JPH029742B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a parent-child telephone device in which a pair of telephone lines is used by a plurality of telephones.

(Prior art and problems to be solved by the invention) Assuming that one telephone line is used by a plurality of telephones, it is possible to connect a plurality of telephones in parallel to one telephone line or to operate a converter to connect one telephone line to the other. There is a parent-child phone that uses a telephone line connected to one of multiple telephones, but it has the drawback of not having functions such as confidential calls, hold calls, and inter-extension calls. In response, button telephone devices have been proposed, but they are extremely expensive, preventing their widespread use in homes. The present invention aims to eliminate the drawbacks of these conventional measures.

(Means for Solving the Problems) The improved parent-child telephone device according to the present invention connects an additional telephone device to each telephone used as a conventional parent-child telephone using a two-wire communication line. The device is constructed by connecting a two-wire communication line and a two-wire control line to a main device in parallel, and further connecting a pair of telephone lines to the main device. This improved parent-child telephone device according to the present invention is connected as a means for transmitting information such as telephone line capture, telephone line hold, call to another telephone, re-answer to the telephone line, etc. from one additional telephone device to the main device. The change in the loop current flowing between a pair of control lines is used. The main purpose of the present invention is to provide a means for changing the loop current, and the present invention has a self-holding function that is turned on by the contact of the telephone line capture button and causes a first current to flow through the control line between the control lines in the additional device for the telephone. a first semiconductor switching element;
When the extension call button is operated when the semiconductor switching element is on, it will turn on only when it is being operated, and this on action releases the self-holding of the first semiconductor switching element, turns it off, and connects the second control line to the control line. If a second semiconductor switching element that has a self-holding function that allows current to flow and a semiconductor switching element that plays the same role as the first semiconductor switching element in another telephone additional device is turned on, a telephone line capture button is activated. and a constant voltage diode for monitoring the voltage between the control lines, which prevents the operation of the first semiconductor switching element even if is pressed.

The main device also includes a means for detecting the first current to connect the telephone line to a telephone line from the telephone additional device to seize the telephone line, and a means for detecting the second current to connect the telephone line to the telephone line from the additional telephone device. Equipped with a hold relay that holds the

(Example) Hereinafter, the details of the present invention will be explained according to the drawings as an example.

The figure is a circuit configuration diagram as one embodiment of the present invention. In the figure, ME is the main device, and ADP is an additional device for the telephone provided corresponding to each telephone. In the main device ME, terminals L ₁ and L ₂ are telephone lines
Terminals connected to TRK, l ₁ , l ₂ , l ₃ , l ₄ are additional devices
The terminals connected to ADP, L _(P) and L _(S) are the windings of loop monitoring relay L for the telephone line, and L _(P) is the first winding.
The next winding, L _S is its secondary winding, l is the contact of relay L, H is the winding of the always-operating relay, h ⁰ , h ¹ , h ² ,
h ³ , h ⁴ are the contacts of relay H, HL is the winding of the hold relay HL, hl ⁰ , hl ¹ , hl ² are the contacts of relay HL, RV is the calling signal receiving circuit, R is the winding of the calling signal receiving relay , r is the contact of relay R, OSC is the extension call signal generator, AMP is the extension call signal amplifier, SW ₁ is the switching circuit, 1, 2, 3 are the input/output terminals of switching circuit SW ₁ , SW ₂ is the switching circuit ,
4, 5, 6, 7 are input/output terminals of switching circuit SW ₂ , REC ₁₁ and REC ₁₂ are bridge rectifiers,
_D11 , _D12 , _D13 , _D14 , _D15 are diodes, _Tr1 ,
Tr ₂ , Tr ₃ , Tr ₄ are switching transistors,
R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ , R ₁₇ are resistors,
C ₁₁ , C ₁₂ , C ₁₃ , and C ₁₄ are capacitors, CH is a blockage wire, T ₁₁ is a transformer, and E is a power source. Additional equipment
In ADP, l ₁ , l ₂ , l ₃ , and l ₄ are the main device ME
Terminals connected to terminals l ₁ , l ₂ , l ₃ , l ₄ , TL ₁ and
TL ₂ is a terminal for connecting a telephone, RK ⁰ and RK ¹ are contacts for the extension call button RK, LK is a contact for the telephone line capture button LK, SCR ₁ , SCR ₂ , and SCRR ₃ are thyristors, and ZD ₂₁ and ZD ₂₂ are fixed Voltage diode, D ₂₂ ,
D ₂₃ is a diode, R ₂₁ , R ₂₂ , R ₂₃ , R ₂₄ , R ₂₅ ,
R ₂₆ , R ₂₇ , R ₂₈ are resistors, C ₂₁ , C ₂₂ , C ₂₃ are capacitors, T ₂₁ is a transformer, and SP is a speaker. In addition, TEL indicates a normal automatic telephone. In addition,
The circuit of this automatic telephone has not been modified in any way in order to be connected to the device according to the present invention.

