. 5, the same parts as those shown in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 5, the 2-wire-4 wire conversion circuit 30B of the emergency telephone relay device 401 of the third example includes a voltage detection circuit 35 and a variable impedance matching circuit 34B having a variable impedance. Be prepared. Further, the 2-wire / 4-wire conversion circuit 40B of the emergency telephone relay device 401 of the third example includes a voltage detection circuit 45 and a variable impedance matching circuit 44B that makes the impedance variable.

In this example, the variable impedance matching circuits 34B and 44B are each composed of a circuit for switching a plurality of impedance circuits including a series circuit of a resistor and a capacitor, respectively. The impedance circuits of the variable impedance matching circuits 34B and 44B may be configured as a parallel circuit of a resistor and a capacitor. Since the variable impedance matching circuits 34B and 44B have the same configuration, an example in the case of the variable impedance matching circuit 44B is shown in FIG. 6, and the description of the configuration example of the variable impedance matching circuit 34B is omitted here. ..

That is, the variable impedance matching circuit 44B of this example includes a changeover switch circuit 440 and four impedance circuits. In this example, the four impedance circuits are a series circuit of the resistor 441 and the capacitor 442, a series circuit of the resistor 443 and the capacitor 444, a series circuit of the resistor 445 and the capacitor 446, and a series circuit of the resistor 447 and the capacitor 448. It consists of four series circuits of. The changeover switch circuit 440 is switched so as to select one of the four series circuits.

In this third example, the transmitted voice amplifier circuit 50B and the received voice amplifier circuit 60B are configured by an amplifier factor variable amplifier circuit having a configuration in which the amplifier factor is changed and controlled by a control signal from the outside.

The voltage detection circuit 35 of the 2-wire-4 wire conversion circuit 30B is located between the connection point between the resistor 32 and the switch circuit 12 of the loop control / polarity detection circuit 10 and the other line 101b of the 2-wire line 101. It is connected and detects the line voltage E1 on the first line side when the switch circuit 12 of the loop control / polarity detection circuit 10 is turned on, in the example of FIG. 5, on the line 101 side of the two lines. The line voltage E1 on the first line side corresponds to the length of the two lines from the station exchange 100 to the emergency telephone relay device.

Further, the voltage detection circuit 45 of the 2-wire-4 wire conversion circuit 40B has a connection point between the resistor 42 and one end of the winding 41b of the transformer 41, and the other end of the variable impedance circuit 44B and the winding 41b of the transformer 41. It is connected to the connection point and detects the line voltage E2 on the second line side when the emergency telephone 202 is off-hooked, and in the example of FIG. 5, the line 111 side of the two lines. The line voltage E2 on the second line side corresponds to the length of the two lines from the emergency telephone relay device 401 to the emergency telephone 202.

Then, the voltage detection circuit 35 generates a control signal CTL1 corresponding to the detected line voltage E1, and the amplification factor of the transmitted voice amplifier circuit 50B is set by the control signal CTL1 to the station switch 100 of the emergency telephone relay device. The longer the line length on the side, the larger it is controlled, and the changeover switch circuit of the variable impedance matching circuit 34B for reducing the echo of the received voice is adapted to the line length on the station switch 100 side of the emergency telephone relay device. Switching control is performed so that it becomes appropriate.

Further, the voltage detection circuit 45 generates a control signal CTL2 corresponding to the detected line voltage E2, and the amplification factor of the received voice amplifier circuit 60B is off-hooked from the emergency telephone relay device by the control signal CTL2. The longer the line length on the second line side to the telephone, the larger it is controlled, and the changeover switch circuit of the variable impedance matching circuit 44B for reducing the echo of the transmitted voice is off-hooked from the emergency telephone relay device. Switching control is performed so as to be appropriate according to the line length on the second line side up to the emergency telephone.

