JPS6022867B2 - Control information transmission method for button telephone equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a button telephone device, and more particularly to a button telephone device suitable for small businesses or residences.

Conventional key telephone devices of this type are configured to be wired using multi-core cables with approximately 20 core wires.
Wiring work is also not easy, and the arrangement of multi-core cables has the disadvantage of spoiling the aesthetics of the room and increasing construction costs.

In order to eliminate these drawbacks, there is a desire to reduce the number of core wires in distribution cables, but conventionally information between the main device and each slave device was transmitted in parallel within a multi-core cable. Therefore, when reducing the number of core wires, it is necessary to multiplex and transmit this parallel information. However, if all the information is multiplexed and transmitted over the information line, the configuration of the circuit used for information transmission becomes complicated and the cost increases. SUMMARY OF THE INVENTION An object of the present invention is to provide a control information transmission system for a button telephone device that can reduce the number of core wires of a distribution cable with a relatively simple circuit configuration.

The present invention will be explained in detail below.

First, the principle of the entire system of the button telephone bag counterfeit according to the present invention will be explained.

In the present invention, information from the main device to the slave device and information from the slave device to the main device are divided into two blocks, and lamp and amplifier operation information from the main device to the slave device is multiplexed and sent to the information line. We decided to use the telephone line to send button selection, hold, and dialing information from the handset to the main unit. The communication current of the communication line is changed by the constant current circuit inside the handset, button selection, and hold. Dial information is now identified by a detection circuit inside the main device. Putting the above together, 2 central lines and 1 extension line
The table below shows the case of a button telephone device that accommodates lines and connects three handsets. Table 1 clarifies the information and transmission routes, and Table 2 shows an example of the relationship between the status of each handset and the communication current with respect to information sent over the communication line. Table 1 2 The basic matters used in the present invention, including the type of transmission line, are listed below.

[11] The selection of communication paths is performed by switching one line at a cross point using SCR. '21 Office line 1, Office line 2,
The extension is selected by identifying the difference in call current.

'31 The determination of the communication current in order to accurately detect the difference in the communication current in Clause '21 is performed by a constant current circuit using an operational amplifier in the handset.

[When using the 4'SCR cross-point switching method, the transmission of dial pulses from the handset is extremely difficult.

In the case of a normal telephone, when the communication current is cut off during dialing, the holding current of the SCR is cut off, and the formed cross point is canceled. In order to solve this problem, by controlling the constant current circuit on the handset side, even when the current is cut off by the dial, a talking current similar to the self-holding current of the SCR cross point will flow, and when the dial is connected, a predetermined talking current will flow. The difference is identified within the main device and the pulse is relayed to the line. ■
When the hold button is pressed, the constant current circuit in the handset is controlled to increase the call current by about 2 hA compared to the normal call current, and this is detected.

{61 When both the central office line and the extension line have handset outputs and the trunk is empty, a trigger is input to the crosspoint SCR to capture the line; otherwise, the line is not captured and the line is kept confidential. [7] Individual extension calls and single calls to handsets are made by dialing a single digit. '81
In the main device, voice calling of extension lines, transmission of incoming tones, and selection of slave units are performed by cross-point control.

(9) Information transmission via the information line is unidirectional, from the main unit to the slave units, and is performed using time division multiplexing.

As for the information content, 3 bits are used for the lamp information of the office line 1, office line 2, and extension line, and 1 bit is used for the amplifier operation information, making one frame a total of 4 bits. Based on the above principles, the transmission of information between the main device and each child device will be explained in more detail.

First, since a local battery method is used for transmission of dial pulses, it is necessary to relay the dial pulses sent from slave units to the line within the main unit.

In addition, since SCR crosspoint control is used to connect the handset and the central office line trunk, if dial pulses caused by interruptions and breaks in the call current are sent directly from the handset to the main unit as in conventional telephones, the call current will be reduced. When the SCR is disconnected, the holding current of the SCR is lost, so the SCR is restored and the call loop is broken. To solve this problem, when dialing, a current of about 7 mA, which is higher than the SCR's holding current (8 hA), is passed even when the call current is interrupted, and when the call current is connected, the call current (40 or 3 A) is passed as is, and the difference is detected. relay to the line. FIG. 1 shows the change in communication current and the detection level of the office line detection circuit when dialing from the handset to the office line 1.

