Novel high-precision current detection resistor

Abstract

The utility model provides a novel high-precision current detection resistor. Comprising a resistance plate body and two red copper plate bodies, the side walls of the two sides of the resistance plate body are welded and fixed to the side walls of the two red copper plate bodies respectively, two voltage sampling pins extend on the resistance plate body, and current sampling pins extend on the red copper plate bodies. According to the high-precision current detection resistor, the resistor plate body is used for replacing a resistor disc in a traditional high-precision current detection resistor, the resistance value of the red copper plate body is small, the limitation of the thickness of the resistor plate body is avoided through the resistor plate body, and the temperature rise of the resistor plate body in use is reduced; the current sampling pin and the red copper plate body are made of the same material, the current sampling pin and the red copper plate body do not need to be welded, the voltage sampling pin and the resistor plate body are made of the same material, the voltage sampling pin and the resistor plate body do not need to be welded, and the voltage sampling pin and the current sampling pin do not have deviation on welding point positions. Therefore, the voltage sampling pin and the current sampling pin have excellent conductivity and mechanical strength, and the consistency of the voltage sampling pin and the current sampling pin is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a novel high-precision current-detecting resistor. Background Art

[0002] High-precision current-detecting resistors are often used for voltage division, sampling, etc., so there are high requirements for the resistance value and temperature drift of the resistor. In the field of electrical measurement, the accuracy and stability of the current-detecting resistor are crucial for accurately obtaining current data. A precision resistor has a relatively high resistance value accuracy. The common tolerances of resistors we see are generally 5%, 10%, or 1%, etc. A resistor with a tolerance of 1% can also be called a precision resistor, but many customers have higher usage requirements, such as 0.5% or even 0.1%. The structure of the existing small-value high-precision current-detecting resistor includes a resistor chip, an insulating sheet, a heat dissipation plate, and four pins. The four pins are respectively welded to the resistor chip, and the resistor chip, the insulating sheet, and the heat dissipation plate are encapsulated in a housing. However, the traditional high-precision current-detecting resistor has the following disadvantages:

[0003] 1) Since the resistance value of the high-precision current-detecting resistor is small (1mΩ - 5mΩ), the resistor chip needs to be made extremely thin, and due to the structure of the resistor chip, problems such as a large overall heat generation of the resistor chip occur.

[0004] 2) Since welding is required between the four pins and the resistor chip, it is easy to cause a high temperature drift and it is difficult to ensure the consistency of the four pins after welding, which will ultimately affect the measurement results of the high-precision current-detecting resistor.

[0005] 3) High process requirements and high costs.

[0006] The invention with the application number CN202311711066.7 provides a bridge-type coaxial current-detecting resistor, belonging to the field of current detection. The bridge-type coaxial current-detecting resistor includes a current input terminal, a current output terminal, a coaxial connector, a current-detecting resistor, and a compensating inductor; one end of the compensating inductor is connected to the current input terminal, and the other end is connected to the inner conductor of the coaxial connector; the outer conductor of the coaxial connector is connected to the current output terminal; one end of the current-detecting resistor is connected between the compensating inductor and the current input terminal, and is connected between the outer conductor of the coaxial connector and the current output terminal; the characteristic impedance of the coaxial connector is greater than the resistance value of the current-detecting resistor; the ratio of the characteristic impedance of the coaxial connector to the inductance value of the compensating inductor is equal to the ratio of the resistance value of the current-detecting resistor to its parasitic inductance value.

[0007] However, the current-detecting resistor in the above patent technology has many deficiencies in terms of accuracy and heat dissipation. Especially in an environment with high current or long-term operation, its performance is easily affected. Therefore, developing a novel high-precision current-detecting resistor to meet the needs of modern electrical measurement has become an urgent problem in the industry. Summary of the Utility Model

[0008] The purpose of the present utility model is to provide a new type of high-precision galvanometer resistor to solve the problems raised in the above background technology:

[0009] 1), how to ensure that the resistor has a certain thickness while ensuring that the resistance value of the resistor is small, and reduce the problem of large overall heat generation of the resistor chip.

[0010] 2), how to avoid the problem of poor consistency of the four pins caused by welding between the four pins and the resistor chip, and ensure the measurement result of the high-precision galvanometer resistor.

[0011] 3), how to improve the current-carrying capacity, optimize the heat dissipation performance, and at the same time maintain the high-precision measurement ability.

[0012] To achieve the above purpose, the present utility model provides the following technical solutions:

[0013] A new type of high-precision galvanometer resistor;

[0014] It includes a resistor plate body and two copper plate bodies. The side walls on both sides of the resistor plate body are respectively welded and fixed to the side walls of the two copper plate bodies. Two voltage sampling pins extend from the resistor plate body, and current sampling pins extend from the copper plate bodies.

[0015] After adopting such a structure, the resistor plate body is used to replace the resistor chip in the traditional high-precision galvanometer resistor. The copper plate body itself has a small resistance value, and the resistor plate body avoids the limitation of the thickness of the resistor plate body, greatly reducing the temperature rise during the use of the resistor plate body;

[0016] The current sampling pins are made of the same material as the copper plate bodies, and there is no need to weld between the current sampling pins and the copper plate bodies. Similarly, the voltage sampling pins are made of the same material as the resistor plate body, and there is no need to weld between the voltage sampling pins and the resistor plate body. There will be no deviation in the welding points of the voltage sampling pins and the current sampling pins. This design enables the voltage sampling pins and the current sampling pins to have excellent electrical conductivity and mechanical strength, and the consistency of the voltage sampling pins and the current sampling pins is ensured.

[0017] Moreover, this new type of high-precision galvanometer resistor can be directly used without being equipped with an insulating heat dissipation patch and a heat dissipation aluminum sheet, and there is no need to encapsulate the outside of the resistor plate body and the two copper plate bodies.

[0018] On the basis of the above technical solutions, the present utility model can also be improved as follows.

[0019] Further, a resistance adjustment notch is opened at the welding joint between the copper plate body and the resistor plate body. The resistance adjustment notch divides the resistor plate body into a resistance part for current passage and a heat dissipation part that is not in contact with the copper plate body.

[0020] After adopting such a structure, the design of the resistance adjusting notch not only facilitates the adjustment of the resistance value, but also effectively separates the resistance part and the heat dissipation part, improving the heat dissipation efficiency of the resistance.

[0021] After adopting such a structure, by increasing the heat dissipation area and utilizing the excellent heat conduction performance of the metal material, the heat dissipation efficiency of the resistance is further improved, ensuring that the resistance can maintain stable performance in a high-current or long-term working environment.

[0022] Furthermore, it also includes two insulating heat dissipation patches and two heat dissipation aluminum sheets. The two insulating heat dissipation patches and the two heat dissipation aluminum sheets are respectively located on the two side end faces of the resistance plate body and the copper plate body. One side end face of the insulating heat dissipation patch is adhesively fixed to the end faces of the resistance plate body and the copper plate body, and the other side end face of the insulating heat dissipation patch is adhesively fixed to the corresponding heat dissipation aluminum sheet.

[0023] After adopting such a structure, compared with the traditional high-precision galvanometer resistance which only has a heat dissipation plate structure on one side, this new type of high-precision galvanometer resistance has the ability to dissipate heat from both sides and can be applied to more installation environments. And compared with the traditional high-precision galvanometer resistance housing encapsulation structure, this new type of high-precision galvanometer resistance does not require encapsulation, further enhancing the heat dissipation ability of this new type of high-precision galvanometer resistance.

[0024] Furthermore, a first mounting hole is opened on the heat dissipation part of the resistance plate body.

[0025] Furthermore, two heat dissipation aluminum sheets are provided with second mounting holes corresponding to the positions of the first mounting holes of the resistance plate body. The first mounting hole and the second mounting hole are coaxial, and the diameter of the second mounting hole is smaller than that of the first mounting hole.

[0026] The beneficial effects of the present utility model are as follows: By adopting a combined material of manganese copper and copper, a carefully designed resistance adjusting notch, and a heat dissipation structure, high sensitivity, high stability, and excellent heat dissipation performance are achieved. In addition, the present utility model also has the advantages of simple structure, low manufacturing cost, and easy maintenance, and is applicable to various electrical measurement occasions. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of the first embodiment of this new type of high-precision galvanometer resistance.

[0028] Figure 2 is Figure 1 the left view of

[0029] Figure 3 It is a schematic diagram of the resistance plate body and two copper plate bodies in the first embodiment of this new type of high-precision galvanometer resistance.

[0030] Figure 4 It is a chart of the test data of the first embodiment of this new type of high-precision galvanometer resistance.

[0031] Figure 5 It is a test data chart of Comparative Example 1 of the present new high-precision galvanometer resistor.

[0032] Figure 6 It is a schematic structural diagram of Embodiment 2 of the present new high-precision galvanometer resistor.

[0033] Explanation of reference numerals in the figure:

[0034] Resistor plate body - 100; Voltage sampling pin - 110; Resistor part - 120; Heat dissipation part - 130; First mounting hole - 131; Purple copper plate body - 200; Current sampling pin - 210; Resistance adjusting notch - 300; Insulating heat dissipation patch - 400; Heat dissipation aluminum sheet - 500; Second mounting hole - 510. Specific embodiments

[0035] In order to make the above objects, features and advantages of the present utility model more obvious and understandable, the following detailed description of the specific embodiments of the present utility model will be given with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present utility model. However, the present utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.

[0036] The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present utility model belongs. The terms used herein in the specification of the present utility model are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0038] Embodiment 1

[0039] Please refer to Figures 1 to 3 .

[0040] The present new high-precision galvanometer resistor includes a resistor plate body 100, two purple copper plate bodies 200, two insulating heat dissipation patches 400 and two heat dissipation aluminum sheets 500.

