JPH0544239B2 - - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to telephone equipment that accommodates conventional standard telephones, such as the Model 600.

(Prior art and its problems) Conventionally, when a single telephone line accommodates multiple ordinary individual telephones (standard telephones) such as 600-type telephones, branch connections are sometimes used. , 600 type telephones, etc., requires a complicated and expensive exchange such as a PBX, as they do not have calling functions. Additionally, when a PBX is used, a separate, external power outage telephone must be installed to connect directly to the central office line in the event of a power outage, making the system expensive. In such a case, in the case of a device that allows mutual communication between multiple telephones, such as a button telephone device, each handset must be equipped with multiple buttons, indicator lamps, etc., which is expensive. There is a drawback. Furthermore, such button telephone devices and
When using a switching device such as a PBX, it was necessary to back up the call using a battery in order to continue the call even if the power supply was cut off.

(Purpose of the Invention) The present invention provides a structure in which the main phone is equipped with a simple exchange function, thereby making it possible to conduct central office line calls and exchange between extensions using a plurality of ordinary standard telephones other than button telephones without installing a PBX. To provide a telephone device that enables telephone calls and secures communication with a central office line even during a power outage.

(Structure of the Invention) In order to achieve this object, the telephone device of the present invention has a central office line connection circuit 5 connected to the central office line 1, which can take two states, an operating state and a recovery state, and a power outage. a first switching means 7 that switches and selects between the central office line 1 and the extension 51 so as to select the central office line 1 in the restored state; 51, connection terminals T1, T2, T3 for connecting at least one standard type telephone 4b, 4c, 4d installed outside the main body, and the central office line connection circuit. 5 and the connecting terminals T1, T
2. A first DC supply circuit 6a that supplies direct current to T3 for line closure detection and office line communication; at least two second DC supply circuits 6b for supplying DC of
6e, an AC signal connection line interconnecting the two DC supply circuits, and a dial signal detector 15.
, a bell signal generator 17, the first DC supply circuit 6a, the second DC supply circuits 6b to 6e,
The dial signal detector 15 or the bell signal generator 17 is connected to the extension line 51 or the connection terminal T1,
The second switching means 8ab to 8de that selectively switch and connect to T2 and T3, and the control circuit 19 that controls the connection operation by the first and second switching means 7 and 8ab to 8de are used as a master telephone. A normal standard type telephone 4b provided inside the main body and installed externally,
4c and 4d and between the extension lines of the main telephone and the telephone circuit 3 of the main telephone, as well as telephone calls between ordinary standard telephones 4b, 4c and 4d installed outside and the telephone circuit 3 of the main telephone. It is also configured to ensure communication between the central office line 1 and the telephone circuit 3 of the main telephone during a power outage.

(Example) The present invention will be explained in detail below.

FIG. 1 is a configuration diagram of the present invention, in which 1 is a central office line connection terminal, 2 is a telephone device that serves as a main telephone capable of receiving, making and reciprocal calls, 3 is a telephone circuit of telephone device 2, and 4b to 4d are slave telephones. Normal 600 used as a machine
5 is a central line connection circuit of the telephone device 2, 6a to 6e are DC supply and line closure detection circuits for the extension side of the telephone device 2 (hereinafter referred to as DC supply circuit), and 7 is a main telephone. Telephone device 2
Switching means for switching the telephone circuit 3 between the office line side and the extension line side, 8ab to 8de are handset telephones 4b to 4.
9 to 13 are switch means for turning the signal on and off, 14 is a dial tone generator, 15 is a dial signal detector, 16 is a ringback tone generator, and 17 is a bell. Signal generator, 18, busy tone generator, 19
is a control circuit that centrally controls the inside of the telephone device 2. In addition, 51 is an extension to telephone circuit 3, and 6
5 is an AC signal connection path between the DC supply circuits 6c and 6d; T1, T2, and T3 are telephones 4b, 4c, and 4;
This is the connection terminal to d.

First, when power is supplied to the telephone device 2 and no operation is performed, the switching means 7
It is connected to the extension connection line 51 in the operating state. The control circuit 19 includes switch means 8ab, 8bb, 8cb,
It operates to turn on 8 db one by one at regular intervals, and at the same time supplies direct current from the direct current supply circuit 6b to detect line closure.

