JP2990183B1 - AC contact protection device, switching system, and AC contact protection method - Google Patents

Abstract

An inexpensive and inexpensive AC mixing protection device and switching system capable of protecting a subscriber circuit connected to an outdoor transmission line in an exchange from overvoltage and overcurrent, and an AC mixing protection method. To provide. SOLUTION: Provided between a connection point between a first line and a second line and a ground point, an electric energy applied from a second line side power supply (commercial power supply) is discharged to the ground point and is transmitted to the first line. At least one current attraction type voltage protection element 9a, 9b that blocks propagation and self-heats according to the state of release of electric energy to the ground point, and is provided in the first line or the second line, and The amount of heat generated from the voltage protection elements 9a and 9b is monitored, and when it is detected that the self-temperature has reached a predetermined temperature threshold in accordance with the amount of heat generated from the current attraction type voltage protection elements 9a and 9b, the first Railroad and second
Electromagnetic switches 6 and 7 for disconnecting from the line are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection circuit for a subscriber circuit for detecting and protecting AC cross-contact of a subscriber line, and more particularly, to a protection device in an exchange when an outdoor transmission line contacts or short-circuits with a commercial power line. It belongs to an AC contact protection device that protects a subscriber circuit connected to an outdoor transmission line from being destroyed.

[0002]

2. Description of the Related Art In recent years, lightning surge energy induced in outdoor transmission lines and AC (alternating current) due to contact with AC power distribution lines.
Attention has been paid to a technology (AC contact protection device) for protecting devices (for example, a subscriber circuit) in an exchange by absorbing commercial power.

In such an AC contact protection device, usually,
A method of inserting a current attraction type voltage protection element between output lines and, at the same time, placing a PTC whose resistance value increases due to heat generation in series on the outdoor transmission line side from the position where the current attraction type voltage protection element is inserted, and placing a fuse And a method of detecting the applied voltage and opening the switch.

However, in the method of arranging the PTC whose resistance value increases due to heat generation in series with the outdoor transmission line side from the position where the current attraction type voltage protection element is inserted, it is necessary to: 1. the loss increases; 2. The resistance value of the PTC has a large variation; The PTC has a problem of deteriorating transmission quality comprehensively, for example, because the resistance value is changed by repeated operation.

In the method of inserting a fuse in series,
There is a problem in that it is difficult to select a fuse having a capacity that does not blow by a lightning surge that is instantaneously applied and that the design is guaranteed even for temperature changes and aging changes, when the AC contact is applied for a long time.

In the method of arranging fuses, a fuse having a capacity that is blown when an AC contact is applied for a long time and does not blow by a lightning surge that is applied instantaneously is selected, and the design is guaranteed until a temperature change and an aging change. There was a problem that it was difficult.

As an AC contact protection device for solving these problems, there is a conventional technology (for example, Japanese Patent Application Laid-Open No. 8-205) in which an applied voltage is detected and a circuit of a type that opens a switch is added.
No. 210, FIG. 5) is disclosed.

That is, as shown in FIG. 5, a protection circuit for a subscriber circuit disclosed in Japanese Patent Application Laid-Open No. 8-205210 includes a current limiting resistor 1A connected in series with a subscriber line 9A,
The current caused by the overvoltage of the subscriber line 9A is reduced by the current limiting resistor 1.
Arrestor 2A flowing to ground via A and subscriber line 9A
3A, a resistor 1A connected in parallel with the contact 7A of the relay 3A, and the potential of the subscriber line 9A. When the potential becomes positive, it is determined that AC contact has occurred and the subscriber line 9A is determined. A detection circuit 4A for operating the relay 3A so as to disconnect the relay, and a loop current detection circuit for restoring the relay 3A operated by the detection circuit 4A when the off-hook of the subscriber due to the loop current flowing through the subscriber line 9A is detected. It has. Here, the detection circuit 4A is configured to operate the relay 3A a predetermined time after the potential of the subscriber line 9A becomes positive, or the detection circuit 4A keeps the potential of the subscriber line 9A plural times in a cycle corresponding to the AC cycle. When the positive polarity is detected, the contact 3A is determined to be the AC cross-contact of the subscriber line 9A, and the relay 3A is operated. It is disclosed that the resistor 1A connected in parallel with the contact 7A of the relay 3A can be a resistor 1A fuse that is blown by an overcurrent.

