A testing system and a testing device for a multi-core cable

Abstract

The present invention provides a test system and a test device for a multi-core cable. The test device includes a power supply circuit, a main control microprocessor, a human-computer interaction circuit, an alarm circuit, a serial-to-parallel drive circuit, a conduction / insulation resistance detection circuit, and a detection device communication circuit. Through the serial-to-parallel drive circuit, the core number channels can be infinitely expanded. The conduction / insulation resistance detection circuit can perform switching actions on the complex cable relationships between each wire during the test process, and then the main control microprocessor performs data processing and instruction control, so as to realize the conduction and insulation resistance tests of each core wire, making the measurement more convenient, greatly improving the test efficiency, having a stable working state, a simple circuit design, and intuitive test data output, and ensuring that the system can still perform test work without a host computer, thus filling the domestic and foreign market gaps.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-core cable testing, and more specifically, to a multi-core cable testing system and a testing device.

Background Art

[0002] Multi-core cables are commonly used for short-distance power transmission and data transmission. With the gradual improvement of the automation level of equipment, the usage rate of multi-core cables in large equipment such as ships, aircraft, satellites, spacecraft, and vehicles is gradually increasing. The number of cores in multi-core cables can reach several hundred, and the connection relationship between the cable cores is complex. Workers are prone to faults such as wrong soldering, short circuit, and missed soldering during the production process. Therefore, after the cable is manufactured, workers need to measure each wire one by one through an LCR testing device (an LCR tester is an electronic testing device used to measure the inductance L, capacitance C, and resistance R of electronic components), or use an insulation resistance tester to test the insulation resistance between two cores, that is, it is necessary to test the insulation resistance between core 1 and cores 2 to N respectively, and between core 2 and cores 1, 3 to N respectively.

[0003] These two types of tests will increase exponentially with the increase in the number of cable cores. Manual detection has problems such as a large workload, low efficiency, time-consuming, and laborious. Therefore, an automatic testing system is urgently needed to solve such problems to ensure the quality of products.

[0004] Currently, the testing technology for multi-core cables on the market mainly targets the commercial market and mainly has the following problems:

[0005] First, the number of core interfaces of cable testers is generally small, and the scalability is not strong, which cannot meet the growing cable testing needs.

[0006] Second, the insulation resistance test circuit of the testing system usually uses fixed insulation voltage test conditions, and the test voltage generally does not exceed 100V, and it is not well applicable to the insulation resistance test conditions of 500VAC for military cables.

[0007] Third, the use of non-calibrated special equipment during the testing process has a large error value for the accuracy of measurement data.

Summary of the Invention

[0008] In view of this, the technical problem to be solved by the present invention is to provide a multi-core cable testing system and its testing device, which can infinitely expand the number of cores that can be measured, can adapt to the testing of multi-core cables with various core numbers, thereby greatly improving the detection efficiency, and can achieve intelligent automation detection without a host computer, and can also manage and analyze the test results.

[0009] To achieve one of the foregoing objects of the invention, the technical solution adopted in the embodiments of the present invention is: A test system for a multi-core cable, comprising a test device, a conduction resistance tester, and an insulation resistance tester;

[0010] The test device includes a power supply circuit, a main control microprocessor, a human-computer interaction circuit, an alarm circuit, a serial-to-parallel drive circuit, a conduction / insulation resistance detection circuit, and a detection device communication circuit;

[0011] The power supply circuit supplies power to the main control microprocessor, the human-computer interaction circuit, the alarm circuit, the serial-to-parallel drive circuit, the conduction / insulation resistance detection circuit, and the detection device communication circuit respectively;

[0012] The main control microprocessor is used for data processing and instruction control of the test system, and is respectively connected to the human-computer interaction circuit, the alarm circuit, the serial-to-parallel drive circuit, the USB-to-serial circuit, and the detection device communication circuit; the serial-to-parallel drive circuit is also connected to the conduction / insulation resistance detection circuit;

[0013] The serial-to-parallel drive circuit is used for expanding the number of cable cores to be tested;

[0014] The conduction / insulation resistance detection circuit is used to perform switching actions on the connection relationships of each core wire in the circuit during the test process, and control each core wire to be in a conduction state or an insulation resistance detection state;

