Adjustment circuit, current detection device, and manufacturing method of current detection device

Abstract

To provide a technique capable of performing a precise output adjustment in current detection.SOLUTION: An adjustment circuit comprises a first amplifier, and a first resistance circuit connected to the inverted input and output of the first amplifier, the first resistance circuit has first multiple pads capable of mounting a resistor or a jumper, either the resistor or the jumper is mounted on each of the first multiple pads or none of them is mounted, and the first resistance circuit has a first combined resistance value corresponding to the combination, and adjusts the gain of an input voltage by the first combined resistance value and outputs the voltage.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a regulation circuit, a current detection device, and a method for manufacturing a current detection device. [Background technology]

[0002] A method using a shunt resistor is known as a method for detecting current. Specifically, a shunt resistor is connected in series to a flow path through which a current to be measured flows, and the voltage generated across the shunt resistor is detected to calculate the current value. A current detection device using this type of method includes a shunt resistor and a current detection circuit, which includes, for example, an amplifier, an A / D converter, a microcontroller, etc. The voltage detected from the shunt resistor is amplified by the amplifier circuit. Furthermore, the amplified voltage is further adjusted in gain and offset by an adjustment circuit. For example, Patent Document 1 discloses technology related to the adjustment circuit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-85407 Summary of the Invention [Problem to be solved by the invention]

[0004] In the current detection devices described above, output errors occur for each current detection device due to variations in the resistance value of the shunt resistor, and therefore, in order to improve accuracy, it is necessary to adjust the volume for each device.

[0005] Figure 1 illustrates the problems inherent in conventional current sensing devices. As shown in Figure 1, the relationship between input voltage (Vin) and output voltage (Vout) is ideally proportional, as indicated by a straight line passing through the origin. However, the relationship between input voltage and output voltage before adjustment deviates from the ideal value due to errors. Furthermore, the degree of deviation varies depending on the current sensing device manufactured. Possible methods for adjusting this output error include using variable resistors, electronic volume controls, or thick-film resistors for functional trimming. However, these components have poor temperature characteristics (large temperature coefficient of resistance, TCR), and self-heating can increase output error. Therefore, these components are unsuitable for use in current sensing devices that require high-precision detection of large currents. In particular, thin-film resistors for functional trimming have improved temperature characteristics, but the resistor element is exposed due to laser trimming, which means there is no protective coating. This increases the risk of problems caused by electrolytic corrosion, which is unique to thin-film resistors, and requires high moisture-proofing measures such as coatings.

[0006] One possible method is to implement multiple resistors with different resistance values ​​and switch between them using a relay to adjust the required resistance value. However, to finely adjust the resistance value, it is necessary to implement many resistors and relays, which makes the circuit large-scale. In addition, the temperature characteristics and weather resistance of the relay may be affected, which may affect the quality or lifespan.

[0007] Another possible method for adjusting output error is to replace the mounted thin-film resistor after measuring the characteristics. However, this requires manual work using a soldering iron, making the process cumbersome. Furthermore, if this process is adopted, heat is applied three times: first by reflow mounting the thin-film resistor, then by soldering the thin-film resistor, and then by soldering the thin-film resistor again. This applies thermal stress to the board and other components, which may affect the quality or lifespan of the device. Furthermore, because this is manual work and requires a long lead time, there are concerns about increased costs.

[0008] Therefore, the present disclosure provides a technique that enables highly accurate output adjustment in current detection. [Means for solving the problem]

[0009] In order to solve the above problem, the adjustment circuit of the present disclosure comprises a first amplifier and a first resistance circuit connected to the inverting input and output of the first amplifier, the first resistance circuit having a plurality of first pads on which resistors or jumpers can be mounted, each of the plurality of first pads having either the resistor or the jumper mounted thereon or neither mounted thereon, the first resistance circuit having a first combined resistance value according to the combination thereof, and adjusting and outputting the gain of the input voltage using the first combined resistance value.

