KR100248261B1 - Complex subscriber line interface circuit of tdx-1b subscriber board - Google Patents

Abstract

The present invention can greatly improve the reliability of the subscriber matching circuit by modularizing the subscriber matching circuit into a circuit component that can prevent damage and destruction from lightning or ground in the TDX exchange subscriber board that matches the subscriber telephone and the switch. The multiple subscriber registration circuit of the TDX-1B subscriber board

In the present invention, in the TDX-1B subscriber board, the subscriber matching circuit (SLIC) is replaced with a hybrid device so that there is no change of the existing printed circuit board (PCB). It is equipped with a strong transformer and a hybrid function of matching this transformer with a combo mounted on an existing board and a two-wire circuit of a transformer, and detecting the hook on / off. A hook trip circuit for detecting hook on / off and blocking the operation of the ring upon hook on is constructed and modularized.

Description

Multi subscriber registration circuit of TDX subscriber board

The present invention relates to a multi-subscriber matching circuit of a TDX-1 (TDX-1B) subscriber board, and particularly to prevent damage and destruction of the subscriber matching circuit from lightning or ground faults in the TDX switchboard subscriber board matching the subscriber phone and the switch. The present invention relates to a multi-subscriber matching circuit of a TDX exchanger (TDX-1B) subscriber board, which can be complexed into circuit components, thereby greatly improving the reliability of the subscriber matching circuit.

In general, as shown in FIG. 1, the analog subscriber board is a matching device between the subscriber telephone and the switch and performs various functions for subscriber line matching. The basic function is “BORSCHT”, and the overvoltage protection, test drive ( TEST Relay, Ring Relay, Overvoltage Protection, SLIC Codec and Filter from Overvoltage. Among them, the overvoltage protection circuit is configured to protect the internal circuits from overcurrent and overvoltage caused by lightning or ground fault coming from the subscriber line.

The conventional TDX-1B subscriber board configured to have such a function is an overvoltage protection circuit, a subscriber matching circuit (SLIC), and a codec / filter (COMBO) as main components of the subscriber board, as shown in FIG. The primary overvoltage protection circuit is for bypassing the overcurrent due to lightning to ground, and the secondary overvoltage protection circuit is for protecting the subscriber matching circuit SLIC from the ground fault. For the TDX-1B subscriber board, THBT200D was used as the primary overvoltage protection circuit and THDT58D was used as the secondary overvoltage protection circuit. And a positive temperature coefficient element (PTC) is used as an overcurrent protection element. Looking at the operation of the circuit in the event of a lightning strike, the primary overvoltage protection circuit THBT200D is activated and this circuit cuts the voltage to about 290V, but the circuit acts as if it is almost shorted, so a large amount of current flows. In this case, the resistors R1 and R2 are located at the rear of the protection circuit so that they do not play a role in blocking the current, and the subscriber board acts as an overcurrent sink. This causes a lot of damage to the SLIC. The subscriber matching circuit (SLIC) is responsible for the feed (Battery feed), monitoring (Supervision), hybrid (Hybrid) function of the BORSCHT function of the subscriber board. It is supposed to supply -48V to detect the hook on / off of the subscriber. When the subscriber hooks off (HooK off), the switch of the subscriber telephone is turned on and the current value is increased so that the exchange recognizes this. This function is called monitoring. The hybrid function is to convert 2-wire to 4-wire, which must be balanced to reduce return loss. The data is sent to COMBO through the converted 4-wire.

COMBO is responsible for code / decode and filtering.

As such, the conventional TDX exchanger subscriber board adopts an overvoltage protection circuit to protect the board from the effects of lightning or ground fault. The elements used in the protection circuit use two overvoltage protection elements and one overcurrent protection element. However, the subscriber board is very vulnerable to lightning or ground fault due to a fault in the circuit design, so that the failure rate is high and the reliability of the semiconductor component of the subscriber matching circuit SLIC has been easily broken.

Nevertheless, it is important to replace SLIC without changing the printed circuit board (PCB) of the subscriber board or affecting other devices to improve it.

