A high resistance measuring device
By combining a current amplifier module and a ruthenium oxide resistor, the problem of low voltage tolerance of the tested component is solved, enabling convenient and accurate measurement of high resistance values and reducing the impact of environmental interference.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING HANGUANG XINYUAN TECHNOLOGY CO LTD
- Filing Date
- 2025-08-12
- Publication Date
- 2026-07-17
AI Technical Summary
Existing measurement methods are limited by the low withstand voltage of the measured component, which prevents the application of excessively high voltages, resulting in insufficient current and making it difficult to accurately measure high-resistance components.
By employing a current amplifier module and measuring instruments, the current signal is amplified and converted into a voltage signal. Combined with the resistance of ruthenium oxide material and the coaxial terminal connector of polytetrafluoroethylene material, the influence of environmental interference is reduced, and high resistance measurement is achieved.
It enables convenient and accurate high-resistivity measurement, reduces the impact of environmental fluctuations on measurement results, and improves the reliability of measurement.
Smart Images
Figure CN224518812U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of measurement technology, and more specifically, to a high-resistance measuring device. Background Technology
[0002] In engineering practice, it is often necessary to measure 10 12 ~10 13 In the case of Ω resistors, the resistance value within this range is generally measured by increasing the measurement voltage to 500V~1500V. This increases the measurement current, making it easier for the measuring instrument to accurately capture the current value and fundamentally reducing measurement errors.
[0003] However, some components being measured cannot withstand voltages of more than 50V, and cannot be subjected to excessively high voltages. This results in insufficient current in the test circuit, which is difficult to capture, increasing the difficulty of measurement and leading to inaccurate measurement results. Utility Model Content
[0004] The problem this invention aims to solve is that existing measurement methods are limited by the performance of the measured component, which has low pressure tolerance.
[0005] To solve the above problems, in a first aspect, this utility model provides a high-resistance measuring device, including a current amplifier module and a measuring instrument, wherein the current amplifier module includes a first power supply, a second power supply, a first resistor, a second resistor, and a current amplifier;
[0006] The positive terminal of the first power supply is connected to one end of the component under test, and the negative terminal of the first power supply is grounded. One end of the second resistor is connected to the other end of the component under test. The other end of the second resistor and one end of the first resistor are both connected to the negative input terminal of the current amplifier. The positive input terminal of the current amplifier is grounded. The output terminal of the current amplifier is connected to the other end of the first resistor and the input terminal of the measuring instrument, respectively. The output terminal of the measuring instrument is grounded. The positive and negative terminals of the second power supply are connected to the positive and negative power supply terminals of the current amplifier, respectively.
[0007] Optionally, the current amplifier module is fitted with a metal shielding shell.
[0008] Optionally, the resistance of the first resistor is 10 GΩ.
[0009] Optionally, the voltage of the first power supply is 50V.
[0010] Optionally, the first resistor is a resistor made of ruthenium oxide.
[0011] Optionally, the plugs at both ends of the component under test are coaxial terminal connectors made of polytetrafluoroethylene.
[0012] Optionally, the current amplifier module is mounted on a PCB board, and the negative input terminal of the current amplifier, the other end of the second resistor, and one end of the first resistor are connected to a polytetrafluoroethylene isolation post inserted on the PCB board via a silver-plated polytetrafluoroethylene high-temperature wire.
[0013] This invention provides a high-resistance measuring device. Compared with the prior art, it has the following advantages:
[0014] A voltage is applied to one end of the component under test, and the other end is connected to a current amplifier. The current through the component under test is calculated according to Ohm's law. The current through the component under test is injected into the negative input terminal of the current amplifier through the second resistor. After amplification, the current is output as a voltage from the output terminal of the current amplifier U1. The output voltage can be connected to a millivoltmeter to display the measured value. It can be measured directly, is convenient, and has little fluctuation due to environmental influences. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a schematic diagram of a high-resistance measuring device provided in an embodiment of the present invention. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0018] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.
[0019] like Figure 1 As shown in the figure, a high-resistance measuring device provided in this application embodiment includes a current amplifier module and a measuring instrument. The current amplifier module includes a first power supply, a second power supply, a first resistor R1, a second resistor R2, and a current amplifier U1.
[0020] The positive terminal of the first power supply is connected to one end of the component under test R, and the negative terminal of the first power supply is grounded. One end of the second resistor R2 is connected to the other end of the component under test R. The other end of the second resistor R2 and one end of the first resistor R1 are both connected to the negative input terminal of the current amplifier U1. The positive input terminal of the current amplifier U1 is grounded. The output terminal of the current amplifier U1 is connected to the other end of the first resistor R1 and the input terminal of the measuring instrument, respectively. The output terminal of the measuring instrument is grounded. The positive and negative terminals of the second power supply are connected to the positive and negative power supply terminals of the current amplifier U1, respectively.