[0009]

However, in the protection circuit for the subscriber circuit described in Japanese Patent Application Laid-Open No. 8-205210, the circuit configuration becomes complicated, the equipment cost increases, and the power consumption increases. There was a problem.

[0010] The present invention has been made in view of such a problem, and an object thereof is disclosed in JP-A-8-205.
AC without adding special electronics like 210
Protects the subscriber circuit connected to the outdoor transmission line in the exchange located downstream of the AC contact protection device from overvoltage and overcurrent from commercial voltage and lightning surge voltage, and additionally protects the heating state of the current attraction type voltage protection element. from detecting overvoltage source in providing inexpensive and no power loss AC incompatible protector and exchange system as well as AC incompatible coercive <br/> protection method can be disconnected the protected circuit.

[0011]

According to the first aspect of the present invention, there is provided:
The point is that the first line is in electrical contact or short circuit with the second line
The first line side device connected to the first line
The first line and the first line side device so that the
AC contact protection device installed between the
A terminal for electrically connecting one line to the first line-side device;
At least one current-sinking protection element between ground terminals
However, the temperature rise due to the heat generated by the current-sinking type protection element may occur.
The first line and the first line when a certain temperature threshold is reached;
At least one electromagnetic switch that cuts off the electrical connection with the side device
The present invention is directed to an AC contact protection device characterized by having:
The gist of the invention described in claim 2 is that the electromagnetic switch
Monitors the heating temperature of the current attraction type voltage protection element.
And the heat generation temperature of the current attraction type voltage protection element.
The first line when detecting that the degree has reached a predetermined threshold.
To cut off the electrical connection between the road and the first trackside device.
2. The exchange according to claim 1, wherein
Exist in the flow contact protection device. Further, according to the third aspect of the present invention,
The point is that the electromagnetic switch is provided with the current attraction type voltage protection element.
Monitor the heating temperature of the
Type before the voltage protection element self-heats and reaches the ignition temperature.
Disconnecting an electrical connection between the first line and the first line side device;
Claim 1 or Claim 2 characterized by being constituted so that
Is in the AC contact protection device described in 2. Claim 4
The gist of the invention described in (1) is that the electromagnetic switch comprises the first wire
Blockage for connecting or disconnecting a road with the first trackside device
A magnetic circuit, wherein the cut-off magnetic circuit is of the current attraction type.
In the process of receiving heat from the voltage protection element and generating heat,
The current attraction type voltage protection element self-heats and reaches the ignition temperature
Before the electromagnetic force disappears and before it is connected to the first line
Releasing the first track side device from the first track,
Protecting the first line-side device connected to the first line;
4. The apparatus according to claim 3, wherein
It exists in the above-mentioned AC contact protection device. Further, according to claim 5
The gist of the invention is that the outdoor transmission line is in contact with the commercial power line or
In the event of a short circuit, it detects AC cross contact of the subscriber line and
Connected to an outdoor transmission line Subscriber circuit is not destroyed
AC touch protection device is installed inside the subscriber circuit
Switching system arranged in each case, AC cross-contact protection
The device has a ground point, the outdoor transmission line and the subscriber loop.
At least one connection point with a road,
Releases the electrical energy applied from the line to the ground point
To prevent inflow to the subscriber circuit,
Self-powered according to the state of release of the electrical energy to the point
Heating current-sinking protection element, and current-sinking protection element
When the temperature rise due to the heat generation of the
Disconnecting the electrical connection between the outdoor transmission line and the subscriber's circuit
An exchange having at least one electromagnetic switch.
Exist in the switching system. In addition, the essentials of the invention described in claim 6
This means that the outdoor transmission line has contacted or shorted the commercial power line.
Detects AC cross-contact of the subscriber line in case of
Keep the subscriber circuits connected to the track from being destroyed.
An AC contact protection method for protecting the commercial power supply line
Discharge the electric energy applied from the power supply to the ground point
The transmission to the outdoor transmission line is electrically cut off and the ground
The amount of heat generated according to the state of release of the electrical energy to the point
Monitoring, the calorific value reached the predetermined temperature threshold
The outdoor transmission line and the subscriber circuit
AC contact protection method characterized by disconnecting the electrical connection with the
Be in the law.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an AC contact protection device according to the present invention; FIG. 1 is an electric circuit diagram showing a basic configuration of one embodiment of an AC contact protection device 20 of the present invention.

First, the circuit configuration of the AC contact protection device 20 will be described with reference to the electric circuit diagram of FIG.