[0015] The conduction / insulation resistance detection circuit includes a conduction resistance tester terminal J1, an insulation resistance tester terminal J2, a first multi-core cable terminal J3, a second multi-core cable terminal J4, and a double-pole double-throw relay Ki, where i = 1, 2...n, and n is determined by the number of core wires to be tested; any double-pole double-throw relay Ki includes two power supply terminals, two normally open static contacts, two normally closed static contacts, and two moving contacts. The power supply terminals are connected to the power supply circuit, the two normally open static contacts are connected to the conduction resistance tester terminal J1, the two normally closed static contacts are connected to one end of the insulation resistance tester terminal J2, the other end of the insulation resistance tester terminal J2 is connected to a port of the conduction resistance tester J1, and the two moving contacts are respectively connected to the first multi-core cable terminal J3 and the second multi-core cable terminal J4.

[0016] The conduction resistance tester terminal J1 is connected to the conduction resistance tester, and the insulation resistance tester terminal J2 is connected to the insulation resistance tester.

[0017] To achieve the second object of the foregoing invention, the technical solution adopted in the embodiments of the present invention is as follows: A testing device for a multi-core cable, comprising a power supply circuit, a main control microprocessor, a human-computer interaction circuit, an alarm circuit, a serial-to-parallel driving circuit, a conduction / insulation resistance detection circuit, and a detection device communication circuit;

[0018] The power supply circuit supplies power to the main control microprocessor, the human-computer interaction circuit, the alarm circuit, the serial-to-parallel driving circuit, the conduction / insulation resistance detection circuit, and the detection device communication circuit respectively;

[0019] The main control microprocessor is used for data processing and instruction control of the test system, and is respectively connected to the human-computer interaction circuit, the alarm circuit, the serial-to-parallel driving circuit, the USB-to-serial circuit, and the detection device communication circuit; The serial-to-parallel driving circuit is also connected to the conduction / insulation resistance detection circuit;

[0020] The serial-to-parallel driving circuit is used for expanding the number of core wires of the test cable;

[0021] The conduction / insulation resistance detection circuit is used to perform switching actions on the connection relationships of each core wire in the circuit during the test process, and control each core wire to be in a conduction state or an insulation resistance detection state;

[0022] The conduction / insulation resistance detection circuit includes a conduction resistance tester connection terminal J1, an insulation resistance tester connection terminal J2, a first multi-core cable connection terminal J3, a second multi-core cable connection terminal J4, and a double-pole double-throw relay Ki, where i = 1, 2...n, and n is determined by the number of core wires to be tested; Any double-pole double-throw relay Ki includes two power supply connection terminals, two normally open static contacts, two normally closed static contacts, and two moving contacts. The power supply connection terminals are connected to the power supply circuit, the two normally open static contacts are connected to the conduction resistance tester connection terminal J1, the two normally closed static contacts are connected to one end of the insulation resistance tester connection terminal J2, the other end of the insulation resistance tester connection terminal J2 is connected to a port of the conduction resistance tester J1, and the two moving contacts are respectively connected to the first multi-core cable connection terminal J3 and the second multi-core cable connection terminal J4.

[0023] The advantages of the present invention are as follows: The test device of the present invention has a serial-to-parallel drive circuit and a conduction / insulation resistance detection circuit, enabling the infinite expansion of the core number channels. Moreover, due to the special structure of the conduction / insulation resistance detection circuit, each core wire is controlled by a double-pole double-throw relay. The double-pole double-throw relay can perform switching actions for the complex cable relationships between various wires during the test process, and then the main control microprocessor conducts data processing and instruction control, making the measurement more convenient and greatly improving the test efficiency. Additionally, the test device of the present invention also has a stable DC-to-DC buck voltage regulation circuit system. The test system of the present invention uses special testers, including a conduction resistance tester and an insulation resistance tester, making the test data more accurate; thus filling the gaps in the domestic and foreign markets. The circuit design is simple. The test system integrates a human-computer interaction circuit (such as buttons and display windows or touch screens, etc.), and the test data output is intuitive, ensuring that the system can still perform test work without a host computer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings in conjunction with embodiments.

[0025] Figure 1 It is a schematic structural diagram of the test system of the present invention.

[0026] Figure 2 It is a schematic structural diagram of the test device of the present invention.

[0027] Figure 3 It is a schematic structural diagram of the conduction / insulation resistance detection circuit of the present invention.

[0028] Figure 4 It is a schematic structural diagram of the serial-to-parallel drive circuit of the present invention.

