KR19990043685A - Trunk Line Transfer Circuit and Method in Private Switching System - Google Patents

Abstract

end. The technical field to which the invention described in the claims belongs

Trunk Line Switching Circuit and Method in Private Switching System

I. The technical problem that the invention is trying to solve

It provides a circuit and method for one-to-one connection between CO line and extension telephone in case of main power failure during operation of private switching system.

All. Summary of the Solution of the Invention

In the private switching system, a relay driver for driving a relay in response to a signal applied from an external device or a control unit, and a relay for connecting a contact point between a trunk line and a trunk and a subscriber under control of the relay driver, and when a forced transfer is requested. Alternatively, when the main power is bad or when a forced changeover is ordered from the system, the relay is controlled to automatically connect the trunk line with the extension telephone.

la. Important uses of the invention

If the private exchange system does not operate properly due to power outages, the CO line and the extension phone can be automatically connected.

Description

Trunk Line Transfer Circuit and Method in Private Switching System

The present invention relates to evacuation of trunk lines of a private switching system, and more particularly, to a trunk line switching circuit and a method for automatically connecting a trunk line and an extension telephone when an error occurs in the private branch exchange.

Normally, evacuation of trunk line in a private exchange system is not connected to the private branch line to the private branch line. You can use CO line.

The circuit for performing trunk line evacuation in the conventional private exchange system is as shown in FIG. 1.

Referring to Figure 1 will be described the operation of the circuit performing the trunk line evacuation function in the conventional private switching system. When the private exchange 110 operates normally, the switches S3 and S4 are connected as a solid line path, so that the trunk line 100 is connected to the TRK111, and the extension telephone 120 is connected to the SLC112. On the other hand, when an error occurs in the private exchange 110, the switches S1 to S4 are manually switched in accordance with the manual. That is, when an abnormality occurs in the private exchange 110, the switches S3 and S4 are respectively switched like a dotted line path so that the trunk line 100 and the extension telephone 120 are directly connected.

As described above, when the private exchange 110 does not operate normally due to a power failure lamp in the conventional private exchange system, it is troublesome to manually switch over using the manual switches S1 to S4. In addition, when the private exchange 110 operates abnormally in such a conventional private exchange system, it takes a long time to manually switch the manual switches S1 to S4, and thus there is a problem in that it cannot be quickly dealt with. That is, the conventional private exchange system should evacuate the CO line if the private exchange fails to function properly if the power is not properly supplied, but if there is no prompt response from the service personnel, the external private call or internal call cannot be made. Cause.

Accordingly, it is an object of the present invention to provide a trunk line switching circuit and method for automatically connecting a trunk line and an extension telephone when a private exchange does not operate due to a power failure.

Another object of the present invention is to provide a trunk line switching circuit and method for rapid trunk line evacuation in a private exchange system.

It is another object of the present invention to provide a trunk line switching circuit and method for a simple trunk line evacuation in a private exchange system.

In order to achieve the above object, the present invention provides a relay driver for driving a relay in response to a signal applied from an external or control unit in a private exchange system, and a relay for connecting a contact point between a trunk line and a trunk and a subscriber under control of the relay driver. It is characterized in that the configuration. In addition, the present invention is characterized in that the private switching system automatically connects the CO line and the extension telephone by controlling the relay when a forced transfer request from the outside or when the main power is bad or when the forced transfer command from the system.

1 is a diagram illustrating a trunk line switching circuit of a conventional private switching system.

2 is a diagram illustrating a trunk line switching circuit of a private exchange system according to an embodiment of the present invention;

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

2 is a diagram illustrating a trunk line switching circuit of a private exchange system according to an exemplary embodiment of the present invention, and includes a switch S5, a resistor R1, a diode D1, a relay driver 210, and a relay 220. The switch S5 switches the input of the 5V power supply to the resistor R1 in accordance with the abnormality of the private exchange 110. The anode terminal of the diode D1 is connected to the resistor R1, and the cathode terminal is connected to the relay driver 210 to be turned on / off according to the signal applied to the anode terminal and the cathode terminal. The relay driver 210 controls the driving of the relay 220 by receiving an enable signal EN applied from the controller according to the on / off of the diode D1. The relay 220 connects the tip terminal and the ring terminal of the trunk line with TRK111, which is the trunk line receiving circuit of the private exchange 110, or the extension telephone under the control of the relay driver 210. That is, when the private exchange 110 operates normally, the relay 220 connects the tip terminal of the trunk line with the TRK111 which is the trunk line receiving circuit of the private exchange 110. On the contrary, when the private exchange 110 operates abnormally, the relay 220 disconnects the tip terminal of the trunk line from the TRK111, which is the trunk line receiving circuit, and directly connects the extension telephone 120. In addition, when the private exchange 110 operates normally, the relay 220 connects the ring terminal of the trunk line with the TRK111 which is a trunk line receiving circuit of the private exchange 110. On the contrary, when the private exchange 110 operates abnormally, the relay 220 disconnects the ring terminal of the trunk line from the TRK111, which is the trunk line receiving circuit, and directly connects the extension telephone 120. Accordingly, the extension telephone 120 is connected to the subscriber interface card SLC112 when the private switch 110 operates normally, and the ring terminal and the tip terminal of the trunk line are indirectly connected through the private switch 110.