Regarding station line hold, the constant current circuit of the handset is controlled so that when the hold button of the handset is pressed, the call current increases by 2 hA compared to the normal call current, and this increase is detected within the main device.

On the information line, a total of 4 bits of information, 3 bits of lamp information and 1 bit of amplifier operation information, sent from the main device to the slave device are time-division multiplexed and sent.

Regarding the synchronization method, it is impossible to send the synchronization signal over 80 lines, and the start-stop synchronization method would complicate the circuitry of the handset, so the information signal and the synchronization signal are sent at the same time.

The synchronization signal is sent as a pulse with a level of about 10V, and the information signal is sent as a pulse with a level of about 24V on top of the synchronization signal, and the synchronization pulse and the information pulse are separated and used in the slave device. Regarding the reset pulse, one frame uses about 8 bits for the information amount of 4 bits on the information line, and 4 bits are used for the empty information line.
As for the bit, there is also no synchronization pulse, and a reset pulse is generated within the slave device when the synchronization pulse does not exist continuously. FIG. 2 shows an overview of the information content of the information line and the information processing within the handset.

According to the above principle, the button telephone device according to the present invention can be constructed as shown in FIG.

The main device and each slave device #1, #2, #3 are connected by four wires. The four lines are, from the top of FIG.

Power is sent through the power supply (10) line P and power supply (1) line G, and communication current is sent through the power supply (10) edge P and the communication line T. Also, depending on the difference in the current flowing through the communication line T, information is sent from the slave device to the main device. Information sent from the main device to the slave device is sent as a 4-bit multiplexed signal through an information line. The incoming tone signal and extension ringing voice signal that notify you of an incoming call from the central office line are sent to the telephone line T.
is sent through the power supply (1) line G, amplified by the slave amplifier 24, and then sent out from the speaker 25. The lamp status signal from the main device to the slave unit and the signal for operating the slave unit amplifier are as follows: [Slave unit lamp control circuit 9 → Incoming tone → Circuit 10 → Parallel/serial conversion circuit 14 → Information line J → Series/parallel conversion circuit 23], each lamp 31, 32,
33 and slave amplifier 24. The button selection information, central line capture and abandonment information, dial information, and hold information sent from the handset to the main device are controlled by the call current control circuit 21 in the handset and button or dial operations to control the call current to a set current value. Each slave device detection circuit 8-1, 8-2, 8-3 in the main device, detection circuit 2-1-2 of station line 1, detection circuit 2-2-2 of station line 2, and It is identified by the extension detection circuit 3-2 and the main device is controlled. Button selection information is S
Since this is information before the cross point is formed by CR, it is identified by slave device detection circuits 8-1, 8-2, 8-3,
The output forms an SCR cross point, and the respective office lines are coupled through trunks 2-1, 2-2, and 3 of the office line 1, office line 2, and extension line. When a cross point is formed by SCR and a communication path is established, the handset detection circuit 8-
1, 8-2, 8-3 are separated from the communication path, and are replaced by respective detection circuits 2-1-2, 2-2-2 for the central office line 1, central office line 2, and extension line.
, 3-2 are in operation, dial information, hold information,
Identify and control the abandonment information of central office line extensions. FIG. 4 shows a specific example of the main device in the embodiment of FIG. 3, and FIG. 5 shows a specific example of the slave device.

Next, the operation of the basic functions will be explained.

(Operation for calling the office line) When the office line 1 button of handset #1 is pressed and the handset of the handset goes up and the hook switch HS is activated, the operational amplifier O
A talking current of 4 hA is determined by the resistor R203 of the constant current circuit constituted by P201 and the transistor Tr201 and R204 selected by the button switch LKI, and this
Hook switch HS→BS contact→talk line T (#1)] flows to talk line T.