[0021] Specifically, such as Figure 1 As shown, the resistance of the first resistor R1 is 10. 11 The resistance of the second resistor R2 can be selected as 100kΩ, the voltage of the first power supply is 50V, the voltage of the second power supply is 5V, the current amplifier U1 can be selected as LMC6042, and the measuring instrument can be a pointer-type millivoltmeter.
[0022] In this optional embodiment, a voltage is applied to one end of the component under test R, and the other end is connected to a current amplifier U1. It is assumed that the resistance of the component under test R is 10 ohms. 12 Given an applied voltage of 50V, according to Ohm's law, the current through the measured component R is 5 x 10⁻⁶. ˉ11 A current (the second resistor R2 is negligible relative to the measured component R, and their resistances differ by at least 10 orders of magnitude) flows through the measured component R and is injected into the negative input terminal of the current amplifier U1 via the second resistor R2. After passing through 10... 1° The amplification factor is output as a voltage from the output terminal of the current amplifier U1. The output voltage of the current amplifier U1 is -0.5V (inverting amplification). The output voltage can be directly measured by connecting a millivoltmeter, which is convenient and has little fluctuation due to environmental influences.
[0023] In an optional embodiment of this application, the first resistor R1 is a resistor made of ruthenium oxide. This material has good resistance stability, low temperature drift, and low voltage coefficient, ensuring the stability of the amplification factor of the current amplifier U1.
[0024] In an optional embodiment of this application, the current amplifier module is fitted with a metal shielding shell. The current amplifier U1 has a too high amplification factor (10). 1 (°), which is highly susceptible to electromagnetic interference and must be shielded with an electromagnetic shield to isolate the interference.
[0025] In an optional embodiment of this application, the plugs at both ends of the component R under test are coaxial terminal connectors made of polytetrafluoroethylene (PTFE). This material has excellent insulation properties, reducing the impact of leakage current shunting between connectors on the measurement.
[0026] In an optional embodiment of this application, the current amplifier module is mounted on a PCB board. The negative input terminal of the current amplifier U1, the other end of the second resistor R2, and one end of the first resistor R1 are connected to a PTFE isolation post inserted into the PCB board via a silver-plated PTFE high-temperature wire. The PTFE isolation post is connected to adjacent devices via a 0.2 mm silver-plated PTFE high-temperature wire. The high-temperature wire does not touch the casing, PCB, or adjacent wires, ensuring insulation performance and reducing the impact of leakage current shunting between connectors on the measurement.
[0027] After cleaning the PCB board with anhydrous alcohol, bake it in a drying oven at 80 degrees Celsius for 2 hours. This improves the PCB's insulation performance and reduces the impact of leakage current shunts on measurements. Wear silicone protective gloves during assembly to prevent contamination and insulation degradation.
[0028] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0029] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A high resistance measuring device, characterized by, It includes a current amplifier module and a measuring instrument. The current amplifier module includes a first power supply, a second power supply, a first resistor, a second resistor, and a current amplifier. The positive terminal of the first power supply is connected to one end of the component under test, and the negative terminal of the first power supply is grounded. One end of the second resistor is connected to the other end of the component under test. The other end of the second resistor and one end of the first resistor are both connected to the negative input terminal of the current amplifier. The positive input terminal of the current amplifier is grounded. The output terminal of the current amplifier is connected to the other end of the first resistor and the input terminal of the measuring instrument, respectively. The output terminal of the measuring instrument is grounded. The positive and negative terminals of the second power supply are connected to the positive and negative power supply terminals of the current amplifier, respectively.
2. The high resistance measuring device of claim 1, wherein, The current amplifier module is covered with a metal shielding shell.
3. The high resistance measuring device of claim 1, wherein, The resistance of the first resistor is 10 GΩ.
4. The high resistance measuring device of claim 1, wherein, The voltage of the first power supply is 50V.
5. The high resistance measuring device of claim 1, wherein, The first resistor is a resistor made of ruthenium oxide.
6. The high resistance measuring device of claim 1, wherein, The two plugs of the component under test are coaxial terminal connectors made of polytetrafluoroethylene.
7. The high resistance measuring device of any one of claims 1-6, wherein, The current amplifier module is mounted on a PCB board. The negative input terminal of the current amplifier, the other end of the second resistor, and one end of the first resistor are connected to a polytetrafluoroethylene isolation post inserted on the PCB board via a silver-plated polytetrafluoroethylene high-temperature wire.