JPH0220995A - Speech switching system in faulty state - Google Patents

Abstract

PURPOSE:To continue a talk without being supplied with the electric power from a battery even in the case of a power failure by turning on a current self-holding type switch element corresponding to a telephone set which is connected to an opposite device in response to the indication from a central controller in case of abnormality occurrence. CONSTITUTION:If a power failure occurs, an abnormality detecting circuit 11 detects that to recover a channel switching relay CH and also send a signal to the central controller 5 of a telephone exchange. The central controller 5 sends a control signal to a switch circuit 12 until the power source in the telephone exchange turns off after the recovery of the channel switching relay CH to turn on a optical coupling type thyristor 9 corresponding to the telephone set which is connected to a trunk line through the current self-holding type switch driving circuit 6 in a switching circuit 12. Consequently, the talk can be continued without being supplied with the electricity from the battery.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a call switching system in the event of an abnormality in a telephone exchange device receiving current supply from a counterpart device (while making a call).

[Conventional technology]

An abnormal situation refers to a situation in which it becomes impossible to continue a call.Specifically, various situations can be considered, such as an abnormality in the communication path, an abnormality in the power supply, a power outage, etc.Here, we will take the case of a power outage as an example, and the details are as follows. Add an explanation.

As is well known, in conventional switching equipment, according to the technical standards of PBX, in the event of a power outage, it is not possible to hold a call until the call is completed even if there is a connection between the central office line and the extension line or between the central office line and the operator. As a countermeasure, the fourth
As shown in the diagram, a battery is installed for power outage protection, and in the event of a power outage, power is supplied from the battery, and then calls to the central office line are monitored, and as soon as the calls are completed, the central office line and the extension line are connected directly. It was the way to go.

[Problem to be solved by the invention]

The above-mentioned conventional example requires a battery for power outage maintenance, which is uneconomical, and the battery itself is large, making the entire replacement device bulky, which poses a problem in realizing a compact replacement device.

The purpose of the present invention is to maintain the connection between the office line and the extension line, and between the office line and the operator, by using the communication current supply from the other party's device, without receiving power supply from the batch IJ-, even during a power outage. To provide a call switching system in the event of an abnormality, which allows a call to be continued until the call ends even if the call is terminated.

[Means to solve the problem]

The feature of the present invention is that when an abnormality occurs, the communication line is switched to the switch circuit by the operation of the abnormality detection circuit, and the current self-holding switch corresponding to the telephone that is in communication with the other party's device is instructed by the central control unit. By making the device conductive, maintaining the communication by using the communication current from the other party's device, and also monitoring the end of the communication, the communication can be continued without a power supply.

[Effect]

If an abnormality occurs in the telephone exchange equipment, hold the call until the call is completed even if the telephone exchange equipment is connected to an extension or operator without power supply such as a battery to the telephone exchange equipment. I can do it.

〔Example〕

An embodiment of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows a circuit according to the invention, in which the telephone switching equipment is in the energized state, and the communication line switching relay C, not shown, is shown in FIG.
H is operating, therefore the contact Ch of the communication line switching relay
0 to ch' are closed, and the optically coupled thyristor switches 9 and 10 are in an off state.

Assume that the extension telephone TFiL-C is currently talking to the central office line, and the extension telephone device-A and the extension telephone TFiL-B are talking between extensions.The route of the call at that time is as follows.
Extension telephone device-C-communication path switching relay contact ch',
ch' - Call path switch 4 - Bidirectional office line trunk 7 -
Contacts ch', ah' of the communication path switching relay - Office line and extension telephone equipment - A - Contacts ch' of the communication path switching relay,
ch'-channel switch 4-channel switching relay contacts ch", ch"-extension telephone device-B.

Now, if an abnormality, that is, a power outage occurs in this state, the abnormality detection circuit 11 detects it, and immediately restores the communication path switching relay CH and issues a signal to the central control unit 5 of the telephone exchange.