In the main device, the output of IC4 is low and no current flows through the photocoupler POI, so the transistor Trl connected to it is OFF, and the OR circuit IC2 and N
Through the OT circuit IC3, the transistors Tr2 and Tr3
is in the ON state. Here, when a communication current of 4 plates A flows from the handset, the communication current flows to the resistor R3 through the transistor Tr3, and a voltage corresponding to 40 hA is generated across the resistor R3. Comparator C in slave device detection circuit 8-1
ompl operates and its output is input to AND circuit IC9. In addition, in the detection circuit 2-1-2 of the central office line 1, the communication current flows through the transistor Tr3 and the resistor R3 and the transformer LTCOI.
Since no current flows to resistor R8, comparator Com
p4 is FF, and its output is low. The output of the comparator Comp4 passes through the NOT circuit IC54 and is applied to the AND circuit IC9. That is, when the trunk 2-1 of the office line 1 is not in use, the handset detection circuit 8-1
When an output that captures the station line ICOLI is added, AND
Circuit IC9 is set to High output, and slave #1 and office line 1 are connected.
Trigger the SCR gate of S1 that connects trunk 2-1. At the same time, the Hi output of AND circuit IC9 is [O
Transistors Tr2 and Tr3 are turned off through the path of R circuit IC4 → OR circuit IC2 → NOT circuit IC3], and the communication current is passed through the path of [resistance R4 → photocoupler PDI → SCR of SI → central line 1 transformer LTCOI → resistor R8]. flows. When a communication current flows through the photocoupler PDI, the transistor Trl turns on, and [NOT circuit ICI→
Through the path of OR circuit IC2→NOT circuit IC3],
The transistors Tr2 and Tr3 are kept OFF. When a communication current flows through the resistor R8, a voltage is generated across the resistor R8, the comparator Comp4 operates, and the high output turns on the transistor Tr5, thereby operating the relay AI. The line of the office line ICOLI is closed by the contacts a, -, and the slave unit # is passed through the office line 1 transformer LTCOI.
1 completes the acquisition of station line 1. In addition, when the AI relay operates, the lamp signal of the station line 1 applied to the data selector 67 terminal 4 by contacts a and -2 becomes H; gh, so
After parallel/serial conversion by the parallel/serial conversion circuit 14, the LDI information on the information line J becomes High. This signal is sent to Koiso through the information line J, and is sent to the comparator Comp201.
, Comp202, the pulse is separated into a synchronization pulse and an information pulse, and the serial/parallel conversion circuit 23 converts the pulse into serial/parallel, turning on the transistor Tr202 and lighting the lamp LDI. Here, when handset #1 makes a dial call, the dial opens and closes contact DPI, and when contact DPI is open, resistor R204 of the handset constant current circuit is disconnected by contact DPI, and the call current is determined by resistor R203. 1 enemy hA.

Also, when the contact DPI is closed, the current is 4 hA, similar to when talking. Also, contact DP2 connects telephone circuit T during dialing.
Short-circuiting EL not only prevents noise from the receiver due to intermittent current, but also prevents disturbance of the waveform of intermittent current due to L and C of the telephone circuit TEL. The intermittent current generated by the dial is sent to the main unit through the telephone line T, which is connected to the [anecdotal line T (
#1) → Resistor R4 → Photocoupler PDI → SI SCR →
A voltage pulse is generated across the resistor R8. This voltage pulse is detected by comparator Comp5, and when the communication current is 15 hA or less, comparator Comp5 becomes Hi.
Outputs gh output. The output of comparator Comp5 is N
The transistor Tr6 is turned on through the OT circuit IC12 and the AND circuit 13, and the DI relay is turned on.
A dial pulse is sent to the line through contacts d, -, of the DI relay. Since a minimum call current of 7mA is ensured even during dialing, the current flowing through the SI's SCR is equal to the SCR.
The minimum holding current becomes 5 hA or more, and the SCR maintains the ON state. When dialing is completed, the call to the other party is made through the trans LTCOI. When handset #1 is talking through central line 1, handset #2 attempts to interrupt central line 1 by pressing the button on central line 1 and raising the handset. It operates and transmits a predetermined communication current from the handset side to the communication line T (
#2) to the main device. At this time, in the main device, transistors Tr9 and Trlo of the slave device detection circuit 8-2 are turned on.
In this state, a current flows through the resistor R15 through the transistor Trlo, and a voltage is generated across the resistor R15, which causes the comparator Comp7 to operate, and the output of the comparator Comp7 is input to the AND circuit ICI. However, at that time, the station 1 transformer LTCOI is being used by handset #1, so the communication current from handset #1 flows into resistor R8 in the detection circuit 2-1-2 of station line 1, and the communication current from handset #1 flows into both ends of it. Voltage is present. Therefore, the comparator Comp4 operates and its output is input to the AND circuit ICIO through the NOT circuit 54. Since this input is at a low level while the transformer LTCOI is in use, Even if there is an output from 2, A
The ND circuit ICI O is not opened, a trigger pulse is not applied to the SCR of S2 that connects the handset #2 and the office line 1 transformer LTCOI, and the handset #2 and the office line 1 transformer LTCOI are not coupled. By the above-described operation, the confidentiality of the telephone call on the central office line 1 of the handset #1 is protected. At this point, when handset #1 lowers the handset,
When the hook switch HS was turned off, there was no communication current, and the SC of the SI, which had connected the station 1 trunk and slave unit #1,
The holding current of R disappears and SI is restored.

