Device for quickly judging cable fault point

Abstract

The invention belongs to the field of cable fault detection, and relates to a cable fault point rapid judgment device which comprises a transmitter and a receiver, the transmitter comprises an inverter transformer, a voltage-doubler rectifier, a time relay and a battery, the inverter transformer boosts the battery to 480V alternating voltage, the voltage is boosted to 1000V direct-current high-frequency voltage through the voltage-doubler rectifier, the time relay is connected with the time relay, and the time relay is connected with the time relay. The time relay controls signal emission, and the receiver comprises a resistor, a capacitor, a change-over switch, a triode, an ampere meter and a detection rod. When a cable fault is detected, the 1000V direct-current voltage of the transmitter is connected into a cable fault phase, a changing magnetic field is generated in the cable fault phase under the action of electromagnetic induction, the changing magnetic field can generate electricity under the action of the transmitter, and when the cable fault is detected by using the detection rod, the change condition of an ampere meter is observed, so that a cable fault point can be found.

Description

Technical Field

[0001] The invention belongs to the field of cable fault detection and relates to a device for quickly judging a cable fault point. Background Art

[0002] With the continuous development of social economy, my country's urban power grid is developing more and more rapidly. The rapid development of power grid has also promoted the rapid development of power cables. As an important power transmission equipment, power cables are widely used in industrial and residential power supply and distribution systems for their convenient laying, regional beautification and good insulation performance. It has become a trend to replace overhead lines in production and life.

[0003] As people's demand for electricity is increasing, while paying attention to the quality of electricity use, they are also paying more attention to the safety of electricity use. At present, distribution network cable failures occur from time to time, which has a great impact on people's lives and work. Due to the high cost of cable fault detection vehicles, cable fault detection vehicles have not been configured for each power supply service center. When a distribution network cable failure occurs, the fault point of the cable cannot be located in the first time. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a device for quickly determining cable fault points which is simple to operate and convenient to display.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] The present invention provides a device for quickly judging a cable fault point, comprising: a transmitter and a receiver, wherein the transmitter comprises an inverter transformer, a voltage doubler rectifier, a time relay, and a battery, wherein the inverter transformer boosts the battery voltage to a 480V AC voltage, and then the voltage is increased to a 1000V DC high-frequency voltage through the voltage doubler rectifier, and the time relay controls the signal transmission, and when detecting a cable fault, the 1000V DC voltage of the transmitter is connected to the cable fault phase, and a changing magnetic field is generated in the cable fault phase under the action of electromagnetic induction; the receiver comprises a resistor, a capacitor, The conversion switch, transistor, ammeter, detection rod, resistor and capacitor are used for filtering, and the current signal generated by electromagnetic induction is amplified by transistor Q1 and transistor Q2. The detection rod is connected to the ammeter, and the signal is displayed on the ammeter display. The transistor Q3 is used for ungrounded fault detection. When the ungrounded situation occurs, the transistor Q3 will amplify the current and conduct, and the ammeter needle will suddenly change greatly. Under the action of the transmitter, the changing magnetic field will generate electricity. When using the detection rod to detect cable faults, the cable fault point can be found by observing the changes in the ammeter.

[0007] Furthermore, one side of the inverter transformer of the transmitter is connected to a voltage doubler rectifier composed of high-voltage and low-voltage rectifier tubes and high-voltage capacitors, and the voltage doubler rectifier is connected to a time relay, the time relay is connected to a time controller, and the amplifier circuit on the other side of the inverter transformer of the transmitter is connected to the time controller.

[0008] Further, the transmitter includes resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, resistor R7, resistor R8, capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6, capacitor C7, capacitor C10, capacitor C11, high-voltage capacitor C12, diode D1, high-voltage and low-voltage rectifier D2, transistor BG1, transistor BG2, transistor BG3, transistor BG4, inverter transformer, and relay; connector No. 1 of the inverter transformer is respectively connected to the collector of transistor BG4, the positive electrode of capacitor C10, The emitter of transistor BG2, the positive electrode of capacitor C1, the positive electrode of capacitor C2, resistor R1, the first power supply and the second power supply, the No. 2 connector of the inverter transformer are respectively connected to resistor R2, the negative electrode of capacitor C4, and resistor R5 and grounded, the other end of resistor R5 is respectively connected to resistor R7 and the emitter of transistor BG4, the No. 3 connector of the inverter transformer is connected to the other end of resistor R7, the base of transistor BG4 is connected to the negative electrode of capacitor C3, the positive electrode of capacitor C3 is connected to the emitter of transistor BG3, the base of transistor BG3 is respectively connected to the positive electrode of capacitor C4 and the other end of resistor R2, The collector of transistor BG3 is connected to the positive electrode of capacitor C6, the negative electrode of capacitor C6 is respectively connected to resistor R3, resistor R4, and the emitter of transistor BG1, the other end of resistor R3 is connected to the negative electrode of capacitor C7, the positive electrode of capacitor C7 is connected to the other end of resistor R4 and the base of transistor BG2, the collector of transistor BG2 is connected to resistor R8, the collector of transistor BG1 is respectively connected to the negative electrode of high-voltage and low-voltage rectifier tube D2, the relay, the negative electrode of capacitor C1, the negative electrode of capacitor C2 and grounded, the base of transistor BG1 is respectively connected to the other end of resistor R1 and the negative electrode of capacitor C5, The positive electrode of capacitor C5 is connected to resistor R6, the other end of resistor R6 is respectively connected to the other end of resistor R8, the negative electrode of capacitor C10, the positive electrode of high-voltage and low-voltage rectifier tube D2, and the other end of the relay, the common end of the relay contact is connected to the signal network HV+, the normally closed end of the relay contact is connected to the high-voltage capacitor C12, the other end of the high-voltage capacitor C12 is respectively connected to capacitor C11, connector No. 5 of the inverter transformer, and signal network HV-, the normally open end of the relay contact is respectively connected to the other end of capacitor C11 and the negative electrode of diode D1, and the positive electrode of diode D1 is connected to connector No. 4 of the inverter transformer.

[0009] Further, the receiver includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a diode D1, a diode D2, a transistor Q1, a transistor Q2, a transistor Q3, and an inductor L1; the emitter of the transistor Q3 is respectively connected to the positive electrode of the capacitor C3, the capacitor C6, and the ungrounded conversion switch The base of transistor Q3 is respectively connected to the positive electrode of capacitor C10 and resistor R12, the collector of transistor Q3 is respectively connected to the other end of resistor R12, the positive terminal, and the grounded switching switch, the negative electrode of capacitor C3 is respectively connected to the other end of capacitor C6, the negative terminal, and the ungrounded switching switch, the other end of capacitor C10 is respectively connected to resistor R6, capacitor C8, and the grounded switching switch, the other end of resistor R6 is respectively connected to the other end of capacitor C8, capacitor C1, resistor R11, and the collector of transistor Q2, the other end of resistor R11 is respectively connected to the positive electrode of capacitor C12, the positive electrode of capacitor C13, resistor R8, resistor R13, and the positive terminal, the negative electrode of capacitor C12 is respectively connected to the negative electrode of capacitor C13, the negative electrode of capacitor C14, and capacitor The cathode of C15, the anode and the cathode end of the diode D2, the other end of the resistor R13 are respectively connected to the anode of the capacitor C14, the anode of the capacitor C15, the resistor R9, the resistor R10, and the resistor R14, the cathode of the diode D1 is respectively connected to the cathode of the diode D2 and the capacitor C7, the other end of the capacitor C7 is respectively connected to the base of the transistor Q1, the other end of the resistor R10, and the resistor R4, the collector of the transistor Q1 is connected to one end of the inductor L1, the other end of the inductor L1 is respectively connected to the other end of the resistor R9 and the anode of the capacitor C9, the cathode of the capacitor C9 is respectively connected to the other end of the resistor R8, the base of the transistor Q2, the capacitor C2, and the resistor R3, the other end of the capacitor C1 is respectively connected to the ungrounded conversion switch, the emitter of the transistor Q2, The other end of capacitor C2, the other end of resistor R3, the emitter of transistor Q1, resistor R1, resistor R2, the negative electrode of capacitor C5, the negative electrode of capacitor C11, capacitor C16, the positive electrode of diode D2, and the ground end; the other end of resistor R4 is respectively connected to the other end of resistor R1 and the positive electrode of capacitor C4; the negative electrode of capacitor C4 is respectively connected to resistor R5 and an ungrounded test coil; the other end of resistor R14 is respectively connected to the positive electrode of diode D1, the other end of capacitor C16, and an ungrounded test coil; the other end of resistor R5 is respectively connected to the other end of resistor R2, the positive electrode of capacitor C5, resistor R7, and the strong end; the other end of resistor R7 is respectively connected to the positive electrode of capacitor C11, resistor R15 and the weak end; the other end of resistor R15 is connected to the weak end.

