JPH01118375U

JPH01118375U -

Info

Publication number: JPH01118375U
Application number: JP1087188U
Authority: JP
Priority date: 1988-01-29
Filing date: 1988-01-29
Publication date: 1989-08-10
Anticipated expiration: 2003-01-29
Also published as: JPH076539Y2

Description

[Brief explanation of the drawing]

第１図は本考案の一実施例を示す回路図、第２
図ａのイ，ロおよび第２図ｂのイ，ロは本考案の
一実施例における動作を示す波形図、第３図は従
来の故障電流検出装置の回路図、第４図イ，ロは
従来の故障電流検出装置の動作波形図。符号の説明、１……架空地線、２……変流器、
３……負荷抵抗、４，５……ツエナーダイオード
、７，８，９，１０……整流用ダイオード、１１
，１２……レベル変換用抵抗、１３……発光ダイ
オード。 Figure 1 is a circuit diagram showing one embodiment of the present invention;
Figures A and B in Figure A and A and B in Figure 2B are waveform diagrams showing the operation of an embodiment of the present invention, Figure 3 is a circuit diagram of a conventional fault current detection device, and Figure 4 A and B are waveform diagrams showing the operation of an embodiment of the present invention. FIG. 2 is an operation waveform diagram of a conventional fault current detection device. Explanation of symbols, 1...Overhead ground wire, 2...Current transformer,
3... Load resistance, 4, 5... Zener diode, 7, 8, 9, 10... Rectifier diode, 11
, 12... Level conversion resistor, 13... Light emitting diode.

Claims

[Scope of Claim for Utility Model Registration] (1) Detection signals corresponding to forward and reverse fault currents flowing in the overhead ground wire are supplied to an optical signal generating means, and a measuring optical signal is generated based on the forward direction detection signal. A fault current detection device for a power transmission line that generates a correction optical signal based on a detection signal in the opposite direction, comprising: a first Zener diode having a Zener voltage greater than the maximum value of the detection signal; a first level conversion circuit in which a second Zener diode having a Zener voltage smaller than the second Zener voltage is connected in series in the opposite direction and is arranged in parallel with the detection signal generating section; a second level conversion circuit which converts the level of the detection signal using different constants in forward and reverse directions when the Zener voltage is smaller than the Zener voltage of , and supplies the detected signal to the optical signal generating means. Current detection device. (2) The second level conversion circuit includes a plurality of level conversion circuits having different resistance values inserted in series with the first and second signal lines that supply the detection signals in the forward and reverse directions to the optical signal generating means. 2. The fault current detection device for a power transmission line according to claim 1, wherein the fault current detection device is configured to include a first resistor and a second resistor.