JPH0363863B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a telephone switching device that switches and connects a public telephone and a general subscriber telephone to a public telephone line.

[Prior art]

Conventionally, in the case of pink telephones, the signal sent from the exchange side changes polarity depending on the called party's response, as shown in FIG. 1 (A). At this time, the inserted coins are simultaneously stored and mutual communication becomes possible, and the signal from the exchange side remains inverted from then on. On the other hand, since general subscriber telephones also perform the same polarity reversal operation as shown in Figure 1, by adding a switching device to the public telephone line, it is possible to It was also possible to make and receive calls.

However, with the introduction of the wide-area time and minute system, there was a shift from traditional public telephones to indoor desk public telephones (large pink telephones) for new services.
The signal from the exchange side also changed to something like the one shown in Figure 2, which changed polarity depending on the called party's response (a), and began to send periodic polarity reversal signals as coin storage signals. (b) Therefore, it is no longer possible to perform switched calls using a conventional switching device consisting of a simple switch. Therefore, as the needs for telephones change with the diversification and labor saving of society, for example, when installing a telephone in a store and residence, it is necessary to connect a public telephone line and a general telephone line, respectively. In addition to high costs, there were also problems in terms of service to users.

Therefore, an additional circuit equipped with a capacitor for smoothing the transmitting current when a polarity reversal signal arrives and a diode bridge that gives a certain polarity to this capacitor is connected in front of the regular subscriber telephone, and the transmitting current is smoothed when the polarity reversal signal arrives. A telephone device has been proposed which is provided with means for detecting interruption and preventing the formation of a loop due to the diode bridge, thereby allowing normal telephone calls to be made even from a general subscriber telephone. however,
From the point of view of service improvement, it is desirable not only to be able to make calls from general subscriber telephones, but also to be able to transfer calls during calls.

[Object and structure of the invention]

The present invention has been made in view of the above circumstances, and its object is to provide a telephone switching device that allows a call to be freely transferred from the general subscriber telephone side to the public telephone side during a call.

In order to achieve such an objective, the present invention
A diode bridge DB that outputs a positive signal to one output terminal regardless of the polarity of the input signal from the exchange side, and capacitors C2 and C4 connected to the diode bridge for noise absorption and transmitting current smoothing. and an additional circuit that normally has connection terminals L1 and L2 of the public telephone line and a changeover switch SW.
1, SW2, and switching means A, MA, ma1, ma2, which connects this connection terminal and an additional circuit of the changeover switch by a polarity reversal signal when the called party answers.
ma3, the incoming call response relay drive capacitors C11, C12, and C13, which are charged by the DC voltage line DB1 that is rectified from the commercial power supply, and the switch are operated to transfer the call from the general subscriber telephone TEL2 to the public telephone. Switch means L, LP, lp3, SW5, RV connects the incoming call response relay driving capacitor to the public telephone set in order to send out the charge charged in the incoming call response relay driving capacitor as an instantaneous polarity reversal signal. , rv1,2,3,
4, and by switching the changeover switch, an instantaneous polarity reversal signal is sent to the public telephone to drive the incoming call response relay. Hereinafter, the present invention will be explained in detail using Examples.

〔Example〕

FIG. 3 is a circuit diagram showing one embodiment of the present invention, and FIG.
The figure is a circuit diagram showing some details of a public telephone.
In this embodiment, a general subscriber telephone and a public telephone are provided for connection terminals L1 and L2 of a public telephone line to which polarity reversal signals arrive as shown in FIG. It has been made possible. That is, in the figure, the public telephone TEL1 and the general subscriber telephone TTEL2 are generally well-known telephones equipped with all the functions necessary for making calls, and are connected to connection terminals T1, T2 and T by switching switches SW1 and SW2, respectively.
3, connected to connection terminals L1 and L2 via T4. Note that the switches SW3 to SW5 are also switched at the same time. A response monitoring relay A is connected between the connection terminal L2 and the connection terminals T4 and T2. On the other hand, a loop supervisory control relay MA is connected to the commercial power supply, and when the response supervisory relay A is activated by the polarity reversal signal when the called party responds and the switch a that constitutes its contact is closed, this relay MA Operating current flows through. This makes up the switch ma that makes up that contact.
1 to ma4 are switched, and an additional circuit including a diode bridge DB consisting of capacitors C2 and C4 and diodes D1 to D4 is connected together with the response monitoring relay A before the changeover switch SW1. A capacitor C4 constituting an additional circuit supplies a communication current to the telephone during the interruption period (t3, t5 in FIG. 2) of a periodic polarity reversal signal as a coin storage signal to prevent a momentary interruption of voice. Capacitor and diode bridge DB for smoothing the transmitting current when arriving
ZD1 and ZD2 are constant voltage diodes for controlling the terminal voltage to downsize capacitor C4, and C1 supplies current in a fixed direction to the capacitor C4 and the telephone regardless of the polarity of the signal coming from the exchange side. and C3 is a capacitor for DC blocking, C2 is a capacitor for absorbing noise caused by the rise and fall of the polarity reversal signal, CH1 is a choke coil to prevent the audio signal from being shorted by capacitor C2, and CH2 is also capacitor C4. This is a choke coil for preventing voice signal short circuits, and the components of these additional circuits are similar to those commonly used in public telephones. Note that DB1 is a diode bridge that maintains the direction of current flowing through each subsequent relay regardless of the polarity of the commercial power supply voltage.

