Intelligent digital loop resistance tester

Abstract

An intelligent digital loop resistance tester provided by the present invention comprises a host and a pair of handheld devices, the handheld devices and the host are connected through a cable to form a closed loop, and the handheld devices are fixedly connected with current thimbles and slidably connected with voltage thimbles. The cable is provided with a current lead connected with the current ejector pin and a voltage lead connected with the voltage ejector pin, a sub-control module in wireless communication connection with the host and a microswitch electrically connected with the sub-control module are arranged in the handheld device, and the microswitch is arranged at the tail end of the voltage ejector pin; according to the invention, the wiring function is integrated into the equipment, the traditional manual wiring step is cancelled, all operations can be completed by only one person, and the manpower demand is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of loop resistance testing, and in particular to an intelligent digital loop resistance tester. Background Art

[0002] Loop resistance testing, a key component of power equipment maintenance, focuses on verifying the contact quality of high-voltage electrical connections. Abnormal resistance at the connections between various conductive components in an electrical system can cause localized overheating or even equipment damage, necessitating high-precision measurement methods to ensure safe grid operation. Currently, the industry generally employs measurement methods based on DC excitation. These methods inject a steady current into the circuit under test, simultaneously capturing the voltage signal and calculating the resistance value based on the laws of physics. However, these methods place high demands on the equipment's anti-interference capabilities and signal acquisition accuracy.

[0003] Existing technical solutions generally adopt a split-type design, with a main unit and multiple sets of external test fixtures forming a complete measurement system. During operation, the device requires separate current excitation and voltage sampling circuits, with manual operations required to sequentially complete the clamping, testing, data recording, and removal processes. Although some improved models have achieved increased portability by reducing the size of the main unit, the traditional test model's strong reliance on human intervention remains fundamentally unchanged. Measurement efficiency is limited by repetitive manual steps, especially in scenarios with multiple measurement points, which expose the pain points of cumbersome and time-consuming processes.

[0004] The closest prior art to the present invention is a handheld loop resistance tester. Referring to Chinese Patent Publication No. CN216013501U, a handheld loop resistance tester relates to the field of resistance tester technology and includes a handheld loop resistance tester body, an anti-drop assembly, and a shock-absorbing protective assembly. The handheld loop resistance tester body is provided with an elastic block on the front edge. The anti-drop assembly includes an assembly box, an anti-drop bracelet, a guide rope, and a reeling mechanism. The anti-drop bracelet is disposed within the assembly box, one side of which is connected to one end of the guide rope. A drive box is provided on one side of the assembly box, and the reeling mechanism is disposed within the drive box. By providing the anti-drop assembly consisting of the assembly box, anti-drop bracelet, guide rope, and reeling mechanism, the anti-drop bracelet and guide rope can be used to connect the handheld loop resistance tester body to the user's wrist, thereby preventing the handheld loop resistance tester body from falling out of the user's hand and causing collision damage during use. While maintaining the basic measurement principle, this technical approach enables single-handed operation through a compact structural design. However, this type of product still has obvious limitations in engineering practice: although the physical form tends to be portable, all the steps of traditional four-wire wiring must be completed in actual operation. It has neither broken through the inherent mode of multi-fixture collaborative work nor built an automated testing process. In essence, it still has not solved deep-seated problems such as the high proportion of wiring time and insufficient intelligence in the testing process. Summary of the Invention

[0005] The present invention solves the problems of high labor cost and low efficiency in traditional loop resistance testing. It proposes an intelligent loop resistance tester that integrates the wiring function into the device, eliminating the traditional manual wiring steps. Only one person is needed to complete the entire operation, greatly reducing manpower requirements.

[0006] A further purpose of the present invention is to flexibly select the structure and function of a pair of handheld devices according to the structure of the load to be tested. It is possible to select a solution with the same mirror image structure of the two handheld devices, which can be flexibly interchanged and used, and their shape characteristics can be used to adapt to different usage spaces, thereby improving the versatility of the device; it is also possible to distinguish between the main device and the auxiliary device, and only control the connection and disconnection through the main device, making the operator's operation more convenient and labor-saving, and optimizing the user experience.

[0007] In order to achieve the above objectives, the following technical solutions are proposed: A smart digital loop resistance tester includes a host and a pair of handheld devices. The handheld devices and the host are connected by cables to form a closed loop. The handheld devices are fixedly connected to a current pin and movably connected to a voltage pin. The cables are provided with a current wire connected to the current pin and a voltage wire connected to the voltage pin. The handheld devices are equipped with a sub-control module connected to the host for wireless communication and a micro switch electrically connected to the sub-control module. The micro switch is arranged at the end of the voltage pin.

[0008] The traditional method requires multiple steps such as manual wiring, equipment operation, and result verification. The entire process is time-consuming, which forces the substation power outage detection time to be extended. The present invention can omit the wiring step and automatically measure through the design of the ejector pin, so as to quickly complete the test, shorten the power outage time, and reduce the impact on the power supply of the power grid and economic losses. Traditional testing requires at least three people to work together, with high labor costs and low efficiency. The present invention integrates the wiring function into the equipment, eliminates the traditional manual wiring steps, and only one person is needed to complete all operations, greatly reducing manpower requirements. Traditional fixtures are easily stuck or unable to clamp on narrow, inclined or complex contact surfaces, resulting in measurement failure. The present invention is designed with a flexibly adjustable test probe that can adapt to contact surfaces of different angles and shapes, such as bends or hidden joints, significantly improving the adaptability of test scenarios.

[0009] Preferably, a current connecting copper sheet is provided in the handheld device, one end of the current connecting copper sheet is close to the inner wall of the handheld device, the threaded end of the current thimble passes through the handheld device and the current connecting copper sheet in turn and is threadedly connected to the current connecting nut, the other end of the current connecting copper sheet is fitted and fixed to the current copper joint, and the current copper joint is connected to one end of the current wire.

[0010] The inner cavity of the handheld device of the present invention is provided with a current connecting copper sheet, one end of the current connecting copper sheet is bent and tightly attached to the inner wall of the handheld device, the bottom surface of the current connecting copper sheet is fitted and fixed to the inner lower wall of the handheld device, the other end of the current connecting copper sheet is fitted and fixed with a current copper joint, the current copper joint is connected to one end of the current wire, one end of the current thimble extends out of the handheld device, the other end of the current thimble is provided with a thread, and the other end of the current thimble passes through the handheld device and the current connecting copper sheet in sequence and then is threadedly connected to the current connecting nut.

[0011] Preferably, the voltage ejector pin includes a voltage ejector column and a voltage sliding column. The voltage sliding column and the voltage ejector column are integrally formed and have a smaller diameter than the voltage ejector column. The end of the voltage sliding column is threadedly connected with a trigger nut. The voltage sliding column is connected to the voltage wire. The voltage sliding column is provided with a reset spring, and the reset spring is arranged between the voltage ejector column and the outer wall of the handheld device.

[0012] The voltage ejector pin of the present invention comprises an integrally formed voltage ejector pin and a voltage sliding pin. The voltage sliding pin has a smaller diameter than the voltage ejector pin. The voltage sliding pin has a threaded end, to which a trigger nut is connected. The end of the trigger nut is rounded, and the trigger nut engages and disengages with the microswitch as the voltage ejector pin translates. The voltage sliding pin is connected to the host via a voltage wire and is equipped with a return spring, which is positioned between the stepped surface formed by the voltage ejector pin and the voltage sliding pin and the outer wall of the handheld device.

[0013] Preferably, a sleeve is provided on the voltage sliding column, and the sleeve is slidably connected to the handheld device. A limiting ring is provided on the end face of the sleeve, and the outer diameter of the limiting ring is larger than the outer diameter of the sleeve and larger than or equal to the diameter of the voltage ejection column. The reset spring is arranged between the outer wall of the limiting ring and the step surface formed by the voltage ejection column and the voltage sliding column.

[0014] The voltage sliding post of the present invention is covered with a sleeve to protect the voltage ejector pin. The outer wall of the sleeve is slidably connected to the handheld device. The end face of the sleeve is equipped with a retaining ring with an outer diameter larger than the sleeve's. The outer diameter of the retaining ring is greater than or equal to the diameter of the voltage ejector post. The return spring is positioned between the stepped surface formed by the voltage ejector post and the voltage sliding post, and the outer wall of the retaining ring. Because the voltage ejector pin needs to move frequently, the sleeve of the present invention is provided to prevent frequent friction between the voltage ejector pin and the handheld device body, thereby extending the service life of the voltage ejector pin and the handheld device.

[0015] Preferably, a voltage connecting copper sheet is fixed between the sleeve and the trigger nut, and the voltage connecting copper sheet is connected to the voltage wire.

[0016] The voltage wire of the present invention is connected to the voltage pin via a voltage connecting copper sheet, and the voltage connecting copper sheet is clamped and fixed between the sleeve and the trigger nut.

[0017] Preferably, the host is provided with a power output module and a current and voltage acquisition module, and the outer wall of the host is provided with a pair of current interfaces and a pair of voltage interfaces. The power output module outputs a constant current to the loop resistor through the current interface, and the current and voltage acquisition module obtains the output current value through the current interface and obtains the voltage value generated by the loop resistor through the voltage interface.

[0018] The host of the present invention is provided with a power output module for outputting a constant current to the loop resistor and a current and voltage acquisition module for obtaining the output current value and the voltage value generated by the loop resistor. The outer wall of the host is provided with a pair of voltage interfaces and a pair of current interfaces. The current interface is connected to the output end of the power output module, and the current interface and the voltage interface are connected to the input end of the current and voltage acquisition module.

[0019] Preferably, one end of the current conductor of the cable is connected to the current pin, and the other end of the current conductor of the cable is plugged into the current interface through a current plug; one end of the voltage conductor of the cable is connected to the voltage pin, and the other end of the voltage conductor of the cable is plugged into the voltage interface through a voltage plug.

[0020] The current pin of the present invention is connected to one end of the current conductor, the other end of which is connected to a current plug that plugs into the current interface. The voltage pin of the present invention is connected to one end of the voltage conductor, the other end of which is connected to a voltage plug that plugs into the voltage interface. Conventional equipment connections are prone to loosening, and poor contact can lead to data fluctuations and even test interruptions. The present invention adopts a "one-touch plug-in" interface design, which automatically locks after insertion, allowing for quick connection while ensuring stable contact and avoiding data errors.

[0021] Preferably, the ejection end of the current ejector pin and the ejection end of the voltage ejector pin are both frustums.

[0022] In order to improve the accuracy of the measurement points, the present invention designs the ejection ends of the current ejector and the voltage ejector into the shape of a frustum. During actual operation, the frustum end of the ejector can be inserted into the connection hole at an angle to first connect the power supply to the host through the current ejector, and then insert the voltage ejector to trigger the micro switch to start the test. The connection sequence is cleverly achieved through the simple feature of the frustum end of the ejector.

[0023] Preferably, the housing of the handheld device is provided with an integrally formed handheld portion and an ejection portion, the handheld portion and the ejection portion form a certain angle, and the certain angle ranges from 145° to 170°.

[0024] The housing of the handheld device of the present invention comprises a grip portion and an ejection portion, which are integrally formed and have an included angle between 145° and 170°. A current ejector pin and a voltage ejector pin extend perpendicularly from the end face of the ejection portion. This arrangement is intended to avoid twisting the wrist when the current and voltage ejector pins come into contact with the loop resistor, reducing the burden on the user and making the handheld device more convenient to use.

[0025] Preferably, the sub-control module and the micro switch are arranged in the ejection part, and the handheld part is provided with a handheld device power supply for supplying power to the sub-control module.

[0026] The micro switch and sub-control module of the present invention are arranged in the ejection part, the handheld part is provided with a handheld device power supply, the handheld device power supply supplies power to the sub-control module, and the housing of the handheld device is provided with a charging interface, the charging interface is used to charge the handheld device power supply.

[0027] The beneficial effects of the present invention are as follows: the traditional method requires multiple steps such as manual wiring, equipment operation, and result verification. The entire process is time-consuming, which forces the substation power outage detection time to be prolonged. The present invention can omit the wiring step and automatically measure through the design of the ejector pin, so as to quickly complete the test, shorten the power outage time, and reduce the impact on the power supply of the power grid and economic losses. Traditional testing requires at least three people to work together, with high labor costs and low efficiency. The present invention integrates the wiring function into the equipment, eliminates the traditional manual wiring steps, and only requires one person to complete all operations with both hands, greatly reducing manpower requirements. Traditional clamps are easily stuck or unable to clamp on narrow, inclined or complex contact surfaces, resulting in measurement failure. The present invention is designed with a flexibly adjustable test probe that can adapt to contact surfaces of different angles and shapes, such as bends or hidden joints, significantly improving the adaptability of test scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0029] Figure 2 It is a schematic diagram of the current ejector structure connection of the present invention.

[0030] Figure 3 is a cross-sectional view of a handheld device of the present invention.

[0031] Figure 4 It is a partially enlarged schematic diagram of the voltage ejector structure of the present invention.

[0032] Among them: 1. Main unit; 2. Handheld device; 3. Connecting cable; 11. Current interface; 12. Voltage interface; 21. Current ejector pin; 22. Voltage ejector pin; 23. Current connecting copper sheet; 24. Current connecting nut; 25. Housing; 26. Handheld device power supply; 27. Sub-control module; 28. Micro switch; 29. ​​Sleeve; 31. Current plug; 32. Voltage plug; 33. Current copper connector; 210. Trigger nut; 211. Voltage connecting copper sheet; 212. Reset spring; 221. Voltage ejector column; 222. Voltage sliding column; 251. Handheld part; 252. Ejector part; 291. Limiting ring. DETAILED DESCRIPTION

[0033] Example 1: This embodiment proposes an intelligent digital loop resistance tester, referring to Figure 1, including a host 1, a pair of handheld devices 2 and a cable 3. The host 1 and the handheld device 2 are connected together through the cable 3. The handheld device 2 is provided with a copper current pin 21 and a voltage pin 22. The current pin 21 is fixedly connected to the handheld device 2, and the voltage pin 22 is slidably connected to the handheld device 2. The cable 3 is provided with a current wire and a voltage wire. The host 1 is connected to the current pin 21 through the current wire, and the host 1 is connected to the voltage pin 22 through the voltage wire. The handheld device 2 has a built-in sub-control module 27 and a micro switch 28. The sub-control module 27 is wirelessly connected to the host 1, and the micro switch 28 is electrically connected to the sub-control module 27. The micro switch 28 is set at the end of the voltage pin 22.

[0034] The handheld device replaces the traditional test fixture. Current and voltage wires are routed internally to two pins on the outside of the device. The current pin is fixed, while the voltage pin is retractable. These pins connect to the load under test. The cable connecting to the main unit uses quick-connect terminals. During measurement, the current pin first contacts the load under test, then compresses the voltage pin. This displacement triggers a microswitch. The sub-control module detects this measurement status and transmits a test request to the main unit via wireless communication technology. The main unit outputs a constant current to the load under test, then measures the voltage across it, calculates its resistance, and transmits the test data to the handheld device and a mobile app via Bluetooth. The device is compact and can be clipped to a belt for easy portability. The sub-control module can be a single-chip microcontroller, and the wireless communication technology uses Bluetooth or 4G communication. Furthermore, the sub-control module can be electrically connected to a display to show the measured resistance and an indicator light to indicate that the microswitch has been triggered. Both the display and the indicator light can be integrated into the handheld device.

[0035] The host program timing is as follows: S1, the host starts up and the peripherals and parameters are initialized; S2, waiting for the test, the mobile phone and handheld terminal control or the host button to start the test; S3, start the test, the power supply starts to output the set current value, and samples the output current value and the voltage drop caused by the loop resistance; S4, calculate the data and determine whether the data is within the rated range of the instrument. If it exceeds the range, the test will be stopped immediately; S5: The test is completed, the test data is displayed and uploaded, and the next round of test data is waiting.

[0036] The traditional method requires multiple steps such as manual wiring, equipment operation, and result verification. The entire process is time-consuming, which forces the substation power outage detection time to be extended. The present invention can omit the wiring step and automatically measure through the design of the ejector pin, so as to quickly complete the test, shorten the power outage time, and reduce the impact on the power supply of the power grid and economic losses. Traditional testing requires at least three people to work together, with high labor costs and low efficiency. The present invention integrates the wiring function into the equipment, eliminates the traditional manual wiring steps, and only one person is needed to complete all operations, greatly reducing manpower requirements. Traditional fixtures are easily stuck or unable to clamp on narrow, inclined or complex contact surfaces, resulting in measurement failure. The present invention is designed with a flexibly adjustable test probe that can adapt to contact surfaces of different angles and shapes, such as bends or hidden joints, significantly improving the adaptability of test scenarios.

[0037] refer to Figure 2 The inner cavity of the handheld device 2 of the present invention is provided with a current connecting copper sheet 23, one end of the current connecting copper sheet 23 is bent and close to the inner wall of the handheld device 2, and the bottom surface of the current connecting copper sheet 23 is fit and fixed to the inner lower wall of the handheld device 2, and the other end of the current connecting copper sheet 23 is fit and fixed with a current copper joint 33, which is connected to one end of the current wire. One end of the current thimble 21 extends out of the handheld device 2, and the other end of the current thimble 21 is provided with a thread, and the other end of the current thimble 21 passes through the handheld device 2 and the current connecting copper sheet 23 in sequence and then is threadedly connected to the current connecting nut 24.

[0038] The host of the present invention is provided with a power output module for outputting a constant current to the loop resistor and a current and voltage acquisition module for obtaining the output current value and the voltage value generated by the loop resistor. The outer wall of the host is provided with a pair of voltage interfaces 12 and a pair of current interfaces 11. The current interface 11 is connected to the output end of the power output module, and the current interface 11 and the voltage interface 12 are connected to the input end of the current and voltage acquisition module.

[0039] The current pin 21 of the present invention is connected to one end of the current conductor, the other end of which is connected to a current plug 31 that plugs into the current interface 11. The voltage pin 22 of the present invention is connected to one end of the voltage conductor, the other end of which is connected to a voltage plug 32 that plugs into the voltage interface 12. Conventional equipment connections are prone to loosening, and poor contact can lead to data fluctuations and even test interruption. The present invention adopts a "one-touch plug-in" interface design that automatically locks after insertion, allowing for quick connection while ensuring stable contact and avoiding data errors.

[0040] In order to improve the accuracy of the measurement point, the present invention designs the ejection end of the current ejector pin 21 and the ejection end of the voltage ejector pin 22 to be in the shape of a truncated cone.

[0041] In this embodiment, the left and right handheld devices of a pair of handheld devices have mirror-image internal structures, each including a current pin 21 and a voltage pin 22. The current pin 21 is fixedly connected to the handheld device 2, while the voltage pin 22 is slidably connected to the handheld device 2. The host computer supplies power to the sub-control modules of both handheld devices via cables.

[0042] Example 2: This embodiment optimizes the structure of the voltage pin 22 based on the embodiment 1, and proposes an intelligent loop resistance tester. Figure 1 , including a host 1, a pair of handheld devices 2 and a cable 3. The host 1 and the handheld device 2 are connected together through the cable 3. The handheld device 2 is provided with a copper current pin 21 and a voltage pin 22. The current pin 21 is fixedly connected to the handheld device 2, and the voltage pin 22 is plugged into the handheld device 2. The cable 3 is provided with a current wire and a voltage wire. The host 1 is connected to the current pin 21 through the current wire, and the host 1 is connected to the voltage pin 22 through the voltage wire. The handheld device 2 has a built-in sub-control module 27 and a micro switch 28. The sub-control module 27 is wirelessly connected to the host 1, and the micro switch 28 is electrically connected to the sub-control module 27. The micro switch 28 is set at the end of the voltage pin 22.

[0043] The handheld device replaces the traditional test fixture. Current and voltage wires are routed internally to two pins on the outside of the device. The current pin is fixed, while the voltage pin is retractable. These pins connect to the load under test. The cable connecting to the main unit uses quick-connect terminals. During measurement, the current pin first contacts the load under test, then compresses the voltage pin. This displacement triggers a microswitch. The sub-control module detects this measurement status and transmits a test request to the main unit via wireless communication technology. The main unit outputs a constant current to the load under test, then measures the voltage across it, calculates its resistance, and transmits the test data to the handheld device and a mobile app via Bluetooth. The device is compact and can be clipped to a belt for easy portability. The sub-control module can be a single-chip microcontroller, and the wireless communication technology uses Bluetooth or 4G communication. Furthermore, the sub-control module can be electrically connected to a display to show the measured resistance and an indicator light to indicate that the microswitch has been triggered. Both the display and the indicator light can be integrated into the handheld device.

[0044] The host program timing is as follows: S1, the host starts up and the peripherals and parameters are initialized; S2, waiting for the test, the mobile phone and handheld terminal control or the host button to start the test; S3, start the test, the power supply starts to output the set current value, and samples the output current value and the voltage drop caused by the loop resistance; S4, calculate the data and determine whether the data is within the rated range of the instrument. If it exceeds the range, the test will be stopped immediately; S5: The test is completed, the test data is displayed and uploaded, and the next round of test data is waiting.

[0045] The traditional method requires multiple steps such as manual wiring, equipment operation, and result verification. The entire process is time-consuming, which forces the substation power outage detection time to be extended. The present invention can omit the wiring step and automatically measure through the design of the ejector pin, so as to quickly complete the test, shorten the power outage time, and reduce the impact on the power supply of the power grid and economic losses. Traditional testing requires at least three people to work together, with high labor costs and low efficiency. The present invention integrates the wiring function into the equipment, eliminates the traditional manual wiring steps, and only one person is needed to complete all operations, greatly reducing manpower requirements. Traditional fixtures are easily stuck or unable to clamp on narrow, inclined or complex contact surfaces, resulting in measurement failure. The present invention is designed with a flexibly adjustable test probe that can adapt to contact surfaces of different angles and shapes, such as bends or hidden joints, significantly improving the adaptability of test scenarios.

[0046] refer to Figure 2 The inner cavity of the handheld device 2 of the present invention is provided with a current connecting copper sheet 23, one end of the current connecting copper sheet 23 is bent and close to the inner wall of the handheld device 2, and the bottom surface of the current connecting copper sheet 23 is fit and fixed to the inner lower wall of the handheld device 2, and the other end of the current connecting copper sheet 23 is fit and fixed with a current copper joint 33, which is connected to one end of the current wire. One end of the current thimble 21 extends out of the handheld device 2, and the other end of the current thimble 21 is provided with a thread, and the other end of the current thimble 21 passes through the handheld device 2 and the current connecting copper sheet 23 in sequence and then is threadedly connected to the current connecting nut 24.

[0047] refer to Figure 4 The voltage ejector pin 22 of the present invention includes an integrally formed voltage ejector pin 221 and a voltage sliding pin 222. The diameter of the voltage sliding pin 222 is smaller than that of the voltage ejector pin 221. The end of the voltage sliding pin 222 is provided with a thread, to which a trigger nut 210 is connected via the thread. The end of the trigger nut 210 is rounded, and the trigger nut 210 contacts or disconnects with the micro switch as the voltage ejector pin 22 moves in translation. The voltage sliding pin 222 is connected to the host 1 via a voltage wire. The voltage sliding pin 222 is provided with a reset spring 212, which is arranged between the step surface formed by the voltage ejector pin 221 and the voltage sliding pin 222 and the outer wall of the handheld device 2.

[0048] The voltage sliding post 222 of the present invention is sleeved with a sleeve 29 that protects the voltage ejector pin 22. The outer wall of the sleeve 29 is slidably connected to the handheld device 2. The end face of the sleeve 29 is provided with a retaining ring 291 having an outer diameter greater than that of the sleeve 29. The outer diameter of the retaining ring 291 is greater than or equal to the diameter of the voltage ejector post 221. The return spring 212 is disposed between the stepped surface formed by the voltage ejector post 221 and the voltage sliding post 222, and the outer wall of the retaining ring 291. Because the voltage ejector pin 22 needs to move frequently, the sleeve 29 of the present invention is provided to prevent frequent friction between the voltage ejector pin 22 and the main body of the handheld device 2, thereby extending the service life of the voltage ejector pin 22 and the handheld device 2.

[0049] The voltage wire of the present invention is connected to the voltage pin 22 via a voltage connecting copper sheet 211 , and the voltage connecting copper sheet 211 is clamped and fixed between the sleeve 29 and the trigger nut 210 .

[0050] The host of the present invention is provided with a power output module for outputting a constant current to the loop resistor and a current and voltage acquisition module for obtaining the output current value and the voltage value generated by the loop resistor. The outer wall of the host is provided with a pair of voltage interfaces 12 and a pair of current interfaces 11. The current interface 11 is connected to the output end of the power output module, and the current interface 11 and the voltage interface 12 are connected to the input end of the current and voltage acquisition module.

[0051] The current pin 21 of the present invention is connected to one end of the current conductor, the other end of which is connected to a current plug 31 that plugs into the current interface 11. The voltage pin 22 of the present invention is connected to one end of the voltage conductor, the other end of which is connected to a voltage plug 32 that plugs into the voltage interface 12. Conventional equipment connections are prone to loosening, and poor contact can lead to data fluctuations and even test interruption. The present invention adopts a "one-touch plug-in" interface design that automatically locks after insertion, allowing for quick connection while ensuring stable contact and avoiding data errors.

[0052] In order to improve the accuracy of the measurement point, the present invention designs the ejection end of the current ejector pin 21 and the ejection end of the voltage ejector pin 22 to be in the shape of a truncated cone.

[0053] In this embodiment, the left and right handheld devices of a pair of handheld devices have different internal structures, but both include a current thimble 21 and a voltage thimble 22; any handheld device serves as a master device, and its current thimble 21 is fixedly connected to the handheld device 2, and the voltage thimble 22 is slidably connected to the handheld device 2, and the structure is the same as described above. Figure 4The disclosed handheld devices have the same structure. Another handheld device, serving as a secondary device, includes a current pin 21 and a voltage pin 22. However, the voltage pin, like the current pin, is fixedly connected to the secondary device, rather than being movably connected. It also eliminates the need for a microswitch and sub-control module. Instead, the voltage pin is connected to the main device via a voltage conductor. This allows the secondary device to operate by simply inserting the negative terminal directly into the load being measured. The closed loop can then be controlled through the main device, enabling single-handed control without the need to simultaneously maintain the voltage pins of both devices in contact, making it easier and more labor-saving.

[0054] Example 3: This embodiment optimizes the housing of the handheld device based on the second embodiment and proposes an intelligent loop resistance tester. Figure 1 , including a host 1, a pair of handheld devices 2 and a cable 3. The host 1 and the handheld device 2 are connected together through the cable 3. The handheld device 2 is provided with a copper current pin 21 and a voltage pin 22. The current pin 21 is fixedly connected to the handheld device 2, and the voltage pin 22 is slidably connected to the handheld device 2. The cable 3 is provided with a current wire and a voltage wire. The host 1 is connected to the current pin 21 through the current wire, and the host 1 is connected to the voltage pin 22 through the voltage wire. The handheld device 2 has a built-in sub-control module 27 and a micro switch 28. The sub-control module 27 is wirelessly connected to the host 1, and the micro switch 28 is electrically connected to the sub-control module 27. The micro switch 28 is set at the end of the voltage pin 22.

[0055] The handheld device replaces the traditional test fixture. Current and voltage wires are routed internally to two pins on the outside of the device. The current pin is fixed, while the voltage pin is retractable. These pins connect to the load under test. The cable connecting to the main unit uses quick-connect terminals. During measurement, the current pin first contacts the load under test, then compresses the voltage pin. This displacement triggers a microswitch. The sub-control module detects this measurement status and transmits a test request to the main unit via wireless communication technology. The main unit outputs a constant current to the load under test, then measures the voltage across it, calculates its resistance, and transmits the test data to the handheld device and a mobile app via Bluetooth. The device is compact and can be clipped to a belt for easy portability. The sub-control module can be a single-chip microcontroller, and the wireless communication technology uses Bluetooth or 4G communication. Furthermore, the sub-control module can be electrically connected to a display to show the measured resistance and an indicator light to indicate that the microswitch has been triggered. Both the display and the indicator light can be integrated into the handheld device.

[0056] The host program timing is as follows: S1, the host starts up and the peripherals and parameters are initialized; S2, waiting for the test, the mobile phone and handheld terminal control or the host button to start the test; S3, start the test, the power supply starts to output the set current value, and samples the output current value and the voltage drop caused by the loop resistance; S4, calculate the data and determine whether the data is within the rated range of the instrument. If it exceeds the range, the test will be stopped immediately; S5: The test is completed, the test data is displayed and uploaded, and the next round of test data is waiting.

[0057] The traditional method requires multiple steps such as manual wiring, equipment operation, and result verification. The entire process is time-consuming, which forces the substation power outage detection time to be extended. The present invention can omit the wiring step and automatically measure through the design of the ejector pin, so as to quickly complete the test, shorten the power outage time, and reduce the impact on the power supply of the power grid and economic losses. Traditional testing requires at least three people to work together, with high labor costs and low efficiency. The present invention integrates the wiring function into the equipment, eliminates the traditional manual wiring steps, and only one person is needed to complete all operations, greatly reducing manpower requirements. Traditional fixtures are easily stuck or unable to clamp on narrow, inclined or complex contact surfaces, resulting in measurement failure. The present invention is designed with a flexibly adjustable test probe that can adapt to contact surfaces of different angles and shapes, such as bends or hidden joints, significantly improving the adaptability of test scenarios.

[0058] refer to Figure 2 The inner cavity of the handheld device 2 of the present invention is provided with a current connecting copper sheet 23, one end of the current connecting copper sheet 23 is bent and close to the inner wall of the handheld device 2, and the bottom surface of the current connecting copper sheet 23 is fit and fixed to the inner lower wall of the handheld device 2, and the other end of the current connecting copper sheet 23 is fit and fixed with a current copper joint 33, which is connected to one end of the current wire. One end of the current thimble 21 extends out of the handheld device 2, and the other end of the current thimble 21 is provided with a thread, and the other end of the current thimble 21 passes through the handheld device 2 and the current connecting copper sheet 23 in sequence and then is threadedly connected to the current connecting nut 24.

[0059] refer to Figure 4 The voltage ejector pin 22 of the present invention includes an integrally formed voltage ejector pin 221 and a voltage sliding pin 222. The diameter of the voltage sliding pin 222 is smaller than that of the voltage ejector pin 221. The end of the voltage sliding pin 222 is provided with a thread, to which a trigger nut 210 is connected via the thread. The end of the trigger nut 210 is rounded, and the trigger nut 210 contacts or disconnects with the micro switch as the voltage ejector pin 22 moves in translation. The voltage sliding pin 222 is connected to the host 1 via a voltage wire. The voltage sliding pin 222 is provided with a reset spring 212, which is arranged between the step surface formed by the voltage ejector pin 221 and the voltage sliding pin 222 and the outer wall of the handheld device 2.

[0060] The voltage sliding post 222 of the present invention is sleeved with a sleeve 29 that protects the voltage ejector pin 22. The outer wall of the sleeve 29 is slidably connected to the handheld device 2. The end face of the sleeve 29 is provided with a retaining ring 291 having an outer diameter greater than that of the sleeve 29. The outer diameter of the retaining ring 291 is greater than or equal to the diameter of the voltage ejector post 221. The return spring 212 is disposed between the stepped surface formed by the voltage ejector post 221 and the voltage sliding post 222, and the outer wall of the retaining ring 291. Because the voltage ejector pin 22 needs to move frequently, the sleeve 29 of the present invention is provided to prevent frequent friction between the voltage ejector pin 22 and the main body of the handheld device 2, thereby extending the service life of the voltage ejector pin 22 and the handheld device 2.

[0061] The voltage wire of the present invention is connected to the voltage pin 22 via a voltage connecting copper sheet 211 , and the voltage connecting copper sheet 211 is clamped and fixed between the sleeve 29 and the trigger nut 210 .

[0062] The host of the present invention is provided with a power output module for outputting a constant current to the loop resistor and a current and voltage acquisition module for obtaining the output current value and the voltage value generated by the loop resistor. The outer wall of the host is provided with a pair of voltage interfaces 12 and a pair of current interfaces 11. The current interface 11 is connected to the output end of the power output module, and the current interface 11 and the voltage interface 12 are connected to the input end of the current and voltage acquisition module.

[0063] The current pin 21 of the present invention is connected to one end of the current conductor, the other end of which is connected to a current plug 31 that plugs into the current interface 11. The voltage pin 22 of the present invention is connected to one end of the voltage conductor, the other end of which is connected to a voltage plug 32 that plugs into the voltage interface 12. Conventional equipment connections are prone to loosening, and poor contact can lead to data fluctuations and even test interruption. The present invention adopts a "one-touch plug-in" interface design that automatically locks after insertion, allowing for quick connection while ensuring stable contact and avoiding data errors.

[0064] In order to improve the accuracy of the measurement point, the present invention designs the ejection end of the current ejector pin 21 and the ejection end of the voltage ejector pin 22 to be in the shape of a truncated cone.

[0065] refer to Figure 3 The housing 25 of the handheld device 2 of the present invention includes a grip portion 251 and an ejection portion 252. The grip portion 251 and the ejection portion 252 are integrally formed, and the angle between the grip portion 251 and the ejection portion 252 is between 145° and 170°. The current ejector pin 21 and the voltage ejector pin 22 extend perpendicularly from the end surface of the ejection portion 252. This arrangement is intended to prevent the user from twisting their wrist when the current ejector pin 21 and the voltage ejector pin 22 come into contact with the loop resistor, reducing the burden on the user and making the handheld device more convenient to use.

