JPH05227267A - Divider for communication line - Google Patents

Abstract

PURPOSE:To improve the reliability of the divider by using a switch circuit conductive with a voltage given to a line terminal so as to hold a semiconductor switch with a supply current. CONSTITUTION:When a voltage less than a primary control voltage is applied between line terminals L1, L2, both a switch circuit 1 and a remote measurement circuit 2 are turned off. Furthermore, at the application of a voltage over the control voltage, the circuit 1 is turned on and conductive. When a communication equipment is hooked off, a voltage is generated in a current holding type semiconductor switch circuit and the circuit is conductive, a voltage between the two terminals is lower but the conductive state is held till the supply current is received. When the communication equipment is hooked on and no current flows to the communication line, the current holding type semiconductor switch circuit is opened. The circuit is controlled by the primary control voltage, the circuit employing only the divider used to short-circuit fuses F1, F2 is used and the reliability is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used for maintenance of telephone lines and other communication lines. The present invention is used for separating maintenance demarcation points of communication lines. The present invention relates to telemetry of communication lines.

[0002]

2. Description of the Related Art A maintenance demarcation point of a communication line between a telecommunications carrier and a user is set at or near a point of introduction of a communication line into a house. A widely-used contract has a protective demarcation point, which is a protector installed at the point of entry of the telephone line into the home. The protector is equipped with a lightning arrestor that grounds the communication line when an abnormally high voltage arrives on the telephone line, and a fuse that disconnects the line when an abnormally large current occurs on the telephone line. The carrier is responsible for maintaining the line, and the user is responsible for maintaining the line on the in-home device side of this protector.

When an abnormality is found in a communication line, it is important for the communication company to know which side of the maintenance demarcation point of the communication line has the cause. In the old days, a worker of a telecommunications carrier was dispatched to connect a measuring device or a telephone to the protector of an abnormal communication line to check whether there was an abnormality on the station side line. In this method, even if there is something wrong with the inside of the maintenance demarcation point, it takes a lot of man-hours for the worker to be dispatched.Therefore, the technology to separate the communication line with the protector by remote control is used. ing.

FIG. 7 shows a schematic circuit diagram thereof. L1 and L2 are line terminals to which line on the office side is connected. I1 and I2 are home terminals, to which home equipment (for example, a telephone) is connected via a home line. E is a ground terminal, AR is an arrester, and F1 and F2 are fuses. In this circuit, in a normal communication state, the contacts r1 and r2 connect the line terminals L1 and L2 to the home terminals I1 and I2 as shown in the figure, but the line terminals L1 and L2 are connected from the station side.
When the switching signal is transmitted between L2, the relay control circuit RL operates to switch the contacts r1 and r2 to the terminal circuit T side, the house terminals I1 and I2 are opened, and the terminal circuit T is connected between the line terminals L1 and L2. Are connected. This relay is a self-holding type and is held until the switchback signal arrives at the line terminals L1 and L2.

When the line side terminals L1 and L2 are connected to the termination circuit T, a test is conducted from the station side. If the communication line is normal, the station side can see the series circuit of the communication line and the termination circuit T. Therefore, it is possible to know the abnormality or normality of the communication line up to the switch. After the test is completed, a cutback signal is transmitted from the station side to the communication line to restore the contacts r1 and r2.

[0006]

This conventional circuit is an excellent circuit capable of performing remote measurement by performing separation at the maintenance demarcation point by remote control, but since it has a relay and a relay contact as a switch circuit inside. There is a risk of damage to the contacts due to ingress of moisture or aging. Further, in a circuit including a contact, if the contact is kept in a constant state for a long period of time, it may not operate, and it is necessary to try operating this contact for a certain period, for example, every month. Therefore, the maintenance man-hours are increased. In order to improve this, it has been attempted to use a semiconductor circuit as the switch circuit, but since a power supply cannot be provided inside such a switch, it is possible to realize a circuit that employs a semiconductor switch circuit. However, the use of relays and relay contacts as described above has come into practical use. Further, the relay and the relay contact have hindered the miniaturization of the switch.