In the above configuration, when making a call from the general subscriber telephone TEL2, when the loop detection relay L connected between the switch SW1 and the connection terminal T3 operates due to the following loop formation, the control circuit of the commercial power supply section Since the switch 1 constituting the contact is closed, the transistor Tr1 becomes conductive, and the relay LP operates. As a result, the switches lp1 to lp4 forming the contacts are switched. D6
is a diode.

L1(+)−ma1−ma2−SW1−L−T3 −TEL2−T4−SW2 −D6−ma3−L2(−) …(1) Next, relay A is activated as follows by the polarity reversal signal when the called party responds. When is activated, relay MA is activated by the control circuit of the commercial power supply section as described above. D
5 is a diode.

L2(+)−ma3−A−D5−T4−TEL2 −T3−L−SW1−ma2 −ma1−L1(−) …(2) This allows additional circuits including capacitors C2, C4, diode bridge DB, etc. Connected within the loop.

L2(+)−D3−CH2−ma2−SW1−L−T3−TEL2
−T4 −SW2−D6−ma3−D2−CH1−ma1−L1(−)…
(3) At this time, relay A is short-circuited by diode D6 connected in parallel and recovers, but
Relay MA is self-held by the self-contact (ma4) and continues to operate. So the polarity is L1 (+)
Then, L1(+)−ma1−CH1−D1−CH2−ma2−SW1−L
−T3 −TEL2−T4−SW2−D6−ma3−D4−L2(−)…
(4) After that, loop (3) during polarity change, and (4) during L1 (+)
The call can be continued in the loop. Further, during the interruption time of the polarity reversal signal (t3, t4 in FIG. 2), the transmitting current is covered by the discharge of the capacitor C4 that was charged during the polarity reversal (simultaneously with the formation of the loop 3).

C4(+)−CH2−ma2−SW1−L−T3−TEL2−T4−SW2
−D6−ma3−C4(−)…(5) When the handset is lowered, relay L is restored, so relay LP, relay MA is restored, and capacitor C2,
Disconnect the additional circuits including C4 and diode bridge DB from the loop and restore the exchange. The reason why the loop detection relay L is provided to disconnect the additional circuit during on-hook is to prevent a loop from remaining formed due to the diode bridge DB even during on-hook. Also, the reason why this additional circuit is connected with the polarity reversal signal when the called party answers is because if it is connected immediately by off-hook operation, the dial pulse will be distorted by capacitors C2 and C4, and it is not necessary to connect it when there is an incoming call. Depends on the matter. An incoming call is made as follows.

L1(+)−ma1−ma2−SW1−L−T3−TEL2−T4−SW2
-D6-ma3-L2(-)...(6) Next, an explanation will be given of the operation when a call is transferred to the public telephone TEL1 during a call on the general subscriber telephone TEL2.

When a call is being made using the general subscriber telephone TEL2, whether it is an incoming call or an outgoing call, the relay LP is operating, so the incoming call response relay driving capacitor C1 is connected to the commercial power supply.
1, C12, and C13 are charged via resistors R14 and R15.

Here, the switches rv1 to rv4 constitute the contacts of the instantaneous polarity reversal signal sending relay RV.

In this state, selector switch SW1~
When SW5 is switched, the relay LP is restored by the restoration of the relay L, and as a result, the relay RV in the commercial power supply section is instantaneously activated by the discharge current of the capacitor C10.

C10(+)−RV−SW5−lp3−C10(−) …(8) The operation of this relay RV causes switches rv1 to rv
4 is switched, capacitors C111, C12, C
13 is connected in series to the public telephone TEL1, and as a result, as the discharge current of each capacitor, the public telephone
An instantaneous polarity reversal signal is sent to TEL1 and drives incoming call response relay R.

In addition, in FIG. 4, r1 and r2 are switches configuring the contacts of the incoming call response relay R, HS1,
HS2 is a switch, T is a transmitter, and INDUC.
is a guiding wire. When transferring, switch SW1
~Prior to switching SW5, call the public phone in advance.
To raise the handset of 1, press the switch.
Both HS1 and HS2 are in the opposite state to that shown in the figure.

Here, since the public telephone TEL1 is a generally well-known telephone, that is, a back-loop public telephone, as described above, a telephone call circuit cannot be formed simply by off-hooking the handset. When making a call, a coin is inserted after off-hook and the coin contact cc is closed to form a call circuit, but when a call is received, a call response relay R is activated by a ringing signal of 16 Hz, 75 from the station to form a call circuit. ing. A ringing signal from the station is input, and when off-hook is performed based on this, the hook switch HS2 is switched and a ringing signal current flows through the incoming call response relay R. The calling signal is an AC signal, but it operates when the connection terminal L2 of the public telephone line is energized (+),
Thereafter, the operating state is maintained magnetically. Contacts r1 and r2 are switched by the operation of the incoming call response relay R,
The coin contact cc is bypassed to form an incoming call circuit. It would be better if the same signal as the ringing signal could be generated when switching the switch, but since the circuit would be complicated, the present invention generates an instantaneous polarity change signal, sends this signal to the public telephone, operates the incoming call response relay R, and then operates the call circuit. We are trying to form a

Due to the operation of the incoming call response relay R, an incoming call circuit is formed at the end of the instantaneous operation of the relay RV, and the call can be continued. In other words, if the transfer is during an incoming call, the relay MA is not operating, During an outgoing call, relay MA is operating, so L1(+)−ma1−CH1−D1−CH2−ma2−SW1−l
p1− rv1−T1−TEL1−T2−rv2−lp2−SW2−A−
ma3−D4−L2(−)…(11) Also in this call transfer, public telephone TEL1
The signal path inside is an incoming call circuit similar to the loop in (10). In this way, in order to form a loop by driving the incoming call response relay R even when transferring outgoing calls, the noise absorbing capacitor C2 and the sending current smoothing capacitor C, which are originally provided in public telephones, are used.
4 etc. will not work. For this reason, an additional circuit including these capacitors C2 and C4 and diode bridge DB is installed in front of the changeover switches SW1 and SW2, and is configured so that it is added during an outgoing call and even while the call is being transferred to the public telephone TEL1. be.

In this way, capacitors C11, C12, C13
During an incoming call, by sending an instantaneous polarity reversal signal to the public telephone TEL1 using the discharge of
Public phone TEL during any outgoing call
Transfer to the first side can be performed. Moreover, the above capacitors C11, C12, and C13 are used for general subscriber telephones.
While talking on TEL2, that is, while switches LP1 and LP2 are operating, it is charged by the commercial power supply, and as sufficient voltage can be secured, relay R can be easily driven.
Therefore, transfer can be performed with the additional circuits including capacitors C2, C4, etc. connected. Therefore, by switching the changeover switches SW1 to SW5, the relay
Even if the LP is restored immediately, the formation of a loop with the exchange side is maintained by the additional circuit, so there is no need to particularly consider adjusting the restoration time of the relay LP. Furthermore, by using a capacitor charged by a commercial power source as described above, it is also possible to transfer the periodic polarization signal during the interruption period (t3, t5 in FIG. 2).

When the handset is lowered, relay R is restored, and relay A is restored by disconnection of the transmitting current. In the case of an outgoing call, the relay MA is further restored here,
The loop with the station is completely broken.

When making and receiving calls from public telephone TEL1 from the beginning, relay A operates, but relay LP,
MA and RV do not work, so you can make and receive calls normally as a regular public telephone. In addition, transfer from public telephone TEL1 to general subscriber telephone TEL2 is as follows:
This can be done freely during both incoming and outgoing calls.