A trunk line switching circuit and a method of a private exchange system according to an embodiment of the present invention will be described with reference to FIG. 2. The relay driver 210 receives an enable signal from a controller (not shown) and controls driving of the relay 220 in response to the enable signal. The enable signal is a signal applied from the private exchange 110, and outputs a high signal when the private exchange is in a normal state, and outputs a low signal when the private exchange is abnormal. When the private exchange 110 operates normally, since the switch S5 is turned on, the + 5V power is applied to the resistor R1 to turn on the diode D1. The relay driver 210 receives the enable signal in a high state and controls the relay 220 in response to the applied signal. The relay 220 is connected to the contacts P1 and P3 because current flows through the coil under the control of the relay driver 210. That is, the relay 220 connects the tip terminal and the ring terminal of the trunk line with TRK111 which is the trunk line receiving circuit of the private exchange 110 under the control of the relay driver 210. Therefore, the extension telephone 120 is connected to the subscriber interface card SLC112 and indirectly connected to the ring terminal and the tip terminal of the trunk line through the private exchange 110.

On the other hand, when the private exchange 110 is abnormal, the switch S5 is turned off. In the embodiment of the present invention, the case where the private exchange 110 is abnormal refers to a case in which the main power supply is bad or a forced transfer from the outside is required, or a case in which the internal exchange is to be performed. Since the switch S5 is turned off and the diode D1 is turned off, the low signal is applied to the relay driver 210. The relay driver 210 controls the relay 220 by receiving an enable signal in a low state and applying a signal corresponding to a state of the applied enable signal to the relay 220. The relay 220 connects the contact point P1 and the contact point P2 since no current flows in the coil by a control signal applied from the relay driver 210. Therefore, the extension telephone 120 is directly connected to the tip terminal and the ring terminal of the trunk line when the private switch 110 does not operate normally.

As described above, the present invention automatically performs the trunk line evacuation function so that the case where the power is not supplied to the extension telephone due to the abnormality of the power in the private switching system does not occur. Therefore, the present invention has the advantage of improving the reliability of the private exchange because it can immediately deal with the power failure in the private exchange system. In addition, the present invention has the advantage that can be forcibly switched private exchange system, the switchover is made even when the main power supply of the system is defective to perform the trunk line evacuation function. In addition, the present invention does not use a separate relay between the trunk line and trunk line trunk line to switch trunks in each port in the private switching system has the advantage that the number of relays can be reduced to reduce the cost.

Claims (4)

In the trunk line switching circuit in a private exchange system, A relay driver which controls the driving of the relay by receiving a changeover request or a signal corresponding thereto from the outside; A trunk line switching circuit, comprising: a relay for connecting a tip terminal and a ring terminal of a trunk line to a trunk line receiving circuit or an extension telephone of a private branch exchange under control of the relay driver. In the trunk line switching circuit in a private exchange system, Switch on / off depending on whether the private exchange is abnormal, A diode turned on / off in response to a signal applied according to the on / off of the switch; A relay driver for controlling driving of the relay in response to a control signal applied according to an abnormality of the private exchange; And a relay for switching the tip terminal and the ring terminal of a trunk line to a trunk line receiving circuit or an extension telephone of a private switch under control of the relay driver. The method of claim 2, When the private exchange does not operate normally, when the switch is turned on and the diode is turned on as the switch is turned on, the relay driver controls the relay in response to a control signal from the controller to tip the ring terminal and tip of a trunk line. A trunk line switching circuit, characterized in that the terminal is directly connected to the extension telephone. In a private line switching method in a private line exchange system having a relay driving unit for driving a relay for connecting a tip terminal and a ring terminal of a trunk line to a private branch exchange or an extension telephone in accordance with the abnormality of the private branch exchange, The relay driving unit drives the relay to directly connect the tip terminal and the ring terminal of the trunk line to the extension telephone when a forced transfer is requested from the outside, or when the main power is bad, or when the transfer is ordered from the private exchange. CO line transfer method to use.