[0010] Furthermore, the voltages of the first power supply and the second power supply in the transmitter are both 6V.

[0011] The advantages and positive effects of the present invention are:

[0012] When the present invention detects cable faults, the 1000V DC voltage of the transmitter is connected to the cable fault phase. Under the action of electromagnetic induction, a changing magnetic field is generated in the cable fault phase. Under the action of the transmitter, the changing magnetic field generates electricity. When the cable fault is detected with a detection rod, the cable fault point can be found by observing the changes in the ammeter. The present invention has low cost, small size, and is easy to carry. When detecting low-voltage cables, the success rate can reach more than 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Circuit diagram of the transmitter for this application;

[0014] Figure 2 A circuit diagram of the receiver for this application;

[0015] Figure 3 A physical picture of the launcher for this application;

[0016] Figure 4 A physical picture of the receiver for this application;

[0017] Figure 5 This is a physical picture of the detection rod for this application. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below through specific examples. The following examples are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0019] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0020] like Figure 1-Figure 5As shown, the present invention provides a device for quickly determining a cable fault point, comprising: a transmitter and a receiver. The transmitter and the receiver are used together to detect and locate the fault point of the cable.

[0021] The transmitter includes an inverter transformer, a voltage doubler rectifier, a time relay, and a battery. The inverter transformer boosts the battery voltage to 480V AC, and then the voltage is increased to 1000V DC high-frequency voltage through the voltage doubler rectifier. The time relay controls the signal transmission. When detecting a cable fault, the 1000V DC voltage of the transmitter is connected to the faulty phase of the cable. Under the action of electromagnetic induction, a changing magnetic field is generated in the faulty phase of the cable.

[0022] like Figure 1 As shown, one side of the transmitter's inverter transformer is connected to a voltage doubler rectifier composed of high-voltage and low-voltage rectifier tubes and high-voltage capacitors, and the voltage doubler rectifier is connected to a time relay, and the time relay is connected to a time controller. The amplifier circuit on the other side of the transmitter's inverter transformer is connected to the time controller.

[0023] like Figure 1As shown, the transmitter includes resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, resistor R7, resistor R8, capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6, capacitor C7, capacitor C10, capacitor C11, high-voltage capacitor C12, diode D1, high-voltage and low-voltage rectifier D2, transistor BG1, transistor BG2, transistor BG3, transistor BG4, inverter transformer, and relay; connector No. 1 of the inverter transformer is connected to the collector of transistor BG4, the positive electrode of capacitor C10, and the transistor The emitter of BG2, the positive electrode of capacitor C1, the positive electrode of capacitor C2, resistor R1, the first power supply and the second power supply, connector No. 2 of the inverter transformer are respectively connected to resistor R2, the negative electrode of capacitor C4, resistor R5 and grounded, the other end of resistor R5 is respectively connected to resistor R7 and the emitter of transistor BG4, connector No. 3 of the inverter transformer is connected to the other end of resistor R7, the base of transistor BG4 is connected to the negative electrode of capacitor C3, the positive electrode of capacitor C3 is connected to the emitter of transistor BG3, the base of transistor BG3 is respectively connected to the positive electrode of capacitor C4 and the other end of resistor R2, the The collector of transistor BG3 is connected to the positive electrode of capacitor C6, the negative electrode of capacitor C6 is respectively connected to resistor R3, resistor R4, and the emitter of transistor BG1, the other end of resistor R3 is connected to the negative electrode of capacitor C7, the positive electrode of capacitor C7 is connected to the other end of resistor R4 and the base of transistor BG2, the collector of transistor BG2 is connected to resistor R8, the collector of transistor BG1 is respectively connected to the negative electrode of high-voltage and low-voltage rectifier tube D2, the relay, the negative electrode of capacitor C1, the negative electrode of capacitor C2 and grounded, the base of transistor BG1 is respectively connected to the other end of resistor R1 and the negative electrode of capacitor C5, The positive electrode of capacitor C5 is connected to resistor R6, and the other end of resistor R6 is respectively connected to the other end of resistor R8, the negative electrode of capacitor C10, the positive electrode of high-voltage and low-voltage rectifier tube D2, and the other end of the relay. The common end of the relay contact is connected to the signal network HV+, the normally closed end of the relay contact is connected to the high-voltage capacitor C12, and the other end of the high-voltage capacitor C12 is respectively connected to capacitor C11, the No. 5 connector of the inverter transformer, and the signal network HV-. The normally open end of the relay contact is respectively connected to the other end of capacitor C11 and the negative electrode of diode D1, and the positive electrode of diode D1 is connected to the No. 4 connector of the inverter transformer. Wherein, the voltages of the first power supply and the second power supply in the transmitter are both 6V.