[0010] The current detection device disclosed herein comprises a shunt resistor having a voltage detection terminal, an amplifier circuit connected to the voltage detection terminal and amplifying the voltage detected from the voltage detection terminal, and a first adjustment circuit connected to the output of the amplifier circuit and adjusting the gain of the voltage amplified by the amplifier circuit, wherein the first adjustment circuit has a first amplifier and a first resistance circuit connected to the inverting input and output of the first amplifier, the first resistance circuit has a plurality of first pads on which resistors or jumpers can be mounted, each of the plurality of first pads having either the resistor or the jumper mounted thereon or neither mounted thereon, the first resistance circuit having a first combined resistance value corresponding to the combination of these, and adjusting the gain of the input voltage using the first combined resistance value and outputting it.

[0011] A manufacturing method of a current detection device according to the present disclosure is a manufacturing method of a current detection device including a shunt resistor and a detection circuit board, the manufacturing method including: mounting predetermined components on the detection circuit board to form an amplifier circuit that amplifies a voltage detected from the shunt resistor; and a first adjustment circuit that adjusts the gain of the voltage amplified by the amplifier circuit; performing primary mounting, the first adjustment circuit having a first amplifier and a first resistance circuit that is connected to an inverting input and an output of the first amplifier and has a plurality of secondary mounting pads; and, after performing the primary mounting, performing an electrical test of the detection circuit board; deriving an optimum first composite resistance value of the first resistor circuit based on the results of an electrical test; calculating a combination to select either mounting a secondary adjustment resistor, mounting a jumper, or not mounting on each of the plurality of secondary mounting pads based on the first composite resistance value, and selecting a resistance value of the secondary adjustment resistor; performing secondary mounting to mount the secondary adjustment resistor or the jumper on the plurality of secondary mounting pads; and connecting a detection circuit board after the secondary mounting process to a voltage detection terminal provided on the shunt resistor to complete the current detection device.

[0012] Further features related to the present disclosure will become apparent from the description of this specification and the accompanying drawings. Also, aspects of the present disclosure are achieved and realized by the elements and combinations of various elements and the aspects of the following detailed description and the appended claims. The description of this specification is merely exemplary and does not limit the scope or application of the claims of the present disclosure in any way. [Effects of the Invention]

[0013] According to the technology of the present disclosure, highly accurate output adjustment is possible in current detection. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram for explaining a conventional technique. [Figure 2] FIG. 2 is a perspective view of a shunt resistor included in the current detection device according to the first embodiment. [Figure 3] 1 is a perspective view of a current detection device according to a first embodiment. [Figure 4] 1 is a circuit diagram of a current detection device having an adjustment circuit according to a first embodiment. [Figure 5] 5 is a flowchart showing a method for manufacturing the current detection device according to the first embodiment. [Figure 6] FIG. 10 is a circuit diagram of a current detection device having an adjustment circuit according to a second embodiment. [Figure 7] FIG. 10 is a circuit diagram of a current detection device having an adjustment circuit according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] [First embodiment] <Configuration example of current detection device> 2 is a perspective view of a shunt resistor 10 included in the current detection device according to the first embodiment. The shunt resistor 10 includes a resistive element 11, electrodes 12 and 13, voltage detection terminals 14 and 15, and busbar mounting holes 16 and 17.

[0016] The resistor 11 is formed in the shape of a rectangular plate having a predetermined thickness and width. Examples of materials for the resistor 11 include alloys such as copper-nickel alloys, copper-manganese alloys, iron-chromium alloys, and nickel-chromium alloys. The pair of electrodes 12 and 13 are connected to both sides of the resistor 11 by, for example, welding. Examples of welding methods include electron beam welding, laser beam welding, and brazing. The electrodes 12 and 13 are plate-shaped and made of a highly conductive metal such as copper. The voltage detection terminal 14 is provided near the resistor 11 so as to protrude from the top surface of the electrode 12. The voltage detection terminal 15 is provided near the resistor 11 so as to protrude from the top surface of the electrode 13. The busbar mounting hole 16 is provided in the electrode 12. The busbar mounting hole 17 is provided in the electrode 13.