In addition, in Fig. 3, switch SW4 and diode D9 are provided for general subscriber telephones.
When it is connected to the TEL2 side, the recovery time of relay LP is lengthened to prevent the relay LP from fluttering during dial operation, and the recovery time of relay MA is lengthened only when the switch is switched for transfer. This is to speed up recovery when the vessel is lowered.

By the way, in the above-mentioned embodiment shown in FIG. 3, in a call using the general subscriber telephone TEL2, the time is T4 (+) as shown in Leap 2 until the relay MA operates after the called party responds, but the relay MA If it operates, it becomes T3 (+) as shown in loops 3 and 4. For this reason, it is inconvenient when performing some kind of control based on the continuation of the T4 (+) signal for a certain period of time, such as in an answering machine, for example. This is the same as when a general subscriber phone is continued on a general telephone line.
Figure 5 shows an example of the operation where the polarity is changed to T4 (+).

That is, the difference between FIG. 5 and FIG. 3 is that the diodes D1 to D1, which constitute the diode bridge DB of the additional circuit, are
By reversing the direction of D4 and the polarity of the general subscriber telephone TEL2 side, the operation of the incoming call response relay R on the public telephone TEL1 side, and therefore the relay is interrupted.
Add a relay MB in parallel to the MA and use it as a public telephone
This is done by reversing the polarity on the TEL1 side and returning it to its original state. In addition, in this example, the relay MA
As mentioned above, a new relay MB is used due to the restriction on the number of contact pairs, but the relay MB operates and recovers in exactly the same way as the relay MA. relay MB
It goes without saying that the contacts of the relay MA may be used instead of the switches mb1 and mb2 which constitute the contacts of the relay MA.

〔Effect of the invention〕

As explained above, according to the present invention, a capacitor for driving an incoming call response relay is provided, and this capacitor is connected to a public telephone when a call is transferred from a general subscriber telephone to a public telephone, and an instantaneous polarity reversal signal is sent to the public telephone as the discharge current. By connecting additional circuits including noise absorbing capacitors, transmitting current smoothing capacitors, etc. in front of the changeover switch, it is possible to operate the public telephone's incoming call response relay during transfer. By forming an incoming call circuit in this way, it is possible to transfer calls to the public telephone during both outgoing and incoming calls. In addition, since the capacitor for driving the incoming call response relay is charged by the commercial power supply during a call from a regular subscriber telephone, the same transfer can be performed even when the periodic polarity change signal is interrupted, and in the end,
You can transfer calls completely freely.

[Brief explanation of drawings]

Figure 1 is a diagram showing a signal arriving from the exchange side for a conventional small pink telephone, and Figure 2 is a diagram showing a periodic polarity change signal arriving for an indoor desk public telephone (large pink telephone). , FIG. 3 is a circuit diagram showing one embodiment of the present invention, FIG. 4 is a partially detailed diagram thereof, and FIG. 5 is a circuit diagram showing another embodiment of the present invention. TEL1...Public telephone, TEL2...General subscriber telephone, L1, L2...Public telephone line connection terminal, R...
Incoming call response relay, C11, C12, C13...Capacitor for driving the incoming call response relay, C1-C4...Capacitor forming additional circuit, CH1, CH2...Chiyoke coil, DB...Diode bridge, SW
1 to SW5...Switches, ma1 to ma3...Switches for connecting additional circuits, rv, rv1 to rv4...Switches for switching and connecting incoming call response relay drive capacitors.

Claims (1)

[Claims] 1. A public telephone line to which a periodic polarity change signal arrives,
In a telephone switching device equipped with a switch that switches and connects a public telephone with an incoming call response relay and a general subscriber telephone, a diode switch that outputs a positive polarity signal to one output terminal regardless of the polarity of the input signal from the exchange side. An additional circuit including a capacitor connected to a diode bridge for noise absorption and smoothing of the transmitting current is normally connected to the connection terminal of the public telephone line and the above changeover switch, and when the called party answers a switching means that connects the additional circuit between this connection terminal and the changeover switch in response to a polarity reversal signal; and a capacitor for driving an incoming response relay that is connected to a DC voltage source obtained by rectifying the commercial power supply and charged by this DC voltage. and switch means that operates when the changeover switch is operated to transfer a call from the general subscriber's telephone to the public telephone, and connects the capacitor for driving the incoming call response relay to the public telephone, the incoming call response relay A telephone switching device characterized in that the driving capacitor transmits the charged electric charge as an instantaneous polarity reversal signal when connected to a public telephone.