[0024] The receiver includes resistors, capacitors, conversion switches, transistors, ammeters, and detection rods. Resistors and capacitors are used for filtering, and the current signal generated by electromagnetic induction is amplified by transistors Q1 and Q2. The detection rod is connected to the ammeter, and the signal status is displayed on the ammeter display. Transistor Q3 is used for ungrounded fault detection. When the ungrounded situation occurs, transistor Q3 will amplify the current and turn on, and the ammeter needle will suddenly change greatly. Under the action of the transmitter, the changing magnetic field will generate electricity. When using the detection rod to detect cable faults, the cable fault point can be found by observing the changes in the ammeter.

[0025] like Figure 2As shown, the receiver includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a diode D1, a diode D2, a transistor Q1, a transistor Q2, a transistor Q3, and an inductor L1; the emitter of the transistor Q3 is respectively connected to the positive electrode of the capacitor C3, the capacitor C6, and the ungrounded conversion switch, and the transistor The base of transistor Q3 is respectively connected to the positive electrode of capacitor C10 and resistor R12, the collector of transistor Q3 is respectively connected to the other end of resistor R12, the positive terminal, and the grounded switching switch, the negative electrode of capacitor C3 is respectively connected to the other end of capacitor C6, the negative terminal, and the ungrounded switching switch, the other end of capacitor C10 is respectively connected to resistor R6, capacitor C8, and the grounded switching switch, the other end of resistor R6 is respectively connected to the other end of capacitor C8, capacitor C1, resistor R11, and the collector of transistor Q2, the other end of resistor R11 is respectively connected to the positive electrode of capacitor C12, the positive electrode of capacitor C13, resistor R8, resistor R13, and the positive terminal, the negative electrode of capacitor C12 is respectively connected to the negative electrode of capacitor C13, the negative electrode of capacitor C14, and capacitor C1 5, the positive electrode and the negative terminal of the diode D2, the other end of the resistor R13 is respectively connected to the positive electrode of the capacitor C14, the positive electrode of the capacitor C15, the resistor R9, the resistor R10, and the resistor R14, the negative electrode of the diode D1 is respectively connected to the negative electrode of the diode D2 and the capacitor C7, the other end of the capacitor C7 is respectively connected to the base of the transistor Q1, the other end of the resistor R10, and the resistor R4, the collector of the transistor Q1 is connected to one end of the inductor L1, the other end of the inductor L1 is respectively connected to the other end of the resistor R9 and the positive electrode of the capacitor C9, the negative electrode of the capacitor C9 is respectively connected to the other end of the resistor R8, the base of the transistor Q2, the capacitor C2, and the resistor R3, the other end of the capacitor C1 is respectively connected to the ungrounded conversion switch, the emitter of the transistor Q2, and the The other end of capacitor C2, the other end of resistor R3, the emitter of transistor Q1, resistor R1, resistor R2, the negative electrode of capacitor C5, the negative electrode of capacitor C11, capacitor C16, the positive electrode of diode D2, and the ground end; the other end of resistor R4 is respectively connected to the other end of resistor R1 and the positive electrode of capacitor C4; the negative electrode of capacitor C4 is respectively connected to resistor R5 and an ungrounded test coil; the other end of resistor R14 is respectively connected to the positive electrode of diode D1, the other end of capacitor C16, and an ungrounded test coil; the other end of resistor R5 is respectively connected to the other end of resistor R2, the positive electrode of capacitor C5, resistor R7, and the strong end; the other end of resistor R7 is respectively connected to the positive electrode of capacitor C11, resistor R15 and the weak end; the other end of resistor R15 is connected to the weak end.