An object of the present invention is to improve the reliability of the slicing machine. An object of the present invention is to eliminate the need for a contact circuit of a switch. Another object of the present invention is to reduce the size of the slicing device. SUMMARY OF THE INVENTION It is an object of the present invention to provide a slicing machine of a new idea which can use a semiconductor switch circuit without requiring an internal power supply.

[0008]

The present invention is characterized in that a switch circuit is constituted by a current-holding type semiconductor switch which is made conductive by a voltage applied to a line terminal and held by a supply current. Here, the current-holding type semiconductor switch is a two-terminal circuit in which a semiconductor element is used, and when the voltage between the two terminals reaches a predetermined value, it becomes conductive and a current flows between the two terminals. As long as the voltage between the two terminals falls below the predetermined value as long as it is maintained, the conductive state is maintained, and when the current value becomes a certain small value or less, the two terminals are opened. Some elements known by the names such as thyristors, triacs, sydacs, and diacs have the above characteristics by themselves, and are realized by combining these elements and combining these elements with diodes and resistors. An example of such a switch circuit is. Then, the predetermined value of the voltage is selected to be a voltage somewhat lower than the voltage applied to the line terminal, and a constant small value of the current value is selected to be a current value smaller than the supply current (or call current).

The divider of the present invention can be made extremely small so that it can be mounted in a protector including a lightning arrester and a fuse. Also, as the above telemetry circuit,
The circuit configuration can be simplified by adopting a configuration including a series circuit of a resistor and a capacitor and a constant voltage diode pair connected in parallel with the capacitor.

[0010]

In the present invention, the communication line is not used,
For example, when the communication device or the telephone is in the on-hook state, the communication line has almost no current. When there is no current in the communication line, the current holding type semiconductor switch circuit is automatically opened. At this time, the in-home terminal and the in-home communication equipment are substantially separated from the communication line, but there is no problem in practical use.

When the communication device is off-hook, a voltage is generated in the current-holding type semiconductor switch circuit and it becomes conductive.
The voltage between the two terminals of the current-holding type semiconductor switch circuit decreases when it becomes conductive, but the supply current (or call current)
Is maintained as long as is maintained. Therefore, there is no problem in communication.

When the communication device is a telephone and a current of 16 Hz for calling arrives, the current holding type semiconductor switch circuit becomes conductive twice a cycle with a voltage whose absolute value exceeds a predetermined value, and the current holding type semiconductor switching circuit is turned on. Pass a 16 Hz current.
Therefore the bell rings.

As the impedance value connected between the line terminals, it is possible to select a value that does not interfere with communication. Further, by providing a semiconductor switch circuit, the impedance value connected to the line terminals can be changed depending on the voltage and type (AC or DC) applied to the line. It can be set to change its impedance value.

Since the slicing device of the present invention does not include a contact and a relay, the influence of moisture intrusion and aging hardly poses a problem, and extremely high reliability and long-term stability can be expected. Further, the slicing device can be downsized.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the first embodiment device of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing the configuration of the first embodiment device of the present invention.

According to the present invention, a pair of line terminals L1 and L2 to which communication lines are connected, a pair of home terminals I1 and I2 to which home devices are connected, line terminals L1 and L2, and home terminal I.
In the communication line severing device including the switch circuit 1 inserted between I and I2 and the telemetry circuit 2 connected to the pair of line terminals L1 and L2, the switch circuit 1 includes
It is characterized in that it is constituted by a current holding type semiconductor switch which is rendered conductive by a voltage applied to the line terminals L1 and L2 and is held by a supply current. The current holding type semiconductor switch is composed of one triac and a pair of Zener diodes connected between the gate electrode and the anode electrode of the triac.

Further, the communication line divider which is the first embodiment of the present invention is a lightning arrester AR and fuses F1 and F2.
A telemetry circuit 2 mounted in a protector 3 including a zener diode pair Z connected in parallel to the series circuit of resistors R1 and R2 and a capacitor C, and the capacitor C.
This is a configuration including 1 and Z2.

