A shunt resistor with temperature detection function

Abstract

The application provides a shunt resistor with temperature detection function, which comprises a first electrode, a second electrode, an intermediate resistor and a circuit board collecting device, and the intermediate resistor is located between the first electrode and the second electrode. The circuit board collecting device comprises a substrate, a sampling output connector, a temperature collecting module and a voltage collecting module. The substrate is provided with a contact surface and an observation surface, the contact surface faces the intermediate resistor, and a gap exists between the contact surface and the intermediate resistor, and the sampling output connector is arranged on the observation surface. Two pads are arranged on the contact surface, and the two pads correspond to the first electrode and the second electrode respectively. Temperature isolation walls are arranged at the two ends of the intermediate resistor, and the temperature isolation walls and the contact surface form a breathable gap. The shunt resistor can collect the temperature of the shunt resistor in real time, compensate the resistance value of the product at different temperatures, improve the measurement accuracy, control the flow range of the molten welding liquid during welding, and realize stable and firm welding.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shunt resistor, in particular to a shunt resistor with temperature detection function. BACKGROUND

[0002] In a wideband power meter and a power analyzer, a shunt resistor is a main sensor for realizing current measurement function, and its function is to convert a current signal into a voltage signal within a certain range based on Ohm's law. During use of the shunt resistor, the shunt resistor will heat up and the resistance value will change due to the material characteristics when the current passes through the shunt resistor. However, due to the continuous change of temperature, the influence of temperature change on the resistance value is often ignored during the use in the past, and the resistance value of the shunt resistor is defaulted as a constant. This leads to a decrease in the measurement accuracy of the shunt resistor during use.

[0003] Meanwhile, when the existing collection device and the shunt body are subjected to high-temperature welding, the molten welding liquid is easy to penetrate into the gap between the parts, and the short circuit phenomenon between the collection device and the shunt body is easy to occur.

[0004] Therefore, how to design a shunt resistor with temperature detection function, which can collect the temperature of the shunt resistor in real time, compensate the resistance value of the product at different temperatures, and improve the measurement accuracy, and at the same time, control the flow range of the molten welding liquid during welding to prevent the short circuit phenomenon, is a technical problem to be solved by those skilled in the art. SUMMARY

[0005] The present application aims to overcome the shortcomings in the prior art, and provides a shunt resistor with temperature detection function, which can collect the temperature of the shunt resistor in real time, compensate the resistance value of the product at different temperatures, and improve the measurement accuracy, and at the same time, control the flow range of the molten welding liquid during welding to prevent the short circuit phenomenon.

[0006] The present application is achieved by the following technical solutions:

[0007] A shunt resistor with temperature detection function, comprising: a first electrode, a second electrode, an intermediate resistor body, and a circuit board collection device, wherein the intermediate resistor body is located between the first electrode and the second electrode;

[0008] The first electrode, the second electrode and the intermediate resistor body jointly form a die body, and the circuit board collection device is arranged on the die body; the circuit board collection device comprises a substrate, a sampling output connector, a temperature collection module and a voltage collection module;

[0009] The substrate is provided with a contact surface and an observation surface, the contact surface faces the intermediate resistor, and a gap exists between the contact surface and the intermediate resistor; the observation surface is away from the intermediate resistor, and the sampling output connector is arranged on the observation surface;

[0010] Two pads are arranged on the contact surface, and the two pads correspond to the first electrode and the second electrode respectively, and the substrate is connected with the first electrode and the second electrode through the pads;

[0011] The thickness of the first electrode and the second electrode is H1, the distance of the gap is H2, and H1>H2; temperature insulation walls are arranged at two ends of the intermediate resistor respectively, the thickness of the temperature insulation wall is H3, and H3<H2, and an air permeable gap is formed between the temperature insulation wall and the contact surface.

[0012] In one of the embodiments, a plurality of welding blocks are arranged on each of the pads, the plurality of welding blocks are arranged in a matrix manner, and a blank gap is formed between two adjacent welding blocks.

[0013] In one of the embodiments, the welding block is made of solder.

[0014] In one of the embodiments, the temperature acquisition module is arranged on the substrate, the temperature acquisition module comprises an NTC temperature sensor and a temperature sampling lead wire, and the NTC temperature sensor is electrically connected with the sampling output connector through the temperature sampling lead wire.

[0015] The voltage acquisition module comprises a voltage sampling lead wire, and the sampling output connector and the pad are electrically connected through the voltage sampling lead wire.

[0016] In one of the embodiments, a label is arranged on the contact surface of the substrate.

[0017] In one of the embodiments, H2=0.25H1~0.4H1.

[0018] In one of the embodiments, mounting holes are arranged on the first electrode and the second electrode, and the two mounting holes are symmetrically arranged with the intermediate resistor as the center.