[0026] The working principle of this device is:

[0027] (1) Ground fault: Connect the positive and negative poles of the receiver to the ground. During the detection of the cable path with the probe rod, the current will change at any time. Before reaching the fault point, the ammeter needle gradually swings to the decimal point. When passing the fault point, the ammeter needle swings to the large point. Then, the detection is carried out in the return direction. When the ammeter needle does not swing, it is the fault point.

[0028] (2) Ungrounded fault: Connect the positive and negative poles of the receiver to the ground. When using the probe to detect the cable path, the current will change at any time. When the ammeter needle suddenly increases, then suddenly decreases, and does not change again, it is the fault point. If the ammeter needle does not swing much during the detection process, then the fault point is at the source of the cable (starting point or end point).

[0029] The device has been completed and put into use. Its advantages are low cost, small size, and easy to carry. When detecting low-voltage cables, the success rate can reach more than 95%.

[0030] The above description is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept, which all belong to the protection scope of the present invention.

Claims

1. A device for quickly determining cable fault points, characterized in that: include: Transmitter and receiver, The transmitter includes an inverter transformer, a voltage doubler rectifier, a time relay, and a battery. The inverter transformer boosts the battery voltage to 480V AC voltage, and then the voltage is increased to 1000V DC high-frequency voltage through the voltage doubler rectifier. The time relay controls the signal transmission. When detecting a cable fault, the 1000V DC voltage of the transmitter is connected to the cable fault phase. Under the action of electromagnetic induction, a changing magnetic field is generated in the cable fault phase. The receiver includes resistors, capacitors, conversion switches, transistors, ammeters, and detection rods. The resistors and capacitors are used for filtering, and the current signal generated by electromagnetic induction is amplified by transistors Q1 and Q2. The detection rod is connected to the ammeter, and the signal status is displayed on the ammeter display screen. The transistor Q3 is used for ungrounded fault detection. When the ungrounded situation occurs, the transistor Q3 will amplify the current and turn on, and the ammeter needle will suddenly change greatly. Under the action of the transmitter, the changing magnetic field will generate electricity. When using the detection rod to detect cable faults, the cable fault point can be found by observing the changes in the ammeter.

2. The device for quickly determining cable fault points according to claim 1 is characterized in that: One side of the inverter transformer of the transmitter is connected to a voltage doubler rectifier composed of high-voltage and low-voltage rectifier tubes and high-voltage capacitors, and the voltage doubler rectifier is connected to a time relay, and the time relay is connected to a time controller. The amplifier circuit on the other side of the inverter transformer of the transmitter is connected to the time controller.

3. The device for quickly determining cable fault points according to claim 2 is characterized in that: The transmitter includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C10, a capacitor C11, a high-voltage capacitor C12, a diode D1, a high-voltage and low-voltage rectifier D2, a transistor BG1, a transistor BG2, a transistor BG3, a transistor BG4, an inverter transformer, and a relay; connector No. 1 of the inverter transformer is respectively connected to the collector of the transistor BG4, the positive electrode of the capacitor C10, and the transistor B The emitter of G2, the positive electrode of capacitor C1, the positive electrode of capacitor C2, resistor R1, the first power supply and the second power supply, the No. 2 connector of the inverter transformer is respectively connected to the resistor R2, the negative electrode of capacitor C4, and the resistor R5 and grounded, the other end of the resistor R5 is respectively connected to the resistor R7 and the emitter of transistor BG4, the No. 3 connector of the inverter transformer is connected to the other end of the resistor R7, the base of transistor BG4 is connected to the negative electrode of capacitor C3, the positive electrode of capacitor C3 is connected to the emitter of transistor BG3, the base of transistor BG3 is respectively connected to the positive electrode of capacitor C4 and the other end of resistor R2, the The collector of BG3 is connected to the positive electrode of capacitor C6, the negative electrode of capacitor C6 is respectively connected to resistor R3, resistor R4, and the emitter of transistor BG1, the other end of resistor R3 is connected to the negative electrode of capacitor C7, the positive electrode of capacitor C7 is connected to the other end of resistor R4 and the base of transistor BG2, the collector of transistor BG2 is connected to resistor R8, the collector of transistor BG1 is respectively connected to the negative electrode of high-voltage and low-voltage rectifier tube D2, the relay, the negative electrode of capacitor C1, the negative electrode of capacitor C2 and grounded, the base of transistor BG1 is respectively connected to the other end of resistor R1 and the negative electrode of capacitor C5, capacitor The positive electrode of C5 is connected to resistor R6, the other end of resistor R6 is respectively connected to the other end of resistor R8, the negative electrode of capacitor C10, the positive electrode of high-voltage and low-voltage rectifier tube D2, and the other end of the relay, the common end of the relay contact is connected to the signal network HV+, the normally closed end of the relay contact is connected to the high-voltage capacitor C12, the other end of the high-voltage capacitor C12 is respectively connected to capacitor C11, connector No. 5 of the inverter transformer, and signal network HV-, the normally open end of the relay contact is respectively connected to the other end of capacitor C11 and the negative electrode of diode D1, and the positive electrode of diode D1 is connected to connector No. 4 of the inverter transformer.

