JP2002281662A - Lightning protection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightning protection device which has a converting means and lightning protecting function of simple constitution. SOLUTION: From AC power source lines connected with a commercial AC power source, an AC voltage is applied to AC input terminals 5, 5 and inputted in a rectifying means 3 via fuses 4, 4, respectively. By the rectifying mean 3, the AC voltage is rectified and converted to a DC voltage, which is applied to a communication apparatus via DC output terminals 6, 6. A signal inputted in signal input terminals 11 connected with signal lines from the communication apparatus is again outputted to the communication apparatus connected with the signal lines from signal output terminals 12 via overcurrent protecting means 14. When an overvoltage permeates into the signal input terminals 11 from the signal lines, the overvoltage is conducted to the AC input terminals 5, via the overcurrent protecting means 14, signal line side voltage-limiting elements 17, a bias line 19, AC power source line side voltage-limiting elements 16, and the fuses 4. The voltage is conducted from the AC input terminals 5 to the AC power source lines, thereby protecting the communication apparatus from overvoltage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning prevention device for protecting a device using the output of a conversion means from noise input to a signal line.

[0002]

2. Description of the Related Art Conventionally, as a lightning protection device of this type, for example, a configuration described in Japanese Patent Application Laid-Open No. 9-182276 is known.

[0003] In the lightning protection device described in Japanese Patent Application Laid-Open No. 9-182276, two signal lines and two AC power lines are connected to a communication device, and each of the two signal lines serves as a voltage limiting element. Of the bidirectional two-terminal thyristors are connected, and the other ends of these bidirectional two-terminal thyristors are commonly connected. Further, one end of a series circuit of a fuse, a varistor and a lightning arrester is connected to each of the two AC power supply lines, and the other ends of these series circuits are commonly connected.
The other end of the bidirectional two-terminal thyristor is connected to the other end of the series circuit.

When an overvoltage such as a lightning surge occurs on a communication line, an overvoltage is led from the communication line to an AC power supply line via a bidirectional two-terminal thyristor, a lightning arrester, a varistor, and a fuse. Protect.

Further, as another lightning protection device, for example, a configuration described in Japanese Patent Application Laid-Open No. 9-191562 is known.

The lightning protection device described in Japanese Patent Application Laid-Open No. 9-191562 has two external signal lines and four
The internal signal lines are connected to one end of a bidirectional two-terminal thyristor as a voltage limiting element.
Each book is connected in common and connected to an external connection line. A bidirectional two-terminal thyristor is connected between these external connection lines.

When an overvoltage occurs in the internal communication line or the external communication line, the overvoltage is guided by the bidirectional two-terminal thyristor, and the communication device is protected from the overvoltage.

[0008]

However, in general, a communication device converts an AC voltage of a commercial AC power supply into a DC voltage by a rectifier and inputs the DC voltage, and has such a protection means therein. In such a communication device, it is necessary to separately connect the lightning protection device to the communication device by bypassing or the like, and this has a problem that the configuration is complicated and the connection is complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a lightning protection device having a simple structure and a lightning protection function together with a conversion means.

[0010]

According to a first aspect of the present invention, there is provided a lightning protection device which is connected to at least a pair of AC power supply lines of AC voltage, and which converts and outputs an AC voltage by inputting and outputting an AC voltage. A signal input means for inputting a signal from a signal line and a signal output means for outputting a signal from the signal line, and a voltage limiting means connected between the signal input means and the AC power supply line, Even if an overvoltage occurs in the signal line, it is led to the AC power supply line via the voltage limiting means.
A device used by converting an AC voltage by a conversion unit without using a separate device is protected from overvoltage of a signal line.

According to a second aspect of the present invention, in the lightning protection device according to the first aspect, the conversion means is a rectification means for inputting an AC voltage and outputting a DC voltage, and rectifying the AC voltage. The device used after rectification is protected from overvoltage of the signal line.

According to a third aspect of the present invention, in the lightning protection device according to the first aspect, the conversion means is a voltage conversion means for inputting an AC voltage and converting a voltage value. The device used by conversion by the conversion means is protected from overvoltage of the signal line.

