JPH0759101B2 - Home telephone exchange device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention accommodates an analog telephone line for general subscribers as an external line and performs a switching operation by a dial signal from a telephone connected to an internal line. It is about.

[Prior Art] As a conventional home telephone exchange apparatus of this type, as shown in FIG. 2, an analog telephone line for general subscribers is accommodated as an external line l ₁ through a slicing device G and a security device H. And a plurality of telephone outlets B respectively connected to the telephone exchange A by an extension l ₂ and a control line l ₃ , so that a commercially available telephone C can be detachably connected to the telephone outlet B. There is something I did. In this home telephone exchange device,
The telephone exchange A switches the call path between the external line l ₁ and the internal line l ₂ or the internal line l _{2 in} response to the dial signal from the telephone set C so that the telephone line C can perform the external line call and the internal line call. In this in-home telephone exchange device, the intercom D is connected to the telephone exchange A by the call line l ₄ , and the telephone C is connected.
You can also make intercom calls using.

By the way, each telephone outlet B has a modular jack M
A general commercial telephone C is detachably connected by the modular jack M. The telephone outlet B is also sent via the control line l ₃ and a speaker SP for reproducing a notification signal such as an extension ringing sound or a doorphone ringing sound sent via the control line l _3. Equipped with light emitting display sections La and Lb for discriminating the display signal which is a voltage signal and displaying during an internal call or an external call, etc., the speaker SP and the light emitting indicators La, Lb perform notification and display operations. The volume of the speaker SP can be adjusted with the volume adjustment switch VS.

Since this in-home telephone exchange apparatus performs call processing such as extension call and hold by the dial signal input from the telephone C, whether the dial signal input from the telephone C is a dial signal for outgoing call, or other It is necessary for the telephone exchange A to identify whether or not it is a dial signal for call processing.

Therefore, in the conventional telephone exchange A, a timer is used to perform the above-mentioned identification in time. For example, when the time t ₁ between digits of the dial signal shown in FIG. 3 exceeds a certain time, it is determined that an external telephone call has been started, and the telephone call processing can be performed by the dial signal inputted thereafter, or the dial signal can be processed. After a certain time t ₀ has elapsed after the start of inputting, the method of enabling call processing was adopted.

However, with the above method, even if the call is terminated and the other party answers and the outside line call is started,
Call processing could not be performed during t ₀ or t ₁ .

Therefore, there is a method in which the polarity signal of the current or voltage of the telephone line is detected to be reversed, so that the dial signal input from the telephone after the polarity reversal is determined to be the dial signal for call processing.

[Problems to be Solved by the Invention] However, when the detecting means for detecting the reversal of the polarity of the telephone line is connected in series to the telephone line, even if the reversal of the polarity is not detected, the detecting means detects the telephone line There was a problem that the direct current resistance increased.

The present invention has been made in view of the above points, and an object thereof is to provide a home telephone that enables reverse detection without increasing the DC resistance of the telephone line except when reverse detection is performed. It is to provide a switching device.

[Means for Solving the Problems] In order to achieve the above object, the present invention accommodates an analog telephone line for general subscribers as an outside line, and performs a switching operation by a dial signal of a telephone connected to an extension line. In the switching device, the polarity reversal detection means for detecting reversal of the polarity of the current or voltage of the external line connected in series to the external line, and the dial signal input from the telephone after the polarity reversal is the dial signal for call processing. The determining means includes a determining means and a short-circuiting means which is connected in parallel with the polarity reversing means and bypasses a signal transmitted through the external line except when the polarity reversal is detected.

[Operation] According to the present invention configured as described above, the short circuit connected in parallel with the polarity reversal detection means short-circuits the input and output of the polarity reversal detection means during a period except when the polarity reversal is detected, and the external line is connected. To bypass the signal transmitted through
The DC resistance component of the polarity reversal detection means can be removed.

[Embodiment] FIG. 1 shows an embodiment of the present invention. The home telephone exchange device of this embodiment has the same system configuration as that shown in FIG.
By inputting a dial signal from the telephone C, call processing such as holding and extension calling can be performed.

The telephone exchange A of this embodiment has a relay Ry having a relay contact r for controlling the disconnection of the extension l ₂ to which the telephone C is connected from the outer line l ₁ , as indicated by a broken line frame a in FIG. 1. Dial pulse / hookup detection circuit 2 for detecting dial pulses and hookups, and power supply circuit 4 for supplying power to telephone C when relay contact r is disconnected from outside line l _1.
And an audio amplifier circuit 23 for amplifying various calling signals sent to the telephone outlet B for each extension l ₂ . Here, the dial pulse / hookup detection circuit 2 is configured by using a bidirectional photocoupler PC ₁ connected in series to the extension l ₂ , and detects the dial signal and the hookup state from the interruption of the current flowing in the telephone C. To do.