4. The device for quickly determining cable fault points according to claim 1 is characterized in that: The receiver includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a diode D1, a diode D2, a transistor Q1, a transistor Q2, a transistor Q3, and an inductor L1; the emitter of the transistor Q3 is respectively connected to the positive electrode of the capacitor C3, the capacitor C6, and the ungrounded conversion switch, and the transistor The base of the transistor Q3 is respectively connected to the positive electrode of the capacitor C10 and the resistor R12, the collector of the transistor Q3 is respectively connected to the other end of the resistor R12, the positive terminal, and the grounded conversion switch, the negative electrode of the capacitor C3 is respectively connected to the other end of the capacitor C6, the negative terminal, and the ungrounded conversion switch, the other end of the capacitor C10 is respectively connected to the resistor R6, the capacitor C8, and the grounded conversion switch, the other end of the resistor R6 is respectively connected to the other end of the capacitor C8, the capacitor C1, the resistor R11, and the collector of the transistor Q2, the other end of the resistor R11 is respectively connected to the positive electrode of the capacitor C12, the positive electrode of the capacitor C13, the resistor R8, the resistor R13, and the positive terminal, the negative electrode of the capacitor C12 is respectively connected to the negative electrode of the capacitor C13, the negative electrode of the capacitor C14, and the capacitor C15 The cathode of the diode D1 is connected to the anode and cathode of the diode D2, the other end of the resistor R13 is connected to the anode of the capacitor C14, the anode of the capacitor C15, the resistor R9, the resistor R10, and the resistor R14 respectively, the cathode of the diode D1 is connected to the cathode of the diode D2 and the capacitor C7 respectively, the other end of the capacitor C7 is connected to the base of the transistor Q1, the other end of the resistor R10, and the resistor R4 respectively, the collector of the transistor Q1 is connected to one end of the inductor L1, the other end of the inductor L1 is connected to the other end of the resistor R9 and the anode of the capacitor C9 respectively, the cathode of the capacitor C9 is connected to the other end of the resistor R8, the base of the transistor Q2, the capacitor C2, and the resistor R3 respectively, the other end of the capacitor C1 is connected to the ungrounded conversion switch, the emitter of the transistor Q2, and the capacitor The other end of C2, the other end of resistor R3, the emitter of transistor Q1, resistor R1, resistor R2, the negative electrode of capacitor C5, the negative electrode of capacitor C11, capacitor C16, the positive electrode of diode D2, and the ground end; the other end of resistor R4 is respectively connected to the other end of resistor R1 and the positive electrode of capacitor C4; the negative electrode of capacitor C4 is respectively connected to resistor R5 and an ungrounded test coil; the other end of resistor R14 is respectively connected to the positive electrode of diode D1, the other end of capacitor C16, and an ungrounded test coil; the other end of resistor R5 is respectively connected to the other end of resistor R2, the positive electrode of capacitor C5, resistor R7, and the strong end; the other end of resistor R7 is respectively connected to the positive electrode of capacitor C11, resistor R15 and the weak end; the other end of resistor R15 is connected to the weak end.

5. The device for quickly determining cable fault points according to claim 3 is characterized in that: The voltages of the first power supply and the second power supply in the transmitter are both 6V.

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