Next, the operation of the first embodiment device of the present invention will be described with reference to FIG. FIG. 2 is an equivalent circuit diagram for explaining the operation of the first embodiment device of the present invention. Each switch represents ON or OFF of a diode or a switch circuit.

Here, the triac T of the switch circuit 1
RIAC1 and TRIAC2, Zener diode Z
The voltage at which the bidirectional switching semiconductor element with a voltage discrimination function constituted by 3 to Z6 is turned on is the primary control voltage, and the Zener diode Z1 of the telemetry circuit 2 is used.
A voltage that is connected in series with two bidirectional voltage discriminating semiconductor elements constituted by Z2 and Z2 and is in an ON state together is a secondary control voltage. The primary control voltage is set lower than that and the secondary control voltage is set higher than that based on the DC voltage during a silent period supplied to the telephone line from the exchange. The control voltage set in this way enables line control in three states.

That is, when a voltage lower than the primary control voltage is applied between the line terminals L1 and L2, both the switch circuit 1 and the telemetry circuit 2 are turned off as shown in FIG. 2 (a). .. That is, the communication line side and the terminal device side are completely disconnected.

When a voltage higher than the primary control voltage is applied between the line terminals L1 and L2, the switch circuit 1 is turned on as shown in FIG. 2 (b). This state is also a state in which the terminal device is in a call.

Further, when a voltage higher than the secondary control voltage is applied between the line terminals L1 and L2, the terminal equipment is turned off.
In the state, as shown in FIG. 2C, the switch circuit 1
Is transiently turned on for a moment while the capacity inside the subscriber terminal is charged, but thereafter it is turned off and the telemetry circuit 2 is turned on. Communication line is resistor R1
And R2. The capacitor C is 1
When 6 Hz is applied, it becomes a charge / discharge state. When an AC power supply such as a voice signal is used as the test power supply, it operates as a measurement impedance.

Thus, the voltage control of the bidirectional switching semiconductor element with the voltage discriminating function of the switch circuit 1 and the bidirectional voltage discriminating semiconductor element of the telemetry circuit 2 is performed in consideration of the usage state of the terminal equipment. Due to
It is possible to disconnect, connect and terminate communication lines.

The setting of the control voltage will be described more specifically. The primary control voltage is the Zener diode Z3.
(Or Z4) and the zener voltage of Z5 (or Z6), and the secondary control voltage is zener diode Z
It is a Zener voltage of 1 (or Z2). This control voltage can be arbitrarily set by the Zener voltage of the Zener diode. Normally, the supply voltage from the exchange is DC48.
Since it is V, the primary control voltage is set lower than that and the secondary control voltage is set higher than that.

Next, with reference to FIG. 3, a procedure for determining a failure point of the first embodiment device of the present invention will be described. FIG. 3 is a flow chart showing a fault point determination procedure of the first embodiment device of the present invention.

First, a voltage lower than the primary control voltage is applied between the line terminals L1 and L2. At this time, since no current flows through the Zener diodes Z3 to Z6, the triac T
RIAC1 and TRIAC2 do not operate. Therefore, the terminal equipment is completely disconnected from the communication line,
The applied DC current does not flow. At this time, if a direct current flows, it means that there is an insulation failure on the communication line side.

Next, DC 48V is applied between the line terminals L1 and L2.
Is applied. Generally, in a telephone, a 0.9 μF capacitor is in series with a bell coil in a standby state and is connected between lines. Therefore, the Zener diodes Z3 to Z6 are only momentarily charged until this capacitor is charged.
Current flows to the TRIAC TRIAC1 and TRI
AC2 operates and a transient current flows. If this transient current does not flow, the communication line side or the terminal device side is broken.
On the other hand, when the current continues to flow, it may be due to an insulation failure on the terminal equipment side or the telephone is busy. Is not done).

Next, a voltage higher than the secondary control voltage is applied between the line terminals L1 and L2. Also at this time, the DC48V
A transient current flows instantaneously as in the case of applying the current, the Zener diode Z1 (or Z2) operates at the same time, and a DC loop current flows by terminating between the line terminals L1 and L2 by the resistors R1 and R2. When this DC loop current does not flow, the communication line side is broken. DC4
When this DC loop current is confirmed without a transient current flowing at the time of applying 8 V, it is possible to determine the disconnection of the terminal device.