When SI is restored, the voltage across resistor R8 disappears, comparator Comp4 turns OFF, and transistor T
r5 turns OFF. Relay AI is restored by turning off transistor Tr5, and its contacts a, -, are opened to open the line. Also, when Relay AI is restored, the station line 1 lamp information is turned OFF by contacts a and -2, and this information is transmitted in parallel and
After being parallel-to-serial converted by the serial conversion circuit 14, it is sent to each slave unit through the information line, and the office line 1 lamp of each slave unit is turned off. As described above, handset #1 acquires central line 1 from the state in which the handset is initially placed, but when using a key telephone, for example, immediately after the telephone call on central line 2 or an extension ends, When acquiring central office line 1, the acquired line may be changed by directly pressing the central office line 2 or extension button to the central office line 1 button without putting down the handset. The operation of this device at this time is as follows. Assume that the button for the office line 2 is now switched to the button for the office line 1.
While capturing office line 2, [power supply (10) wire P → constant current circuit → telephone circuit TEL → switch LK2 → switch LKI → hook switch HS → spot contact → talking line (#1) → resistor R4
→ Photocoupler PDI → SCR of S4 → Transformer LTC02 of office line 2 → Resistor R20 → Earth) When the communication line 2 is captured by transformer LTC02, the switch LKI of the office line 1 button is When turned on, it is linked to the station line 1 button and the BS in that call path is activated for a moment.
The contact opens and the communication current is cut off. Therefore, the cross-point thyristor S4 is restored. Also, since the communication current is cut off, the photocoupler PDI is turned off, and the transistor Tr1 is turned off. OF of transistor Trl
By F, [NOT circuit ICI→OR circuit IC2→NO
The transistor Tr2 is connected to O through the path of the T circuit IC3].
At this time, the transistor Tr3 is turned on. Since the BS point turns OFH for a moment and then turns ON immediately, the communication current determined by the contact LKI of the office line 1 button and the resistor R204 is as follows: [Power supply (10) line P → Constant current circuit → Telephone circuit TE
L → Switch LKI → Hook switch HS → BS contact →
The signal flows through the communication line T (#1) -> transistor Tr3 -> resistor R3 -> ground], and thereafter operates in the same way as the capture operation of the office line 1 described above. (Operation of incoming call on central office line) When an incoming call is received on central office line 1 and a ringing signal is added, relay RI operates through capacitors CI4 and CI5, and then the output of OR circuit IC66 becomes Hj due to points r and -2. The slave amplifier operation information applied to the terminal 7 of the data selector IC 67 becomes ON.

This information is parallel-to-serial converted by a parallel-to-serial conversion circuit 14 and sent to each child unit through an information line J. On the handset side, the information is serial-parallel converted by the serial-parallel conversion circuit 23, and the transistor Tr205 is turned on to operate the C relay. The amplifier circuit output is connected to the speaker 25 through the contact c, and the amplifier circuit becomes operational.