The operation of the circuit according to the embodiment of the present invention will be explained in detail below with reference to the drawings.

In the main device ME, the switching circuit _SW1 is always on, and the terminals 1-3 are electrically connected. Therefore, the relay H is always operated in the earth-winding H-switching circuit _SW1 -power supply E circuit,
The contacts h ⁰ , h ¹ , h ² , h ³ , and h ⁴ are operating in the direction shown by the dotted line. When a calling signal arrives from the telephone line, terminal L ₁ - contact hl ⁰ - contact h ² - bridge rectifier
REC ₁₃ - Winding R - Bridge rectifier REC ₂ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ｜ ― Capacitor C ₁₄ ― - Capacitor C ₁₁ - Contact HL ¹ - Terminal L ₂ route of the calling signal receiving circuit RV Relay R operates in synchronization with the arrival period of the calling signal, and the operation of contact r activates amplifier AMP in the circuit of amplifier AMP, diode _D14 , contact r, and power supply E. Therefore, the signal of the signal generator OSC is amplified and applied through the transformer T ₁₁ between the terminals l ₃ and l ₄ . The calling signal between terminal _L3 and terminal _L4 is sent to terminal _L3 of the additional device ADP corresponding to each telephone.
- terminals l ₄ , so that in the additional device ADP terminals l ₃ - capacitor C ₂₂ - transformer T ₂₁ - contacts
A ringing signal is induced in the transformer T ₂₁ on the route RK ⁰ -terminal l ₄ , causing the speaker SP of each additional device ADP to ring to indicate an incoming call from the telephone line.