FIG. 7 shows the four impedance circuits in the case of the variable impedance matching circuit 44B, the line voltage E2 detected by the voltage detection circuit 45, and the second from the emergency telephone relay device to the off-hook emergency telephone. It is a figure which shows an example of the relationship with the line length (distance) of a line side. In FIG. 7, the patterns 1, 2, 3 and 4 correspond to the terminals 1, 2, 3 and 4 of the changeover switch circuit 440 of the impedance matching circuit 44B, respectively. The magnitudes of the line voltages Ea, Eb, Ec, Ed, and Ee are Ea> Eb> Ec> Ed> Ee. R1, R2, R3, and R4 are values of resistors 441,443,445,447, respectively, and C1, C2, C3, and C4 are capacitances of capacitors 442,444,446,448, respectively.

For example, in FIG. 1, when the emergency telephone 202 at a distance of D11 = 500 meters from the emergency telephone relay device 401 is off-hooked, the line voltage E2 detected by the voltage detection circuit 45 is Ea <E2. Since ≦ Eb, the changeover switch circuit 440 is connected to the terminal 1 corresponding to the pattern 1 in FIG. 7 by the control signal CTL2 from the voltage detection circuit 45. Further, when the emergency telephone 202 at a distance of D12 = 1500 meters from the emergency telephone relay device 401 is off-hooked, the line voltage E2 detected by the voltage detection circuit 45 becomes Eb <E2 ≦ Ec. Therefore, the changeover switch circuit 440 is connected to the terminal 2 corresponding to the pattern 2 in FIG. 7 by the control signal CTL2 from the voltage detection circuit 45. Further, when the emergency telephone 202 at a distance of D3 = 3500 meters from the emergency telephone relay device 401 is off-hooked, the line voltage E2 detected by the voltage detection circuit 45 becomes Ed <E2 ≦ Ee. Therefore, the changeover switch circuit 440 is connected to the terminal 4 corresponding to the pattern 4 in FIG. 7 by the control signal CTL2 from the voltage detection circuit 45.

Similarly, the relationship between the line voltage E1 detected by the voltage detection circuit 35 and the line length (distance) on the first line side from the station switch 100 to the emergency telephone off-hook from the emergency telephone relay device. The variable impedance matching circuit 34B is controlled by the control signal CTL1 from the voltage detection circuit 35.

As described above, according to the emergency telephone relay device of the third example, the transmitted voice and the transmitted voice and the distance of the off-hook emergency telephone from the station switch 100 and the emergency telephone relay device are used. Since the amplification factor of the received voice is controlled and the matching impedance for the transmitted voice and the received voice is switched and controlled, even if the two-line line is extended, the quality of the call voice in the emergency telephone is prevented from deteriorating. can do.

[Other embodiments or modifications]
In the emergency telephone relay device of the third example of the above-described embodiment, both the transmitted voice and the received voice are controlled at the amplification factor and the impedance control for echo reduction. The amplification factor may be controlled and the impedance control for echo reduction may be performed only for either the voice or the received voice.

In the emergency telephone relay device of the third example of the above-described embodiment, the amplification factor of the transmitted voice is the distance between the emergency telephone relay device detected by the voltage detection circuit 35 and the station switch 100. It is controlled based on the corresponding voltage, and the amplification factor of the received voice is controlled based on the voltage according to the distance between the emergency telephone relay device detected by the voltage detection circuit 45 and the off-hooked emergency telephone. I made it. However, the amplification factor of the transmitted voice and the amplification factor of the received voice are the distance between the emergency telephone relay device and the station switch 100 and the distance between the emergency telephone relay device and the off-hooked emergency telephone. It is desirable to control according to the total distance, and in that case, the transmitted voice amplifier circuit 50B and the received voice are obtained by the control signal generated from the detection voltage of the voltage detection circuit 35 and the detection voltage of the voltage detection circuit 45. The amplification factor of the amplifier circuit 60B is controlled.

Further, the variable impedance matching circuits 34B and 44B are configured to switch between four impedance circuits in the above example, but are not limited to four, and are more detailed so as to switch a large number of impedance circuits. It may be configured. Further, as the variable impedance matching circuits 34B and 44B, those capable of continuously variablely controlling the impedance may be used, of course.