[0066] The micro switch 28 and sub-control module 27 of the present invention are arranged in the ejection part 252, and the handheld device power supply 26 is provided in the handheld part 251, and the handheld device power supply 26 supplies power to the sub-control module 27. The housing 25 of the handheld device 2 is provided with a charging interface, and the charging interface charges the handheld device power supply 26.

Claims

1. An intelligent digital loop resistance tester, characterized by: The invention comprises a host (1) and a pair of handheld devices (2), wherein the host (1) and the pair of handheld devices (2) are connected via a cable (3) to form a closed loop, wherein a current pin (21) is fixedly connected to the handheld device (2) and a voltage pin (22) is slidably connected to the handheld device (2), wherein the cable (3) is provided with a current conductor connected to the current pin (21) and a voltage conductor connected to the voltage pin (22), wherein the handheld device (2) is provided with a sub-control module (27) connected to the host (1) via wireless communication and a micro switch (28) electrically connected to the sub-control module (27), wherein the micro switch (28) is provided at the end of the voltage pin (22); The displacement of the voltage ejector pin (22) triggers the micro switch (28), and the sub-control module (27) detects the triggering state of the micro switch (28) and sends a test request to the host (1) via wireless communication.

2. The intelligent digital loop resistance tester according to claim 1, characterized in that: A current connection copper sheet (23) is provided in the handheld device (2), one end of the current connection copper sheet (23) is in close contact with the inner wall of the handheld device (2), one end of the current pin (21) having a thread passes through the handheld device (2) and the current connection copper sheet (23) in sequence and is threadedly connected to the current connection nut (24), the other end of the current connection copper sheet (23) is fitted and fixed to the current copper joint (33), and the current copper joint (33) is connected to one end of the current conductor.

3. The intelligent digital loop resistance tester according to claim 1, characterized in that: The voltage ejector pin (22) comprises a voltage ejector post (221) and a voltage sliding post (222); the voltage sliding post (222) and the voltage ejector post (221) are integrally formed and have a smaller diameter than the voltage ejector post (221); a trigger nut (210) is threadedly connected to the end of the voltage sliding post (222); the voltage sliding post (222) is connected to a voltage wire; a reset spring (212) is sleeved on the voltage sliding post (222); and the reset spring (212) is arranged between the voltage ejector post (221) and the outer wall of the handheld device (2).

4. The intelligent digital loop resistance tester according to claim 3, characterized in that: A sleeve (29) is sleeved on the voltage sliding post (222), and the sleeve (29) is slidably connected to the handheld device (2). A limiting ring (291) is provided on the end face of the sleeve (29), and the outer diameter of the limiting ring (291) is larger than the outer diameter of the sleeve (29) and larger than or equal to the diameter of the voltage ejection post (221). The return spring (212) is arranged between the outer wall of the limiting ring (291) and the step surface formed by the voltage ejection post (221) and the voltage sliding post (222).

5. The intelligent digital loop resistance tester according to claim 4, characterized in that: A voltage connection copper sheet (211) is clamped and fixed between the sleeve (29) and the trigger nut (210), and the voltage connection copper sheet (211) is connected to a voltage wire.

6. The intelligent digital loop resistance tester according to claim 1, characterized in that: The host is provided with a power output module and a current and voltage acquisition module. The outer wall of the host is provided with a pair of current interfaces (11) and a pair of voltage interfaces (12). The power output module outputs a constant current to the loop resistor through the current interface (11). The current and voltage acquisition module obtains the output current value through the current interface (11) and obtains the voltage value generated by the loop resistor through the voltage interface (12).

7. The intelligent digital loop resistance tester according to claim 6, characterized in that: One end of the current conductor of the cable (3) is connected to the current pin (21), and the other end of the current conductor of the cable (3) is plugged into the current interface (11) via the current plug (31); one end of the voltage conductor of the cable (3) is connected to the voltage pin (22), and the other end of the voltage conductor of the cable (3) is plugged into the voltage interface (12) via the voltage plug (32).

8. The intelligent digital loop resistance tester according to any one of claims 1 to 7, characterized in that: The ejection end of the current ejector pin (21) and the ejection end of the voltage ejector pin (22) are both frustums.

9. The intelligent digital loop resistance tester according to any one of claims 1 to 7, characterized in that: The housing (25) of the handheld device (2) is provided with an integrally formed handheld portion (251) and an ejection portion (252), wherein the handheld portion (251) and the ejection portion (252) form a certain angle, and the certain angle ranges from 145° to 170°.

10. The intelligent digital loop resistance tester according to claim 9, characterized in that: The sub-control module (27) and the micro switch (28) are arranged in the ejection portion (252), and a handheld device power supply (26) for supplying power to the sub-control module (27) is provided in the handheld portion (251).

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