[0017] 3 is a perspective view of a current detecting device 100 according to the first embodiment. The current detecting device 100 includes a shunt resistor 10 and a detection circuit board 20. The detection circuit board 20 is disposed on top of the shunt resistor 10, and the shunt resistor 10 and the detection circuit board 20 are electrically connected by inserting voltage detection terminals 14 and 15 into through holes formed in the detection circuit board 20 and soldering or the like. The detection circuit board 20 includes an amplifier circuit 23, an A / D converter 24, a microcontroller 25, a connector 26, and an adjustment circuit 30.

[0018] The potentials of the electrodes 12 and 13 at the positions of the voltage detection terminals 14 and 15 of the shunt resistor 10 are input to the amplifier circuit 23. The amplifier circuit 23 has an amplifier, amplifies the difference (voltage) between the input potentials, and outputs it as a voltage signal. The output voltage signal is input to the adjustment circuit 30. The adjustment circuit 30 adjusts the gain of the input voltage and outputs the adjusted voltage signal to the A / D converter 24. The A / D converter 24 A / D converts the input voltage signal and outputs a digital signal. The output digital signal is input to the microcontroller 25. The microcontroller 25 processes the digital signal to calculate a voltage value, and calculates a current value (measured current value) based on the voltage value and the resistance value of the shunt resistor 10.

[0019] By using a shunt resistor 10 having a temperature coefficient of resistance (TCR) close to 0 as the shunt resistor 10 used in the current detection device 100, it becomes possible to detect current with high accuracy over the entire temperature range of the usage environment.

[0020] <Example of adjustment circuit configuration> Fig. 4 is a circuit diagram of a current detection device 100 including an adjustment circuit 30 according to the first embodiment. Only the shunt resistor 10, the amplifier circuit 23, and the adjustment circuit 30 are shown in Fig. 4. The amplifier circuit 23 includes resistors R1 and R2, a resistor C1, and an isolation amplifier 231.

[0021] The adjustment circuit 30 has two resistors R3, a resistor R5, a resistance circuit 301, and an amplifier 302. The resistance circuit 301 is located in a feedback circuit connecting the inverting input and output of the amplifier 302. The resistance circuit 301 is provided with pads R41 to R44 (hereinafter sometimes referred to as "secondary mounting pads") on which resistors can be mounted, two in series and two in parallel. Although the number of pads is four in FIG. 4, it can be any number greater than two (multiple). The resistance circuit 301 is also provided with terminals T1 and T2 that can be connected to the outside.

[0022] Resistors (hereinafter may be referred to as "secondary adjustment resistors") or jumpers are mounted on each of the pads R41 to R44 as needed. The resistance value (first combined resistance value) of the resistance circuit 301 is adjusted by a combination of resistors or jumpers (short) mounted on the pads R41 to R44 and pads (open) that are not mounted. This combined resistance value adjusts the gain of the voltage output from the amplifier circuit 23. Since the resistance value is always necessary for the resistance circuit 301, at least one of the two pads arranged in series has a resistor mounted on it, and the other has a resistor or jumper mounted on it or is unmounted (open). There is also a case where resistors are mounted on all of the pads R41 to R44.

[0023] For example, a chip resistor, which is a fixed resistor for general surface mounting, can be used as the resistor. Thin film chip resistors in particular have excellent temperature characteristics. The temperature coefficient of resistance is ±100×10 -6 It is preferable to use chip resistors in the range of ±10 × 10 -6 / K resistors have a smaller temperature coefficient of resistance (TCR), resulting in less change in resistance value over temperature. Furthermore, chip resistors generally have a lower risk of electrolytic corrosion than thin-film resistors for function trimming, since the resistive element is protected by a protective coating. Thus, by using thin-film chip resistors and combining them with jumpers and opens to form resistor circuit 301, a high-quality current detection device with high current detection accuracy can be realized.