Referring to the operational flow shown in FIG. 2a, the operation of extension calls in the embodiment shown in FIG. 1 will be explained by taking the telephones 4b and 4c as an example.

When the telephone 4b is taken off-hook now, the switch means 8bb is turned on by the control circuit 19, and DC is supplied from the DC supply circuit 6b, causing a loop current to flow through the telephone 4b, line closure detection is performed, and control is performed. Notify circuit 19. Control circuit 1
When 9 learns that the line has been closed, it stops the operation of detecting the off-hook of each telephone set at regular intervals, continues to connect to the corresponding telephone set 4b, and outputs the dial tone generator 14 and dial signal. In order to operate the detector 15, the switch means 9, 10 are closed. As a result, a dial tone is input to the telephone set 4b, so it is known that the telephone set 4b is ready to make a dial call, and when a dial signal is sent from the telephone set 4b to another telephone to be connected, for example, 4c, the dial signal detector 15 detects the dial signal and sends it to the control circuit 19. When the control circuit 19 reads the dial signal, it opens the switch means 9 to stop the dial tone. Thereafter, when the control circuit 19 detects a dial signal of the required number of digits, it opens the switch means 10 to open the dial signal detector 15, and at the same time opens the switch means 8bb.
is turned off, and control is performed to stop the DC supply from the DC supply circuit 6b. On the other hand, the control circuit 19
When it is detected from the dial number that the called telephone 4c is not in use, the DC supply circuit 6c
At the same time, the switching means 8 starts supplying direct current.
bc and switch the DC supply to telephone 4b,
Further, the switch means 11 is turned on and off at regular intervals, and control is performed to send a ring back tone to the telephone 4b indicating that the called party is being called. At the same time, if the called party, for example, the telephone 4c is selected as described above, the switch means 8
CD is closed, the DC supply circuit 6d is activated to supply DC to the telephone 4c, and the switching means 12 is repeatedly turned on and off at regular intervals to send a calling signal from the bell signal generator 17 to the telephone 4c and ring the bell. . When the telephone 4c goes off-hook, the DC supply circuit 6d detects the off-hook and notifies the control circuit 19 of the off-hook. When the control circuit 19 detects that the telephone 4c has been taken off-hook, it restores the operation of the switch means 11 and 12, stops the ring back tone and the ringing signal, and switches from [telephone 4b→connection terminal _T1 →switch means 8bc]. Closed) → DC supply circuit 6c → Connection wire 65 →
Through the call loop of DC supply circuit 6d → switch means 8cd (closed) → connection terminal T ₂ → telephone 4c],
It is now possible to talk between the telephones 4b and 4c.

When the call is completed and each telephone goes on-hook, the line closing circuit of each DC supply circuit 6c or 6d detects the on-hook and notifies the control circuit 19. When the control circuit 19 detects each on-hook, the control circuit 19 controls the DC supply circuit 6c, the switching means 8bc,
The operations of the DC supply circuit 6d and the switch means 8cd are turned off, and the call operation is completed. It is clear that this may be any combination of the telephone section 3 and the telephones 4b to 4d.

When making a call from the telephone 4b, if the called party sends a busy tone to the calling party due to a telephone conversation, etc., the operation up to dial reception is the same as described above, but the control circuit 19 receives the required number of digits and makes a call. If it is determined that connection is not possible, the DC supply circuit 6b and the switch means 8bb are turned off, and then the DC supply circuit 6e is operated, the switch means 8be is closed, the switch means 13 is turned on and off at regular intervals, and a busy tone is emitted. to occur.
When the telephone 4b is turned on, the line closure detection circuit of the DC supply circuit 6e detects that the line has been opened, and notifies the control circuit 19 of this. When the control circuit 19 detects on-hook, the control circuit 19 switches the DC supply circuit 6
e and switch means 8be are turned off to complete the operation.