Therefore, subscriber matching circuit (SLIC) should be configured to be easy to replace without affecting other devices, and also be composed of reliable circuit elements that are not affected by lightning or ground fault, but can fully perform existing matching circuit functions. It should be configured to

An object of the present invention is to configure the subscriber matching circuit (SLIC) in the TDX-1B subscriber board to be easily and easily replaced without affecting other devices, and also by configuring circuit components resistant to lightning and ground faults. It is intended to significantly improve the reliability of subscriber matching circuits by preventing breakage and damage.

In order to realize the above object, the present invention replaces a pin-to-pin hybrid with a conventional PCB so that it is easy to replace the subscriber-sequence circuit (SLIC) in the TDX-1B subscriber board without affecting other devices. This hybrid is characterized by the use of transformers that are resistant to lightning and ground faults.

1 is a typical subscriber board block diagram

2 is a one-channel block diagram of a conventional TDX-1B subscriber board.

Figure 3 1-Channel Block Diagram of the Invention TDX-1B Subscriber Board

4 is a block diagram of the present invention of the multi-subscriber matching circuit.

Explanation of symbols for main parts of the drawings

1: Subscriber Line Interface Circuit (SLIC): Subscriber Matching Circuit

2: PTC (Positive Temperature Coefficient): Positive Temperature Coefficient

3: R1, R2: Feeding Resistance 4: COMBO (CODEC and filter); Combo

5: K1: internal test relay 6: K2: external test relay

7: K3: ring relay

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

3 is a 1-channel block diagram of the TDX-1B subscriber board of the present invention, and FIG. 4 is a block diagram of the composite subscriber matching circuit of the present invention. A TDX-1B subscriber board comprising a number (PTC), first and second overvoltage protection circuits, a subscriber matching circuit (SLIC), and a codec / filter (COMBO), wherein the subscriber matching circuit (SLIC) is hybridized. It is configured to replace the existing printed circuit board (PCB) by replacing with a hybrid element, but the hybrid has a transformer resistant to lightning and ground fault, and a magnetization control circuit for adjusting the magnetic field of the transformer. (magnetization control circuit), hook on / off detection for detecting the hook on / off, and a ring trip circuit (hook on / off, ring trip) for interrupting the driving of the ring upon hook on.

The present invention configured as described above is to add a subscriber matching circuit (SLIC) to the existing subscriber board by hybridizing the transformer, magnetization control circuit, hook on / off detection and ring trip circuit, that is, the transformer (transformer) circuit By separating the primary and secondary, it enables the feeding function, one of the SLIC functions, by supplying -48V to the primary side without lightning or ground fault sent to the secondary side.

In addition, the hook on / off detection function detects the hook on / off by detecting the current of the primary side of the transformer. In addition, the ring trip function should cut off the driver driving the ring so that the ring no longer rings when the subscriber hooks on while the ring is ringing. In other words, when the hook is on, the voltage rises from -48V to 0V, so the ring is cut at the moment of rising from -48V to 0V.

As described above, the present invention configures a subscriber matching circuit (SLIC) in a TDX-1B exchanger subscriber board as a hybrid so that replacement is easy without affecting other devices. By using a transformer resistant to grounding, circuit breakage and damage can be prevented, thereby providing an effect of greatly improving the reliability of the subscriber matching circuit.

Claims (1)

TDX consisting of static temperature coefficient (PTC), first and second overvoltage protection circuit, subscriber matching circuit (SLIC) and codec / filter (COMBO) as overcurrent protection device from tip and ring. In the -1B subscriber board, the subscriber matching circuit (SLIC) is replaced with a hybrid device so as not to change the existing printed circuit board (PCB), but the hybrid (hybrid) is a transformer resistant to lightning or ground fault ( transfomer), and a ring trip circuit for blocking the hook on / off detection and the hook trip circuit for blocking the hook on / off when detecting the hook on / off of the TDX-1B subscriber board. Multi subscriber registration circuit.

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