JPH06225034A - Terminal switching device for private branch telephone - Google Patents

Abstract

PURPOSE:To connect by switching a terminal other than a telephone set by connecting by selecting a line connecting an exchange to the terminal to a telephone set with display, and finding out a control line as confirming the display of the telephone set by an inspection switch. CONSTITUTION:Lines L1-L4 of four-wire constitution from the exchange are connected to the terminal (business phone) via a relay contact circuit, while they are connected to an audio signal circuit consisting of a transformer Tr, an amplifier OP, a crystal speaker SP, etc., with two rires via a relay contact E. The business phone can control a terminal telephone set with display including the lighting of a lamp L by connecting the two wires of a control line out of four wires between the exchange to the exchange. The contacts A1, A2, etc., of the relay contact circuit are switched by relays A-D, and are selected by a rotary switch R-SW. Connection to the telephone set with display is performed as selecting the two wires out of the four wires connecting the exchange to the terminal, and the control line is bound out as confirming the display of the telephone set.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a premises telephone device, and more particularly to a premises telephone device which is switched to a premises telephone terminal to connect another terminal.

[0002]

2. Description of the Related Art In a private telephone, usually, a main exchange and each terminal are provided with two lines for transmitting a voice signal and two lines for transmitting a control signal including a display signal. It is connected by four lines consisting of. In such a telephone device, it is considered to switch and use another terminal device such as a facsimile or a personal computer in addition to the telephone terminal device, and one line can be used for a plurality of terminal devices by an appropriate switching device. Being tried.

Here, the specifications of the manufacturers of the in-house telephones are different from each other, and the control line and the communication line are properly used among the four lines in various forms. Therefore, in order to connect another terminal, it is necessary to confirm which two lines out of the four lines are control lines and which two lines are communication lines.

To this end, a switching device is connected to an external line through an exchange so that a voice signal can be obtained. For example, a rotary switch is used to combine two lines out of four lines, and the two lines are taken out. I am trying to confirm whether a voice signal can be obtained.

Since this system uses a voice signal, it is necessary to confirm the voice from the speaker or the earphone, which is troublesome in that it cannot be visually confirmed.

Also, depending on the model of the exchange, the four lines are not clearly separated into the call line and the control line, and the four lines to the two lines
If the lines are sequentially switched and selected, the circuit may be cut off and signal transmission may not be possible.

The present invention has been made in consideration of the above points, and it is possible to switch and connect a terminal other than a telephone terminal by visually locating two lines of a telephone line among four lines in a private telephone. It is an object of the present invention to provide a device capable of

[0008]

In order to achieve the above object, according to the present invention, a terminal telephone with a display and a MODEM which are connected to a main exchange by four lines consisting of a telephone line and a control line.
In a terminal switching device of a private telephone for sharing a single line with a plurality of terminals by switching connection with another terminal which should be connected to the communication line via a 4 line according to a switching operation. A switching circuit for selectively taking out two wires from the inside and connecting to the terminal telephone with the display, and a terminal for connecting another two wires to the other terminal, and the other terminal. A first inspection switch which is closed by an operation for checking whether or not the state of being connected to the other two wires is obtained, and an inspection for switching the signal of the other two wires from the terminal telephone to the terminal The second inspection switch that is closed by operation and the MODE for the other two wires
A first terminal for connecting another terminal having a built-in M, a second terminal for connecting another terminal having no built-in MODEM to the other two wires, and the first and the first terminals. Depending on the logic circuit that produces a signal corresponding to whichever one of the inspection switches of 2 or the first or second output terminal is the closed circuit first, and the signal output from this logic circuit. Connection control means for connecting one of the first and second terminals to the other two wires and for preventing the logic circuit from responding to the operation of the first and second check switches. A terminal switching device for a private telephone, which is characterized by the above.

An insulation transformer may be provided in the switching circuit. Further, the isolation transformer may be one with a midpoint tap.