A lightning protection device according to a fourth aspect of the present invention is the lightning protection device according to any one of the first to third aspects, wherein a plurality of signal input means and a plurality of signal output means are provided, respectively, and the voltage limiting means is the signal input means. And a signal line side voltage limiting element having one end connected to the signal input means and the other end connected to each other, and one end connected to the AC power supply line corresponding to the number of the AC power supply lines. An AC power supply line side voltage limiting element, the other end of which is connected to each other, and a bypass line connecting the other end of the signal line side voltage limiting element and the other end of the AC power supply line side voltage limiting element. In this case, the signal line side voltage limiting element and the AC line side voltage limiting element are connected to each other and connected by a bypass line, thereby further simplifying.

According to a fifth aspect of the present invention, there is provided a lightning protection device according to any one of the first to fourth aspects, further comprising an overcurrent protection means connected between the signal input means and the voltage limiting means. The current is cut off by the overcurrent protection means, and when the voltage limiting means is damaged, a failure due to the overcurrent is prevented from spreading.

A lightning protection device according to a sixth aspect of the present invention is the lightning protection device according to any one of the first to fifth aspects, further comprising a fuse connected between the AC power supply line and the voltage limiting means. The fuse is cut off to prevent a fault due to overcurrent from spreading when the voltage limiting means is damaged.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the lightning protection device of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a lightning protection device 1 includes a housing 2
Housed within. A rectifying means 3 for full-wave rectification such as a bridge circuit is accommodated in the housing 2 as a converting means for converting an AC voltage into a DC voltage. The rectifying means 3 has two AC input terminals and two DC It has output terminals, and these AC input terminals are connected to an AC input terminal 5 as AC input means via fuses 4 respectively. The AC input terminal 5 is connected to an AC power supply line (not shown) connected to a commercial AC power supply or the like. On the other hand, a dc output terminal of the rectifier 3 is connected to a dc output terminal 6 as dc output means for outputting dc, and a communication device or a signal control device (not shown) using dc as a power supply is connected to the dc output terminal 6. Have been.

A signal input terminal 11 for inputting a signal from a communication device or a signal control device (not shown), and two signal output devices for outputting a signal to the communication device or the signal control device. A signal output terminal 12 is provided, and the signal input terminal 11 and the signal output terminal 12 are connected via an overcurrent protection means 14, respectively.

A voltage limiting means 15 is connected between the AC input terminal 5 via the fuse 4 and the signal input terminal 11 via the signal output terminal 12 and the overcurrent protection means 14. This voltage limiting means 15 is connected to one of two AC power supply line side voltage limiting elements 16 such as zinc oxide varistors, respectively, to two AC input terminals 5 via fuses 4 respectively. Voltage limiting element 16
Are connected to each other. A zinc oxide varistor and a PN are connected between two signal input terminals 11 and two signal output terminals 12 via the overcurrent protection means 14, respectively.
One ends of two signal line side voltage limiting elements 17 such as a bidirectional two-terminal thyristor or a gas arrester, which are PN thyristors, are connected, and these two signal line side voltage limiting elements 17 are connected.
Are connected to each other. Further, a bypass line 18 is connected between the other end of the AC power supply line side voltage limiting element 16 and the other end of the signal line side voltage limiting element 17.

Next, the operation of the above embodiment will be described.

Normally, an AC voltage is applied to AC input terminals 5 and 5 from an AC power supply line connected to a commercial AC power supply,
Input to the rectifying means 3 via the fuses 4 and 4, respectively.
The rectifier 3 rectifies and converts the AC voltage into a DC voltage and applies the voltage to communication equipment or signal control equipment via DC output terminals 6 and 6.

A signal input to a signal input terminal 11 connected to a signal line from a communication device or a signal control device is supplied from a signal output terminal 12 via an overcurrent protection means 14 to a communication device connected to the signal line again. Output to device or signal control device.

On the other hand, when an overvoltage enters the signal input terminal 11 from the signal line, the overcurrent protection means 14, the signal line side voltage limiting element 17, the bypass line 18, the AC power supply line side voltage limiting element 16, and the fuse 4 , To the AC input terminal 5 and from the AC input terminal 5 to an AC power supply line to protect the communication device or the signal control device from overvoltage.

Also, when an overcurrent enters from an AC power supply line, an overvoltage is similarly introduced to the signal line to protect it from overvoltage.

Further, the overcurrent protection means prevents an overcurrent from entering from the signal line via the signal input terminal 11.