The incoming tone circuit 10 is operated by the r and -2 contacts, and the tone ringer signal is amplified by the AMP circuit 11, and the tone ringer signal is amplified by the tone sending transformer T. It is input to T. One end of the secondary side of the transformer is given a potential of approximately 5V by a Zener diode ZD4, and the other terminals are connected to the communication lines T(#1) and T(#2) of all slave units through diodes D6, D7, and D8. ), T(
#3). Now, when handset #1 is not in use, [15V → transformer T. T→Diode D6→
Communication line T (#1) → Hook switch HS → Resistor R208
] current flows through the path, diode D6 turns on, and the tone ringer signal is superimposed on this path, causing the slave unit #
1, is amplified by the slave amplifier 24, and is transmitted to the speaker 25.
sounds. Also, when handset #2 is talking on the central office line, the communication current is [communication path T (#2) of handset #2 → photocoupler aD]
2→S5 SCR→transformer LTOC2 of office line 2→resistance R20], diode D7 is reverse biased and turned off, and the communication line T(
No tone ringer signal is sent to #2).

By the above operation, only the speaker 25 of the handset that is not in use is made to sound without affecting the call in use. Furthermore, for handsets that are preset to stop the station ringing signal, it is also possible to stop the station ringing tone by not installing the diodes D6, D7, or D8 that connect the communication line of the handset. When the relay RI operates, its contacts r, -,
The oscillation circuit OSC (2H) in the slave lamp control circuit 9 is
Z), a 2Hz square wave signal oscillates, and the AND circuit IC6
0 and OR circuit IC64, 2H is set to station line 1 lamp information.
Z intermittent signal is added. This is converted into parallel/serial and sent to each handset through the information line J, converted into serial/parallel, and the station line 1 lamps of all handsets flash at 2Hz. Here, when handset #1 presses the office line 1 button and raises the handset, it operates to make a call to the office line, and the output from the handset detection circuit 8 and the office line detection circuit 2-1-2 of office line 1 are transmitted. A trigger is applied to the SCR gate of the SI that connects the station line 1 transformer LTCOI and the handset #1 by the status output of , and the SI is turned ON.

The communication current is [handset #1 → communication line T (#1) → resistor 4 → photocoupler PDI → SCR of SI → transformer LTCOI →
The voltage generated across the resistor R8 operates the comparator Comp4, and its output turns on the transistor Tr5, thereby operating the relay AI. Rire A
When I operates, its contact aH closes the line of the central office line 1. When the central office line 1 is closed, the calling signal stops, so the relay RI is restored, and the tone ringer signal is stopped by the contacts r and -2. is turned OFF, and the intermittent signal of the station line 1 lamp is ANDed by contacts r, -,
Since it is blocked by the circuit IC60, it becomes a continuous signal, and the office line 1 lamp information becomes continuous lighting information through the OR circuit IC64. The handset amplifier operation OFF signal and the lighting information of the office line lamps are sent to the handsets through the information line J, and all the handset amplifiers are stopped, and the office line 1 lamp is turned on continuously. The operation for terminating a call is the same as for calling a central office line. (Operation of Holding and Reacquisition of Local Line) Next, the operation of holding and reacquiring after a call with the local line will be explained.

Assume that the caller presses the hold button while handset #1 is talking on the local line using central line 1.