10 ... Loop control / polarity detection circuit, 20 ... Loop detection / polarity control circuit, 100 ... Station switch, 30.30A, 30B ... 2-wire-4-wire conversion circuit, 40, 40B ... 2-wire-4 wire conversion circuit, 50 ... Speaking voice amplifier circuit, 50B ... Speaking voice amplifier circuit with variable amplification factor, 60 ... Received voice amplifier circuit, 60B ... Receiving voice amplifier circuit with variable amplification factor, 70 ... AC / DC conversion circuit, 80 ... Power supply circuit, 101, 102, 111, 112 ... 2 lines

Claims (6)

A two-wire first line on the exchange side of the telephone office and a two-wire second line provided so as to extend the first line and to which one to a plurality of emergency telephones are connected. It is an emergency telephone relay device provided between the telephone offices to enable emergency telephone calls through the exchange of the telephone office.
The first 2-wire-4-wire conversion circuit provided on the first line side, and
The second 2-wire-4-wire conversion circuit provided on the second line side, and
A transmission amplifier circuit and an emergency transmission amplifier circuit provided between the first 2-wire to 4-wire conversion circuit and the second 2-wire to 4-wire conversion circuit to amplify a transmission audio signal from the emergency telephone. A receiver amplifier circuit that amplifies the received audio signal to the telephone,
A power supply circuit that supplies power to one or more emergency telephones connected to the second line, and
An emergency telephone relay device characterized by being equipped with. A loop control and polarity detection circuit provided between the first 2-wire / 4-wire conversion circuit and the first line,
A loop detection and polarity control circuit provided between the second 2-wire / 4-wire conversion circuit and the second line,
Equipped with
The loop control and polarity detection circuit receives the first control signal from the loop detection and polarity control circuit, transmits the loop closing by the off-hook of the emergency telephone to the first line side, and the first line side. The polarity of the line 1 is detected, and a second control signal for controlling the polarity of the power supply to the emergency telephone by the power supply circuit is generated according to the detection result.
The loop detection and polarity control circuit detects loop closure due to the off-hook of the emergency telephone to generate the first control signal, and receives the second control signal to receive the polarity of the power supply by the power supply circuit. The emergency telephone relay device according to claim 1, wherein the device is controlled. The loop control and polarity detection circuit is directly connected to the first 2-wire-4-wire conversion circuit without an isolated circuit.
The emergency telephone relay according to claim 2, wherein the loop detection and polarity control circuit and the power supply circuit are connected to the second 2-wire-4 wire conversion circuit via an insulation circuit. Device. First, the line length from the own device to the off-hooked emergency telephone among the one or more emergency telephones is detected by the line voltage between the two lines of the second line at the time of loop formation by the off-hook. A second line length detection circuit that detects the line length detection circuit and the line length from the telephone office switch to the own device by the line voltage between the two lines on the first line side when the loop is formed by the off-hook. And one or both
Based on the detection result of the first line length detection circuit, the impedance on the second line side is variably controlled in order to reduce the echo of the received voice.
One of claims 1 to 3, wherein the impedance on the first line side is variably controlled in order to reduce the echo of the transmitted voice based on the detection result of the second line length detection circuit. Emergency telephone relay device described in. First, the line length from the own device to the off-hooked emergency telephone among the one or more emergency telephones is detected by the line voltage between the two lines of the second line at the time of loop formation by the off-hook. A second line length detection circuit that detects the line length detection circuit and the line length from the telephone office switch to the own device by the line voltage between the two lines on the first line side when the loop is formed by the off-hook. And one or both
The amplification factor of the receiver amplifier circuit is controlled by the detection result of the first line length detection circuit.
The emergency telephone relay device according to any one of claims 1 to 4, wherein the amplification factor of the transmission amplifier circuit is controlled by the detection result of the second line length detection circuit. First, the line length from the own device to the off-hooked emergency telephone among the one or more emergency telephones is detected by the line voltage between the two lines of the second line at the time of loop formation by the off-hook. A second line length detection circuit that detects the line length detection circuit and the line length from the telephone office switch to the own device by the line voltage between the two lines on the first line side when the loop is formed by the off-hook. And with
It is characterized in that the amplification factor of the receiver amplifier circuit and the amplification factor of the transmission amplifier circuit are controlled based on the detection result of the first line length detection circuit and the detection result of the second line length detection circuit. The emergency telephone relay device according to any one of claims 1 to 4.

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