The fuse 4 prevents overcurrent from entering from the AC power supply line via the AC input terminal 5, and the fuse 4 and the overcurrent protection means 14 control the AC power supply side voltage limiting element 16 or signal. When the line-side voltage limiting element 17 is damaged, the failure is prevented from spreading.

According to the above-described embodiment, by providing a bypass function such as a voltage limiting means 15 for lightning protection in the housing 2 together with the rectifying means 3, a separate device for lightning protection becomes unnecessary. The configuration can be simplified.

In the above embodiment, the rectifier 3 is used as the converter. However, instead of the rectifier 3, an AC voltage is input and the voltage is converted, for example, a rectifier, a chopper circuit, and an inverter circuit. The same effect can be obtained by using a voltage converter combining the above.

[0029]

According to the lightning protection device of the first aspect, even if an overvoltage occurs in the signal line, the signal line is led to the AC power supply line via the voltage limiting means, so that the AC voltage is converted without using a separate device. The device used after conversion can be protected from overvoltage of the signal line.

According to the lightning protection device of the second aspect, in addition to the lightning protection device of the first aspect, the device used by rectifying the AC voltage by the rectifying means is protected from the overvoltage of the signal line.

According to the lightning protection device of the third aspect, in addition to the lightning protection device of the first aspect, the device used by converting the AC voltage by the voltage conversion means is protected from the overvoltage of the signal line.

According to the lightning protection device of the fourth aspect, in addition to the lightning protection device of any one of the first to third aspects, the signal line side voltage limiting element and the AC power supply line side voltage limiting element are connected to each other. The connection can be further simplified by using a bypass line.

According to the lightning protection device of the fifth aspect, in addition to the lightning protection device of any one of the first to fourth aspects, the overcurrent is cut off by the overcurrent protection means, and the overcurrent is cut off when the voltage limiting means is damaged. It is possible to prevent the failure caused by the current from spreading.

According to the lightning protection device of the sixth aspect, in addition to the lightning protection device of any one of the first to fifth aspects, the overcurrent is interrupted by a fuse, and if the voltage limiting means is damaged, a fault due to the overcurrent is caused. Can be prevented from spreading.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a lightning protection device according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lightning protection device 3 Rectifier means as conversion means 4 Fuse 11 Signal input terminal as signal input means 12 Signal output terminal as signal output means 14 Overcurrent protection means 15 Voltage limiting means 16 AC power line side voltage limiting element 17 Signal Line side voltage limiting element 18 Bypass line

Continued on the front page (72) Atsushi Kitagawa 2-17-7 Shimomeguro, Meguro-ku, Tokyo Daito Communication Equipment Co., Ltd. (72) Seiichi Yamano 2-3-1 Otemachi, Chiyoda-ku, Tokyo Japan Telegraph and Telephone Co., Ltd. F term (reference) 5G013 AA05 BA03 CA18 CB11 DA01 DA08 DA12

Claims (6)

[Claims] 1. A conversion means connected to at least a pair of AC power supply lines of AC voltage for inputting, converting and outputting an AC voltage, and a signal input for inputting a signal from a signal line electrically connected to each other. A lightning protection device comprising: signal output means for outputting a signal from the means and a signal line; and voltage limiting means connected between the signal input means and the AC power supply line. 2. The converter according to claim 1, wherein the converter is a rectifier that inputs an AC voltage and outputs a DC voltage.
Lightning protection device as described. 3. The lightning protection device according to claim 1, wherein the conversion means is a voltage conversion means for inputting an AC voltage and converting a voltage value. 4. A plurality of signal input means and a plurality of signal output means are provided, respectively, and the voltage limiting means corresponds to the number of the signal input means. One end is connected to the signal input means and the other end is connected to each other. A signal line side voltage limiting element, and an AC power supply line side voltage limiting element corresponding to the number of the AC power supply lines, one end of which is connected to the AC power supply line and the other end of which is connected to each other; 4. The lightning protection device according to claim 1, further comprising a bypass line connecting between the other end of the limiting element and the other end of the AC power supply line side voltage limiting element. 5. The lightning protection device according to claim 1, further comprising an overcurrent protection means connected between the signal input means and the voltage limiting means. 6. The apparatus according to claim 1, further comprising a fuse connected between the AC power supply line and the voltage limiting means.
6. The lightning protection device according to any one of claims 5 to 5.