When the hold button is pressed, the button for the central office line 1 is not restored, and when the hold button is restored, the central office line 1 button is also restored at the same time. So, if you press the hold button,
Since a resistor R207 is added by the HK contact in addition to the resistors R203 and R204 for determining the current of the constant current circuit, the current flowing through the resistor R207 is added to the normal communication current.
The value of the resistor R207 is determined so that this increase will be approximately 2 hA. Further, at this time, the HK contact short-circuits the telephone circuit TEL to prevent a voltage drop due to the telephone circuit TEL. The increased communication current is sent to the main device through the communication line, [communication line T (#1) → resistor R4 → photocoupler PDI
→ SCR of SI → transformer LTCOI → resistor R8], and the voltage across resistor R8 increases. The comparator Comp6 detects this increase in voltage, and its output turns on the transistor Tr7 to operate the HI relay. When the HI relay operates, its contacts h, -, operate, and the line is closed by the contacts h, -, and the resistor R42. If you release the hold button at this point, the central office line 1 button will be restored along with the hold button, so the call current will disappear and the SI
The SCR of is turned off and the voltage across resistor R8 disappears. When the voltage disappears, the comparators Comp4 and Comp6 are turned off. The AI relay is restored by the output of comparator Comp4, and its contact a
,-, is closed. Although the transistor Tr7 is turned off by the output of the comparator Comp6, the HI relay is self-held by the contacts h, -2 and contacts a, -3, and is in a suspended state. When the AI relay is restored and the HI relay operates, contacts h, -3 and a, -2 turn on the AND circuit 62 and the OR circuit IC64, so that the station line 1 lamp information is changed from continuous information to 1/ The signal changes to a 2Hz intermittent signal and is sent to each handset through the information line J, and the office line 1 lamp of each handset changes from continuous lighting to 1/2Hz blinking. In this state, when handset #1 presses the office line 1 button again to raise the handset and go to reacquire it, the AI relay operates in the same way as when making a call to the office line, and its contacts a, -, transformer ltc
Closed by OI. Also, contacts a and -3 restore the HI relay, and contacts h and -3 and a and -2 turn off 62 in the AND circuit and 64 in the OR circuit, so the station line 1 lamp information is a 1/2 Hz intermittent signal. The signal changes from then to a continuous signal, and the station line 1 lamp of each slave unit changes from blinking to continuously lighting. Termination of the call is the same as for the central office line originating operation. (
(Extension call and extension call) When the extension button of handset #1 is pressed and the handset is raised, switch LK3 turns on resistor R203.
and R206 operate the constant current circuit, and the communication current of the two plates A flows, and this communication current is [power supply (10) wire P→constant current. Current circuit → Telephone circuit TEL → Switch LK3 → Switch L
K2 → Switch LKI → Hook switch HS → Spot contact →
It is sent to the main device through the communication line T (#1).

In the main device, since the transistor Tr3 is ON, the communication line T (#1) connects the transistor Tr3 and the resistor R.
3, and a voltage is generated across the resistor R3. This voltage operates comparator Comp3, and AND circuit I
It is input to the AND circuit IC35 through C8. Also, when the extension transformer IT is not used, the extension detection circuit 3
-2 current flows through resistor R39 and comparator Comp
16 is not operating, the NOT circuit IC41 and OR
It is input to the AND circuit IC35 through the circuit IC38. Therefore, AND circuit IC35 opens and handset #1
A trigger is applied to the gate of the SCR of S7 for coupling with the extension transformer IT, and S7 is turned ON. AND circuit IC35
The outputs of OR circuit IC4, OR circuit IC2 and NO
It is connected to the transistor Tr2 through the T circuit IC3, and the transistor Tr2 is turned off and the transistor T[3 is also turned off.
It becomes F. When the transistor Tr3 is turned off, the communication current flowing through the transistor Tr3 and the resistor R3 is transferred to the SCR of S7.
is ON, so [Talking line T (#1) → Resistor R4 → Photocoupler PDI → SCR of S7 → Extension transformer IT → Resistor R
39]. Since the communication current flows through the photocoupler PDI, the transistor Trl is turned on and [NO
The transistors Tr2 and Tr3 are kept OFF through a path of T circuit ICI→OR circuit IC2→NOT circuit IC3]. Since an anecdotal current of 2 hA flows through the resistor R39,
The comparator Comp16 operates based on the voltage across the voltage. The extension lamp information is turned on by the output of the comparator Comp16, and this information is transferred to the parallel/serial conversion circuit 14.
The information is converted into information and sent to each slave unit via the information line J. In each slave unit, comparator Comp201, Com
After being separated into synchronization pulse and information pulse at p202,
It is converted into parallel information by the serial/parallel conversion circuit 23, turns on the transistor Tr204 through the resistor R212 and the Schmitt trigger IC207, and lights up the extension lamp. Next, when the handset #1 is dialed for an individual call or a single call, the operation is as follows.

'1' In the case of individual calling, when the call current is cut off by dialing, the constant current circuit on the handset side is connected to the resistor R20 by the contact DPI.
6 is disconnected and the talking current is 7 mA due to the resistor R203, and when the dial is in the saddle, the resistor R206 is connected by the contact DPI, so the same current as the talking current of 2 A flows.