[0024] <Method of manufacturing the current detection device> FIG. 5 is a flowchart showing a manufacturing method of the current detection device 100 according to the first embodiment. As will be described below, this manufacturing method uses a computer (not shown) configured to calculate an optimal resistance value (combined resistance value) of the resistor circuit 301 of the adjustment circuit 30. Information necessary for current measurement, such as information (resistance value) of the shunt resistor 10, is stored in advance in a storage device of the computer. The computer is also configured to be able to control a resistance value switching system (not shown) connected to terminals T1 and T2 of the resistor circuit 301. The resistance value switching system has multiple fixed resistors and multiple relays, and a variable resistance circuit whose resistance value can be changed by switching the relays is constructed. A software program for realizing the above-mentioned functions is pre-installed in the computer.

[0025] Step S1: Primary implementation The manufacturer mounts components other than the secondary adjustment resistors and jumpers on the detection circuit board 20. In the primary mounting, for example, surface-mounted components are mounted by reflow soldering.

[0026] Step S2: Current test (resistance value calculation and resistor selection) The manufacturer performs an electrical test on the detection circuit board 20. In the electrical test, the manufacturer connects the above-described resistance value switching system to terminals T1 and T2 of the resistor circuit 301. The manufacturer also connects a measurement fixture (jig) to the detection circuit board 20.

[0027] In step S21, the computer adjusts the energization of the measurement fixture according to a program based on information (such as resistance value) of the shunt resistor 10. The computer then calculates the optimum resistance value of the resistor circuit 301 according to the desired gain. Here, by using the actual measured value as the information (such as resistance value) of the shunt resistor 10, the optimum resistance value of the resistor circuit 301 can be accurately calculated. Instead of the actual measured value, the resistance value of the shunt resistor 10 for each production lot may be used.

[0028] In step S22, the computer selects a secondary adjustment resistor by deriving a combination of the secondary adjustment resistor, jumper, and open based on the calculated resistance value of the resistance circuit 301. In selecting the secondary adjustment resistor, the resistance value of each secondary adjustment resistor is derived from a plurality of thin film chip resistors having different inherent resistance values ​​so that the combined resistance value of the resistance circuit 301 becomes the calculated optimum resistance value.

[0029] Here, the resistance tolerance of the thin-film chip resistor can be, for example, ±0.5%. Furthermore, thin-film chip resistors with E12 series resistance values ​​can be prepared and selected from the E12 series. This allows the resistance value of the resistance circuit 301 to be adjusted in increments of 0.5 Ω or less. Furthermore, since fewer resistor varieties are available as secondary adjustment resistors, manufacturers no longer need to stock large quantities of resistors. On the other hand, if the resistance circuit 301 is to be realized with a single resistor, the thin-film chip resistor that can be prepared is the E192 series. In this case, adjustment in increments of 0.5 Ω or less is not possible, and more varieties than the E12 series are available.

[0030] Step S3: Secondary implementation The manufacturer mounts the selected secondary adjustment resistors and jumpers on the secondary mounting pads (pads R41 to R44). That is, up to four chip resistors selected as combinations with the same or similar resistance value as the resistance value calculated in step S21 are mounted on the secondary mounting pads. By configuring the secondary mounting pads as a circuit combining series and parallel connections, it is possible to accommodate various resistance values ​​depending on the mounting method in addition to the resistance value of the chip resistors. The mounting method involves applying solder with a dispenser, mounting the secondary adjustment resistor, and then performing laser soldering or iron soldering.

[0031] Step S4: Incorporating a current detection device In step S3, the manufacturer assembles the detection circuit board 20 on which the secondary adjustment resistor is mounted and the shunt resistor 10. In this way, the current detection device 100 is completed.