When you remove the handset of a certain telephone TEL in order to answer an incoming call from the telephone line or make a call to the telephone line, an earth air --- Resistor R ₁₁ --- Blockage wire CH -- ｜ ｜ ｜ ｜ ｜ ｜ - Transistor Tr ₂ - Contact h ⁰ - Terminal l ₁ - Terminal l ₁ - Resistor R ₂₈ - Diode
D ₂₃ −Terminal TL ₁ −Telephone TEL−Terminal TL ₂ −Terminal l ₂
−Terminal l ₂ −Contact h ¹ −Cold flow coil CH −Resistor R ₁₆ ――――――――――――――――Power supply E | | | | | | —Transistor Tr ₄ —Diode D ₁₅ — Since current flows through the circuit, transistor Tr ₂ turns on. At this time, the transistor Tr ₄ is connected to the resistor R ₁₆ and diode D ₁₅ of the main device ME, since the resistor R ₂₈ in the additional device ADP has a sufficiently large value.
Due to this, it will not turn on. When transistor Tr ₂ is turned on, the ground - Transistor Tr ₂ - Resistor R ₁₂ - Transistor Tr ₁ - | | | | | | | | | | | | | | --Resistor R ₁₃ --- | | | | | | | | Capacitor C ₁₃ ------- - Transistor Tr ₁ is turned on in the power supply E circuit, and a voltage is applied between terminal l ₃ and terminal l ₄ . Pressing the telephone line capture button LK in the additional device ADP closes the contact LK. At that time, the switching transistor _Tr1 in the main device ME is on and a voltage is applied between the terminals _l3 and _l4 , so
Earth - terminal l ₄ - terminal l ₄ - contact LK - resistor R ₂₁ - constant voltage diode ZD ₂₁ - - resistor R ₂₂ --- terminal l ₃ | | | | | | | - Capacitor C ₂₁ - - -Terminal l ₃ -Transformer T ₁₁ -Resistor R ₁₅ -Transistor
A circuit of Tr ₁ -power supply E is completed, the constant voltage diode ZD ₂₁ in the additional device ADP becomes conductive, a potential difference, that is, a starting voltage of the thyristor SCR ₁ is generated across the resistor R ₂₂ , and the thyristor SCR ₁ is turned on. Therefore,
Even if you release the button LK, the ground - terminal l ₄ - terminal l ₄ - thyristor SCR ₁ --- resistor R ₂₃ --- terminal l ₃ | | | | | | | ---resistor R ₂₄ -Resistor R ₂₅ - -Terminal l ₃ -Transformer T ₁₁ -Resistor R ₁₅ -Transistor
Tr ₁ - Thyristor SCR ₁ is maintained in the on state in the power supply E circuit. At this time, the resistance value of the resistor R ₂₃ in the additional device ADP is small, so the current increases, the potential difference across the resistor R ₁₅ in the main device ME and the transformer T ₁₁ increases, and the terminal l ₃ - terminal The terminal voltage between l _{and 4} decreases. Therefore, even if you press the button LK of the additional device ADP corresponding to another telephone TEL after the terminal voltage between terminal l ₆ and terminal l ₄ has decreased in this way, the constant voltage diode ZD ₂₁ will not conduct, so the addition Thyristor SCR ₁ of the device ADP is never turned on. Thyristor is activated by pressing button LK.
When SCR ₁ is turned on and current flows between terminals _l3 and _l4 , the potential difference across resistor _R15 in the main device ME causes continuity between terminals 4 and 6 of switching circuit _SW2 . become. Therefore, the transistor Tr 3 is turned on in the circuit of earth air - transistor Tr ₃ - resistor R ₁₄ - terminal 6 of switching circuit SW ₂ - _terminal 4 of switching circuit SW ₂ - transistor Tr ₁ - power supply E, and the earth air - Transistor Tr ₃ - Diode D ₁₁ - Switching circuit Since the circuit of terminal 2 of SW ₁ is created, the switching circuit is always operating.
Switch between terminals 1 and 3 of SW ₁ is turned off. Therefore, relay H is restored and its contacts h ⁰ , h ¹ , h ² ,
h ³ and h ⁴ are restored. Due to the restoration of contacts h ⁰ and h ¹
TRK - terminal L ₂ - contact hl ¹ - bridge rectifier REC ₁₁
- Winding L _(S) - Contact h ¹ - Terminal l ₂ - Telephone line - Terminal l ₂ -
Terminal TL ₂ - Telephone TEL - Terminal TL ₁ - Diode
D ₂₂ - Constant voltage diode ZD ₂₂ - Resistor R ₂₇ - Resistor R ₂₆ - Terminal _{l 1} | _| ^| _(P) −bridge rectifier
REC ₁₁ - Contact hl ⁰ - Terminal L ₁ - Telephone line TRK circuit is completed. At this time, the voltage on the telephone line TRX side is high, so the constant voltage diode ZD ₂₂ in the additional device ADP
conducts and the voltage difference across resistor R ₂₆ , i.e. the starting voltage of thyristor SCR ₃ , causes the thyristor
SCR ₃ turns on and the phone is ready to talk to the phone line. In the embodiment, the current detection circuit described in the claims refers to the resistor R ₁₅ , the switching circuits SW ₁ , SW ₂ and other circuits around the switching circuit SW ₁ , and the current flowing through the resistor R ₁₅ is the input. Become. In addition, due to the restoration of relay H, terminal l ₁ ,
After terminal l ₂ is connected to the telephone line TRK,
Even if the handset is removed from the other telephone TEL, the voltage between terminal _l1 and terminal _l2 is reduced due to the loop closure by the telephone TEL that is in the talking state with the telephone line, so the handset is removed later. The constant voltage diode ZD ₂₂ in the additional device ADP corresponding to the telephone TEL does not conduct, and the thyristor SCR ₃ of the additional device ADP
is not turned on, so a secret story is constructed. That is,
If one telephone TEL seizes the telephone line, other telephones TEL cannot seize the telephone line even if the handset is removed. On the other hand, the telephone loop closed by the thyristor SCR ₃ being turned on activates the loop monitoring relay L of the main device ME, and the closing of its contact l causes the earth-contact l-diode D ₁₂ to be activated. -Contact ^h3 -The circuit at terminal 2 of switching circuit _SW1 keeps the switching circuit _SW1 in the OFF state. Also, earth - contact L - diode D ₁₃ - resistor R ₁₂ - transistor Tr ₁ - power supply E | | | | | | | | ---Resistor R ₁₃ --- | | | | | --- -------- Capacitor C ₁₃ --- The switching transistor Tr ₁ is kept in the on state by the circuit. Note that when the contacts h ⁰ and h ¹ are restored, even if the transistor Tr 2, which had been on due to the telephone loop, is turned off, the transistor Tr ₂ remains on until the contact l is closed due to the discharge of the capacitor C ₁₃ . ₁
Since the switching circuit SW ₂ and the transistor Tr ₃ remain on, the relay H remains on.
Continue the recovery state. Also, even if relay L operates intermittently by sending a dial impulse from the telephone side, the _transistor
Tr ₁ is kept on, and thyristor SCR ₁ in the additional device ADP is also kept on.

