KR19990032173A - Overcurrent cut-off device in CO line automatic receiving board - Google Patents

Abstract

The present invention relates to a trunk line automatic receiving board in a simple exchange system, in particular due to the ground or short-circuit of the tip terminal or ring terminal of the trunk line automatic receiving board in a loop formed between the national exchange system and the trunk line automatic receiving board. The present invention relates to an overcurrent blocking device in a trunk line automatic receiving board that immediately cuts off an overcurrent flowing in a loop.

In the conventional COS automatic receiving board, a poly switch is used as a means of blocking overcurrent. In this case, there is a problem in that it is not able to cut off quickly even when overcurrent flows in the CO line and the price of the poly switch is very expensive. In addition, there is a problem in that the production efficiency of the CO line receiving board is lowered because the volume of the balance resistor is large and needs to be assembled by the CO line receiving board by hand.

The present invention removes the poly switch configured on the automatic trunk line receiving board of the simple switching system and adds a loop detection circuit to detect the overcurrent flowing in the communication path, thereby driving the relay to cut the corresponding communication path to quickly cut off the overcurrent. In addition, the balance resistor can be automatically assembled to the CO line by using the balance resistor with small power value, thereby improving the production efficiency of the CO line.

Description

Overcurrent cut-off device in CO line automatic receiving board

The present invention relates to a trunk line automatic receiving board in a simple exchange system, in particular due to the ground or short-circuit of the tip terminal or ring terminal of the trunk line automatic receiving board in a loop formed between the national exchange system and the trunk line automatic receiving board. The present invention relates to an overcurrent blocking device in a trunk line automatic receiving board that immediately cuts off an overcurrent flowing in a loop.

In general, a simple exchange system is connected to a DI (Direct Inward) trunk line of a national exchange system, and a direct inward dialing board (DIDB) performs a function of processing a call signal transmitted through a DI trunk line from a local exchange system. ) Is built. The trunk line automatic receiving board (DIDB) in such a simple switching system has only a function of receiving a call signal from the local switching system, and it is established with a small number of DI trunk lines regardless of the number of the subscribers connected to the simplified switching system. When connected to a switching system and receiving a call signal from the local switching system, a call path is established with an extension subscriber for the call signal.

Referring to Figure 1 attached to the function of the trunk line automatic receiving board (DIDB1) in the conventional simple exchange system as described above is as follows.

As shown in FIG. 1, the trunk line automatic receiving board DIDB1 in the conventional simple switching system includes the relays 11 and 17, the transformers 12 and 18, the polarity inversion circuit 13, and the balance resistors 14 and 19. ), A poly switch 15, a power supply 16, a control unit 20, and a loop detection circuit 21.

The relays 11 and 17 are installed between the transformers 12 and 18 and the local exchange system to perform a switching operation between calls between the transformers 12 and 18 and the local exchange system under the control of the control unit 20. 12 and 18 transmit a signal applied through the polarity inversion circuit 13 to the local exchange system via the relay 11 or transmit a signal received from the local exchange system via the relay 17 to the polarity reverse circuit. (13) It performs the role of delivering to the side. The polarity inversion circuit 13 performs an operation of switching the polarity of the voltage (-48V) provided from the power supply 16 under the control of the control unit 20 so as to convey to the local exchange system that the communication path is configured. , The balance resistors 14 and 19 are connected to the polarity inversion circuit 13, the transformer 12, the relay 11, and the local switching system side via the poly switch 15 from the power supply 16. ) And between the polarity inversion circuit 13 and the ground of the ring line from the local exchange system to the ground via the relay 17, transformer 18, and polarity inversion circuit 13. It is installed on the circuit board to withstand the overcurrent flow in the line and plays a role of perfect matching between the two lines in order to minimize the transmission loss of the signal between the tip line and the ring line. The poly switch 15 is installed between the balance resistor 14 and the power supply 16 so that the tip terminal of the trunk line automatic receiving board DIDB1 is shorted or grounded, and an over-current flows in the tip line so that the balance resistor 14 and the power supply 16 ) Is heated above a certain temperature and at the same time, if over current over a certain current flows on the tip line, the switch is turned off to cut off the tip line to cut off the overcurrent to protect the trunk line automatic receiving board (DIDB1). It plays a role. The power supply 16 provides a voltage of '-48V' in the trunk line automatic reception board DIDB1 to allow the trunk line automatic reception board DIDB1 to perform a normal operation, and the control unit 20 receives a trunk line automatic reception board ( DIDB1) controls the operation of the whole system, such as monitoring the call path and controlling the call path connection, and controlling the call path to be configured by driving the relays 11 and 17 according to the off-hook signal applied from the loop detection circuit 21. When the communication path is configured, the polarity inversion circuit 13 is controlled to switch the polarity of the voltage (-48 V) provided from the power supply 16 to convey to the relevant local exchange system that the communication path is configured. The loop detection circuit 21 detects an off-hook signal from a line between the polarity inversion circuit 13 and the balance resistors 14 and 19 and applies the control signal to the control unit 20 under the control of the control unit 20. do.