[0010]

There are 6 combinations when two lines are taken out of the four lines by the switching circuit. For one of these six combinations, the switching connection of the telephone with a display is made. If the first inspection switch is operated and closed in this state, the connection control means opens the line to the other terminal and connects the terminal telephone with the display to the two lines taken out by the switching circuit. If the two lines are not the control line, the terminal telephone with a display does not display. Therefore, the switching circuits are sequentially switched until the display is performed, and the inspection is sequentially performed by the first inspection switch.

The switching position at which the display-equipped terminal telephone displays is the position at which the control line is connected to the display-equipped terminal telephone. Therefore, the two lines that are not connected to the terminal telephone with the display are the call lines, and this call line may be connected to another terminal.

As another terminal, one with MODEM and one without MODEM are connected by the first and second separate terminals. When one with a MODEM is connected to the first terminal or one without a MODEM is connected to the second terminal, the connection control means stops the operation of the logic circuit by the operation of the first and second check switches, and the like. Keep the terminal connected to the call line.

When the other terminal is pulled out from the terminal, the connection control means operates the logic circuit in response to the operation of the first and second check switches or the connection of another terminal to the first or second terminal. To do so.

Further, a transformer with a midpoint tap and a relay contact are combined in the switching circuit, and the switching circuit has 6
In addition to the street, one or more switching positions are provided, and at the added switching position, it is possible to maintain the state in which the above four lines are connected according to the model of the exchange by using the middle point tap of the transformer. Make sure that the device-equipped terminal phone does not become inoperable.

The insulation transformer separates the exchange from other terminals in a direct current manner. If the isolation transformer has a midpoint tap, the midpoint tap is used to put the control line as well as the communication line in the four lines in the connected state.

[0016]

As described above, according to the present invention, it is possible to connect to a telephone with a display while selecting two lines out of four lines connecting an exchange and a terminal and whether the terminal is connected to a control line by an inspection switch. M is used to connect other terminals with the call line that is reflexively obtained by inspecting whether or not the control line is found while visually checking the display on the telephone with display.
In addition to connecting to either the terminal with ODEM or without MODEM, the operation of the inspection switch was disabled by connecting with another terminal, so after clearly recognizing that the call line was found, Other terminals can be connected instead of the local telephone.

Further, the other terminals can support both with and without MODEM. In order to preferentially operate whichever is driven first, another terminal is driven later to drive the other terminal. It does not interfere with the drive state of.

Further, since it is possible to select a state in which two lines of the four lines connecting the exchange and the terminal are not separated according to the type of the exchange, it is possible to connect other terminals to the exchanges of all existing models. it can.

Further, in the present invention, since the balanced type insulating transformer is inserted in the switching circuit, the common mode noise is canceled and the noise is reduced by providing the time constant circuit on the primary side and the secondary side of the transformer. In addition, the number of turns on the primary side of the transformer is set to be larger than the number of turns on the secondary side, so that noise that enters from the line can be suppressed and the signal output to the line can have a larger amplitude, resulting in a large S / N ratio. Can be improved.

Further, according to the present invention, a current control circuit capable of controlling the current supplied to the other terminal so as to match the ideal NTT (registered trademark) line is provided, and the matching with the NTT line is excellent. You can

[0021]

1 and 2 show a circuit configuration of an embodiment of the present invention divided into two diagrams for convenience of drawing.

In FIG. 1, a four-wire line from the exchange is connected to a business phone, which is a terminal, by four wires via a relay contact circuit, while two wires are on the right side of the audio signal circuit. It is connected to.

By connecting two lines of the control line among the four lines with the exchange to the exchange, the business phone can perform the control operation of the terminal telephone with the display including the lighting of the lamp L. Therefore, if the control line 2 of the exchange and the two terminals for inputting the control line of the business phone are connected by connecting or disconnecting the relay contact circuit, the state can be visually confirmed by lighting the lamp of the business phone.

The relay contact circuit energizes and deenergizes the four relays A, B, C and D on the lower side of the figure to disconnect their contacts A1, A2, B1, B2, C1, C2 and D. Instead, create 6 different connection states.

