JPH0350989A - Line trunk interface device - Google Patents

Abstract

PURPOSE:To satisfy the function of a line trunk interface by providing a relay short-circuiting an adaptor circuit including an inductance circuit. CONSTITUTION:A relay R is provided to short-circuit a common mode choke 5 as an adaptor circuit with a sleeve wire of a line interface circuit 1. In this case, the sleeve wire 7 is used as a control signal wire for the relay R and the inductive component of the choke 5 is made zero by short-circuiting the relay R. Moreover, when a signal of on-hook/off-hook state of a line 3 is sent through the sleeve wire 7 from the circuit 1, the inductance of the choke 5 is short-circuited at on-hook. Thus, even when the adaptor circuit has the inductive component, the function of the line trunk interface is satisfied.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a line trunk interface device,
In particular, it relates to improvements in adapter circuits for line interface circuits.

[Prior Art] As shown in FIG. 3, a line trunk interface device is generally configured by a combination of a line interface circuit 1 and an adapter circuit 2. In FIG. 3, a switching power supply circuit is used as the adapter circuit 2. 6 is combined with the line interface circuit 1. Third
The figure shows various combination examples of the line interface circuit 1 and the adapter circuit 2. As shown in FIG. 3, the adapter circuit 2 adds various external functions to the line interface circuit 1. It is used as a circuit to
The adapter circuit 2 is connected to a terminal 4 via a line 3.

As the adapter circuit 2, for example, the following one is used.

One of them is a common mode choke 5 as shown in FIG. 3(B) for guarding AC induction (commercial line induction) induced into the line 3. In addition, the other one is shown in Figure 3 (
This is a switching power supply circuit 6 having a switching power supply 8 as shown in C).

In other words, in order to extend the distance of the line 3, a boost function is required to increase the value of the communication current, but this is achieved by connecting the switching power supply circuit 6 to the line 3 in series, as shown in Figure 3 (C). This is accomplished by inserting.

In this way, the adapter circuit 2 connects the common mode choke 5
Alternatively, the switching power supply circuit 6 is a circuit having an inductance component, and is used as the adapter circuit 2 of the line interface circuit 1.

[Problems to be Solved by the Invention] However, since both the common mode choke 5 and the switching power supply circuit 6 have an inductance component, they cannot fully satisfy the BOR8CHT function, which is the basic performance of the line interface circuit 1. do not have. That is,
Among the BOR8CRT functions, °' R” (Ringi
ng ; ringing) function, °゛T′“ (Test
;Test) functions are the target, and these functions cannot be fully utilized.

The II T"° function is a so-called exchange test function, and is especially necessary to measure line impedance such as the ground-to-ground capacity of line 3 and check the normality of line 3. An AC waveform is sent and the impedance is measured, but if inductance exists,
The impedance of the adapter circuit 2 is added to the original line impedance, making it impossible to check normally.

In this way, conventionally, when testing the impedance of the line 3 from the line interface circuit 1 (the line's ground-to-ground capacity, the line's leak resistance value, etc.), for example, as shown in FIG.
The line is connected to the inductance of the common mode choke 5 to guard against commercial line induction, as shown in FIG. 3 impedance is added, which has the disadvantage that accurate testing is not possible.

In addition, the II R11 function sends a ringing signal (Rin
ging signal; Frequency: 16Hz to 66F (z)
However, when sending a call signal to the terminal 4, there is a voltage drop due to the inductance of the common mode choke 5 and the inductance of the secondary transformer of the switching power supply circuit 6, and it is not possible to send a normal voltage to the terminal 4. It is not possible to send a signal, and the terminal 4 stops ringing.

In this way, from the line interface circuit 1, the Ring
If there is an inductance component when sending the Ring signal (calling signal) to the terminal 4, the Ring
ing signal voltage drops and terminal 4 receives a normal Ring signal.
ing signal waveform is not sent, and the ring tone of the terminal 4 does not sound normally.

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems, and aims to fully satisfy the function of the line interface. In a line trunk interface device configured to include an adapter circuit including an inductance circuit and a line trunk interface circuit, a relay is provided to short-circuit the adapter circuit including an inductance circuit, and the relay is controlled by a sleeve wire of the line trunk interface circuit. It is configured as follows.

[Example code] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing one embodiment of a line trunk interface device according to the present invention.

This embodiment shows a configuration in which a common mode choke 5 is used as the adapter circuit 2 in a line trunk ink face device including a line interface circuit 1 and an adapter circuit 2, where the adapter circuit 2 has an inductance circuit. .

In FIG. 1, a relay R is provided for short-circuiting the adapter circuit 2 (here, the common mode choke 5) by the sleeve wire 7 of the line interface circuit 1. By using the sleeve wire 7 as a control signal for the relay R and shorting the relay R, the inductance component of the common mode choke 5 can be made zero.

0NHOOK10FFHOOK of line 3 with sleeve line 7
Send the status signal from line interface circuit 1 and set it to 0.
At the time of NHOOK, the inductance of the common mode choke 5 is short-circuited.

FIG. 2 shows the sleeve wire 7 of the line interface circuit 1.
, adapter circuit 2 (here switching power supply 8
An example is shown in which a relay R is provided to switch between a switching power supply circuit 6) having a power supply circuit 6) and a resistance circuit 11.

When the signal of the sleeve wire 7 is 0NHOOK, the resistance circuit 11
is always connected to. When 0FFHOOK is performed, contact r of relay R is switched, thereby connecting switching power supply circuit 6 to line 3. By being connected, the original adapter circuit configuration is established.

With the above configuration, the BOR8CHT function of the line interface circuit 1 operates normally.

That is, when testing the impedance of the line 3 from the line interface circuit 1 or when sending a calling signal to the terminal 4, the inductance of the adapter circuit 2 causes
This prevents accurate testing and prevents the ringer from ringing properly.
(on-hook) / 0FFHOOK (off-hook) function is detected, and when 0NHOOK (on-hook), connect to the pure resistance circuit of the adapter circuit or short-circuit the inductance circuit, and when 0FFHOOK (off-hook), the original function of the adapter circuit By connecting to a circuit (for example, common mode choke 5 in Figure 1, switching power supply circuit 6 in Figure 2) with
R11 function works normally.

In this way, the adapter circuit 2 including the inductance circuit
In the line trunk interface device having the configuration, even if the adapter circuit 2 is a circuit having an inductance component, the Te5t function checks whether the impedance of the line 3 is normal, and the Ringing voltage is sent normally. The Ringing function can be fully satisfied.

[Effects of the Invention] As explained above, the present invention provides a line trunk interface device configured to include an adapter circuit including an inductance circuit and a line trunk interface circuit, in which the adapter circuit including the inductance circuit is short-circuited. Since a relay is provided and the relay is controlled by the sleeve wire of the line trunk interface circuit, it is possible to fully satisfy the function of the lined interface even if the adapter circuit has an inductance component. becomes.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram showing one embodiment of the line trunk interface device according to the present invention, FIG. 2 is a block circuit diagram showing another embodiment of the line trunk interface device according to the present invention, and FIG. 1 is a block diagram showing a conventional line trunk interface device. 1...Line interface circuit 2...Adapter circuit 3...Line 4...Terminal common mode choke switching power supply circuit sleeve wire switching power supply resistance circuit relay contact

Claims (1)

[Claims] A line trunk interface device configured to include an adapter circuit including an inductance circuit and a line trunk interface circuit, further comprising a relay that short-circuits the adapter circuit including the inductance circuit, and the relay is configured to short-circuit the adapter circuit including the inductance circuit. A line trunk interface device characterized in that it is controlled by a sleeve wire.