The above is the fault point determination procedure of the device of the first embodiment of the present invention, and it is possible to easily determine the four faults of disconnection and insulation failure on the communication line side and disconnection and insulation failure on the terminal equipment side.

Next, the configuration of the apparatus of the second embodiment of the present invention is shown in FIG.
Will be described. FIG. 4 is a block diagram of the apparatus of the second embodiment of the present invention.

This is the case where the telemetry circuit 2 is connected to the transistor T.
This is an example of a semiconductor switch circuit using R1 and TR2.

When the Zener diode Z1 (or Z2) is turned on, the transistor TR1 (or TR
2) is turned on, and the communication line has a resistor R2 (or R
4). There is an advantage that the termination resistance value can be freely changed by changing the resistance value of the resistor R2 (or R4).

Next, the configuration of the apparatus of the third embodiment of the present invention is shown in FIG.
Will be described. FIG. 5 is a block diagram of the apparatus of the third embodiment of the present invention.

This is one in which thyristors SCR1 to SCR4, which are unidirectional switching elements, are connected in antiparallel instead of the triacs TRIAC1 and TRIAC2 of the device of the first embodiment of the present invention.
1 and TRIAC2 have an advantage that a semiconductor element can be switched with a smaller current.

Next, the configuration of the apparatus of the fourth embodiment of the present invention is shown in FIG.
Will be described. FIG. 6 is a block diagram of the device of the fourth embodiment of the present invention.

This is a bidirectional two-terminal thyristor DIA instead of the triacs TRIAC1 and TRIAC2 and the Zener diodes Z1 to Z6 of the device of the first embodiment of the present invention.
This is an example in which C1 to DIAC3 (generally called diac or sidac) are used.

In the above example, the circuit of the present invention is mounted on the protector. However, except the lightning arrester AR in the structure of FIG. Thus, the present invention can be implemented.

[0038]

As described above, not only the contact circuit of the slicing device is unnecessary but the reliability and stability are dramatically improved, but the slicing circuit can be simplified and the size of the slicing device can be reduced. Furthermore, it enables remote separation regardless of the polarity of the communication line. Further, the control voltage can be set arbitrarily, and the control voltage can reliably determine the failure between the communication line side and the terminal device side.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an apparatus according to a first embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram for explaining the operation of the first embodiment device of the present invention.

FIG. 3 is a flowchart for explaining the operation of the first embodiment device of the present invention.

FIG. 4 is a configuration diagram of a second embodiment device of the present invention.

FIG. 5 is a configuration diagram of an apparatus according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram of an apparatus according to a fourth embodiment of the present invention.

FIG. 7 is a diagram illustrating a conventional example.

[Explanation of symbols]

 1 Switch Circuit 2 Telemetry Circuit 3 Protector E Ground Terminal C Capacitor AR Lightning Arrester R1 to R5 Resistor D1 to D4 Diode L1, L2 Line Terminal I1, I2 Home Terminal F1, F2 Fuse Z1 to Z6 Zener Diode TRIAC1, TRIAC2 TRIAC SCR1 to SCR4 Thyristor DIAC1 to 3 bidirectional 2-terminal thyristor

Claims (3)

[Claims] 1. A pair of line terminals to which a communication line is connected,
A pair of home terminals to which the home device is connected, and a switch circuit inserted between the line terminal and the home terminal,
A switch for a communication line, comprising: a telemetry circuit connected between the pair of line terminals, wherein the switch circuit is in a conducting state at a voltage applied to the line terminal and is held by a supply current. A communication line severing device comprising a semiconductor switch. 2. The communication line slicing device according to claim 1, which is mounted in a protector including a lightning arrester and a fuse. 3. The communication line slicing device of claim 1 wherein the telemetry circuit includes a series circuit of a resistor and a capacitor and a constant voltage diode pair connected in parallel with the capacitor.