The telephone TEL that is currently talking to the telephone line, i.e. the telephone TEL corresponding to the additional device ADP with thyristor SCR ₁ turned on, transfers the call to another telephone.
If you are trying to transfer to TEL, please use the extension call button
When RK is pressed, its contacts RK ⁰ and RK ¹ operate.
At this time, since the thyristor SCR ₁ in the additional device ADP is turned on, the potential difference across the resistor R ₂₃ is applied as the gate activation voltage of the thyristor SCR ₂ through the resistors R ₂₄ and R ₂₅ , so that the contact RK ⁰ The operation turns on thyristor SCR ₂ . thyristor
When SCR ₂ is turned on, the terminal l ₃ and terminal l ₄ are short-circuited, so the thyristor SCR is turned off. Thyristor SCR ₂ remains on as long as button RK is pressed. If thyristor SCR ₂ turns on, earth - terminal l ₄ - terminal l ₄ - contact RK ⁰ - thyristor
SCR ₂ - terminal l ₃ - terminal l ₃ - transformer T ₁₁ - resistor R ₁₅ -
Current flows through the circuit between transistor Tr ₁ and power supply E. Since this current has a larger current value than when the thyristor SCR ₁ is in the on state, the potential difference across the resistor R ₁₅ in the main device ME increases. The switching circuit SW ₂ is configured so that when the potential difference between both ends of the resistor R ₁₅ is large, the terminals 4-7 are conductive and the terminals 4-6 are non-conductive. Winding HL - Switching circuit SW ₂ (7-4) -
The relay HL operates in the transistor Tr ₁ -power supply E circuit, and its contacts hl ⁰ , hl ¹ , and hl ² operate. contact
Due to the operation of hl ⁰ and hl ¹ , the direct current circuit of the telephone line is held by the holding resistor _R17 . This also cuts off the operating circuit of relay L, so that it can be restored. As a result, contact 1 is opened, and since there is no conduction between terminals 4 and 6 of switching circuit SW ₂ , transistor Tr ₃ is turned off, so terminal 2 of switching circuit SW ₁ is opened. As a result, relay H operates again. Therefore, the telephone
TEL is connected to the power supply circuit through the blockage wire CH by contacts h ⁰ and h ¹ . In addition, due to the reactivation of contact h ⁴ , the ground voltage - winding HL - contact h ⁴ - contact hl ² - transistor
Tr ₁ - Relay HL is self-maintaining in the power supply E circuit.
On the other hand, since the telephone TEL is connected to the power supply circuit again, the transistor Tr ₂ is turned on as explained earlier, so even if the contact l is restored, the switching transistor Tr ₁ remains on, and the terminal
Continue to apply voltage between l ₃ and terminal l ₄ . Therefore,
As long as transistor Tr ₂ is turned on by the telephone loop, the relay HL is held. Additional device ADP
When you release button RK, thyristor SCR ₂ turns off,
From now on, even if button RK is pressed, the thyristor SCR will not turn on again because it is off. thyristor
If SCR ₂ turns off, the terminal l ₃ - terminal l ₄ of the additional device ADP
Since the gap is open, the resistor of the main device ME
The potential difference across _R15 disappears, and the switching circuit
SW ₂ is off, that is, both terminals 6 and 7 are open, and transistor Tr ₃ is not turned on. Therefore, the original state is restored. On the other hand, after the thyristor SCR ₂ is turned off, when pressing the button RK to call another telephone TEL, the current flowing through the telephone loop and resistor R ₂₈ is terminal l ₁ - terminal l ₂
The current between the resistor R ₂₈ and the closing of the button RK
is shorted, so it stays high while button RK is pressed. Therefore, the potential difference across the resistor _R16 in the main device ME becomes large, so each time the button RK is pressed, the transistor _Tr4 turns on, and the amplifier AMP
starts, and a ringing signal is generated between terminals _l3 and _l4 through transformer _T11 . The alternating current that is the calling signal between this terminal _l3 and terminal _l4 is connected to the capacitor _C22 and transformer in the additional device ADP corresponding to the other telephone TEL.
Make speaker SP sound through T ₂₁ . This allows you to call other telephones.