Next, referring to FIG. 2b, the central office line transmission in the embodiment of FIG. 1 will be explained. When a call is made from telephone 4b to a central office line, the process is the same until the dial signal described above is detected. When the control circuit 19 determines that the call is to the central office line, it disconnects the telephone 4b and the DC supply circuit 6b as described above, captures the central office line by the central office line connecting circuit 5, and at the same time disconnects the telephone 4b from the DC supply circuit 6a. Then, the switch means 8ba is closed to supply direct current to the telephone 4b.
After that, all you have to do is dial the other party's dial number and make a call, just like you would with a normal telephone. At the end of the call, the line closure detection circuit of the DC supply circuit 6a detects the off-hook of the telephone 4b and notifies the control circuit 19 of the detection. The control circuit 19 commands the opening of the DC supply circuit 6a and the office line circuit 5. As a result, the line and office line are released. The above operation for the central office line is the same for telephones 4c and 4d.

Next, referring to FIG. 2c, the case where the telephone circuit 3 makes a call to the office line will be explained. telephone circuit 3
Press the button inside to make a call to the central office line. When the control circuit 19 detects that the button is pressed, it connects the switching means 7 to the central office line side. The subsequent operations for outgoing calls are similar to those of a normal telephone. The control circuit 1 indicates that the call has ended and the handset of the telephone circuit 3 has been turned on or the button for opening the central office line has been pressed.
9 operates the switching means 7 to change the connection to the extension side and open the central office line. Since the telephone call at this time is directly connected between the office line and the telephone circuit 3, there is also the advantage that there is no loss.

During a power outage, the switching means 7 is connected to the central office line side.
However, since power is not supplied to each part within the telephone device 2, operation is impossible. However, by capturing the central office line from the telephone circuit 3 off-hook, the central office line can be closed and normal telephone calls are possible.

FIG. 3 shows an example of the office line connection circuit 5. The operation of receiving a call in this circuit is as follows. Office line L
When an incoming signal is input between 1 and L2, when L1 is (+), [L1 → CO-1 relay contact → diode bridge D ₁ (~) input → D ₁ (+) output →
Photocoupler Q1 diode cathode → Q1 diode anode → Zener diode D2 →
D1 (~) input → D1 (~) output → CO-2 relay contact → L2], and when L2 is (+), [L2 → CO-2 relay contact → D1 (~) input → D1 (+) output → Q1 diode cathode → Q1 diode anode → Zener diode D2 → D1 (-) input → D1 (~) output → CO
-1 relay contact→L1], current flows through it. Then, an output voltage is generated at the load resistor R3 at the output of the photocoupler Q1, and is inputted to the transistor Q2 through the smoothing circuit R4, C3 and the Zener diode D3. The output is input to the control circuit 19, and the incoming call is detected.

In a telephone device such as the present invention, the polarity of the central office line is detected in order to reverse the polarity of the central office line when the called party answers or when an incoming signal arrives, thereby preventing a collision between a calling party and an incoming call. is necessary.

Next, the operation of this polarity detection by the office line connection circuit 5 will be explained. To determine the polarity between the station lines L1 and L2, operate the R relay and turn on its contact R. If L1 is (+) now, [L1→
Current flows through R10 → Photoepura Q10A → R relay contact → L2]. Then, the output of the photocoupler Q10A becomes low level, and the bistable circuit 12 is set. On the other hand, photocoupler Q1
The output of 0B becomes high level, and bistable circuit Q1
Cancel the reset in step 2. Therefore, bistable circuit Q
The output of No. 12 becomes high level. Also, L2 is (+)
In the case of , current flows through [L2→R relay contact→photocoupler Q10B→resistance R10→L1]. Then, the output of photocoupler Q10B becomes low level, resetting the bistable circuit Q12. On the other hand, the output of the photocoupler Q10A becomes high level, and the setting to the bistable circuit Q12 is released. Therefore, the output of bistable circuit Q12 becomes low level.

Furthermore, if the power supply is temporarily not connected to the station line due to a change in station connection, etc., photo couplers Q10A and Q1
The output of both 0B becomes high level, and bistable circuit Q
12 maintains the same state without changing to any state.

The polarity reversal is determined by determining the output state of the bistable circuit Q12.