[0014] AC incompatible protection device 20 of the present embodiment is a circuit that subscriber circuit outdoor transmission line is connected to the switching equipment outdoor transmission line when in contact or short-circuited with a commercial power line is protected from destruction Yes, it is provided inside each outdoor transmission line-side device connected to the outdoor transmission line.

In the electric circuit diagram of FIG . 1, terminals 3 and 4 are
A terminal connected to an outdoor transmission line (one form of the first line)
1 and 2 are connected to a subscriber circuit protected by the present invention.
ing. A state in which the AC touch protection operation of the present invention is not activated
Then, the subscriber circuit is a terminal of the AC contact protection device of the present invention.
1-Terminal 3 and Terminal 2-Terminal transmission line via terminal 4
Connected to the terminal to enable telecommunication. Terminal 5 is at ground potential
This is the connected GND terminal.

The switch circuit midpoint 6a and the switch circuit break contact 6b, and the switch circuit midpoint 7a and the switch circuit break contact 7b are circuit contacts of the electromagnetic switches 6 and 7 , and are permanent as will be described later with reference to FIG. Each circuit of the electromagnetic switches 6 and 7 is constituted by the magnet core 8. While the permanent magnet core 8 maintains the magnetic force as a permanent magnet, the electrical connection between the switch circuit midpoint 6a and the switch circuit break contact 6b, and the switch circuit midpoint 7a and the switch circuit break contact 7b is maintained. When it loses magnetism due to temperature, it operates to release it.

Each of the input terminals 1 and 2 connected to the internal circuit of the subscriber's circuit is connected to the switch circuit midpoints 6a and 7a. Each of the output terminals 3 and 4 connected to the outdoor transmission line side is connected to the switch circuit break contacts 6b and 7b. Specifically, the current attraction type voltage protection elements 9a, 9b
Each is a connection point between the outdoor transmission line and the subscriber's circuit and a ground point 5
It is installed between. Grounding point 5 is the ground line of the subscriber circuit
Connected to the AC
You.

The current protection type voltage protection elements 9a, 9b
In each case, the outdoor transmission line is electrically connected to the second line (commercial power line).
The electrical energy flowing in the event of contact or short circuit
Excessive electrical energy released to subscriber circuit by discharging to ground point 5
To prevent inflow.

Each of the current attraction type voltage protection elements 9a and 9b generates heat in accordance with the state of release of electric energy to the ground point 5, and the amount of heat generated by each of the current attraction type voltage protection elements 9a and 9b is determined by an electromagnetic switch. 6 and 7 are transmitted.

Next, the structure of the AC contact protection device 20 shown in FIG. 1 will be described. Figure 2 is a sectional view taken along the front direction along the center line of the AC incompatible protector 20 of FIG. 1, FIG. 3 is a sectional view taken along the side direction along the center line of the AC incompatible protector 20 of FIG. 1 FIG. 4 is a cross-sectional view of the AC contact protection device 20 of FIG.

As shown in FIG. 2, one terminal of each of the current attraction type voltage protection elements 9a and 9b is brazed to a GND terminal 5, and the other terminal is connected to an internal circuit of the subscriber circuit. It is desirable that the input terminals 1 and 2 are wire-bonded. In the present embodiment, wire bonds are used to alleviate stress and secure assembly clearance. However, the present invention is not limited to this, and thin lead materials or terminals 1 and 2 are directly brazed to 9a and 9b. The effect of the function is the same even when the structure is used.

Each of the input terminals 1 and 2 connected to the internal circuit of the subscriber's circuit structurally also serves as the switch circuit midpoints 6a and 7a on the electric circuit. The switch circuit break contacts 6b and 7b are desirably formed integrally with the output terminals 3 and 4 connected to the outdoor transmission line side using an iron (Fe) material having a spring property. In this embodiment, the switch circuit break contacts 6b and 7b and the output terminals 3 and 4 connected to the outdoor transmission line are integrally formed. However, the present invention is not limited to this. Alternatively, the same effect can be obtained even if the structure is formed by further dividing and then bonded by brazing or the like.

FIGS. 2, 3 and 4 show the switch circuit break contacts 6b and 7b not in contact with the switch circuit midpoints 6a and 7a in order to illustrate the initial stage of assembly. In this state, the magnet is deformed toward the permanent magnet core 8 by the magnetic attraction of the permanent magnet core 8, and the switch circuit break contacts 6b, 7b are in contact with the switch circuit midpoints 6a, 7a.