As described above, in the trunk line automatic receiving board of the conventional simple switching system, a poly switch is used as a means of blocking overcurrent. In such a case, the problem of failing to cut off quickly even when overcurrent flows in the trunk line automatic receiving board and the price of the poly switch are very high. There is a problem that it is expensive, because the volume of the balance resistor is large, there is a problem that the production efficiency of the CO line receiving board is reduced because it must be assembled by hand.

The present invention is to solve the problems as described above, the object is to additionally configure the loop detection circuit in the CO line board to detect the over-current to drive the relay, to quickly over-current flowing through the CO line board To block.

Another object of the present invention is to cut off the over-current flowing through the CO line board using a loop detection circuit and a relay to remove the poly switch built in the CO line board, and at the same time to quickly cut off the over-current, power value value This small balance resistor can be used to automatically assemble the balance resistor on the CO line receiving board to improve the production efficiency of the CO line receiving board.

Features of the present invention for achieving the above object, the power supply for providing a voltage so that the CO line automatic receiving board can operate normally; A plurality of balance resistors for matching between the two lines in order to withstand a predetermined current flow through the tip line and the ring line of the CO line automatic reception board and to minimize the transmission loss of the signal between the two lines; A polarity inversion circuit for performing an operation of switching the polarity of the voltage provided from the power supply; A plurality of transformers for transmitting a signal applied through the polarity inversion circuit to the local exchange system side or a signal applied from the local exchange system to the polarity reverse circuit side; A trunk line automatic receiving board in a simple switching system having a plurality of relays installed between the transformer and a local exchange system for switching a communication path between the transformer and the local exchange system, wherein the polarity inversion circuit and the balance resistor are provided. A first loop detection circuit for detecting an off-hook signal from the line; A second loop detection circuit for detecting an overcurrent flowing in the communication path from a line between the polarity inversion circuit and a balance resistor when a communication path is configured between the local switching system and the automatic trunk line receiving board; Control the operation of the whole system, such as the monitoring of the call path, the control of the call path connection made in the automatic CO line receiving board, driving the relay in accordance with the off-hook signal applied from the first loop detection circuit to form a call path The polarity inversion circuit is controlled to switch the polarity in order to convey to the local exchange system that the signal is configured, and when the overcurrent is sensed by the second loop detection circuit and a cut signal is applied to the call, the relay is driven to After cutting the communication path, and after a predetermined time has passed to the control unit for controlling the return to the normal state of the call back to the relay.

1 is a block diagram of a trunk line automatic receiving board in the conventional simple switching system.

Figure 2 is a block diagram of a trunk line automatic receiving board in a simple exchange system according to the present invention.

Explanation of symbols on the main parts of the drawings

11, 17, 31, 36: relay 12, 18, 32, 37: transformer

13, 33: polarity inversion circuit 14, 19, 34, 38: balance resistance

15: poly switch 16, 35: power supply

20, 39: control unit 21: loop detection circuit

40: first loop detection circuit 41: second loop detection circuit

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the simple switching system according to the present invention, the trunk line automatic receiving board DIDB2 is a relay 31, 36, a transformer 32, 37, a polarity inversion circuit 33, and a balance resistor 34 as shown in FIG. 38, a power supply 35, a control unit 39, a first loop detection circuit 40, and a second loop detection circuit 41 are configured.