[0032] As described above, by performing the entire process from the electrical test, calculation of the optimum resistance value of the resistor circuit 301, selection of the optimum secondary adjustment resistor, and secondary mounting in one facility, lead time can be shortened. This process reduces the number of times heat is applied to only two times: the first mounting and the second mounting. In other words, by selecting the optimum resistor before mounting the resistor, the work of replacing the resistor after measuring the completed mounting board is eliminated. This improves quality by reducing the heat history when removing the resistor, and improves efficiency by consolidating the processes.

[0033] <Summary of the First Embodiment> As described above, the adjustment circuit 30 according to the first embodiment includes an amplifier 302 (first amplifier) ​​and a resistance circuit 301 (first resistance circuit) connected to the inverting input and output of the amplifier 302. The resistance circuit 301 has pads R41 to R44 (plurality of first pads) on which resistors or jumpers can be mounted. Each of the pads R41 to R44 has either a resistor or a jumper mounted thereon, or neither mounted thereon, and the resistance circuit 301 has a combined resistance value (first combined resistance value) according to the combination of these. The adjustment circuit 30 adjusts the gain of the input voltage using the combined resistance value of the resistance circuit 301 and outputs the result.

[0034] As described above, in the adjustment circuit 30 of this embodiment, the combined resistance value of the resistance circuit 301 is determined by a combination of resistors, jumpers, or non-implementation. Such an adjustment circuit 30 enables highly accurate output adjustment. The current detection device 100 equipped with the adjustment circuit 30 is of high quality and can achieve highly accurate current detection.

[0035] [Second embodiment] <Example of adjustment circuit configuration> 6 is a circuit diagram of a current detection device 200 having an adjustment circuit 40 according to the second embodiment. As shown in FIG. 6, the adjustment circuit 40 (first adjustment circuit) according to the second embodiment differs from the first embodiment in that the resistance circuit 301 has a resistor R45 (sometimes referred to as a "primary adjustment resistor") that is mounted in the primary mounting (step S1). The resistor R45 is connected in series to the pads R41 to R44. A thin-film chip resistor with excellent temperature characteristics can also be used as the resistor R45.

[0036] <Method of manufacturing the current detection device> In the second embodiment, in the electrical test (step S2), the resistance value of the resistor circuit 301 is adjusted by adding the resistance value of the resistor R45. The other points are the same as those in the first embodiment.

[0037] [Third embodiment] <Example of adjustment circuit configuration> Fig. 7 is a circuit diagram of a current detection device 300 having adjustment circuits 40 and 50 according to the third embodiment. As shown in Fig. 7, the current detection device 300 according to the third embodiment further includes an adjustment circuit 50 that adjusts the offset of the voltage output from the amplifier circuit 23. In other words, the current detection device 300 can adjust the gain and offset of the voltage output from the amplifier circuit 23. The other configurations are the same as those of the second embodiment.

[0038] The adjustment circuit 50 for adjusting the offset includes a resistance circuit 501, an amplifier 502, and a resistor R7, similar to the adjustment circuits 30 and 40 for adjusting the gain. The resistance circuit 501 is connected to the non-inverting input of the amplifier 502. The output of the amplifier 502 is connected to the non-inverting input of the amplifier 302. The resistance circuit 501 includes a resistor R65 (primary adjustment resistor), pads R61 to R64 (secondary mounting pads), and terminals T3 and T4. Two pads R61 to R64 are provided in series and two in parallel. Although the number of pads is four in FIG. 7, it can be any number greater than two (more than one). The resistor R65 is connected in series with the pads R61 to R64. A thin-film chip resistor with excellent temperature characteristics can also be used as the resistor R65.