[0029] Figure 5 It is another schematic structural diagram of the test system of the present invention.

[0030] Figure 6 It is a schematic structural diagram of the USB-to-serial port circuit of the present invention.

[0031] Figure 7 It is a schematic flow diagram of the test process of the test system of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] By providing a test system for multi-core cables and its test device in the embodiments of the present invention, the number of core wires that can be measured can be infinitely expanded, which can adapt to the tests of multi-core cables with various numbers of core wires, thus greatly improving the detection efficiency. Moreover, intelligent automatic detection can be achieved without a host computer, and at the same time, the test results can be managed and analyzed.

[0033] The technical solution in the embodiment of the present invention to solve the above problems has the following general idea: the core number channels can be infinitely expanded through the serial-to-parallel drive circuit. Through the special structure of the conduction / insulation resistance detection circuit, each core wire is controlled by a double-pole double-throw relay. Each double-pole double-throw relay can perform switching actions of complex cable relationships between various wires during the test process, and then the main control microprocessor performs data processing and instruction control, so as to realize the conduction and insulation resistance tests of each core wire, making the measurement more convenient and greatly improving the test efficiency. Moreover, the test device of the present invention also uses a DC-to-DC buck voltage regulator circuit to ensure the stable working state of the system. The test system of the present invention uses a dedicated tester, including a conduction resistance tester and an insulation resistance tester, making the test data more accurate. The circuit design is simple and concise. The test system integrates a human-computer interaction circuit (such as keys and display windows or touch screens, etc.), and the test data output is intuitive, which can ensure that the system can still perform test work without a host computer, thus filling the gaps in the domestic and foreign markets.

[0034] To better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific implementation manners.

[0035] Embodiment 1

[0036] Please refer to Figure 1 As shown, this embodiment provides a test system for multi-core cables, including a test device, a conduction resistance tester, and an insulation resistance tester.

[0037] The test device is used to test the state of each core wire of the multi-core cable for conduction resistance or insulation resistance.

[0038] Both the conduction resistance tester and the insulation resistance tester are dedicated test instruments. The system controls the test instruments to perform function detection through instructions, and the accuracy of the data is high.

[0039] As Figure 2 shown, the test device includes a power supply circuit, a main control microprocessor, a human-computer interaction circuit, an alarm circuit, a serial-to-parallel drive circuit, a conduction / insulation resistance detection circuit, and a detection device communication circuit.

[0040] The power supply circuit provides a constant current source, and supplies power to the main control microprocessor, the human-computer interaction circuit, the alarm circuit, the serial-to-parallel drive circuit, the conduction / insulation resistance detection circuit, and the detection device communication circuit respectively.

[0041] The power supply circuit includes a power input interface and a DC-to-DC buck voltage regulator circuit. The power input interface is used to input a DC power supply of 12V - 24V; the DC-to-DC buck voltage regulator circuit is used to convert the DC voltage of 12V - 24V into the voltages required for the normal operation of the USB-to-serial port circuit, the main control microprocessor, the human-computer interaction circuit, the alarm circuit, the serial-to-parallel driver circuit, the conduction / insulation resistance detection circuit, and the detection device communication circuit respectively.

[0042] The main control microprocessor is used for data processing and instruction control of the test system, and is respectively connected to the human-computer interaction circuit, the alarm circuit, the serial-to-parallel driver circuit, the USB-to-serial port circuit, and the detection device communication circuit; the serial-to-parallel driver circuit is also connected to the conduction / insulation resistance detection circuit.

[0043] The serial-to-parallel driver circuit is used for expanding the number of core wires of the test cable.

[0044] The conduction / insulation resistance detection circuit is used to perform switching actions on the connection relationships of each core wire in the circuit during the test process, and control each core wire to be in a conduction state or in an insulation resistance detection state.

[0045] The human-computer interaction circuit is used to receive operation instructions from the test personnel and display the main information of the intelligent sensor, facilitating the test personnel to observe the information.

[0046] The alarm circuit is mainly used for alarming when an abnormal state occurs during the automatic test process. The alarm circuit is an audible and visual alarm circuit.

[0047] All the above functional circuit modules of the test device are designed on the same double-sided patch circuit board. The manufacturing process can be as follows: First, through soldering techniques such as SMT, solder the electronic components of each circuit functional module onto the circuit board; finally, fix the circuit board to the corresponding housing.