[0026] The six ways include how to divide into four lines L1, L2, L3 and L4, including the case where the communication lines are L1 and L2 and the control lines are L3 and L4. It means that there are 6 ways.

The six connection states are relays A, B,
It is selected by the six switching positions of the rotary switch R-SW inserted in the circuit for energizing the C and D coils.

Next, the audio signal circuit is connected from the relay contact circuit to the primary winding of the transformer Tr via the relay contact E, and the secondary winding thereof is connected to the crystal speaker SP via the amplifier OP to output the audio signal. The signal is output as a sound and is connected to the circuit of FIG.

The circuit shown in FIG. 2 is connected to the differential circuit including the transistors Q4 to Q7 from the line indicated by the symbol P through the constant voltage / constant impedance circuit including the transistors Q1 to Q3. When the terminal is connected to either one of the two output terminals OUT1 and OUT2, this differential circuit has a function of giving priority to the one connected first.

That is, when a personal computer connected to the output terminal OUT1 is driven, a collector current flows through the transistor Q6. Then, the low signal (L) is applied from the collector of the transistor Q7 to the input end of the NOR gate NOR1 instead of the high signal (H) so far, so that the output of the NOR gate NOR1 becomes high (H). Since the high signal (H) is inverted by the inverter array IA and given to the lower end of the relay F in the figure instead of the low signal (L),
The relay F is energized to switch the relay contact f to the broken line side in the figure.

At this time, the relay contact g is in the solid line position in the figure, and the output terminal OUT1 continues the priority operation.

The same applies when a personal computer connected to the output terminal OUT2 is driven.

The output terminal OUT1 is a terminal for connecting a personal computer with a MODEM, the other output terminal OUT2 is a terminal for connecting a personal computer without a MODEM, and the MODEM is provided in the apparatus of the present invention. . Both of these terminals make it easy to support both PCs with and without MODEM.

The operating state of the differential circuit is transistor Q5.
Alternatively, it is given to the logic circuit as a decrease in the collector voltage of Q7. This logic circuit is composed of NOR gates NOR1 to NOR4, a diode and an inverter array IA shown in the lower part of the figure.

The decrease in the collector voltage of the transistor Q5 or Q7 is given to NOR gates NOR1 and NOR2 in the logic circuit to activate and deactivate signals of the relays F and G, and to the rotary switch R-SW in the circuit of FIG. Is output as the command signal SW. The outputs of the NOR gates NOR1 and NOR2 are output by the inverter array IA to the transistors Q2 and Q3.
Be fed back to.

Signals from check switches CH1 and CH2 are also applied to NOR gates NOR3 and NOR4 of the logic circuit, and signals for energizing and deactivating relay E and rotary switch R-SW in the circuit of FIG. Outputs are generated as command signal SW and command signal OP to amplifier OP.

The check switch CH1 is for activating the relay E to connect the relay contact circuit to the transformer Tr, and the check switch CH2 is for operating the amplifier OP to cause the speaker SP to produce a sound. The operation is performed.

The operation of this circuit is as follows.

First, it is necessary to know which of the six switching positions of the rotary switch R-SW is the position where the line is correctly connected. This is a rotary switch R-SW
Check switch CH1 for setting the state of connecting the personal computer after setting the switch to any of the six switching positions.
Turn on and check if the lamp L of the business phone lights up.

For simplification of the description, the control line is L
The description will be given assuming that the communication lines are L2 and L3 at 1 and L4, the rotary switch R-SW is switched to an appropriate position, and a proper state has already been found.

FIG. 3 shows a state in which a connection suitable for the conditions of the control lines L1 and L4 and the communication lines L2 and L3 is obtained. To do this, the rotary switch R-SW is set to the "2" position, the check switch CH1 is turned on to generate an output to the NOR gate NOR3, and the signal SW is output from the inverter array IA composed of inverters to the rotary of FIG. Relay B via contact 2 of switch R-SW
And C and energize them. Relays B and C
Biasing the relay contacts B1, B2, C1 and C2
Changes to the lower side in the figure.

Therefore, L2 and L3 of the four wires are connected to the primary winding of the transformer Tr via the relay contact E. Since L2 and L3 indicated by thick lines are communication lines, the voice signal transmitted from the exchange through the lines L2 and L3 is sent to the circuit of FIG. 2 through the transformer Tr. Further, L1 and L4 indicated by thin lines are properly connected to the control signal terminals of the business phone, and the control signal is given to the business phone, so that the lamp L of the business phone is turned on. However, it is not possible to make a call because no voice signal is given to the business phone.

By the operation up to this point, the rotary switch R-SW is switched to match the breakdown of the four lines from the exchange.

Then, the inspection switch CH1 is turned off and the inspection switch CH2 is turned on. Then, for example, "117" or "177" is taken in as a voice signal by a business phone and is sent to the telephone line.

As a result, the output of the NOR gate NOR4 is generated, and the signals SW and OP are output from the inverter array IA. At this time, the signal SW causes relays A to D
Is energized, but relays E, F and G are deenergized.

Therefore, the relays A to D enter the state shown in FIG. 3, the voice signal reaches the transformer Tr via the relay contact E, is further amplified by the amplifier OP shown in FIG. 1, and is sounded from the speaker SP.

It should be noted that, depending on the manufacturer, voice may be produced not only by the speaker SP but also by the handset of the telephone depending on the telephone. In the case of this type of telephone, it cannot be switched as it is in the embodiment shown in FIG. 1 and FIG. 2, so inspection by the operation of the inspection switch CH2 is required. This type of telephone is dealt with by the embodiments shown in FIGS. 5 to 7 which will be described later.

FIG. 4 shows the energization characteristics of the constant voltage / constant impedance circuit composed of the transistors Q1 to Q3. This characteristic is defined by the NTT standard.

FIGS. 5 to 7 show another embodiment of the present invention, which is shown in an exploded manner in three drawings for convenience of drawing. 5 and 6, the circuit portion corresponding to the circuit of FIG. 1 in the embodiment of FIGS. 1 and 2 is generally shown in FIGS. 5 and 6 although the way of disassembling is slightly different from the case of FIGS. 2, a portion corresponding to the circuit of FIG. 2 is generally shown in FIG.

The circuit of FIG. 5 basically shows the circuit configuration of the circuit of FIG. 1 from which the relay energizing circuit portion is removed.

In the circuit of FIG. 5, the transformer T
A r with a middle point tap is used as r, and the middle point is used to connect the switch and the terminal with four wires.
For this reason, relay contacts h1 and h2 are inserted between the midpoint of the transformer Tr and the two lines of the business phone. The relay contacts h1 and h2 are provided in the circuit shown in FIG. 6 as described later.

Further, in the circuit of FIG. 5, the following first to third various noise reduction measures are adopted.

First, the primary side of the transformer Tr is provided with a center tap so that the line input circuit is a balanced circuit so as to cancel out in-phase noises on the two lines.

Secondly, a CR circuit constant is inserted in the primary side circuit to reduce high frequency noise, while a small capacity capacitor CB is connected across the windings in the secondary side circuit to reduce high frequency noise. At the same time, a large capacity capacitor CA is inserted in series to reduce low frequency noise.

Third, the winding ratio of the primary side and the secondary side of the transformer Tr is set to be larger on the primary side than on the secondary side, and the noise penetrating from the line to the switching circuit depends on the number of turns. The S / N ratio is relatively improved by reducing and taking in the signal, and conversely by increasing the voltage of the signal sent from the switching circuit to the line according to the winding ratio to improve the noise-to-noise ratio.
The turns ratio must be 1.1 to 1 in consideration of the loss of the transformer, while the lower limit of the input signal level is 2
There is one to one. The winding ratio will be selected within this range.

In the circuit of FIG. 5, the transistor Q11
The point that the sound generation circuit by Q12 and Q12 is incorporated is different from the circuit of FIG.

Next, regarding the circuit of FIG. 6, in place of the rotary switch R-SW in the circuit of FIG. 1, a binary coded decimal switch BCD-SW (hereinafter simply referred to as BCD-SW) and a binary / decimal conversion circuit B are used. / D (hereinafter simply referred to as a conversion circuit), OR gates OR1 to OR4, and inverters IN1 to IN4 are used.

The circuit composed of the switches S1 and S2, the OR gate OR5, the OR gate OR6, the transistor Q13, the inverter IN, and the relays e and h is a circuit that cooperates with the circuit shown in FIG. 7, and is connected to a personal computer. The output of the BCD-SW is generated only at the stage. The inverter IN is for adding a function in the future.

That is, the H signal is applied to the input terminal of the OR gate OR gate 5 only when the switch S1 is pressed,
BCD-SW comes to work. The switch S2 is
Once pushed, an H signal is applied to the base of the transistor Q12 in the sounding circuit to turn on the transistor Q12 to turn off the transistor Q11, and a line signal is applied from the secondary side of the transformer Tr to the operational amplifier OP11 for amplification. Sound from the speaker SP.

After that, when the switch S2 is opened, the transistor Q12 is turned off and the transistor Q11 is turned on, and the input of the operational amplifier OP11 is AC short-circuited.

Since a large time constant is inserted in the output of the switches S1 and S2, that is, the input terminal of the OR gate OR6 and the path for giving the H signal to the base of the transistor Q12, malfunction of the exchange occurs when the switch S1 or S2 is opened. At the same time, the sounding circuit stops sounding after a certain time.

FIG. 7 shows two output terminals OUT1 and OUT.
When a terminal is connected to any of the two terminals, that terminal is activated preferentially to another terminal connected to another output terminal, and the M connected to the terminal is connected to the other terminal.
It shows a circuit for supplying a current conforming to ODEM, in other words, a current conforming to the ideal circuit of the NTT circuit.

That is, the transistors Q15, Q16,
The diodes D1 and D2 and the relays f and g constitute a circuit for preferentially operating the terminal connected to one output terminal, and the operational amplifier OP12 and the transistor Q14.
Constitutes a circuit that controls the supply current according to the impedance of the terminal.

In this circuit, the light emitting diodes LED1 ...
The LED 3 indicates whether the terminal connected to each output terminal is operating or in the standby state.

The operation of the circuit of FIG. 7 will be described with reference to the circuit of FIG.

It is assumed that a terminal device, that is, a personal computer is connected to the output terminal OUT1. In this case, the base circuit of the transistor Q15 becomes conductive via the NC side of the relay contacts g1 and g2, and the transistor Q15 is turned on. As a result, the relay f is energized and the relay contact f is switched to the NO side, so that the output terminal OUT is output via the relay contact f.
The terminal connected to 2 does not work. Even if the terminal is connected to the output terminal OUT2 again, the terminal does not operate.
At this time, the light emitting diode LED1 connected in parallel with the coil of the relay f is turned on, which indicates that the terminal connected to the output terminal OUT1 is in operation.

When the personal computer connected to the output terminal OUT1 is deactivated, the transistor Q15 is turned off, so that the terminal connected to the output terminal OUT2 can be activated.

When the relay f is energized, the H signal is given to the input terminal of the OR gate OR6, so that the H signal is given from the output terminal of the OR gate OR6 to the input terminal of the OR gate OR5, and the BCD- signal is supplied via the OR gate OR5.
The H signal is given to the COM terminal of SW.

As a result, the conversion circuit B /
A binary signal is output to D and converted into a decimal signal by the conversion circuit B / D. The OR gate OR and the inverter IN operate according to the output from the conversion circuit B / D to activate any one of the relays a to d and h.

For example, when an output occurs at the output terminal Q1 of the conversion circuit B / D, the OR gate OR1 and the OR gate O
The H signal is applied to the input terminal of R2 and the outputs of the OR gates OR are applied to the inverters IN1 and IN2, so that the relay a and the relay b are energized.

Two of the lines L1 to L4 in the circuit of FIG. 5 are selected by energizing the relays a and b, and the output terminals OUT1 and O are output via the transformer Tr and the capacitor CA.
UT2 is connected to the line.