This intermittent current is sent to the main device through the communication line T (#1), [communication line T (#1) → resistor R4 → photocoupler PO
A current flows through the path of I→S7 SCR→extension transformer IT→resistance R39], and the voltage across the resistor R39 changes. Comparator Comp17 detects this and [NOT
Circuit IC5.3 → AND circuit IC50 → Counter IC4
9] to the decoder IC 48.

When the output corresponding to the dial is output to the decoder, the output is M
．． In the case of 2, [AND circuit IC46 → OR circuit IC4
3 → Resistor R32 → Diode D4 → Extension transformer IT →
A calling current flows through the path of the resistor R39], and the diode D4 is turned on. By turning on the diode D4, the audio signal of handset #1 is transferred from [handset #1→talk line T (#
1) → Capacitor CI → SCR of S7 → Diode D4
→ Capacitor C9 → Capacitor C4 → Communication line T (#2)
→ Hook switch HS → Capacitor C202 → AMP2
5→speaker 25], the speaker 25 transmits the calling voice of the slave unit #1.

When the output is output from the decoder IC48, the decoder output is O.
Amplifier operation information is output through the R circuit IC52 and IC66.
Let it be N. This information is sent to the handset through information line J,
The C relay is operated to put the amplifier 24 of each slave unit into an operating state. Also, during calling, from the output of decoder IC48 [64 to AND circuit → OR circuit IC43 → OR circuit IC39 → AN
H to the trigger gate input of the cross point SCR for the extension of the handset called through the path of D circuit IC36].
Add i statement.

When handset #2 responds to the call, the call current 2 is determined by resistors R203 and R206 in the constant current circuit.
Dish A is [power supply (10) wire P → constant current circuit → telephone circuit T
EL → Switch LK3 → Switch LK2 → Switch LK
I → Hook switch HS → BS point → Call line T (#2)
] to the main device. Transistor Trlo is O
Since it is in the N state, the communication current flows through the transistor TrIO.
The voltage flows through the resistor R15 through the resistor R15, a voltage is generated across the resistor R15, and the comparator Comp9 operates. The output of the comparator Comp9 is input to the AND circuit IC36 through the AND circuit IC21. Now, AND circuit I
High is applied to the other input of C36 from the output of decoder IC48 through the path [AND circuit IC46 → OR circuit IC43 → OR circuit 39], so AND circuit IC36 is opened and the connection between slave unit #2 and the extension line is Add a trigger to the SCR gate of S8 that connects the transformer IT,
Turn S8 ON'. The output of the AND circuit IC36 is [
Transistor Tr9 is turned off through the path of OR circuit IC1 7→OR circuit IC1 5→NOT circuit IC16)
Therefore, the transistor Trio is also turned off. When the transistor Trl o turns OFF and the SCR of S8 turns ON, the communication current becomes [communication line T (#2) → resistor R16 →
It flows through the path of phototransistor PD2 → SCR of S8 → extension transformer IT → resistor R39]. When the voltage across the resistor R39 increases, the comparator Comp18 operates, resets the output of the counter IC49 through the NOT circuit IC51, and stops the output of the decoder IC48.
Therefore, the calling diode D4 becomes OFF, and the output of the OR circuit IC52 disappears, so the amplifier operation information becomes OFF. The amplifier information is 〇FF on the slave unit.
Therefore, the C relay is restored and the slave amplifier 24 is stopped.
Here, in handset #1 and handset #2, the SCR of S7 and S8 is O.
Since it is N, they are connected through the extension transformer IT and are in a mutual communication state.

When the call ends and handset #1 and handset #2 both put down their handsets, the call current disappears and the SCRs of S7 and S8 are restored.

When the SCRs of S7 and S8 are restored, the voltage across resistor R39 disappears, so comparators Comp16 and Com
p1 8 turns OFF, comparator Comp1 6
By turning OFF, the extension lamp information is turned OFF, and the extension lamps of each slave unit are turned off. '2} In the case of Issai call, set the dial number for Issai call to "0", and use the decoder I
When the output of C48 is “0”, OR circuit IC42, IC
43, calling diode D3, D through IC44
4. Turn on all D5s, and send the calling voice from handset #1 to the communication lines of all handsets through diodes D3, D4, and D5, amplify it with handset amplifier 24, and send it out from speaker 25. do.

