JPS6110330A - Protecting device of communication equipment - Google Patents

Abstract

PURPOSE:To protect a communication equipment by providing a relay activated by a detection signal of a detection circuit between the detection circuit detecting an overcurrent or an overvoltage via a communication cable and the communication cable itself. CONSTITUTION:The communication equipment 1 is connected to a terminal device 4 via the communication cable 3. The relay 5 disconnecting the equipment 1 and the cable 3 is connected with the connecting point 2. A detection circuit 6 is connected to the relay 5 via an impedance 7 in the equipment 1. The relay 5 detects a voltage drop of the impedance 7 when a lightning surge or contact of commercial lines takes place and the relay 5 is opened.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a protection device for communication equipment that protects communication equipment connected to a communication cable from overcurrent or overvoltage caused by lightning or commercial line cross-axle. The present invention relates to a protection device for communication equipment that can protect the communication equipment against long-term failures caused by excessive energy.

[Prior art] As a technology for protecting communication equipment connected to communication cables from overcurrent or overvoltage generated by lightning or commercial line cross-axes, protective elements such as arresters, varistors, discharge tubes, Zener diodes, etc. are used. It is conceivable that the protection element is activated by the occurrence of overcurrent or overvoltage, and the overcurrent is grounded through this protection element.

However, according to the above technology, the pulse width like a lightning surge is 1ffI11! It can be adequately dealt with in cases of level c, but in the event of long-lasting disturbances such as high-energy lightning surges or cross-contact with commercial lines, it may be difficult to cope with the problem due to heat generated in the protective element itself. ), the protection element may be destroyed, and the communication equipment cannot be effectively protected.

[Purpose of the invention]

The present invention solves the above-mentioned problems, and provides a protection device for communication equipment that can effectively protect communication equipment even when a long-lasting failure such as an excessive lightning surge or contact by a commercial MK occurs. The purpose is to

[Structure of the invention]

In order to achieve the above object of the present invention, the protection device for communication equipment according to the present invention includes a detection circuit that detects overcurrent or overvoltage via the communication cable in the communication equipment connected to the communication cable. , and a relay that is provided between the communication cable and disconnects the communication cable and the communication device in response to a detection signal from a detection circuit.

[Explanation of Examples]

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing a first embodiment of a protection device for communication equipment according to the present invention.

The second factor is a circuit diagram showing more specifically the first embodiment of the communication device protection device according to the present invention.

FIG. 3 is a block diagram showing a second embodiment of the protection device for communication equipment according to the present invention.

In the figure, 1 is a communication device, and a communication cable 3 is connected to the connection point 2.
It is connected to the terminal device 4 via. This is a relay that disconnects the communication device 1 and the communication cable 3, and is interposed between the connection point 2 and the communication device 1.

Inside the communication device 1, as shown in FIG. 2, a detection circuit 6 is connected to a relay 5 via an impedance 7. This detection circuit 6 detects a voltage drop across an impedance 7 when a lightning surge or a commercial line cross-contact occurs, and outputs a detection signal.

8 is a flip-flop, and the detection signal is connected to its set terminal S.
When receiving K, the ζ output terminal becomes H level, and the KQζ output terminal becomes L level. Reference numeral 9 denotes a driver circuit for the relay 7, which is roughly composed of a PNP type transistor Tr whose base is connected to the ζ output terminal of the flip-flop 8, and the coil of the relay 5 connected to its collector. Note that 10 is an LED connected to the ζ output terminal of the flip 70 knob 8 for indicating the occurrence of a failure.

Next, when a surge, a lightning surge, or a power line cross-contact occurs as described in connection with the operation of the first embodiment, an overcurrent flows through the impedance 7 through the closed relay 5. This is K.
A voltage 111 below is generated in the impedance 7 , and the detection circuit 6 detects this and supplies a detection signal (H level) to the flip-flop 8 .

After receiving the detection signal at the set terminal SK, the 7-lip flop 8 is set, and the ζ output terminal is brought to an H level.

This activates the transistor Tru of the driver circuit 9, and the coil of the relay 5 is excited by the collector current, and the relay 5 is opened. By opening this relay 5, the connection between the communication cable 5 and the communication device 6 is cut off, thus preventing the occurrence of a failure in the communication device I.

Incidentally, as the detection signal is applied to the flip-flop 8, its ζ output terminal is set to the L level, so that the LEDIO for indicating the occurrence of a failure emits light. Therefore, this light emission can notify that an abnormal condition has occurred due to lightning surge or commercial line interference.

When the cause of the fault is removed (end of lightning surge or disconnection of utility line cross-contact), reset terminal RK of 7 lip-flop 8
By applying the H level signal K, the flip-flop 8 is reversed, the relay 5 is restored, the communication equipment 1 is placed in the normal mode, and the LED 10 for indicating the occurrence of a failure is turned off.

FIG. 3 is a block diagram showing the second embodiment, which is similar to the first embodiment.
Example Kvjl! Elements (arrester, electrode tube.

This is a book with 11 added (varistors, diodes, etc.).

This protective element 11 is used to absorb short-lived energy such as lightning surges.

〔Effect of the invention〕

As explained above, according to the protection device for communication equipment according to the present invention, the detection circuit is provided at the connection between the communication equipment and the communication cable, and the detection signal of the detection circuit is used to connect the communication cable and the communication equipment. The feature is that it is equipped with a relay that cuts off the connection, so it can prevent overvoltage or
When an overcurrent is applied to the communication cable, the detection circuit detects this and opens the relay.
Therefore, even if a long-lasting failure such as an excessive lightning surge or interference with a commercial line occurs, the communication equipment connected to the communication cable can be effectively protected.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of a communication equipment protection device related to an unexploded 8AK. FIG. 2 is a circuit diagram showing more specifically the first embodiment of the protection device for communication equipment according to the present invention. FIG. 3 is a block diagram showing a second embodiment of the protection device for communication equipment according to the present invention. 1... Communication equipment 2... Connection point 3... Communication cable 4... Terminal 5... Relay
6...Detection circuit 7...Impedance 8
...7 Lip-flop 9...Driver circuit 10...LED for failure indication t'r...Transistor

Claims (1)

[Claims] In a communication device connected to a communication cable, a detection circuit that detects overcurrent or overvoltage via the communication cable, and a detection circuit provided between the communication device and the communication cable, based on the detection signal of the detection circuit. A protection device for communication equipment, comprising a relay that disconnects the communication cable from the communication equipment.