The input terminals 1 and 2 connected to the internal circuit of the subscriber's circuit, the output terminals 3 and 4 connected to the outdoor transmission line side, and the GND terminal 5 are held at predetermined positions of the terminal holding unit 10. . In the present embodiment, a structure in which the terminal holding unit 10 is integrally formed of a mold resin is shown as an example.

On the other hand, the electromagnetic switches 6 and 7 monitor the heating temperature of the current attraction type voltage protection elements 9a and 9b, and adjust the heating temperature of the current attraction type voltage protection elements 9a and 9b to a predetermined threshold value (permanent magnet core 8). (Curie temperature), the connection between the outdoor transmission line and the subscriber circuit is detected.
Shut off.

The electromagnetic switches 6 and 7 monitor the heating temperature of the current attraction type voltage protection elements 9a and 9b, and before the current attraction type voltage protection elements 9a and 9b generate heat to reach the ignition temperature. Connection between outdoor transmission line and subscriber circuit
Electrical connection is cut off.

The electromagnetic switches 6, 7 are connected to an outdoor transmission line.
Equipped with an interrupting magnetic circuit that connects or shuts off the incoming circuit
I have.

The cutoff magnetic circuit is connected to the switch circuit midpoints 6a, 7
a, switch breaker contacts 6b, 7b, and a permanent magnet core 8. In the process of generating heat by receiving heat generated from the current attraction type voltage protection elements 9a, 9b via the silicon resin 11, current attraction type voltage protection is provided. Before the elements 9a and 9b self-heat and reach the ignition temperature, an electromagnetic force (a force that holds the switch circuit midpoint 6a and the switch circuit break contact 6b in a connected state;
Switch circuit midpoint 7a and switch circuit and loss of force) for holding the break contact 7b in the connected state, the outdoor transmission line side device connected to the outdoors transmission line open outdoor transmission line outdoor Protect the outdoor transmission line side device connected to the transmission line.

The permanent magnet core 8 has a Curie temperature of 200
It is made of a magnetic material of about ° C., and has a structure surrounding the current attraction type voltage protection elements 9a and 9b for thermal coupling. As shown in FIGS. 2 and 3, in the present embodiment, in order to enhance the thermal coupling, the silicon resin 1 having high thermal conductivity is used.
1 is filled. The cover 12 is, as shown in FIG.
The AC contact protection device 20 is hermetically sealed by fitting with the terminal holding portion 10.

Next, the operation of the present invention will be described.

It is desirable that each of the current attracting type voltage protection elements 9a and 9b use a bidirectional thyristor or zener diode having a breakover voltage of an AC commercial voltage value, and the output terminal 3 connected to the outdoor transmission line side. , 4 are turned on when an AC commercial voltage is applied.
The energy applied here is discharged to the GND terminal 5 via the current attraction type voltage protection elements 9a and 9b.
The internal circuit connected to the input terminals 1 and 2 connected to the internal circuit of the subscriber circuit can be protected.

On the other hand, when the AC commercial voltage is applied for a long time, the current attraction type voltage protection elements 9a and 9b generate heat (that is, the amount of heat generated from the current attraction type voltage protection elements 9a and 9b is generated). ), Thermally bonded permanent magnet core 8
Is heated. Here, since the Curie temperature of the permanent magnet core 8 is about 200 ° C., it loses magnetism due to a temperature rise, and a switch circuit is formed by a repulsive force determined by the material and plate thickness of the output terminals 3 and 4 connected to the outdoor transmission line side. Break contact 6
b, 7a was opened, AC mixed to interrupt the absorption of energy
It is possible to prevent ignition due to heating of the touch protection device 20 itself.

In the case of a surge input with a short application time, since the total heat generation due to the surge energy in the current attraction type voltage protection elements 9a and 9b is small, the AC touch protection is not performed until the permanent magnet core 8 is heated. Device 20
Of the present embodiment because the characteristics of the
The contact protection device 20 also has the function of a surge protection element.

[0034]

Since the present invention is configured as described above, it is possible to reduce the AC mains voltage without adding a special electronic circuit.
Protects the subscriber circuit connected to the outdoor transmission line in the switchboard after the AC touch protection device from overvoltage and overcurrent from lightning surge voltage, and additionally detects the heating state of the current attraction type voltage protection element. There is an effect that an inexpensive AC touch protection device that can separate the protected circuit from the overvoltage supply source and has no power loss can be realized.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram showing a basic configuration of an embodiment of an AC contact protection device of the present invention.