[0019] In one of the embodiments, the first electrode and the second electrode are made of red copper.

[0020] In summary, the shunt resistor with temperature detection function of the present application can collect the temperature of the shunt resistor in real time, compensate the resistance value of the product at different temperatures, and improve the measurement accuracy; at the same time, the flow range of molten solder can be controlled during welding to prevent short circuit phenomenon. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0022] Figure 1 A plan view of the shunt resistor with temperature detection function of the present application;

[0023] Figure 2 A side view of the shunt resistor with temperature detection function as shown in Figure 1

[0024] Figure 3 A perspective view of the die body of the shunt resistor with temperature detection function;

[0025] Figure 4 A plan view of the die body of the shunt resistor with temperature detection function;

[0026] Figure 5 A plan view of the circuit board collection device as shown in Figure 1

[0027] Figure 6 A plan view of the circuit board collection device as shown in Figure 1

[0028] Figure 7 A partial sectional view of the shunt resistor with temperature detection function as shown in Figure 1

[0029] Figure 8 A temperature compensation curve obtained by fitting according to the test values. DETAILED DESCRIPTION

[0030] In order to facilitate the understanding of the present application, the present application will be described more fully with reference to the related drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be realized in many different forms, and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0031] ​​​​It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. As used herein the terms "vertical", "horizontal", "left", "right", and the like are merely used for the purpose of explanation and are not intended to be limiting.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0033] The present application provides a shunt resistor with temperature detection function, as shown in Figure 1 , Figure 2 , Figure 3 and Figure 4 , which comprises a first electrode 100, a second electrode 200, an intermediate resistor body 300 and a circuit board collecting device 400. The intermediate resistor body 300 is located between the first electrode 100 and the second electrode 200, and the nominal resistance value of the shunt resistor 10 is determined by the size and size of the intermediate resistor body 300. The first electrode 100, the second electrode 200 and the intermediate resistor body 300 together form a die body, and the circuit board collecting device 400 is arranged on the die body.

[0034] As shown in Figure 5 and Figure 6 , the circuit board collecting device 400 comprises a substrate 410, a sampling output connector 420, a temperature collecting module 430 and a voltage collecting module 440. The substrate 410 is provided with a contact surface 411 and an observation surface 412. The contact surface 411 faces the intermediate resistor body 300, and there is a gap 401 between the contact surface 411 and the intermediate resistor body 300. The observation surface 412 is away from the intermediate resistor body 300, and the sampling output connector 420 is arranged on the observation surface 412. Two pads 413 are arranged on the contact surface 411, and the two pads 413 correspond to the first electrode 100 and the second electrode 200 respectively. The substrate 410 is connected with the first electrode 100 and the second electrode 200 through the pads 413.

[0035] In the embodiment, as shown in Figure 5 , the temperature collecting module 430 is arranged on the substrate 410, and the temperature collecting module 430 comprises an NTC temperature sensor 431 and a temperature sampling lead 432. The NTC temperature sensor 431 is electrically connected with the sampling output connector 420 through the temperature sampling lead 432.

[0036] As shown in Figure 6 The voltage sampling line 441 is electrically connected between the sampling output connector 420 and the pad 413.

[0037] The working principle of the shunt resistor 10 with temperature detection function is as follows:

[0038] In use, first, the circuit board acquisition device 400 is welded to the die body, and the sampling output connector 420 is electrically connected with an external reading device; then, the first electrode 100 and the second electrode 200 are respectively connected to the positive and negative electrodes of a power supply, and the current passes through the first electrode 100, the intermediate resistor body 300 and the second electrode 200 in sequence. Next, the resistance value of the NTC temperature sensor 431 is read by the external reading device, so as to obtain the surface temperature of the intermediate resistor body 300 at this time, and further obtain the resistance value of the shunt resistor 10 at this time. At the same time, the voltage across the die body can be read by the external reading device by using the voltage acquisition module 440 of the circuit board acquisition device 400, and the current of the shunt resistor 10 at this time can be calculated by using the formula.

[0039] As shown in Figure 8 The abscissa represents temperature, and the ordinate represents resistance ratio (the resistance value measured at each temperature divided by the resistance value at the reference temperature). The resistance value of the shunt resistor is calibrated by testing at different temperatures and different currents, and then the temperature compensation curve is obtained according to the test value.

[0040] Compared with the traditional shunt resistor, the shunt resistor 10 of the present application can obtain the temperature of the intermediate resistor body 300 in real time through the NTC temperature sensor 431, and then match the temperature compensation curve to obtain the resistance value of the intermediate resistor body 300 at different temperatures, so that the circuit test precision of the shunt resistor 10 at different temperatures is higher and the measurement is more accurate.

