JPS6213395Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a communication protector used at a line lead-in point for telephones and other wired communication household equipment.

A communication protector is installed at the indoor lead-in point of the track.
To protect in-house equipment and protect operators from danger when communication lines come into contact with power lines or when surges arrive on the lines due to lightning. In recent years, semiconductor integrated circuits have come to be used in household equipment, and there has been a demand for higher performance communication protectors.

Conventionally, excellent circuits of communication protectors have been improved in response to the above requirements. In other words, in a two-wire line configuration, a discharge tube is maintained between the line terminal and the home equipment terminal, and if an abnormally high voltage is applied to the line due to a lightning surge or power line contact, the discharge tube will be discharged. There is a known technique for protecting indoor equipment by short-circuiting the lines so that the terminals of the indoor equipment are at the same potential. In addition, in a two-wire line configuration, fuses are connected between the pair of line terminals and the home equipment terminals, and contact breakers that are normally closed are connected to these, and these and the discharge tubes are connected to each other. Circuits that combine these are also known. This circuit generally protects household equipment by discharging the discharge tube and shorting the line terminals when a short-duration lightning surge occurs. In addition, if abnormally high voltage persists due to power line cross-contact, etc., the discharge tube is discharged and the line terminals are shorted to protect the household equipment, and the contact breaker is operated and the fuse is blown.
Opens the circuit through step-by-step operation to more safely protect home equipment.

As described above, the conventional technology is excellent, but if this technology is applied to a point of entry for multiple lines, the number of contact breakers increases, resulting in a disadvantage that the protector becomes larger.

The present invention improves on this point, and can protect in-home equipment connected to multiple lines from lightning surges, etc., without making the device complicated.
It is an object of the present invention to provide a communication protector that can reduce costs and facilitate circuit recovery operations.

This invention connects line terminals L ₁ and L ₂ and home equipment terminals.
Fuses inserted between T ₁ and T ₂ respectively
Two electrodes are connected to F ₁ , F ₂ , contacts K ₁ , K ₂ of a contact breaker connected in parallel with these fuses F ₁ , F ₂ , respectively, and the home equipment terminals T ₁ , T ₂ . In a communication protector having a plurality of circuits each having a triode discharge tube A, the third electrode of the triode discharge tube A is connected across the plurality of circuits, and the potential point of the third electrode and A drive winding M connected to ground and interlocking the contacts K ₁ and K ₂ of the contact breaker over the plurality of lines, and a diode discharge tube B connected in parallel to the drive winding M. It is characterized by being equipped.

An embodiment of the present invention will be described based on the drawings.
The figure is a diagram showing the main circuit configuration of an embodiment of the present invention. Here, to explain the circuit configuration of one line, the line terminal
L ₁ and L ₂ are home equipment terminals via fuses F ₁ and F ₂
Connected to T ₁ and T ₂ respectively. Contacts K ₁ and K ₂ of a contact circuit breaker are connected in parallel to the fuses F ₁ and F ₂ , respectively. Also, fuse F ₁ ,
Two electrodes of a triode discharge tube A are connected between F ₂ and home equipment terminals T ₁ and T ₂ respectively. The circuit configurations of the other lines are similar, and only the circuit configurations of the first and n-th lines are shown in the figure.

The potential point of the third electrode of each of these triode discharge tubes A is connected to one end of one drive winding M provided in common to the contact breakers K ₁ and K ₂ of each circuit. . The other end of this drive winding M is grounded. A diode discharge tube B is connected to this drive winding M in parallel.

The characteristic operation of the present invention will be explained using such a circuit configuration. Since the contacts K ₁ and K ₂ are normally closed, most of the communication current flows through the contacts K ₁ and K ₂ , and only a small proportion is shunted to the fuses F ₁ and F ₂ .
Under such conditions, lightning surges may occur on line L ₁ or L ₂
(for example, L ₁ ), a discharge occurs at the corresponding electrode of the triode discharge tube A. This discharge immediately propagates inside the tube and shorts line terminals L ₁ and L ₂ . As a result, the household equipment terminals T ₁ and T ₂ have the same potential (ground potential), and the household equipment and the user are protected. This lightning surge is short-circuited to ground via contacts K ₁ , K ₂ and triode discharge tube A. Since the duration of a lightning surge is generally short, the contacts K ₁ and K ₂ of the contact circuit breaker
does not work. Therefore, when the lightning surge ends,
The discharge of the triode discharge tube _A1 also ends, and the circuit returns to its normal state.