When the other telephone TEL disconnects the handset, terminals ₁ and ₂ of each additional device ADP are connected in parallel, so the transferer who pressed button RK and
After hearing the ringing of the speaker SP, the transferred party removes the handset and is now able to talk to the transferred party. Main device
The ME blockage ring CH and capacitor _C12 are used to enable this mutual communication.

A two-way conversation between the transferer and the transferee allows the transferer to tell the transferee that the call to the telephone line is being transferred. When the telephone line capture button LK in the additional device ADP is pressed, the thyristor SCR ₁ of the additional device ADP is turned on as already explained, and the switching circuit is activated by conduction of the switching circuit SW ₂ and transistor Tr ₃ in the main device ME.
SW ₁ turns off and relay H is restored. When relay H is restored, the self-holding circuit of relay HL is cut off by its contact ^h4 . Thereby the relay
HL is restored and its contacts hl ⁰ and hl ¹ are restored, so the hold on the telephone line by resistor R ₁₇ is released, the telephone line is connected to the telephone side, relay L is activated, and as already mentioned, the telephone line is connected to the telephone side. Then, the telephone TEL will be able to talk to the telephone line, and you will be able to answer the telephone line again. In this case, the other phone TEL
is made confidential by a confidential circuit constituted by a thyristor SCR ₃ and a constant voltage diode ZD ₂₂ in the additional device ADP. Incidentally, even if the power supply E is cut off due to a power outage or the like while the telephone TEL is talking to the telephone line, the telephone call can be continued without any problem because the relay H has already been restored. Confidentiality is also maintained. When the power supply E is restored in this state, the loop monitoring relay L is operating and its contact l is closed, so that the terminal 2 of the switching circuit SW ₁ is connected to the ground through the diode D ₁₂ and the contact h ³ . Therefore, relay H maintains the restored state. Therefore, even if the power supply E is cut off or restored while the telephone TEL is talking to the telephone line, the telephone call can be continued without any problem.

If you are simply trying to make a two-telephone call instead of transferring calls to and from the phone line, use
Since thyristor SCR ₁ in the additional device ADP is not operating, thyristor SCR ₂ does not turn on even if the extension call button RK is pressed. Therefore, the button
When RK is pressed, the contact RK ¹ activates the amplifier AMP as described above, and it is also possible to send a ringing signal to other telephones. If the other party answers, the call can be made.

In the embodiment described above, in order to call another telephone TEL, the signal from the signal generator OSC is amplified by the amplifier AMP and sent out.
Instead of the signal from the signal generator OSC, the input to the AMP is added with the audio output from the telephone TEL that appears between the contact h ⁰ and contact h ¹ and the block ring CH, to call the other party by voice. be able to.

(Effects of the Invention) As explained in detail above, the improved parent-child telephone device according to the present invention can be used to connect the same number of telephones as the main device and the four-wire parallel connection without modifying the conventional parent-child telephone device. By connecting a combination of two semiconductor switching elements between the communication lines in the telephone auxiliary device, and changing the current flowing through the control line according to the operating state received by the telephone auxiliary device, The information is transmitted to the main device, and the main device detects the current in the control line and performs an extension transfer operation corresponding to the operation performed on the additional telephone device. In the hold operation, the relay HL of the main device is activated and the telephone line is terminated with the hold resistor, and in the special work to capture the held telephone line, the relay HL is deactivated and the relay H is activated to connect the telephone line to the telephone line. Connecting. Furthermore, since the configuration of the additional device for a telephone according to the present invention is a simple and stable circuit configuration using small parts such as semiconductors, the additional device for a telephone is extremely small.
Moreover, it can be constructed at low cost.

[Brief explanation of drawings]

The figure is a circuit configuration diagram illustrating one embodiment of the present invention. ME...Main device, ADP...Additional device.

Claims (1)

[Claims] 1. A telephone additional device is connected to each of a plurality of telephones, and these telephone additional devices are connected in parallel to the main device by a two-wire communication line and a two-wire control line. , in a parent-child telephone device in which multiple telephones use a pair of telephone lines connected to the main device,
The main device includes a relay H that switches the telephone line between the telephone line side and the extension side, a relay HL that holds the telephone line, a hold resistor that terminates the telephone line with the contact of the relay HL, and a control line. It has a power source that supplies current to the control line, and a detection circuit that detects the presence or absence of a first current and a second current of different magnitudes flowing through the control line. The contact of the line capture button is connected in series with a constant voltage diode that conducts when the voltage between the control line exceeds a certain voltage, and the constant voltage diode conducts when the contact of the telephone line capture button is closed. a first semiconductor switching element having a self-holding function that is turned on by obtaining a starting voltage generated by the switching, and a second semiconductor switching element having a self-holding function and a contact point of an extension call button connected in series, When the contact of the telephone line capture button in the first telephone auxiliary device connected to the first telephone is closed, the first semiconductor switching element in the first telephone auxiliary device turns on, and the control line is connected to the first semiconductor switching device. flowing first
The current of Even if the contact point of the telephone line capture button of the second telephone additional device is closed, the voltage across the control line remains below the certain voltage due to the turning on of the first semiconductor switching element, so that the telephone line is closed. The contact of the extension call button in the first telephone additional device connected to the first telephone which has captured the telephone line is closed without making the constant voltage diode connected in series with the contact of the capture button conductive. When the first semiconductor switching element is turned on, the second semiconductor switching element is turned on and the second semiconductor switching element is turned on.
The second current flowing through the control line when the semiconductor switching element is turned on is detected by the detection circuit of the main device, and when the detection circuit detects the second current, the relay is activated.
When the HL is activated and the contact point terminates the telephone line at the hold resistor to put it on hold, the self-holding of the first semiconductor switching element is released and the contact point of the extension call button is released. When the second semiconductor switching element is turned off and the voltage between the control lines becomes higher than the above-mentioned constant voltage, and the contact of the telephone line capture button of one of the telephone additional devices is closed, the first semiconductor switching element of this telephone additional device is turned off. The semiconductor switching element is turned on, and the first semiconductor switching element is turned on.
The detection circuit detects the current, and deactivates the relay HL, and activates the relay H to connect the telephone line to the telephone line, and the contact of the telephone line capture button is connected to the telephone additional device, which is closed. An improved parent-child telephone device characterized in that a telephone set transfers an extension rather than seizes a telephone line.