FIG. 2 is a front sectional view taken along a center line of the AC contact protection device of FIG. 1;

FIG. 3 is a side sectional view taken along a center line of the AC contact protection device of FIG. 1;

FIG. 4 is a cross-sectional view of the AC contact protection device of FIG. 1 in a top direction.

FIG. 5 is an electric circuit diagram showing a basic configuration of a conventional AC contact protection device.

[Explanation of symbols]

1, 2 Input terminals connected to the internal circuit of the subscriber's circuit 3, 4 Output terminals connected to the outdoor transmission line 5 GND (ground) terminal 6, 7 Electromagnetic switch 6a, 7a Electromagnetic switch circuit contact (switch) 6b, 7b Circuit contact of electromagnetic switch (switch break contact) 8 Permanent magnet core 9a, 9b Current attraction type voltage protection element 20 AC contact protection device

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02H 3/08-3/10 H04Q 1/02 H04Q 3/42 104

Claims (6)

(57) [Claims] A first line electrically connected to a second line;
Is the first line connected to the first line in case of short circuit
The first line and the first line so that a roadside device is not destroyed.
An AC contact protection device installed between roadside devices, wherein the first line and the first lineside device are electrically connected.
At least a current-sinking type protective device between
One of which has a temperature rise due to heat generation of the current sink type protection element.
When the temperature rise reaches a predetermined temperature threshold, the first line and the
Reduce the number of electromagnetic switches that cut off the electrical connection with the equipment on one track side
Both AC Incompatible protection device characterized in that it has one. Wherein said electromagnetic switch, the heat generation temperature of the current suction type voltage protection device with monitoring, when the heating temperature of the current attraction type voltage protection device detects that it has reached a predetermined threshold value First line and first line side device
2. The AC cross-contact protection device according to claim 1, wherein the device is configured to cut off an electrical connection with the AC power supply . 3. The electromagnetic switch monitors a heating temperature of the current attraction type voltage protection element, and monitors the first line and the first line before the current attraction type voltage protection element reaches a firing temperature due to self-heating. Electrical connection with the first track side device
The AC touch protection device according to claim 1, wherein the protection device is configured to cut off . 4. The electromagnetic switch according to claim 1, wherein the electromagnetic switch is connected to the first line.
A blocking magnetic circuit that performs connection or disconnection with the first line side device , wherein the blocking magnetic circuit receives the heat generated by the current attracting voltage protection element and generates heat in a process of generating heat. The electromagnetic force disappears before the temperature reaches the ignition temperature due to self-heating, and the first line side device connected to the first line is opened from the first line and connected to the first line. 4. The AC cross-contact protection device according to claim 3, wherein the device is configured to protect the first track side device. 5. 5. An AC system for detecting an AC touch of a subscriber line when an outdoor transmission line comes into contact with or short-circuited with a commercial power supply line, and protects a subscriber circuit connected to the outdoor transmission line in the exchange from being destroyed. An exchange contact protection device, wherein the contact protection device has a ground point, and is connected to the outdoor transmission line.
At least one is provided at a connection point with the subscriber circuit;
The electrical energy applied from the commercial power supply line is connected.
Release to a point to prevent inflow to the subscriber circuit
In addition, the state of release of the electric energy to the ground point
A current-sinking type protection element that generates heat in response to the
Temperature rise due to heat generated by the embedded protection element reaches a predetermined temperature threshold
When it reaches the electrical connection between the outdoor transmission line and the subscriber circuit.
Having at least one electromagnetic switch for breaking the electrical connection
Switching system characterized. 6. An AC switch for detecting an AC touch of a subscriber line when an outdoor transmission line comes into contact with or short-circuited with a commercial power supply line, and protects a subscriber circuit connected to the outdoor transmission line in the exchange from being destroyed. A touch protection method, comprising: discharging electric energy applied from the commercial power line side power supply to a ground point to electrically block propagation to the outdoor transmission line; and releasing the electric energy to the ground point. The amount of heat generated according to the situation is monitored, and when it is detected that the amount of heat generated has reached a predetermined temperature threshold, the outdoor transmission line is detected.
A method for protecting against AC touching, comprising cutting off an electrical connection between a circuit and the subscriber's circuit .