At this time, if the switch S2 is pressed, the transistor Q12 is turned on and the transistor Q11 is turned on as described above.
Is turned off and the operational amplifier O is connected from the secondary side of the transformer Tr.
A signal from the line is given to the non-inverting input terminal + of P11, amplified and sounded by the speaker SP. Therefore, it can be confirmed that the sound is connected to the line. This sounding continues for a predetermined time, for example, 2 seconds after the switch S2 is opened due to the time constant inserted between the switch S2 and the base of the transistor Q12.

Here, when returning to the output terminal of the OR gate OR6, when the H signal is generated at the output terminal of the OR gate OR6, the transistor Q13 which was on until then is turned off. Therefore, the relay contacts e1 and e2 are switched to the NC side, and the line is connected to the primary side of the transformer Tr.

A circuit having a large time constant is inserted between the output terminal of the OR gate OR6 and the output terminal of the OR gate OR5, and relays a to d and h are caused by the intermittent signal when the relay contact e is dialing. Are considered to not open.

When an output is generated at the output terminal Q7 of the conversion circuit B / D, the relays b and c are energized via the OR gates OR2 and OR3 and the inverters IN2 and IN3, and the relay h via the inverter IN7. Is energized to close the relay contacts h1 and h2 in the circuit of FIG. As a result, the two wires that are not connected by the relay contacts a to d are connected to the business phone via the middle point of the primary winding of the transformer Tr. As a result, the present invention can be applied to a terminal telephone of the type in which four lines from the exchange are always connected.

In the above description, the terminal connected to the output terminal OUT1 operates. On the contrary, if the terminal connected to the output terminal OUT2 is activated first, the output terminal OUT2 is also activated preferentially.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a part of an embodiment of the present invention.

FIG. 2 is a circuit diagram showing another part of the embodiment of FIG.

FIG. 3 is a diagram for explaining the operation of a relay circuit in the circuit of FIG.

FIG. 4 is a diagram showing energization characteristics of a constant current / constant impedance circuit in the circuit of FIG.

FIG. 5 is a circuit diagram showing a part of another embodiment of the present invention.

6 is a circuit diagram showing another portion of the embodiment of FIG.

FIG. 7 is a circuit diagram showing still another portion of the embodiment of FIG.

[Explanation of symbols]

 A to G relay a to h relay MODEM modem Q transistor NOR NOR gate OR OR gate OP amplifier

Claims (6)

[Claims] 1. A terminal telephone with a display and a MODE, which is connected to a main exchange by four lines consisting of a telephone line and a control line.
A terminal switching device for a private telephone for sharing a single line with a plurality of terminals by switching connection with another terminal which should be connected to the communication line via M. A switching circuit that selectively takes out two of the lines and connects them to the terminal telephone with a display, and makes each condition for connecting another two wires to a terminal for connecting to the other terminal, and an operation. A first inspection switch for connecting the telephone with a display to the two wires that are closed by the switch circuit and operated for the inspection of switching the signal of the other two wires from the terminal telephone to the terminal. A second check switch that is closed by a logic circuit, a logic circuit that generates a signal corresponding to the first closed circuit of the first and second terminals, and a signal that is output by the logic circuit. Previous Connection control means for connecting one of the first and second output terminals to the other two wires and for preventing the logic circuit from responding to the operation of the first and second check switches. A terminal switching device for a private telephone, which is characterized in that 2. A device according to claim 1, wherein an insulating transformer is inserted in the other two wires. 3. The device according to claim 2, wherein the insulating transformer is of a type having a midpoint tap on the primary side. 4. The device according to claim 2, wherein the insulation transformer T has a secondary side provided with a large-capacity capacitor directly inserted into a communication line and a small-capacity capacitor connected between the communication lines. Terminal switching device for premises phones. 5. The terminal switching device for a private telephone according to claim 2, wherein the number of turns on the primary side of the insulating transformer is larger than the number of turns on the secondary side. 6. The device according to claim 1, wherein the switching circuit includes a circuit that controls a current supplied to the other terminal.