Further, the telephone exchange apparatus A includes an incoming call detection circuit 5 for detecting an incoming call to an outside line, a DC closing circuit 3 for closing a DC line, a dial pulse sending circuit 6 for making an outside line call by a dial pulse,
It consists of a push button (PB) dialer 7 that makes an outside call with a push button tone, a dial tone detection circuit 8 that detects an outside caller, a hold tone transmission circuit 9 that sends a hold tone, and a crosspoint switch that sets a call route. Analog switch network 10, PB receivers 12 and 13 for receiving push button signals, sound generation circuit 17 for generating various notification sounds, and amplification circuit 22 for amplifying the output of sound generation circuit 17 and inputting it to analog switch network 10. , A display control circuit 18 for displaying the call status at the telephone outlet B, a diode bridge DB, a coupling transformer T, and an analog switch S ₁ for controlling switching of signal paths.
S _3, the control circuit 1 composed of a CPU for sending control and signal determination processing of the control information signals of the respective circuits and later to the circuit
1, a power supply circuit 24 that creates a drive power supply for the above circuits from a commercial power supply, and the PB dialer 7 and PB receivers 12, 13
An input port expansion circuit 20 for expanding the input / output port for the use of a filter, and a filter circuit 25 provided for sending a pseudo incoming signal to the extension l ₂ . In addition, the photo couplers PC _{2 to} P are provided between the incoming line detection circuit 5, the dial pulse transmission circuit 6, the control circuit 11, the dial tone detection circuit 8, the hold tone transmission circuit 9 and the outside line l _1.
It is galvanically separated by C ₄ and a coupling transformer T.

Furthermore, this telephone exchange A has two intercoms.
It is provided with an intercom monitoring control circuit 14 that performs supervision control of D ₁ and D ₂ , an intercom communication circuit 15, and an alarm sound amplification circuit 21 that amplifies an alarm sound input from the sound generation circuit 17. Although not shown in FIG. 2, the in-home telephone exchange device is also configured so that an alarm unit J and an emergency push button I can be connected, and when an abnormality occurs, a telephone outlet B and a doorphone are connected.
An alarm sound can be sent from D ₁ and D ₂ . In addition,
The alarm signal from the alarm unit J is an alarm signal detection circuit.
The alarm sound generated by the sound generation circuit 17 is detected by the telephone 16 and the telephone outlet B or the intercom D sounds the alarm sound.

The operation of this home telephone exchange device will be described. Telephone exchange A
Then, when the power is turned on and the system starts, the control circuit 11 first makes initial settings and then enters the standby state,
Off-hook determination, further determination of whether there is an incoming call to an outside line and an outside call process, determination of whether there is a doorphone call and a doorphone call process, determination of whether there is an extension call and an extension call process, and an outside call process are performed.

Now, when the handset of any of the telephones C is picked up, the dial pulse hookup detection circuit 2 provided in the extension l ₂ to which the telephone C is connected detects off-hook and outputs a detection signal to the control circuit 11. . At this time, the control circuit 11 switches the relay contact r normally switched to the outside line l ₁ side to the analog switch network 10 side and sends a pseudo transmission signal of 400 Hz to the telephone C off hooked through the extension l ₂ and simultaneously displays it. The control circuit 18 is controlled to turn on the light emitting display portion La for displaying the outside line call in each telephone outlet B.

The transmission of this pseudo transmission signal continues until the input of the dial signal, and when the first dial signal is detected by the dial pulse / hookup detection circuit 2, the control circuit 11 stops the output of the pseudo transmission signal and the dial data. Is stored in the built-in buffer memory, and at the same time, the built-in 3-second timer is operated. When the second dial signal is detected during the operation of this timer, the control circuit 11 determines that the call is an outside call, performs the outside call process, and if the second dial signal is not input within 3 seconds. It is determined that the call is an extension call and the extension call processing is performed.

Now, in the case of outside line transmission, the control circuit 11 sequentially stores the dial signals successively input to the buffer memory, operates the DC closing circuit 3, and causes the dial tone detection circuit 8 to operate.
When the dial tone of the outside line is detected by, the dial data stored in the buffer memory is sequentially read from the first and the dial pulse sending circuit 6 is operated to sequentially output the dial signals to the outside line.
Send to l ₁ . Then, after the dial data stored in the buffer memory is exhausted and a certain time has passed,
The extension l ₂ connected to the off-hook telephone C is connected to the extension l ₁
The relay contact r is switched so as to connect to the outside line to enable an outside line call.