When the line comes into contact with a power line and an abnormally high voltage alternating current is applied to the line terminal L ₁ or L ₂ (for example L ₁ ), a discharge occurs at the corresponding electrode of the triode discharge tube A. This discharge immediately propagates into its tube and shorts the line terminals L ₁ and L ₂ . As a result, the home equipment terminals T ₁ and T ₂ become at the same potential (ground potential) to protect the home equipment and the user.

If this abnormally high voltage continues in this state, the voltage across the drive winding M reaches the drive voltage of the contact breaker, and the contacts K ₁ and K ₂ of each line operate in conjunction. Due to this interlocking operation, in other lines to which no abnormally high voltage is applied, if the abnormally high voltage is propagated, the fuse is blown and the circuit is opened.

Line terminal to which abnormally high voltage is actually applied
In L ₁ and L ₂ , if this abnormally high voltage continues further, the fuse F ₁ or F ₂ will blow, opening the circuit and protecting the household equipment and the user.

When fuse F ₁ or F ₂ melts and opens the circuit, contact K ₁ , except for the cause of abnormally high voltage,
You can manually close _K2 and communicate again. Through this manual operation, the other contacts K ₁ and K ₂ are also restored in conjunction with each other, and the states of the other lines are also restored.
Since this manual operation can be performed by the subscriber, communications can be restored for the time being without the need for maintenance personnel to be dispatched. When a fuse blows, the subscriber notifies the station;
Maintenance personnel will be dispatched to restore the system, but this dispatch of maintenance personnel is not an emergency, and the number of maintenance personnel can be significantly reduced.

Further, when the contact circuit breaker operates due to the application of abnormally high voltage, no spark is generated at the contacts K ₁ and K ₂ .
That is, since the fuses F ₁ and F ₂ are inserted in parallel to the contacts K ₁ and K ₂ , there is almost no spark caused by the opening of the contacts K ₁ and K ₂ . The fuses F ₁ and F ₂ are blown after the contacts K ₁ and K ₂ are sufficiently opened. Therefore, a small and inexpensive contact breaker can be used.

In addition, since the diode discharge tube B is connected in parallel to the drive winding M of the contact breaker, when a lightning surge with an extremely sharp voltage rise occurs, the contacts K ₁ and K ₂ of the contact breaker are operation is prevented. That is, since the impedance of the drive winding M is quite low, a voltage higher than the discharge starting voltage will not be generated at both ends of the diode discharge tube B due to a normal lightning surge or contact with a power line. However, when a lightning surge with an extremely sharp voltage rise arrives and the voltage across the drive winding M becomes momentarily higher than the discharge starting voltage of the diode discharge tube B, the drive winding M are short-circuited, and the operation of contacts K ₁ and K ₂ is prevented.

As a result, the contact circuit breaker is activated by the lightning surge, and contacts K ₁ and K ₂ remain open.
This prevents the device from being used for a long time without being noticed.

As explained above, the present invention has the following features: (1) A device for this purpose is capable of interlocking home equipment connected to multiple lines to protect it from lightning surges and power line cross-contact. (2) Protection of household equipment is achieved through a three-step operation: discharging the triode discharge tube, driving the contact breaker, and blowing the fuse. (3) Even if a fuse blows out, communication can be restored by manually restoring the contact of the contact breaker, and there is no need to urgently replace the fuse. (4) Even if the contact opens due to the operation of the contact breaker, there is no spark because the fuses are connected in parallel, and the contact breaker (5) Since a diode discharge tube is connected to the drive winding, the contact breaker is prevented from operating in the event of a lightning surge with an extremely sharp voltage rise. It has excellent effects such as the fact that the contacts of the contact breaker open due to lightning surges, and the circuit will not be used in this state for a long time.

[Brief explanation of drawings]

The figure is a circuit configuration diagram of a main part of an embodiment of the present invention. L ₁ , L ₂ ... Line terminal, F ₁ , F ₂ ... Fuse,
T ₁ , T ₂ ... Home equipment terminal, K ₁ , K ₂ ... Contact, A
...triode discharge tube, B...dipole discharge tube, M...drive winding.

Claims (1)

[Scope of utility model registration request] Fuses F _{1 and F 2 inserted between line terminals L 1} and L ₂ and household equipment terminals T ₁ and T ₂ , respectively, and contact breakers connected in parallel with these fuses F ₁ and F _{2 , respectively} . Contacts K ₁ and K ₂ and the above home equipment terminals
Triode discharge tube A with two electrodes connected to T ₁ and T ₂
and a third electrode of the triode discharge tube A is connected across the plurality of lines, and is inserted between the potential point of this third electrode and the ground. and a drive winding M that interlocks and drives the contacts K ₁ and K ₂ of the contact breaker over the plurality of lines, and a diode discharge tube B connected in parallel to the drive winding M. A communication safety device featuring: