KR101774037B1 - Apparatus for detecting cable failure place - Google Patents

Abstract

An embodiment of the present invention provides an apparatus for detecting a cable failure position including: a cable failure position detector branching a pulse signal having a transmission frequency to input the branched pulse signals into a cable, and detecting and analyzing a signal reflected from a cable failure position to detect the cable failure position; and a pulse signal removing filter inserted into a cable between two points where the branched pulse signals are input to remove the pulse signal. The cable failure position detector includes: a pulse signal generation unit generating the pulse signal to be input into the cable; a pulse signal branching unit branching the pulse signal, generated by the pulse signal generation unit, into a first branched pulse signal and a second branched pulse signal; a pulse signal transmission unit inputting the first branched pulse signal into the cable connected to one side of the pulse signal removing filter and inputting the second branched pulse signal into the cable connected to the other side of the pulse signal removing filter; a reflected signal receiving unit receiving the signal reflected from the cable failure position, removing a noise, performing a signal processing operation and outputting the processed signal; a reflected signal compensation unit outputting a compensated signal compensated by attenuating or amplifying the reflected signal output by the reflected signal receiving unit according to a strength of the reflected signal; and a failure position determining unit comparing the pulse signal transmitted to the cable with the compensated signal compensated by the reflected signal compensation unit to determine the failure position. The present invention minimizes a distortion of the reflected signal, thereby enhancing a cable failure position detection error.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a cable fault location detecting apparatus,

The present invention relates to an apparatus for detecting a cable fault position, and more particularly, to a fault location detecting apparatus for detecting a fault location of a cable by injecting a specific pulse signal into a cable and detecting and analyzing a signal reflected at a fault location.

Cable cabling systems are used in all fields ranging from military weapons systems such as air defense weapons systems and fighters to civilian industries such as buildings, factories, nuclear power, automobiles, ships, aircraft, have.

Defects (short circuit, contact failure, breakage, disconnection, etc.) of cable wiring system may cause important functions of military and civil electrical / electronic facilities to be lost or cause system malfunction, power outage, fire occurrence and information loss, It can cause enormous damage such as disruption and can threaten public safety.

According to the 2011 National Statistical of Electrical Disaster Statistics of the National Emergency Management Agency and the Korea Electrical Safety Corporation, the majority (20.6%) of electric fires are generated in wiring and wiring equipment, and 21.3% of electrical equipment accidents are related to cable wiring. The technology of detecting and locating cause and location more than cable early is playing an important role in preventing safety accident and reducing enormous damage. Therefore, it is necessary to detect the main cause of the cable fault and develop the technology for the location tracking technology, thereby preventing the accident.

In the prior art, there are a sound detection method for measuring an ultrasonic wave or an audible frequency region due to a discharge in the case of a cable fault, an insulation resistance measurement method in which a DC power is supplied in a power failure state (no power source) Various cable fault diagnosis and position detection techniques such as a partial discharge measurement method for measuring a discharge phenomenon of a cable fault are used.

However, since most of the prior arts conducts inspections after cable is disconnected, there is a fear of interruption of facility operation, cable damage, etc., and an initial failure or an intermittent fault can not be detected, There is a problem that it takes a lot of time.

The present applicant has proposed a cable fault position detector related to cable fault position detection for detecting a failure position of a cable by injecting a specific transmission signal into a cable without detecting a power failure in the cable, (Korean Patent No. 10-1602407).

As shown in Fig. 1, the cable fault position detecting apparatus of the prior patent includes a pulse signal generating section for generating a pulse signal to be injected into a cable, a pulse signal generating section for generating a pulse signal generated by the pulse signal generating section, A pulse signal branching unit for branching to a branching pulse signal and a pulse signal for injecting a first branching pulse signal into a cable connected to one side of the pulse elimination filter and injecting a second branching pulse signal into a cable connected to the other side of the pulse elimination filter, A reflection signal receiving unit for receiving the reflected signal reflected from the fault position of the cable to remove the noise and performing a signal processing on the reflected signal received from the cable, And a cable fault position detector having a position judging section.

However, there is a problem in that a reflected signal received at the time of detecting a fault location with respect to a nearby cable is received as a reflected signal with a large signal intensity, and thus the waveform is received distorted. That is, when a transmission signal of a square wave is input to a nearby cable to detect a failure position, the reflection signal received through the reflection signal reception unit has a large signal intensity, There is a case.

On the contrary, when detecting a fault location with respect to a cable at a long distance, the signal intensity of the reflection signal received via the reflection signal receiver becomes weak, which makes it difficult to measure the detection position.

Korean Patent No. 10-1602407

The technical problem of the present invention is to provide a reflection signal correction means for minimizing distortion when detecting a cable fault position. According to another aspect of the present invention, there is provided a method of separating and processing a reflected signal according to a strength of a reflected signal.

A cable fault location detector for detecting a fault location of a cable by detecting and analyzing a reflected signal reflected at a fault location of the cable by branching the pulse signal having the set transmission frequency and injecting the pulse signal into the cable; And a pulse signal rejection filter inserted in a cable between two points where a branched pulse signal is input to remove the pulse signal, wherein the cable fault position detector comprises: a pulse signal generating circuit for generating a pulse signal Generating part; A pulse signal branching unit for branching the pulse signal generated by the pulse signal generating unit to a first branch pulse signal and a second branch pulse signal; A pulse signal transmitter for injecting the first branch pulse signal into a cable connected to one side of the pulse signal rejection filter and injecting the second branch pulse signal into a cable connected to the other side of the pulse signal rejection filter; A reflection signal receiving unit for receiving a reflected signal reflected from a failure position of the cable to remove noise, processing the signal, and outputting the signal; A reflected signal correcting unit for attenuating or amplifying the reflected signal according to the intensity of the reflected signal output from the reflected signal receiving unit and outputting the corrected signal as a corrected signal; And a failure position determiner for comparing a pulse signal transmitted to the cable with a correction signal corrected through the reflection signal corrector to determine a failure position.

Wherein the reflection signal correction unit comprises: an attenuator for attenuating and outputting the amplitude of the reflection signal output from the reflection signal reception unit; An amplifier for increasing the amplitude of the reflection signal output from the reflection signal receiver; And a switching module that switches the reflection signal output from the reflection signal receiver to one of the attenuator and the amplifier and transmits the switching signal.

And a reflection signal intensity measurement module for measuring an intensity of a reflection signal output from the reflection signal reception unit, wherein the switching module comprises: A signal is switched to the attenuator or a reflection signal outputted from the reflection signal receiver is switched to the amplifier.

The switching module switches to the attenuator when the intensity of the reflected signal is greater than or equal to a preset switching reference signal and to the amplifier when the intensity of the reflected signal is less than the switching reference signal.

The attenuator may be implemented as a variable resistor.

The reflection signal correction unit may include a damping ratio adjustment module that adjusts the resistance value of the variable resistor so as to have a damping ratio in proportion to the intensity of the reflected signal.

According to the embodiment of the present invention, it is possible to improve the detection error of the failure position of the cable by minimizing the distortion of the reflection signal which is the reception signal.

1 is a block diagram of a conventional cable fault location detector.
FIG. 2 is a diagram showing distortion of a received reflection signal. FIG.
3 and 4 are conceptual diagrams for explaining a failure position detection principle of a cable fault position detection apparatus according to an embodiment of the present invention.
Figure 5 shows a cable with two fault locations.
FIG. 6 is a diagram showing a reflection signal received and reflected at two fault locations. FIG.
7 is a schematic configuration diagram of a cable fault position detecting device including a pulse signal rejection filter and a cable fault position detector according to the present invention.
8 is a block diagram of a configuration of a cable fault location detector for detecting a cable fault location according to an embodiment of the present invention;
9 is a detailed block diagram of a reflected signal correcting unit of a cable fault position detector according to an embodiment of the present invention.
10 is a view showing a state where a reflection signal is switched to an attenuator according to an embodiment of the present invention;
11 is a view showing a state where a reflection signal is switched to an amplifier according to an embodiment of the present invention.
12 is a photograph of a measured graph of a reflected signal measured before correction and a graph of a measured graph of a reflected signal corrected through the attenuator of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to achieve them, will be apparent from the following detailed description of embodiments thereof taken in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art. And the present invention is only defined by the scope of the claims. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

FIGS. 3 and 4 are conceptual diagrams for explaining the principle of detecting a fault location of a cable fault location detecting apparatus according to an embodiment of the present invention. FIG. 5 is a view showing a cable having two fault locations, FIG. 7 is a schematic diagram of a cable fault location detecting apparatus including a pulse signal rejection filter and a cable fault location detector according to the present invention. FIG. 7 is a view showing a reflection signal received at two fault locations

Detecting the failure position (cable cutting position, etc.) of the cable 100 uses the basic principle of the laser. As shown in Fig. 3, the distance R = (C x t) / 2 to the target can be obtained. R is the target distance, C is the speed of light (3 × 10 ⁸ m / s), and t is the round trip time. Applying this principle, referring to FIG. 4, it can be seen that the medium is a cable, not an air, and that a specific signal suitable for a cable is injected, a signal reflected at a failure position is detected, .

The cable serves to supply a power signal or a communication signal and is installed in the ground. In the case of this embodiment, a cable for supplying electric power to the street light 10 is described as an example, and the power line may be generally 220 V of 60 Hz or the like.

The loads connected to the cables are not limited to the street lamps 10 but may be used in various fields such as military weapons systems (missile weapons systems, fighters, submarines etc.) and civilian (power, aircraft, Power cable. That is, the cable 10 can be implemented as a cable of a power / signal complex type that carries out communication in addition to power. Communication lines can be largely divided into analog and digital communication. Analog communication has various frequencies and signal levels. Digital communication, baud rate, signal level and protocol can be used in various ways. Hereinafter, the frequency of the power operated through the cable 100 and the frequency of the communication will be referred to as an operating frequency.

On the other hand, when a failure such as disconnection occurs at least two or more than one in the cable 100, it is necessary to accurately detect the position of the failure position. For example, as shown in FIG. 5, when a cable defect occurs at the first defect position and the second defect position in the cable 100, the first reflected signal by the first defect position as shown in FIG. 6, And receives the second reflected signal by the two defect positions. When the reflection signal and the transmission signal are compared with each other, the distance of the corresponding position can be grasped, but the direction can not be determined.

In order to solve such a problem, the cable fault location detecting apparatus may include a pulse signal rejection filter 150 and a cable fault location detector 200 in the cable 100 as shown in FIG. And a capacitance adjusting unit (not shown) for adjusting the pulse frequency of the pulse signal cancellation filter 150.

The pulse signal rejection filter 150 is inserted into the cable 100 between two points at which the branched pulse signal is inputted to remove the pulse signal. For reference, the pulse signal rejection filter 150 may be provided in advance on the cable line when the cable is embedded in the cable. In addition, a pulse signal rejection filter 150 may be provided in a cable connection connector (not shown), which is a connector for connecting a cable and a cable for cable extension. In the case where the pulse signal rejection filter 150 is provided in the cable connection connector, the pulse signal rejection filter 150 may be installed in advance during the embedding of the cable, or the cover covering the cable connection connector may be opened to expose it on the ground, A pulse signal rejection filter 150 may be additionally provided in the connection connector.

By providing the pulse signal rejection filter 150, it is possible to remove only the pulse signal flowing through the cable. For example, when a cable is used as a transmission / reception cable having an operating frequency (power frequency) of 60 Hz and a pulse signal of 300 Hz is used for detecting a failure of the cable, the pulse signal rejection filter 150 passes the operating frequency of 60 Hz And the pulse signal of 300 Hz is removed. Therefore, as shown in FIG. 7, the first branch line L1 is branched at the cable failure position detector 200, and is connected to the first injection position N1 at the left side of the pulse signal rejection filter 150, The pulse signal from the first branch pulse signal to the pulse elimination filter 150 is removed and the pulse signal directed to the first defect position in a direction other than the pulse elimination filter 150 is reflected at the first defect position And is received as the first reflected signal. The second branch pulse signal branched from the cable failure position detector 200 and injected into the second injection position N2 on the right side of the pulse signal rejection filter 150 through the second branch line L2, The pulse signal directed to the filter 150 is removed and a pulse signal directed to a second fault location in a direction other than the pulse signal rejection filter 150 may be reflected at the second fault location and received as a second reflected signal .

The pulse signal rejection filter 150 for removing the pulse signal of a specific pulse frequency can be implemented using various known filters. For example, three kinds of microwave frequency rejection filters 150 using a single mode fiber delay line and a Mach-Zehnder and Fabry-Perot interferometer can be used.

In addition, various known pulse elimination filters 150 may be used. For example, the pulse elimination filter 150 may include a variable capacitor having a variable capacitance to remove a pulse signal having a desired pulse frequency according to a capacitance of the variable capacitor. can do.

And may include a variable capacitance adjusting unit (not shown) when the capacitance of the variable capacitor is varied according to the frequency of the pulse signal to be removed. For reference, the variable capacitor adjusts the capacitance by varying the facing area of the two electrode plates, and the variable capacitance adjuster adjusts the facing area of the two electrode plates. The variable capacitance adjuster may be implemented manually and may receive control input from the user, or it may be electronically implemented and automatically adjusted to a capacitance that can eliminate the pulse frequency. (Not shown) is connected to the cable fault location detector 200. When a pulse frequency is determined, the capacitance is adjusted to be a matched capacitance. And the cable fault location detector 200 adjusts it.

FIG. 8 is a block diagram of a cable fault position detector for detecting a cable fault position according to an embodiment of the present invention. FIG. 9 is a detailed block diagram of a reflected signal correction unit of a cable fault position detector according to an embodiment of the present invention. FIG. 10 is a diagram illustrating a state where a reflection signal is switched to an attenuator according to an embodiment of the present invention, and FIG. 11 is a diagram illustrating a state where a reflection signal is switched to an amplifier according to an embodiment of the present invention.

The cable fault location detector 200 of the present invention branches a pulse signal having a set transmission frequency and injects the pulse signal into a cable to detect and analyze a reflection signal reflected at a fault location of the cable to detect a fault location of the cable. The cable fault location detector 200 includes a pulse signal generator 210, a pulse signal splitter 220, a pulse signal transmitter 230, a reflection signal receiver 240, a reflection signal corrector 250, And a failure location determination unit 260. [

The pulse signal generating unit 210 generates a pulse signal to be injected into the cable. The pulse signal generation unit 210 includes a pulse frequency determination module (not shown) for determining the frequency of the pulse signal, a waveform generator for generating a pulse signal having a pulse frequency input through the pulse frequency determination module, A digital-to-analog converter for converting the generated pulse signal into an analog signal, and an output variable amplification module (not shown) for amplifying the converted signal.

The pulse signal branching unit 220 branches the pulse attenuation signal attenuated by the attenuator 252 into a first branch pulse signal and a second branch pulse signal. For the method of branching the pulse signal, various known branching methods for branching the signal may be used.

The pulse signal transmitting unit 230 injects the first branching pulse signal into a cable connected to one side of the pulse elimination filter and injects the second branching pulse signal into a cable connected to the other side of the pulse elimination filter. The pulse signal transmission unit 230 injects a first branch pulse signal through a first branch line L1 to a cable connected to one side of the pulse signal rejection filter and transmits the first branch pulse signal through a second separation line to a cable connected to the other side of the pulse signal rejection filter The second branch pulse signal is injected.

In the pulse signal injection, the first branch pulse signal and the second branch pulse signal may be respectively injected into the cable using an inductive coupler. Such inductive couplers may be of various known types of inductive couplers.

The reflection signal receiving unit 240 receives the reflected signal reflected from the failure position of the cable, removes the noise, processes the signal, and outputs the signal. When the pulse signal is transmitted after a predetermined time passes after the pulse signal is transmitted, the signal input to the reflection signal receiver 240 receives only the signal reflected at the failure position by the pulse signal elimination filter inserted in the cable. That is, the reflection signal receiving unit 240 receives the first reflection signal reflected from the first defect position from the first branch line L1 and similarly reflects from the second defect position from the second branch line L2 It is possible to receive the second reflected signal coming.

For example, if a cable is used as a transmit / receive cable with an operating frequency (power frequency) of 60Hz and a pulse signal of 300Hz is used to detect a fault in the cable, the pulse reject filter will pass the operating frequency of 60Hz, Remove the pulse signal. Therefore, as shown in FIG. 7, among the 300-Hz first branch pulse signals branched at the fault position detector and injected into the first injection position N1 on the left side of the pulse signal rejection filter through the first branch line L1, The pulse signal directed to the signal rejection filter is removed and the pulse signal directed to the first defect location in a direction other than the pulse rejection filter is reflected at the first defect location and received as the first reflected signal. Similarly, a pulse signal branched from the failure position detector and directed to the pulse signal rejection filter is removed from the second branch pulse signal injected to the second injection position on the right side of the pulse signal rejection filter through the second branch line, A pulse signal directed to a second defect location in a different direction may be reflected at the second defect location and received as a second reflected signal.