[0039] <Method of manufacturing the current detection device> In the primary mounting (step S1), a resistor R65 is mounted. In the electrical test (step S2), the optimum resistance value of the resistor circuit 501 is calculated by connecting terminals T3 and T4 to an external resistance value switching system. The method for adjusting the resistance value (second combined resistance value) of the resistor circuit 501 is the same as the method for adjusting the resistance value of the resistor circuit 301 of the adjustment circuit 30 (FIG. 5). In the secondary mounting (step S3), selected secondary adjustment resistors or jumpers are mounted on pads R61 to R64. The resistance value of the resistor circuit 501 is adjusted by combining the mounted secondary adjustment resistors, jumpers, and opens. As with the first embodiment, thin-film chip resistors having E12 series resistance values ​​can also be used for the secondary adjustment resistors mounted on pads R61 to R64 of the adjustment circuit 50.

[0040] <Summary of the third embodiment> As described above, the adjustment circuit 50 (second adjustment circuit) according to the third embodiment includes an amplifier 502 (second amplifier) ​​and a resistance circuit 501 (second resistance circuit) connected to the non-inverting input of the amplifier 502. The output of the amplifier 502 is connected to the non-inverting input of the amplifier 302. The resistance circuit 501 has pads R61 to R64 (plurality of second pads) on which resistors or jumpers can be mounted. Each of the pads R61 to R64 has either a resistor or a jumper mounted thereon, or neither is mounted thereon, and the resistance circuit 501 has a combined resistance value (second combined resistance value) according to the combination of these. The adjustment circuit 50 adjusts the offset of the input voltage using the combined resistance value of the resistance circuit 501 and outputs the result.

[0041] In this way, highly accurate output adjustment can be performed by adjusting the gain of the input voltage with the adjustment circuit 30 or 40 and adjusting the offset of the input voltage with the adjustment circuit 50. Therefore, a current detection device including the adjustment circuit 30 or 40 and the adjustment circuit 50 is of high quality and can achieve high current detection accuracy.

[0042] [Variations] The present disclosure is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present disclosure, and it is not necessary to include all of the described configurations. Furthermore, a part of one embodiment can be replaced with a configuration of another embodiment. Furthermore, a configuration of another embodiment can be added to a configuration of one embodiment. Furthermore, a part of the configuration of each embodiment can be added to, deleted from, or substituted for a part of the configuration of another embodiment.

[0043] [Contribution to the environment] According to the present disclosure, the current detection accuracy of the current detection device is improved, and its weather resistance is also improved. This allows the device to accurately grasp the current and reduces the risk of breakdown in harsh environments. This contributes to improving the power consumption efficiency and safety of the device. Therefore, this disclosure can contribute to the achievement of Goal 3 "Good health and well-being," Goal 7 "Affordable and clean energy," and Goal 9 "Industry, innovation and infrastructure" of the United Nations' Sustainable Development Goals (SDGs). [Explanation of symbols]

[0044] 100, 200, 300...Current detection device 10...Shunt resistor 11...Resistor 12, 13...electrode 14, 15...Voltage detection terminals 16, 17...Busbar mounting holes 20...Detection circuit board 23...Amplifier circuit 24...A / D converter 25...Microcontroller 26...Connector 30, 40, 50…adjustment circuit 301, 501...Resistance circuit 302, 502...Amplifier

Claims

1. a first amplifier; a first resistor circuit connected to the inverting input and the output of the first amplifier; the first resistance circuit has a plurality of first pads on which resistors or jumpers can be mounted, and either one of the resistors or jumpers is mounted on each of the plurality of first pads, or neither is mounted on each of the plurality of first pads, and the first resistance circuit has a first combined resistance value corresponding to a combination of these; an adjusting circuit that adjusts the gain of an input voltage by the first combined resistance value and outputs the adjusted gain;

2. a second amplifier; a second resistor circuit connected to the non-inverting input of the second amplifier; the output of the second amplifier is connected to the non-inverting input of the first amplifier; the second resistance circuit has a plurality of second pads on which resistors or jumpers can be mounted, and either one of the resistors or jumpers is mounted on each of the plurality of second pads, or neither is mounted on each of the plurality of second pads, and the second resistance circuit has a second combined resistance value corresponding to a combination of these; 2. The adjustment circuit according to claim 1, wherein the offset of the input voltage is adjusted by the second combined resistance value and output.