At this point, the communication on the office line is switched to the communication path 3 side that connects the internal device-C and the office line.

On the other hand, receiving the signal, the central control unit 5 issues a control signal to the switch circuit 12 after the recovery of the communication path switching relay CH and before the power in the telephone exchange equipment is cut off.
Through the current self-holding switch drive circuit 6 in 2, the optically coupled thyristor, in this case thyristor 9, corresponding to the telephone that was in communication with the central office line is brought into conduction.

At this time, extension telephone device-C has its handset set up, and the telephone exchange equipment in the central office conducts a call current, and from then on, it monitors the end of the call on extension telephone horizontally placed-C, and supplies power from the battery. You can continue the call without

Although I did not explain it until now, diode bridge rectifier circuit 8
The purpose of this is to make the direction of current flowing to the optically coupled thyristor switch constant regardless of the polarity of the current supply from the other device.

This is not necessary if a non-polar current self-holding switching element is used.

Furthermore, since there is a momentary interruption at the moment when the polarity of the supplied current is reversed, the thyristor is turned off, but this is not a disadvantage from the purpose of the present invention, which is to save a call in progress.

On the other hand, extension telephone TB-A and extension telephone device-B, which were communicating between extensions, will be disconnected when the call path switching relay CH is restored, and since extension telephone device-A is a direct dial telephone, the call will be passed through call path 1 unconditionally. It will be connected to the central office line.

FIG. 2 shows another embodiment according to the present invention, in which bridge type optically coupled thyristor switches 15 and 14 are used as current self-holding switches, and the same effect can be obtained.

In this case, a diode bridge rectifier circuit is not required.

Also, a relay or the like may be considered as another example of the current self-holding type switching element.

Further, in this embodiment, a case of a power outage is taken up as an abnormal state, but the same system is used for other abnormal states as described above, only the detection method of the abnormal state detection circuit is different.

Furthermore, the configuration of the telephone exchange device of this embodiment is such that the extension telephone 3
Although the explanation has been made with one central office line per unit, the accommodation ratio of extension lines and central office lines may be configured in any manner.

〔Effect of the invention〕

As explained above, according to the present invention, in the event of an abnormality, even if there is no power supply to the telephone exchange device from a battery or the like and the other party's device is connected to an extension or operator, the call will continue until the call is completed. It is economical and the entire exchange device can be made smaller.

[Brief explanation of the drawing]

Fig. 1 and Fig. 2 both show an embodiment of the present invention, Fig. 5 shows a time chart during a power outage using the abnormal call switching system according to the present invention, and Fig. 4 shows a conventional telephone exchange. It is a figure showing the case of an apparatus. [Explanation of symbols] 1.2.3...Call path 4...Call path switch 5...・・・・・・・・・・・・・・・・・・
・Central control unit 6・・・・・・・・・・・・・・・・・・
...Current self-holding element drive circuit 7...
・・・・・・・・・・・・・・・Directory line bidirectional trunk location A
,B,C・・・・・・・・・・・・・・・・・・
Extension telephone 8・・・・・・・・・・・・・・・・・・
...Diode bridge rectifier circuit 9.10...
... Optically coupled thyristor switches 13, 14...
... Bridge type optically coupled thyristor switch 11 ...... Abnormality detection circuit (voltage monitoring circuit) 12 ......・・・
...Switch circuit ch'~ch'...Contact system of communication path switching relay 1 Figure wJz flash diagram Figure 4

Claims (1)

[Claims] 1. If an abnormality occurs in the telephone exchange equipment that receives current supply from the other party's equipment to make a call, the abnormality detection circuit will operate to switch the telephone line to a switch circuit, and the central control unit will send the telephone line to the other party. A call switching system in the event of an abnormality, characterized in that a current self-holding switching element corresponding to a telephone that was in a call state with the device is made conductive to continue the call state, and the end of the call is monitored.