KR0143371B1 - Subscriber matching circuit for exchanger - Google Patents

Abstract

[Operational field to which the claimed invention belongs]

It is a technology for subscriber matching circuit that can match between subscriber and exchange.

[Technical Problem to Solve]

The loop resistance of the subscriber line is limited to 2㏀, so that it can be matched even if it exceeds 2㏀.

[Summary of the solution of the invention]

The booster is used to boost the supply and supply it when the subscriber loop is formed.

[Important Uses of the Invention]

Applies to subscriber matching circuit of switching system.

Description

Subscriber Matching Circuit of Switching System

1 is a conventional subscriber matching circuit diagram

2 is a subscriber matching circuit according to the present invention.

3 is a detailed circuit diagram of a subscriber loop expansion circuit according to the present invention.

* Explanation of symbols for main parts of the drawings

10: overvoltage / overcurrent protection unit 12: line connection relay

14: Ring connection relay 16: Subscriber connection relay

18: Slick 20: Codec

22: subscriber loop expansion circuit

The present invention relates to a subscriber matching circuit of an exchange system, and more particularly, to a subscriber matching circuit that can match between a subscriber and a switch even when the subscriber loop resistance is increased.

In general, the subscriber matching circuit matches a transmission / reception signal between the exchange and the subscriber to make a call. In the conventional subscriber matching circuit, as shown in FIG. 1, the overvoltage / overcurrent protection unit 10 protects the inside of the subscriber circuit from overvoltage, overcurrent, lightning, and static electricity flowing from an external line. The line connection relay 12 performs a function of connecting a line during the line test. The ring connection relay 14 performs a function of connecting the ring to the line side when a ring occurs. Subscriber access relay 16 performs the function of connecting to test the subscriber circuit. The slick 18 performs a function of monitoring a subscriber state, supplying current, and converting a 2-wire signal into a 4-wire signal or converting a 4-wire signal into a 2-wire signal. The codec 20 performs a function of converting an analog voice signal into a digital voice signal or converting a digital voice signal into an analog voice signal. At this time, the slick 18 receives power of -48V from the exchanger and supplies talk current to the subscriber side, where the maximum value of the subscriber loop resistance is 2 kW.

However, in the conventional subscriber matching circuit as shown in FIG. 1 and FIG.

Accordingly, an object of the present invention is to provide a subscriber matching circuit that can match up to 3 kHz for subscriber loop resistance.

Another object of the present invention is to provide a subscriber matching circuit that uses a booster to raise the supply power to match a 3 가입자 subscriber loop.

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

2 is a subscriber matching circuit diagram according to the present invention, which has the same configuration as that of FIG. 1 and the same reference numeral, but has a subscriber loop expansion circuit 22 between the ring connection relay 14 and the subscriber access relay 16 during the first diagram. ) Is connected.

3 is a detailed circuit diagram of a subscriber loop expansion circuit according to the present invention, which includes a booster 3 for boosting a -48V supply and outputting a voltage of -70V to -90V. A relay 32 for switching to form a pouf, a transformer 34 connected to both ends of the relay 32 to match a subscriber loop, a switch of the transformer 34 and the relay 32 ( It is connected between SW1) and consists of a resistor 36 for adjusting the level of the subscriber loop.

One embodiment of the present invention based on the above-described configuration will be described in detail with reference to FIGS. 2 and 3.

In FIG. 2, the same configuration as that of FIG. 1 is described in detail in the related art, and thus, only the operation of FIG. 3 according to the present invention will be described.

In FIG. 3, the booster 30 boosts the -48V power supplied from the exchange system to -70V to -90V and supplies it to the subscriber side. The relay 32 operates when a current flows in an internal coil (not shown) when the telephone handset is hooked off, so that the switch 32 is interlocked so that the switch SW1 is turned on to form a subscriber loop. Therefore, when a loop is formed toward the slick 18, the slick 18 recognizes a hook-off state. At this time, the transformer 34 serves to match the slick side and the track side. Since the booster 30 boosts the power of -48V and is supplied to the line, the subscriber loop can be matched by increasing the subscriber matching impedance up to 3 kHz.

However, when the subscriber puts down the handset of the telephone and is in the hook-on state, no current flows in the internal coil of the relay 32, thereby turning off the switch SW1 of the relay 32. Therefore, the loop of the slick 18 is cut so that the slick 18 detects that the phone is hooked on. The resistor 36, which is not described here, is used for the loop of the slick 18 with a capacity of 1.5 mA.

As described above, since the present invention boosts the supply power using a booster and supplies the subscriber loop when the subscriber loop is formed, there is an advantage of matching a subscriber loop up to 3 dB.

Claims (2)

In the subscriber matching circuit of the switching system, an overvoltage / overcurrent protection unit 10 for protecting the inside of the subscriber circuit from overvoltage, overcurrent, lightning, and static electricity flowing from the line of the switching system, and the overvoltage / overcurrent protection unit 10. And a line connection relay 12 connected to the line during the line test, and a ring connection relay 14 connected to the line connection relay 12 to connect the line when a ring is generated. And a subscriber connection relay 16 which performs a function of connecting to test a subscriber line, and is connected between the ring connection relay 14 and the subscriber connection relay 16 to boost the power supplied from the switching system. Subscriber loop expansion circuit 22 for increasing loop matching impedance and subscriber line relay 16 to monitor subscriber line status, supply current, and 2-wire A slick 18 for converting a call into a 4-wire signal or a 4-wire signal into a 2-wire signal; and a slick 18 connected to the slick 18 to convert an analog voice signal into a digital voice signal or a digital voice signal. Subscriber matching circuit, characterized in that consisting of a codec (20) for performing a function to convert the analog voice signal. The booster circuit (30) according to claim 1, wherein the subscriber loop expansion circuit (18) includes: a booster (30) for boosting a -48V power supplied from the switching system and outputting a voltage of -70V to -90V; A relay 32 connected to the phone handset so as to form a subscriber pore according to the hook on / off of the telephone handset, and a transformer 34 connected to both ends of the relay 32 to match the subscriber loop. Subscriber matching circuit, characterized in that.