Next, in the case of an extension call, the control circuit 11 determines that an extension call is made 3 seconds after the input of the first dial signal, and each telephone outlet B that has been turned on from the off-hook of the telephone C. The light-emitting display unit La indicating that the external call is being made is turned off, and the light-emitting display unit Lb indicating that the extension call is being made is turned on at the same time.
At the same time, the control circuit 11 controls the sound generation circuit 17 to send the extension call notification signal to the telephone outlet B to which the telephone C on the called side is connected via the control line l ₃ , and the telephone outlet B The extension ringing sound is emitted from the speaker SP.
It should be noted that this notification signal is transmitted after being superimposed on the display signal. When the handset of the telephone C connected to the telephone outlet B is picked up by the extension ringing tone,
The dial pulse / hookup detection circuit 2 detects this off-hook, and the control circuit 11 stops the extension ringing tone based on this off-hook, and the analog switch network.
10 by connecting the extension l ₂ where telephone C of the called an extension l ₂ of the phone C is connected with the calling side is connected to allow extension call by.

Next, an external line incoming call will be described. When you receive an outside line,
The built-in bell rings in each telephone C. The incoming signal at this time is detected by the incoming detection circuit 5, and the incoming detection signal is input to the control circuit 11. If the handset of the telephone C is picked up in response to the ringing of the built-in bell of the telephone C, an outside call can be made. When the telephone C is off-hooked in this way, the control circuit 11 lights the light emitting display portion La of each telephone outlet B according to the output of the dial pulse / hookup detection circuit 2 to display that the outside line call is being made.

By the way, in this home telephone exchange device, an outside line call can be held during an outside line call to make an extension line call or a doorphone call.

In this case, when the telephone C inputs a dial signal corresponding to the hold from the telephone C during an outside line call, the control circuit
In 11, read this dial data and set the extension l ₂ to the outside line.
At the same time as disconnecting from l ₁ , the DC closed circuit 3 is operated to put the external line l ₁ in a holding state. Then, the control circuit 11 operates the hold sound sending circuit 9 to send the hold sound melody to the outside line l ₁ through the coupling transformer T. At this time, the control circuit 11 simultaneously controls the display control circuit 18 to turn on both of the light emitting display sections La and Lb for a call and display a message indicating that the call is on hold.

Now, after entering the hold state, if a dial signal for performing an extension call or an intercom call is input from the telephone C, the extension call process described above or the intercom call process described below is performed, and the extension call or the intercom call is performed. It will be possible.

This extension call that is on hold ends when phone C is hooked, and when the handset of phone C is picked up again,
Return to hold status.

Here, if the user wants to make an outside line call again, the hold signal is released by inputting a hold cancel dial signal from the telephone C. At this time, the control circuit 11 stops the operation of the hold sound sending circuit 9, controls each unit to the original outside line communication state, and returns to the outside line communication state. When the call is terminated after releasing the hold, the telephone C may be hooked on the hook.

Hereinafter, a case where a doorphone is called will be described. When calling from the intercom D, the push button provided on the intercom D is pressed. The pressing of this push button is detected by the intercom monitoring control circuit 14, and the control circuit 11 operates the sound generation circuit 17 in response to the detection output to cause the telephone outlet B to ring the intercom ringing tone. When any one of the handsets of the telephone C is picked up in response to the ringing tone of the intercom, the dial pulse / hookup detection circuit 2 provided at the extension l ₂ to which the telephone C off-hook is connected.
The control circuit 11 switches the analog switch network 10 in response to the output of the above and connects the telephone C where the handset is picked up and the intercom communication circuit 15 to enable intercom communication.

By the way, this doorphone call is made from the telephone outlet B even during an outside line call. When the dial signal for specifying the doorphone D is input from the telephone set C after the above-mentioned hold according to this call, the outside line is held and the doorphone is held. You can make calls.

In the above description, the dial pulse type telephone is used as the telephone C and the external line l ₁ which is an analog telephone line for general subscribers is the dial pulse line. However, the external line l ₁ is pushed. If it is a button line,
PB dialer 7 and PB receiver 12 for sending and receiving dial signals
The same operation as described above is performed except that it is performed at.

The above description has been a description of the common part with the conventional home telephone exchange device, but the featured part of the present embodiment will be described below.