[0048] Such as Figure 3As shown, the conduction / insulation resistance detection circuit includes a conduction resistance tester connection terminal J1, an insulation resistance tester connection terminal J2, a first multi-core cable connection terminal J3, a second multi-core cable connection terminal J4, and double-pole double-throw relays Ki, where i = 1, 2... n, and n is determined by the number of core wires to be measured; any double-pole double-throw relay Ki includes two power supply connection terminals, two normally open static contacts, two normally closed static contacts, and two moving contacts. The power supply connection terminals are connected to the power supply circuit. The two normally open static contacts are connected to the conduction resistance tester connection terminal J1. One end of the two normally closed static contacts is connected to the insulation resistance tester connection terminal J2, and the other end of the insulation resistance tester connection terminal J2 is connected to a port of the conduction resistance tester J1. The two moving contacts are respectively connected to the first multi-core cable connection terminal J3 and the second multi-core cable connection terminal J4.

[0049] The conduction resistance tester connection terminal J1 is connected to the conduction resistance tester, and the insulation resistance tester connection terminal J2 is connected to the insulation resistance tester.

[0050] When the double-pole double-throw relay K1 is energized and closed, the conduction resistance detected at the conduction resistance tester connection terminal J1 is the conduction resistance of core wire 1, and the insulation resistance detected at the insulation resistance tester connection terminal J2 is the insulation resistance between core wire 1 and core wires (2 - N). When the double-pole double-throw relay K2 is energized and closed, the conduction resistance detected at the conduction resistance tester connection terminal J1 is the conduction resistance of core wire 2, and the insulation resistance detected at the insulation resistance tester connection terminal J2 is the insulation resistance between core wire 2 and core wires (1, 3 - N). According to this rule, the conduction resistance and insulation resistance of all core wires can be detected.

[0051] As Figure 4 shown, the serial-to-parallel drive circuit includes an IN port P1, an OUT port P2, a shift register U8, a drive chip U9, decoupling and filtering capacitors C29, C30, and current-limiting resistors R1 to R5;

[0052] The IN port P1 is used to connect to the IO port of the main control microprocessor and is connected to the input terminals DS, OE, RCK, SCK, and SCLS of U8 through the current-limiting resistors R1 to R5;

[0053] The OUT port P2 serves as an expansion port and is connected to the IN port P1 of the next serial-to-parallel drive circuit;

[0054] The shift register U8 is used to implement serial-to-parallel logic and uses a 74HC595 chip. The output terminals Q0 to Q7 of the 74HC595 chip are respectively connected to the input terminals IN1 to IN8 of the driver chip U9. The input terminals DS, OE, RCK, SCK, and SCLS are respectively connected to current-limiting resistors R1 to R5. The current-limiting resistors R1 to R5 are used for current-limiting of the input terminals DS, OE, RCK, SCK, and SCLS of U8 to ensure that the input ports of U8 will not be damaged.

[0055] The driver chip U9 is used to increase the driving power and ensure the accurate operation of the executing component, and uses a ULN2803 chip. The power supply of the driver chip U9 uses a relay that can drive a voltage higher than 5V. This relay can select the double-pole double-throw relay in the on / off insulation resistance detection circuit.

[0056] The decoupling and filtering capacitor C29 performs decoupling and filtering for the shift register U8.

[0057] The decoupling and filtering capacitor C30 performs decoupling and filtering for the driver chip U9.

[0058] The decoupling and filtering circuits C29 and C30 can effectively prevent the main control microprocessor from being affected when the relay is energized.

[0059] As Figure 5 shown, among them, the test system can be used alone or in conjunction with the host computer. Thus, the software program compiled by the design can be downloaded from the USB port of the host computer to the main control microprocessor on the circuit board, and data can be uploaded to the host computer for further processing.

[0060] As Figure 6 shown, the test device further includes a USB-to-serial circuit for connecting to the host computer. The USB-to-serial circuit is used to download the compiled system software to the microprocessor and is used for data interaction with the host computer in subsequent use.

[0061] The USB-to-serial circuit includes a chip input port USB1, a fuse F1, an electrostatic protection chip U5, a communication conversion chip U6, a low-pass filter, a serial port data external interface P3, and a serial port output high-level selection circuit.

[0062] The positive power supply pin VUBS of the chip input port USB1 is connected to the host computer through the fuse F1, which is used for USB port short-circuit protection to prevent the USB port of the host computer from being damaged due to excessive power consumption of the circuit board; it is used for USB port short-circuit protection to prevent the USB port of the host computer from being damaged due to excessive power consumption of the circuit board.

[0063] The signals of the D+ and D- pins of the chip input port USB1 are respectively connected to the communication conversion chip U6 through the electrostatic protection chip U5 and the low-pass filter; U5 is used for electrostatic protection of the chip USB input port, and the communication conversion chip U6 is used for communication conversion from USB to serial port. The low-pass filter consists of R14 and C25 and R15 and C26, and is used to improve the communication anti-interference ability.

[0064] The communication conversion chip U6 is also respectively connected to the serial port data external interface P3 and the serial port output high-level selection circuit.

[0065] The serial port output high-level selection circuit consists of R12 and R13, and is used for the selection of the serial port output high level. Only one of the resistors R12 and R13 can be used.

[0066] As Figure 7 shown, the test process and test principle of the test system in this embodiment are as follows:

[0067] S1. The test system is respectively connected to the conduction resistance tester and the insulation resistance tester;

[0068] S2. First connect the test cable to the connector of the test system according to the Figure 3 wiring;

[0069] S3. The test system is powered on and enters the working mode;

[0070] S4. Connect both ends of the cable under test;

[0071] S5. Set the test interval time;

[0072] S6. Select the test mode, and execute the corresponding data parsing program by selecting the conduction resistance test or insulation resistance test mode;

[0073] If the conduction resistance test is selected, the main control microprocessor sends an LCR test instruction to read the conduction resistance tester, and the processed read data is sent to the display screen of the human-computer interaction circuit; the test data can also be sent to the upper computer;

[0074] If the insulation resistance test is selected, the main control microprocessor sends an instruction to read the insulation resistance tester, and the processed read data is sent to the display screen of the human-computer interaction circuit; the test data can also be sent to the upper computer;

[0075] S7. According to the setting of the number of core wires, automatically perform cyclic testing until all the core wires of the cable under test are tested;

[0076] S8. Return to step S3.

[0077] Embodiment 2

[0078] Please refer to Figure 2 As shown, the test device provided in this embodiment is the test device in Embodiment 1. It only includes a power supply circuit, a main control microprocessor, a human-computer interaction circuit, an alarm circuit, a serial-to-parallel drive circuit, a conduction / insulation resistance detection circuit, and a detection device communication circuit; or it also includes a USB-to-serial port circuit for connecting to a host computer.

[0079] For the specific structure, connection relationship, and functional principle of each functional circuit module, please refer to the corresponding description in Embodiment 1 and will not be repeated here.

[0080] The advantages of the present invention are as follows: The test device of the present invention has a serial-to-parallel drive circuit and a conduction / insulation resistance detection circuit, enabling infinite expansion of the core number channels. Moreover, due to the special structure of the conduction / insulation resistance detection circuit, each core wire is controlled by a double-pole double-throw relay. The double-pole double-throw relay can perform switching actions for complex cable relationships between various wires during the test process, and then the main control microprocessor performs data processing and instruction control, making the measurement more convenient and greatly improving the test efficiency; also, the test device of the present invention has a stable DC-to-DC buck voltage regulator circuit system. The test system of the present invention uses a dedicated tester, including a conduction resistance tester and an insulation resistance tester, making the test data more accurate; thus filling the gap in the domestic and foreign markets. The circuit design is simple, and the test system integrates a human-computer interaction circuit (such as buttons and display windows or touch screens, etc.). The test data output is intuitive, ensuring that the system can still perform test work without a host computer.

[0081] Although the specific implementation manners of the present invention have been described above, those skilled in the art of this technology should understand that the specific embodiments we described are illustrative rather than used to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered by the scope protected by the claims of the present invention.

Claims

1. A test system for a multi-core cable, characterized in that: It includes a test device, a conduction resistance tester, and an insulation resistance tester; The test device includes a power supply circuit, a main control microprocessor, a human-computer interaction circuit, an alarm circuit, a serial-to-parallel drive circuit, a conduction / insulation resistance detection circuit, and a detection device communication circuit; The power supply circuit supplies power to the main control microprocessor, the human-computer interaction circuit, the alarm circuit, the serial-to-parallel drive circuit, the conduction / insulation resistance detection circuit, and the detection device communication circuit respectively; The main control microprocessor is used for data processing and instruction control of the test system, and is respectively connected to the human-computer interaction circuit, the alarm circuit, the serial-to-parallel drive circuit, the USB-to-serial port circuit, and the detection device communication circuit; The serial-to-parallel drive circuit is also connected to the conduction / insulation resistance detection circuit; The serial-to-parallel drive circuit is used for expanding the number of core wires of the test cable; The conduction / insulation resistance detection circuit is used to perform switching actions on the connection relationships of each core wire in the circuit during the test, and control each core wire to be in a conduction state or an insulation resistance detection state; The conduction / insulation resistance detection circuit includes a conduction resistance tester terminal J1, an insulation resistance tester terminal J2, a first multi-core cable terminal J3, a second multi-core cable terminal J4, and a double-pole double-throw relay Ki, i = 1, 2…n, n is determined by the number of core wires to be tested; Any double-pole double-throw relay Ki includes two power supply terminals, two normally open static contacts, two normally closed static contacts, and two moving contacts. The power supply terminals are connected to the power supply circuit, the two normally open static contacts are connected to the conduction resistance tester terminal J1, the two normally closed static contacts are connected to the insulation resistance tester terminal J2, and the two moving contacts are respectively connected to the first multi-core cable terminal J3 and the second multi-core cable terminal J4; The conduction resistance tester terminal J1 is connected to the conduction resistance tester, and the insulation resistance tester terminal J2 is connected to the insulation resistance tester; It also includes a host computer, and the test device also includes a USB-to-serial port circuit for connecting to the host computer. The USB-to-serial port circuit is used to download the compiled system software to the microprocessor and is used for data interaction with the host computer in subsequent use; The USB-to-serial port circuit includes a chip input port USB1, a fuse F1, an electrostatic protection chip U5, a communication conversion chip U6, a low-pass filter, a serial port data external interface P3, and a serial port output high-level selection circuit; The positive power supply pin of the chip input port USB1 is connected to the host computer through the fuse F1; The signal pair pins of the chip input port USB1 are respectively connected to the communication conversion chip U6 through the electrostatic protection chip U5 and the low-pass filter; The communication conversion chip U6 is also respectively connected to the serial port data external interface P3 and the serial port output high-level selection circuit.

2. The test system for a multi-core cable according to claim 1, characterized in that: The serial-to-parallel drive circuit includes an IN port P1, an OUT port P2, a shift register U8, a driver chip U9, decoupling and filtering capacitors C29 and C30, and current-limiting resistors R1 to R5; The IN port P1 is used to connect to the IO port of the main control microprocessor and is connected to the input terminals DS, OE, RCK, SCK, and SCLS of the shift register U8 through current-limiting resistors R1 to R5; The OUT port P2 serves as an expansion port and is connected to the IN port P1 of the next serial-to-parallel drive circuit; The shift register U8 is used to implement serial-to-parallel logic and uses a 74HC595 chip. The output terminals Q0 to Q7 of the 74HC595 chip are respectively connected to the input terminals IN1 to IN8 of the driver chip U9; The driver chip U9 is used to increase the driving power and ensure the accurate operation of the execution component. It uses a ULN2803 chip, and the power supply of the driver chip U9 uses a relay that can drive a voltage higher than 5V; The decoupling and filtering capacitor C29 performs decoupling and filtering for the shift register U8; The decoupling and filtering capacitor C30 performs decoupling and filtering for the driver chip U9.

3. The test system for a multi-core cable according to claim 1, characterized in that: The power supply circuit includes a power input interface and a DC-to-DC buck and voltage regulation circuit. The power input interface is used to input a DC power supply of 12V - 24V; the DC-to-DC buck and voltage regulation circuit is used to convert the DC voltage of 12V - 24V into the voltages required for the normal operation of the USB-to-serial port circuit, the main control microprocessor, the human-computer interaction circuit, the alarm circuit, the serial-to-parallel drive circuit, the conduction / insulation resistance detection circuit, and the detection device communication circuit.

4. The test system for a multi-core cable according to claim 1, wherein: The alarm circuit is an audible and visual alarm circuit; all functional circuit modules of the test device are designed on the same double-sided surface-mounted circuit board.

5. A testing device for a multi-core cable, characterized in that: It includes a power supply circuit, a main control microprocessor, a human-computer interaction circuit, an alarm circuit, a serial-to-parallel drive circuit, a conduction / insulation resistance detection circuit, and a detection device communication circuit; The power supply circuit supplies power to the main control microprocessor, the human-computer interaction circuit, the alarm circuit, the serial-to-parallel drive circuit, the conduction / insulation resistance detection circuit, and the detection device communication circuit respectively; The main control microprocessor is used for data processing and instruction control of the test system and is respectively connected to the human-computer interaction circuit, the alarm circuit, the serial-to-parallel drive circuit, the USB-to-serial port circuit, and the detection device communication circuit; the serial-to-parallel drive circuit is also connected to the conduction / insulation resistance detection circuit; The serial-to-parallel drive circuit is used for the expansion of the number of core wires of the test cable; the conduction / insulation resistance detection circuit is used to perform switching actions on the connection relationships of each core wire in the circuit during the test process to control each core wire to be in a conduction state or in a state of insulation resistance detection; The on - state / insulation resistance detection circuit includes a conduction resistance tester connection terminal J1, an insulation resistance tester connection terminal J2, a first multi - core cable connection terminal J3, a second multi - core cable connection terminal J4, and double - pole double - throw relays Ki, where i = 1, 2...n, and n is determined by the number of core wires to be measured; any double - pole double - throw relay Ki includes two power supply connection terminals, two normally open static contacts, two normally closed static contacts, and two moving contacts. The power supply connection terminals are connected to the power supply circuit. The two normally open static contacts are connected to the conduction resistance tester connection terminal J1. One end of the two normally closed static contacts is connected to the insulation resistance tester connection terminal J2, and the other end of the insulation resistance tester connection terminal J2 is connected to a port of the conduction resistance tester. The two moving contacts are respectively connected to the first multi - core cable connection terminal J3 and the second multi - core cable connection terminal J4; It also includes a USB - to - serial port circuit for connecting to a host computer, which is used to download the compiled system software to the micro - processor and for data interaction with the host computer in subsequent use; The USB - to - serial port circuit includes a chip input port USB1, a fuse F1, an electrostatic protection chip U5, a communication conversion chip U6, a low - pass filter, a serial port data external interface P3, and a serial port output high - level selection circuit; The positive power supply pin of the chip input port USB1 is connected to the host computer through the fuse F1; The signal pair pins of the chip input port USB1 are respectively connected to the communication conversion chip U6 through the electrostatic protection chip U5 and the low - pass filter; The communication conversion chip U6 is also respectively connected to the serial port data external interface P3 and the serial port output high - level selection circuit.

6. The testing device for a multi-core cable according to claim 5, wherein: The serial - to - parallel drive circuit includes an IN port P1, an OUT port P2, a shift register U8, a driver chip U9, decoupling and filtering capacitors C29, C30, and current - limiting resistors R1 to R5; The IN port P1 is used to connect to the IO port of the main control micro - processor and is connected to the input terminals DS, OE, RCK, SCK, SCLS of the shift register U8 through current - limiting resistors R1 to R5; The OUT port P2 serves as an extended port and is connected to the IN port P1 of the next serial - to - parallel drive circuit; The shift register U8 is used to implement serial - to - parallel logic and uses a 74HC595 chip. The output terminals Q0 to Q7 of the 74HC595 chip are respectively connected to the input terminals IN1 to IN8 of the driver chip U9; The driver chip U9 is used to increase the driving power to ensure the accurate operation of the execution component and uses a ULN2803 chip. The power supply of the driver chip U9 is used to drive a relay with a voltage higher than 5V; The decoupling and filtering capacitor C29 performs decoupling and filtering for the shift register U8; The decoupling and filtering capacitor C30 performs decoupling and filtering for the driver chip U9.

7. The testing device for a multi-core cable according to claim 5, characterized in that: The power supply circuit includes a power input interface and a DC-to-DC buck voltage stabilizing circuit. The power input interface is used to input a DC power supply of 12V - 24V; the DC-to-DC buck voltage stabilizing circuit is used to convert the DC voltage of 12V - 24V into the voltages required for the normal operation of the USB-to-serial circuit, the main control microprocessor, the human-computer interaction circuit, the alarm circuit, the serial-to-parallel drive circuit, the conduction / insulation resistance detection circuit, and the detection device communication circuit respectively.

8. The testing device for a multi-core cable according to claim 5, characterized in that: The alarm circuit is an audible and visual alarm circuit; all the functional circuit modules of the test device are designed on the same double-sided surface-mount circuit board.

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