The relays 31 and 36 are installed between the transformers 32 and 37 and the local exchange system to perform a switching operation between calls between the transformers 32 and 37 and the local exchange system under the control of the controller 39. 32 and 37 transmit a signal applied through the polarity inversion circuit 33 to the local exchange system via the relay 31 or transmit a signal received from the local exchange system via the relay 36 to the polarity reverse circuit. (33) serves to deliver to the side. The polarity inversion circuit 33 performs an operation of switching the polarity of the voltage (-48V) provided from the power supply 35 under the control of the control unit 39 to convey to the local exchange system that the communication path is configured. , The balance resistors 34 and 38 are the power supply 35 and the polarity inversion circuit 33 of the tip line from the power supply 35 to the polarity inversion circuit 33, the transformer 32, the relay 31 and the local exchange system. Interposed between the polarity inversion circuit 33 and the ground of the ring line which is installed between the relay 36, the transformer 37, and the polarity inversion circuit 33 from the local exchange system to the ground, and a predetermined current in the line. It plays a role of ensuring perfect matching between two lines in order to withstand the flow of the signal and to minimize the transmission loss of the signal between the Tip and Ring lines. The power supply 35 provides a voltage of '-48V' in the trunk line automatic reception board DIDB2 to enable the trunk line automatic reception board DIDB2 to perform a normal operation, and the controller 39 controls the trunk line automatic receiving board ( DIDB2) controls the operation of the entire system such as monitoring the call path and controlling the call path connection. The call path is configured by driving the relays 31 and 36 according to the off-hook signal applied from the first loop detection circuit 40. Control the polarity inversion circuit 33, and control the polarity inversion circuit 33 to switch the polarity of the voltage (-48 V) provided from the power supply 35 to convey to the relevant local exchange system that the communication route is configured. After the predetermined time passes, the relays 31 and 36 cut off the corresponding communication path to drive the relays 31 and 36 according to the call cut signal applied from the second loop detection circuit 41 to cut off the overcurrent. To re-enable Check the return to normal status. The first loop detection circuit 40 detects an off-hook signal from a line between the polarity inversion circuit 33 and the balance resistors 34 and 38 under the control of the control unit 39 and applies it to the control unit 39. 2 The loop detecting circuit 41 balances the current flowing in the corresponding communication path with the polarity inversion circuit 33 under the control of the control unit 39 when the communication path is configured between the national exchange system and the trunk line automatic receiving board DIDB2. When an overcurrent of more than the normal operating current is detected by sensing from the line between the resistors 34 and 38, a cutoff signal is applied to the controller 39 by a call.

As described above, the present invention removes the poly switch configured on the automatic trunk line receiving board of the simple switching system and adds a loop detection circuit to drive the relay by cutting the corresponding channel to quickly cut the overcurrent when an overcurrent flowing in the communication path is detected. It is possible to cut off, and the balance resistor can be automatically assembled to the CO line by using the balance resistor with small power value, thereby improving the production efficiency of the CO line.

Claims (1)

A power supply for providing a voltage for the trunk line automatic reception board to operate normally; A plurality of balance resistors for matching between the two lines in order to withstand a predetermined current flow through the tip line and the ring line of the CO line automatic reception board and to minimize the transmission loss of the signal between the two lines; A polarity inversion circuit for performing an operation of switching the polarity of the voltage provided from the power supply; A plurality of transformers for transmitting a signal applied through the polarity inversion circuit to the local exchange system side or a signal applied from the local exchange system to the polarity reverse circuit side; In the trunk line automatic receiving board in a simple switching system having a plurality of relays installed between the transformer and the local exchange system to switch the communication path between the transformer and the local exchange system, A first loop detection circuit for detecting an off-hook signal from a line between the polarity inversion circuit and a balance resistor; A second loop detection circuit for detecting an overcurrent flowing in the communication path from a line between the polarity inversion circuit and a balance resistor when a communication path is configured between the local switching system and the automatic trunk line receiving board; Control the operation of the whole system, such as the monitoring of the call path, the control of the call path connection made in the automatic CO line receiving board, driving the relay in accordance with the off-hook signal applied from the first loop detection circuit to form a call path The polarity inversion circuit is controlled to switch the polarity in order to convey to the local exchange system that the signal is configured, and when the overcurrent is sensed by the second loop detection circuit and a cut signal is applied to the call, the relay is driven to operate the call. After cutting the furnace, the predetermined time passes, the over-current cut-off device in the automatic trunk line receiving board, characterized in that it comprises a control unit for performing the role of checking the return to the normal state of the communication line again.