The failure location determination unit 260 receives the first branch pulse signal and the second branch pulse signal transmitted through the cable. Then, it compares the reflection signal reflected from the failure position of the cable and determines the failure position. Measure the time difference between the transmitted pulse signal and the reflected signal and measure the distance to the fault location. As shown in FIG. 3, can be obtained by using the transmission time when the pulse signal is transmitted from the cable and the time t from when the reflection signal is received.

[Formula 1]

R = (C x t1) / 2

That is, as described in the above-mentioned [Expression 1], the time t1 from when the pulse signal is transmitted to when the reflected signal is received is multiplied by C, which is the luminous flux (3 x 10 ⁸ m / s) 2, the distance R to the obstacle position can be calculated.

In addition, the failure location determination unit 260 can determine the failure mode of the cable using the shape of the received reflection signal according to the type of the received reflection signal. This is because the shape of the reflected signal differs depending on the failure mode of the fault location. For example, as shown in FIG. 4, when the received reflection signal has the same form as the transmitted pulse signal, it is determined that the fault location is open circuit. Further, when the received reflection signal has a reverse form of the transmitted pulse signal, it is determined that the fault location is short-circuited.

For reference, when the failure position of the first branch line L1 is grasped, the failure position determination unit 260 determines the failure position of the first branch line by using the first reflection signal, The failure location of the second branch line is determined by using the second reflection signal.

On the other hand, the reflected signal received through the reflected signal receiving unit 240 is received as a reflected signal with a high signal intensity, so that the waveform tends to be distorted. In this case, an error may occur in the determination of the failure position in the failure position determination unit 260. Conversely, when the intensity of the reflected signal is weak, it may be difficult to detect the fault position.

In order to solve such a problem, the present invention includes a reflection signal correction unit 250 between the reflection signal reception unit 240 and the failure position determination unit 260.

The reflected signal correcting unit 250 attenuates or amplifies the reflected signal according to the intensity of the reflected signal output from the reflected signal receiving unit 240 and outputs the corrected signal as a corrected signal. The reflection signal correction unit 250 may include an attenuator 252, a damping ratio adjustment module 255, an amplifier 253, a signal intensity measurement module 254, and a switching module 251.

For reference, the drawings and the detailed description below show an example of correcting a single reflected signal, for example, a first reflected signal, but this is only an illustrative example for the sake of understanding. Therefore, the present invention will be similarly applied to the case where the first and second reflection signals are subjected to correction processing on the first and second reflection signals, respectively, and are provided to the failure position determination unit 260.

The attenuator 252 attenuates the amplitude of the reflection signal output from the reflection signal receiver 240 and outputs the attenuated signal to the failure position determiner 260. The attenuator 252 is composed of a resistance network. Since the amplitude is small and the signal waveform is not deformed, the input / output impedances of the attenuator 252 are all matched with the characteristic impedance of the transmission line. The present invention configures the attenuator 252 as a variable resistor.

The attenuator 252 should have a damping ratio that represents the ratio of the attenuated signal waveform in the original signal waveform. The present invention can be implemented by providing a separate damping ratio adjustment module 255 to adjust the resistance value of the variable resistor in the attenuator 252 .

The damping ratio adjustment module 255 adjusts the resistance value of the variable resistor to have a damping ratio in proportion to the intensity of the reflected signal. Therefore, the greater the intensity of the received reflected signal, the more the attenuation increases and the distortion size can be minimized.

For example, when the intensity of the reflected signal has a second damping ratio when the intensity of the reflected signal is a second intensity, when the intensity of the reflected signal has a third intensity higher than the second intensity, The resistance value of the resistor is adjusted. On the other hand, if the intensity of the reflected signal has a first magnitude smaller than the second magnitude, the resistance value of the variable resistor is adjusted to have a first damping ratio that is smaller than the second damping ratio.

The amplifier 253 is disposed in parallel with the attenuator 252 and increases the amplitude of the reflection signal output from the reflection signal receiver 240 and outputs the amplified signal. An amplifier 253 such as an OP amplifier may be used.