In this embodiment, the polarity inversion detection circuit 19 for detecting a reversal of current polarity from the current direction of the serially connected external l ₁ outside line l ₁
And a relay Rk as a short-circuiting means which has a relay contact rk connected in parallel to the polarity reversal detection circuit 19 and short-circuits the input / output value of the polarity reversal detection circuit 19 except when the polarity reversal is detected.
It has and. Here, the polarity reversal detection circuit 19 is
Photocoupler PCk and light emitting diode of this photocoupler PCk
It is composed of a diode Dk connected to PD in anti-parallel. It should be noted that the diode Dk is such that even if the telephone exchange A is connected to the outside line l ₁ with no polarity, a bidirectional current flows through the outside line l ₁ .

Although the above is the difference from the conventional configuration example, the control circuit 11 operates as follows in terms of software in the present embodiment. That is,
In the control circuit 11 of this embodiment, the detection output from the polarity reversal detection circuit 19 is monitored, and the relay contact that is normally open during the outside line call period after the reversal of the current polarity is detected by the polarity reversal detection circuit 19 is detected. Control rk to close. And
It is determined that the dial signal input from the telephone C after the reversal of the current polarity is detected by the polarity reversal detection circuit 19 is a dial signal for call processing.

The operation of the main part of this embodiment will be described. Now, assuming that the telephone C is off-hook in order to make an outside line call, this off-hook is the dial pulse hookup detection circuit 2
The control circuit 11 switches the relay contact r to the analog switch network 10 side based on the detected output. At this time, the relay contact rk is opened. And phone C
The dial signal input from is read and the dial signal is sent to the outside line l ₁ . The exchange of the central office calls the outside line partner after the final dial signal is input. In response to this call, when the telephone of the outside party is off-hook, the exchange of the central office reverses the current polarity of the outside line l ₁ ,
Tell the calling party the response of the other party. At this time, since the operation state of the photocoupler PC ₂ of the polarity inversion detection circuit 19 of the telephone exchange A is inverted, it is judged from this inversion of the operation state that the control circuit 11 is in the call state, and at this time, the relay contact rk is closed, After that, the dial signal for call processing is accepted. At this time, the relay contact r is connected so that the extension l ₂ to which the telephone C that originated the call at the same time is connected to the outer line l _1.
Switch. When the telephone C is on-hook and the call ends, the standby state is returned to the initial state, at which time the relay contact rk is opened. According to the above configuration, the relay contact rk connected in parallel to the photocoupler PCk and the diode Dk of the polarity reversal detection circuit 19 is closed during the period except when the polarity reversal is detected, and the input and output of the photocoupler PCk and the diode Dk are short-circuited. However, since the signal transmitted via the external line l ₁ is bypassed, the DC resistance component of the polarity reversal detection circuit 19 can be removed.

[Advantages of the Invention] As described above, the present invention provides a home telephone exchange device that accommodates an analog telephone line for general subscribers as an external line and performs a switching operation by a dial signal of a telephone connected to the internal line. Polarity reversal detection means connected in series for detecting reversal of the polarity of the current or voltage of the external line, judgment means for judging that the dial signal input from the telephone after the polarity reversal is a dial signal for call processing, Since the polarity reversal means is connected in parallel with the short circuit means for bypassing the signal transmitted through the external line except when the polarity reversal is detected, the polarity reversal detection means is connected to the short circuit means in parallel. The DC resistance component of the polarity reversal detection means is removed in order to short-circuit the input and output of the polarity reversal detection means and bypass the signal transmitted through the external line during the period except the time of detection. Can be removed.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a telephone exchange according to an embodiment of the present invention, and FIG.
FIG. 3 is a system configuration diagram of the same as above, and FIG. 3 is an operation explanatory diagram showing conventional problems. A is a telephone exchange, C is a telephone, 11 is a control circuit, 19 is a polarity reversal detection circuit, Rk is a relay, rk is a relay contact, l ₁ is an outside line, and l ₂ is an extension line.

Claims (1)

[Claims] 1. A home telephone exchange apparatus for accommodating an analog telephone line for general subscribers as an outside line and performing a switching operation according to a dial signal of a telephone connected to the extension line, wherein the current of the outside line is connected to the outside line in series. Alternatively, the polarity reversal detection means for detecting reversal of the polarity of the voltage, the judgment means for judging that the dial signal input from the telephone after the polarity reversal is a dial signal for call processing, and the polarity reversal means are connected in parallel. A home telephone exchange device, comprising: a short-circuit means for bypassing a signal transmitted via an outside line except when polarity reversal is detected.