[0041] The material of the resistor plate body 100 is selected as manganin alloy. The resistor plate body 100 can be made with a thickness of 1 - 2.5 mm. The side walls on both sides of the resistor plate body 100 are respectively welded and fixed to the side walls of two copper plate bodies 200 by an electron beam welding process. Two voltage sampling pins 110 extend from the resistor plate body 100, and current sampling pins 210 extend from the copper plate bodies 200 (the copper plate bodies 200 and the current sampling pins 210 are an integral structure formed by stamping, and the resistor plate body 100 and the voltage sampling pins 110 are also an integral structure formed by stamping). The current sampling pins 210 are made of the same material as the copper plate bodies 200, and the resistor plate body 100 and the voltage sampling pins 110 are made of the same material, and no welding is required, ensuring the consistency of the voltage sampling pins 110 and the current sampling pins 210. A trimming notch 300 is opened at the welding joint between the copper plate body 200 and the resistor plate body 100. The trimming notch 300 divides the resistor plate body 100 into a resistance part 120 for current passage and a heat dissipation part 130 that does not contact the copper plate body 200.

[0042] Two insulating heat dissipation patches 400 and two heat dissipation aluminum sheets 500 are respectively located on the two end faces of the resistor plate body 100 and the copper plate body 200. One end face of the insulating heat dissipation patch 400 is adhesively fixed to the end faces of the resistor plate body 100 and the copper plate body 200, and the other end face of the insulating heat dissipation patch 400 is adhesively fixed to the corresponding heat dissipation aluminum sheet 500.

[0043] A first mounting hole 131 is opened on the heat dissipation part 130 of the resistor plate body 100. The two heat dissipation aluminum sheets 500 are provided with second mounting holes 510 corresponding to the positions of the first mounting holes 131 of the resistor plate body 100. The first mounting hole 131 and the second mounting hole 510 are coaxial, and the aperture of the second mounting hole 510 is smaller than the aperture of the first mounting hole 131.

[0044] Comparative experiment

[0045] In this embodiment, for the new type of high-precision current detecting resistor, the resistance value is 1 mΩ, the rated power is 10, and the tolerance is ±0.5%. The test data of this new type of high-precision current detecting resistor are as follows:

[0046]

[0047] As Figure 4 shown, the test conclusion: Shunt TCR test: 20°C - 60°C ≤ 10 ppm.

[0048] For the comparative example, an aluminum precision resistor of the foreign brand Isabellenhutte with better performance and a resistance value of 1 mΩ is selected. The test data of the aluminum precision resistor in the above comparative example are as follows:

[0049]

[0050] As Figure 5 shown, test conclusion: Shunt TCR test: 20°C - 60°C ≤ 50 ppm.

[0051] Embodiment 2

[0052] As Figure 6 shown.

[0053] In this embodiment, the difference between the new type of high-precision galvanometer resistance and Embodiment 1 is only that: there is no first mounting hole on the resistor plate body 100, but there is a mounting notch 140 on the resistor plate body 100, and the inner diameter of the mounting notch 140 is much larger than the aperture of the second mounting hole.

[0054] The above is only one implementation manner of the present utility model. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present utility model, several variations and improvements can be made, and these should also be regarded as belonging to the protection scope of the present utility model.

Claims

1. A new type of high-precision current-sensing resistor, characterized by: The invention comprises a resistor plate body (100) and two copper plates (200), wherein the side walls of the resistor plate body (100) are respectively welded and fixed to the side walls of the two copper plates (200), the resistor plate body (100) is provided with two voltage sampling pins (110), and the copper plate body (200) is provided with a current sampling pin (210).

2. The novel high-precision current-sensing resistor according to claim 1 is characterized in that: A resistance adjustment notch (300) is provided at the welding point between the copper plate body (200) and the resistor plate body (100), and the resistance adjustment notch (300) divides the resistor plate body (100) into a resistor part (120) for current to pass through and a heat dissipation part (130) that is not in contact with the copper plate body (200).

3. The novel high-precision current-sensing resistor according to claim 2 is characterized in that: It also comprises two insulating heat dissipation patches (400) and two heat dissipation aluminum sheets (500), the two insulating heat dissipation patches (400) and the two heat dissipation aluminum sheets (500) being respectively located on the end surfaces of both sides of the resistor plate body (100) and the copper plate body (200), one end surface of the insulating heat dissipation patch (400) being bonded and fixed to the end surfaces of the resistor plate body (100) and the copper plate body (200), and the other end surface of the insulating heat dissipation patch (400) being bonded and fixed to the corresponding heat dissipation aluminum sheet (500).

4. The novel high-precision current-sensing resistor according to claim 3 is characterized in that: A first mounting hole (131) is formed on the heat dissipation portion (130) of the resistor plate body (100).

5. The novel high-precision current-sensing resistor according to claim 3 is characterized in that: The two heat dissipation aluminum sheets (500) are provided with second mounting holes (510) at positions corresponding to the first mounting holes (131) of the resistor plate body (100); the first mounting hole (131) and the second mounting hole (510) are coaxial, and the aperture of the second mounting hole (510) is smaller than the aperture of the first mounting hole (131).

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