The reflected signal strength measurement module 254 measures the intensity of the reflected signal output from the reflection signal receiver 240.

The switching module 251 switches the reflection signal output from the reflection signal receiver 240 to the attenuator 252 or outputs the reflection signal output from the reflection signal receiver 240 to the amplifier 253 ). When the intensity of the reflected signal is greater than or equal to a preset switching reference signal, the switching module 251 switches to the attenuator 252 to attenuate the signal as shown in FIG. Therefore, in the case of a reflected signal received at a nearby fault location, the reflected signal is strong, so that it is switched to the attenuator 252 to attenuate the reflected signal through the attenuator 252, thereby minimizing the distortion of the received reflected signal.

Conversely, when the intensity of the reflected signal is smaller than the switching reference signal, the switching module 251 switches to the amplifier 253 as shown in FIG. 11 to be amplified and adjusted. In the case of a reflected signal received at a distant failure position, since the signal intensity is small, the signal is amplified through the amplifier 253 by switching to the amplifier 253 so that accurate fault position detection is performed using the received reflected signal Respectively.

12 (a) is a graph showing a measurement graph of a reflection signal measured before being output from the reflection signal receiver 240 and corrected, and FIG. 12 (b) 252) of the reflection signal. It can be seen that the tilt distortion is improved as shown in FIG. 12 (b) through attenuation correction through the attenuator 252.

The embodiments of the present invention described above are selected and presented in order to facilitate the understanding of those skilled in the art from a variety of possible examples. The technical idea of the present invention is not necessarily limited to or limited to these embodiments Various changes, modifications, and other equivalent embodiments are possible without departing from the spirit of the present invention.

210: Pulse signal generation unit 200: Pulse signal generation unit
230: Pulse signal transmitter 240: Reflected signal receiver
250: reflection signal correction unit 251: switching module
252: Attenuator 253: Amplifier
254: Signal strength measurement module 255: Damping ratio adjustment module

Claims (6)

A cable fault position detector for detecting a failure position of a cable by detecting and analyzing a reflection signal reflected at a fault position of the cable by branching a pulse signal having a set transmission frequency and injecting the pulse signal into the cable; And
A pulse signal rejection filter inserted into a cable between two points where a branched pulse signal is input to remove the pulse signal;
/ RTI >
The cable fault location detector comprises:
A pulse signal generator for generating a pulse signal to be injected into the cable; A pulse signal branching unit for branching the pulse signal generated by the pulse signal generating unit to a first branch pulse signal and a second branch pulse signal; A pulse signal transmitter for injecting the first branch pulse signal into a cable connected to one side of the pulse signal rejection filter and injecting the second branch pulse signal into a cable connected to the other side of the pulse signal rejection filter; A reflection signal receiving unit for receiving a reflected signal reflected from a failure position of the cable to remove noise, processing the signal, and outputting the signal; A reflected signal correcting unit for attenuating or amplifying the reflected signal according to the intensity of the reflected signal output from the reflected signal receiving unit and outputting the corrected signal as a corrected signal; And a fault location determination unit for comparing a pulse signal transmitted to the cable with a correction signal corrected through the reflection signal correction unit to determine a fault location,
Wherein the reflection signal correction unit comprises:
An attenuator for attenuating and outputting the amplitude of the reflection signal output from the reflection signal receiver and implemented as a variable resistor; An amplifier for increasing the amplitude of the reflection signal output from the reflection signal receiver; A switching module for switching the reflection signal output from the reflection signal receiver to one of the attenuator and the amplifier and transmitting the switching signal; A reflected signal intensity measuring module for measuring the intensity of the reflected signal output from the reflected signal receiver; And a damping ratio adjustment module for adjusting a resistance value of the variable resistor to have a damping ratio in proportion to the intensity of the reflected signal,
Wherein the switching module switches the reflection signal output from the reflection signal receiver to the attenuator or switches the reflection signal output from the reflection signal receiver to the amplifier according to the intensity of the reflection signal, A device for detecting a cable fault location through compensation.
delete delete The switching power supply according to claim 1,
Wherein the switching signal is switched to the attenuator when the intensity of the reflected signal is equal to or greater than a predetermined switching reference signal and is switched to the amplifier when the intensity of the reflected signal is smaller than the switching reference signal, .
delete delete

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