[0041] In the present embodiment, as shown in Figure 5 The contact surface 411 of the substrate 410 is provided with a label 414. During production, the shunt resistor 10 is calibrated and tested to obtain the temperature compensation curve, and then the nominal value of the shunt resistor 10 is measured. The obtained nominal value and the temperature compensation curve are marked on the label 414 in the form of a two-dimensional code, laser marking or other means, realizing complete and real-time recording of information, so as to more accurately convey to the use end of the product.

[0042] Further, the present application also solves the technical problem of welding the circuit board collecting device 400 and the die body. In the traditional welding mode of electrical connection, the solder is usually applied on the first electrode 100 and the second electrode 200 of the die body, and then the solder is heated to a molten state, and then the circuit board collecting device 400 is pressed on the molten solder. Of course, the circuit board collecting device 400 can also be placed on the solder first, and then the shunt resistor 10 is heated to a high temperature to make the solder melt and solidify after high-temperature melting, thereby realizing welding. However, it is found in actual production process that the above-mentioned traditional welding has the following problems: since the thickness of the intermediate resistor body 300 of the existing die body is flush with the thickness of the first electrode 100 and the second electrode 200, when the circuit board collecting device 400 is on the die body, the gap between them is small, and the gap will form a "solder climbing" capillary effect, so that the molten solder seeps into the gap (equivalent to the molten solder forming a "conductive connecting bridge" between the first electrode 100 and the second electrode 200). In this case, the solder seeping into the gap will adhere to the intermediate resistor body 300, even connecting the first electrode 100 and the second electrode 200, resulting in short circuit of the die body.

[0043] To solve the above technical problems, the shunt resistor 10 of the present application is specially designed, specifically:

[0044] On the one hand, as shown in Figure 7 , the contact surface 411 of the substrate 410 and the intermediate resistor body 300 have a gap 401. Preferably, the thickness of the first electrode 100 and the second electrode 200 is H1, the distance of the gap 401 is H2, H1>H2, and H2=0.25H1~0.4H1. For example, H1=10mm, then H2=2.5mm~4mm. After designing the gap 401, the thickness of the intermediate resistor body 300 will be obviously smaller than the thickness of the first electrode 100 and the second electrode 200 (the difference is H2). In this way, the existence of the gap 401 will interrupt the gap between the circuit board collecting device 400 and the die body, so that there is no "solder climbing" capillary effect. When part of the molten solder overflows, the molten solder will fall into the gap 401. In this way, the molten solder of the two pads 413 cannot be connected to each other, that is, no "conductive connecting bridge" will be formed between them, so that the short circuit phenomenon will not occur;

[0045] On the other hand, as shown in Figure 6 , the contact surface 411 is provided with two pads 413, and the two pads 413 correspond to the first electrode 100 and the second electrode 200 respectively. Preferably, each pad 413 is provided with a plurality of welding blocks 4131, and the plurality of welding blocks 4131 are arranged in a matrix manner, and a blank gap is formed between adjacent two welding blocks 4131. The welding block 4131 is made of solder material;

[0046] In still another aspect, as shown in Figure 3 The two ends of the intermediate resistor 300 are respectively provided with temperature insulation walls 310, the thickness of the temperature insulation walls 310 is H3, and H3 Figure 2 In this embodiment, the temperature insulation walls 310 and the intermediate resistor 300 are integrally formed by stamping the same kind of alloy material; it can be understood that the temperature insulation walls 310 are not completely sealed to the internal gap space 401, and the main purpose of the temperature insulation walls 310 is to ensure the constant temperature inside the gap space 401, prevent the heat generated by the intermediate resistor 300 from escaping too fast due to external influences, so that the NTC temperature sensor 431 can more accurately collect the temperature of the intermediate resistor 300, and improve the accuracy of the reading; in addition, the temperature insulation walls 310 and the contact surface 411 form a breathable gap 301, and the heat generated by the intermediate resistor 300 can be properly dissipated through the breathable gap 301, so that the high heat in the gap space 401 is not blocked and cannot be dissipated, thereby causing damage to related components, which will not cause substantial impact on the accuracy of the reading; the breathable gap 301 between the temperature insulation walls 310 and the contact surface 411 is just the setting of this breathable gap 301, so that the soldering block 4131 in a molten state will not "tin creep" on the contact surface 411 of the intermediate resistor 300 or the substrate 410 through the temperature insulation walls 310, preventing short circuit.