In addition, the output “0” of 48 is applied to the decoder to add High to the gate IC (AND circuit) input for triggering each SCR.
No matter which handset captures the extension and responds, the communication path is connected to the extension transformer IT to form a communication path with handset #1. Once the communication path is established, the decoder I
The output of C48 disappears, and the handsets other than those in the mutual communication state are disconnected from the extension transformer IT and become confidential. Termination of an extension call is the same as for an individual call.

Although the above example has been described in which two central office lines, one extension line, and three handset units are accommodated, the present invention is not limited to such an example, and generally accommodates three or more central office lines and two extension lines. Of course, it can also be applied when accommodating more than one line or four or more handsets, and depending on the number of lines and handsets required, the detection circuits and selection circuits in the main device and the telephone are required. It can be realized by making changes.

As described above, in the control information transmission system in the button telephone equipment layer in which the communication current system is DC-separated from the central office line in the main device according to the present invention, at least identification means 2-1-2, 2-2-2, 3-2, 8-1,
8-2 and 8-3, and is connected to this main device via the communication current system, and is equipped with an operational amplifier OP-2.
01 and the transistor Tr201, the current value of the constant call circuit formed using the transistor Tr201 is connected to the operation button of the handset.
It is equipped with a call current control circuit 21 which is controlled by K1, LK2, LK3 and dial contact DPI, and controls the current value of the call current to a set value according to the selection information and dial operation by the operation button of the handset. It is possible to realize a control information transmission method for a key telephone device characterized in that it is configured to transmit information to the main device.

Further, the speech current control circuit 21 is controlled by an operational amplifier DP201 connected to the speech current system, contacts LK1, LK2, LK3 that operate in conjunction with the operation buttons, and the dial contact DPI, and changes the states of these contacts. Resistance circuits R203, R204, R20 showing corresponding resistance values
5, R206, R207, and a transistor Tr2 that is controlled by the output of the operational amplifier and causes the predetermined communication current corresponding to the resistance value of the resistor circuit to flow through the resistor circuit.
01.

Furthermore, the dial contact can be configured to include a contact DP2 that short-circuits the telephone circuit TEL.
As described above, the present invention contributes to reducing the number of core wires in a distribution cable, and uses a constant current circuit to reduce current regardless of changes in direct current resistance of the telephone circuit, transmitter, and cable. In addition to the effects of being able to set settings and increasing the current during information transmission compared to the normal communication current, there is an effect of increasing the amount of information that can be transmitted.

[Brief explanation of the drawing]

FIG. 1 is a waveform diagram for explaining the transmission of dial pulses in the button telephone device according to the present invention, FIG. 2 is a waveform diagram for explaining the transmission of information in the button telephone device according to the present invention, and FIG. 1 is a block diagram showing the main configuration of the button telephone device according to the present invention, and FIGS. 4 and 5 are circuit diagrams of the main device and the telephone, showing detailed circuit configuration examples of the button telephone device according to the present invention. Ne zu soup 2 zu zu zu size dog zu town bo

Claims (1)

[Scope of Claims] 1. In a control information transmission system for a button telephone device in which a talking current system is DC-separated from a central office line in a main device, the main device is provided with at least one device having a predetermined current value of the talking current. It is equipped with an identification means for identifying by comparison with a reference value, and transmits the current value of a constant current circuit formed using an operational amplifier and a transistor to the button telephone connected to the main device via the communication current system. It is equipped with a speech current control circuit that is controlled by a contact and a dial contact that interlock with the operation button of the telephone, and controls the current value of the speech current to a set value in accordance with the selection information and dial operation by the operation button of the button telephone. 1. A control information transmission method for a button telephone set, characterized in that information is transmitted to the main device via the talking current system. 2. The communication current control circuit includes an operational amplifier connected to the communication current system, and a resistance circuit that is controlled by the contacts linked to the operation button and the dial contact and exhibits a resistance value corresponding to the state of those contacts. , and a transistor that is controlled by the output of the operational amplifier and causes the predetermined communication current to flow through the resistance circuit in accordance with the resistance value of the resistance circuit. Control information transmission method for button telephones. 3. The dial contact includes a contact that short-circuits a telephone circuit.
The control information transmission method in the key telephone set described in 2.