Furthermore, the operation of closing the central line is as follows. When the telephone goes off-hook and captures the central office line in order to connect the central office line, a CO (not shown) accommodated in the central office line connection circuit 5 is activated by instructions from the control circuit 9.
When the relay operates, its contacts CO-1 and CO-2
is switched, and when L1 is (+), [L1→CO
-1 relay contact → diode bridge Q20
(~) → Diode bridge Q20 (+) → Collector of transistor Q21 → Transistor Q21
emitter → resistor R21 → diode bridge Q
20 (-) → Diode bridge Q20 (~) →
Current flows through CO-2 relay contact → L2].
Also, when L2 is (+), [L2 → CO-2 relay contact → diode bridge Q20 (~) →
Diode bridge Q20 (+) → collector of transistor Q21 → emitter of transistor Q21 → resistor R21 → diode bridge Q20
(-) → CO-1 relay contact → L1] Current flows through. Further, R20, R21, D20, and Q21 constitute a constant current circuit. That is, the resistance R
20 limits the current supplied to the constant voltage diode D20 and the transistor Q21, and the constant voltage diode D20 makes the base voltage of the transistor Q21 constant. Therefore, by making constant the voltage drop across resistor R21 connected to the emitter of transistor Q21, the current flowing through transistor Q21 becomes constant. As a result, when the voltage of the telephone line varies from 50 to 5 volts depending on the length of the telephone line, the change in the flowing current can be reduced compared to when using a resistor, and the impedance is sufficiently high for voice signals. So,
Audio signals can be stably extracted through C20 and C21.

FIG. 4 shows an example of the DC supply circuits 6a, 6c, and 6d. To supply DC between L1 and L2,
By applying a voltage to CNT, the output of photocoupler Q43 is shorted, and transistors Q41 and
The constant current circuit by Q42 operates, and [(+)→Q4
1 → L1 → (telephone) → L2 → Photocoupler Q4
4→Q42→(-)], the current flows. At this time, when current flows through the photocoupler Q44, the output of the loop becomes low level, and it is possible to detect that there is a DC loop. Also, the audio signals from L1 and L2 can be taken out to output T via a capacitor.

In FIG. 4, the circuit in which the terminal T is omitted can be applied to the DC supply circuits 6b and 6e.

(Effects of the Invention) As explained above, according to the present invention, it is not necessary to install expensive and complicated equipment such as a button telephone device or a separate power outage telephone, and there is no need to use an exchange such as a PBX. , the telephone device is a two-wire ordinary standard type telephone 4b to 4 such as a 600 type telephone.
Not only can telephones 4b to 4d be connected to each other, and mutual extension calls can be made between the telephones 4b, 4c, or 4d and the telephone circuit 3 housed in the telephone device that is the parent telephone, but also between the telephones 4b, 4d, and 4d. 4
There is an advantage that it can be constructed so that telephone calls can be made from the telephone circuit 3 of the telephone device 2 or the telephone circuit 3 of the telephone device 2. Moreover, in the case of a call from the telephone circuit 3 in the telephone device 2, there is an advantage that there is no loss at all when communicating with a central office line. Furthermore, this telephone device 2
By switching the switch 7 to connect the telephone circuit 3, which is provided in the telephone device so as to be connected to the central office line through the switch 7, even if the power supply to the telephone stops, There is a practical advantage in that central telephone calls can be made from the telephone device which is the main telephone.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 a, b, and c are flowcharts for explaining the operation of the embodiment of Fig. 1, and Fig. 3 is a central office line connection used in the present invention. FIG. 4 is a circuit diagram showing an example of a DC supply circuit used in the present invention.

Claims (1)

[Claims] 1 A central office line connection circuit connected to a central office line that can take two states, an operating state and a recovery state, and switches between the central office line and the extension line so that the central office line is selected in the restored state in the event of a power outage. a first switching means for
a standard telephone circuit connected to the office line or the extension line via the first switching means; a connection terminal for connecting at least one standard telephone installed outside the main body; a first DC supply circuit connected to the line connection circuit and supplying DC to the connection terminal for line closure detection and central line communication;
at least two second direct current supply circuits for supplying direct current to the connection terminal or the extension line for line closure detection and extension communication; and an alternating current signal interconnecting the two second direct current supply circuits. A connecting line, a dial signal detector, a bell signal generator,
A second circuit that switches and connects the first DC supply circuit, the second DC supply circuit, the dial signal detector or the bell signal generator to the extension or the connection terminal.
What is claimed is: 1. A telephone device comprising: switching means; and a control circuit for controlling connection operations by said first and second switching means, in a main body serving as a master telephone.