[0047] The soldering process of the circuit board collection device 400 is as follows: the soldering block 4131 (as shown in Figure 6 The blank gaps are formed between adjacent soldering blocks 4131; then, the worker places the circuit board collection device 400 on the die body, so that the two soldering pads 413 correspond to the first electrode 100 and the second electrode 200 respectively; then, the shunt resistor 10 is heated to a high temperature, and the soldering block 4131 is melted; finally, the shunt resistor 10 is cooled, and the soldering block 4131 is re-solidified into a solid during the cooling period, thereby realizing stable soldering;

[0048] In the process, the solder block 4131 becomes molten solder at high temperature, which will permeate to the surroundings. Since the blank gap exists on the solder pad 413, the molten solder block 4131 will fill the blank gap first, that is, the blank gap provides a housing space for the molten solder, thereby reducing the overflow of the molten solder. At the same time, the blank gap is connected to the outside, so that when the molten solder permeates to the surroundings, the excess air can escape in time, thereby effectively preventing the void problem in the welding process, reducing the welding bubble rate, thereby ensuring the firm connection of the solder pad 413 with the first electrode 100 and the second electrode 200 and good electrical conductivity. It should be further emphasized that, as known from the above, the setting of the temperature insulation wall 310 does not completely seal the internal separation gap 401, and the air gap 301 is formed between the temperature insulation wall 310 and the contact surface 411. The setting of the air gap 301 prevents the molten solder block 4131 from "solder climbing" on the contact surface 411 of the intermediate resistor 300 or the substrate 410, thereby preventing short circuit.

[0049] As known from the above, the setting of the separation gap 401 has the following benefits: first, it blocks the continuity of the gap between the circuit board collecting device 400 and the die body, so that it no longer has the "solder climbing" capillary effect, so that the exuded molten solder will not spread along the gap to form a "conductive connection bridge"; second, the excess molten solder will drip into the separation gap 401, and after it cools and solidifies, the worker can easily remove the solder in the separation gap 401. If there is no separation gap 401, the solder in the gap will be difficult to remove.

[0050] In the embodiment, as shown in Figure 4 The first electrode 100 and the second electrode 200 are both provided with mounting holes 110, and the two mounting holes 110 are symmetrically arranged with the intermediate resistor 300 as the center. The mounting holes 110 are provided to facilitate the electrical connection and installation of the die body. Preferably, the first electrode 100 and the second electrode 200 are both made of red copper material. The red copper material has small resistance, thereby having good electrical conductivity and reducing the self-heating phenomenon.

[0051] In summary, the shunt resistor 10 with temperature detection function of the present application can collect the temperature of the shunt resistor 10 in real time, compensate for the resistance value of the product at different temperatures, and improve the measurement accuracy. At the same time, it can control the flow range of the molten solder during welding, and realize stable and firm welding.

[0052] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A shunt resistor with temperature detection function, characterized in that: The utility model relates to a kind of temperature and voltage acquisition device of middle resistance body, including: First electrode, second electrode, intermediate resistance body and circuit board acquisition device, the intermediate resistance body is between the first electrode and the second electrode; The first electrode, the second electrode and the intermediate resistance body jointly form die body, and the circuit board acquisition device is arranged on the die body;The circuit board acquisition device includes: substrate, sampling output connector, temperature acquisition module and voltage acquisition module; The substrate is provided with contact surface and observation surface, the contact surface is towards the intermediate resistance body, and there is space gap between the contact surface and the intermediate resistance body;The observation surface is away from the intermediate resistance body, and the sampling output connector is arranged on the observation surface; Two pads are arranged on the contact surface, and the two pads correspond to the first electrode and the second electrode respectively, and the substrate is connected with the first electrode and the second electrode by the pad; The thickness of the first electrode and the second electrode is H1, the distance of the space gap is H2, H1> H2;Two ends of the intermediate resistance body are respectively provided with temperature insulation wall, the thickness of the temperature insulation wall is H3, H3< H2, and air gap is formed between the temperature insulation wall and the contact surface; A plurality of welding blocks are arranged on each pad, the plurality of welding blocks are arranged in matrix mode, and blank gap is formed between adjacent two welding blocks. The temperature acquisition module is arranged on the substrate, and the temperature acquisition module includes NTC temperature sensor and temperature sampling lead wire, and the NTC temperature sensor is electrically connected with the sampling output connector by the temperature sampling lead wire; The voltage acquisition module includes voltage sampling line, and the sampling output connector and the pad are electrically connected by the voltage sampling line.

2. The shunt resistor with temperature detection function according to claim 1, characterized in that, The welding block is made of solder material.

3. The shunt resistor with temperature detection function according to claim 1, characterized in that, The contact surface of the substrate is provided with a label.

4. The shunt resistor with temperature detection function according to claim 1, wherein H2=0.25 H1~0.4 H1.

5. The shunt resistor with temperature detection function according to claim 1, characterized in that, Mounting holes are arranged on the first electrode and the second electrode, and the two mounting holes are symmetrically arranged with the intermediate resistance body as the center.

6. The shunt resistor with temperature detection function according to claim 1, wherein The first electrode and the second electrode are made of red copper material.

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