3. The adjustment circuit according to claim 2 , wherein each of the first pads and the second pads is connected in parallel and in series.

4. the first resistance circuit and / or the second resistance circuit further includes a resistor connected in series with the plurality of first pads and / or the plurality of second pads; The adjustment circuit according to claim 3 , wherein the first combined resistance value and / or the second combined resistance value includes a resistance value of the resistor.

5. 5. The adjustment circuit according to claim 3, wherein the resistor is a thin film chip resistor having a resistance tolerance of ±0.5% and having a resistance value in the E12 series.

6. a shunt resistor having a voltage detection terminal; an amplifier circuit connected to the voltage detection terminal and amplifying a voltage detected from the voltage detection terminal; a first adjustment circuit connected to an output of the amplifier circuit and adjusting a gain of the voltage amplified by the amplifier circuit; the first adjusting circuit includes a first amplifier and a first resistor circuit connected to the inverting input and output of the first amplifier; the first resistance circuit has a plurality of first pads on which resistors or jumpers can be mounted, and either one of the resistors or jumpers is mounted on each of the plurality of first pads, or neither is mounted on each of the plurality of first pads, and the first resistance circuit has a first combined resistance value corresponding to a combination of these; A current detection device that adjusts the gain of an input voltage using the first combined resistance value and outputs the adjusted gain.

7. a second adjusting circuit that adjusts the offset of the voltage amplified by the amplifier circuit; the second adjustment circuit includes a second amplifier and a second resistor circuit connected to a non-inverting input of the second amplifier; the output of the second amplifier is connected to the non-inverting input of the first amplifier; the second resistance circuit has a plurality of second pads on which resistors or jumpers can be mounted, and either one of the resistors or jumpers is mounted on each of the plurality of second pads, or neither is mounted on each of the plurality of second pads, and the second resistance circuit has a second combined resistance value corresponding to a combination of these; 7. The current detection device according to claim 6, wherein the offset of the input voltage is adjusted by the second combined resistance value and output.

8. The current detection device according to claim 7 , wherein the plurality of first pads and the plurality of second pads are connected in parallel and in series.

9. the first resistance circuit and / or the second resistance circuit further includes a resistor connected in series with the plurality of first pads and / or the plurality of second pads; The current detection device according to claim 8 , wherein the first combined resistance value and / or the second combined resistance value includes a resistance value of the resistor.

10. 10. The current detection device according to claim 8, wherein the resistor is a thin film chip resistor having a resistance tolerance of ±0.5% and having a resistance value in the E12 series.

11. A method for manufacturing a current detection device including a shunt resistor and a detection circuit board, a first mounting step of mounting predetermined components on the detection circuit board to form an amplifier circuit for amplifying the voltage detected from the shunt resistor and a first adjustment circuit for adjusting the gain of the voltage amplified by the amplifier circuit, the first adjustment circuit having a first amplifier and a first resistor circuit having a plurality of secondary mounting pads connected to the inverting input and output of the first amplifier; After the primary mounting is performed, a current test of the detection circuit board is performed. deriving an optimum first combined resistance value of the first resistor circuit based on a result of the electrical test; calculating a combination of selecting whether to mount a secondary adjustment resistor, mount a jumper, or not mount a secondary adjustment resistor on each of the plurality of secondary mounting pads based on the first combined resistance value, and selecting a resistance value of the secondary adjustment resistor; performing secondary mounting to mount the secondary adjustment resistors or the jumpers on the plurality of secondary mounting pads; connecting the detection circuit board after the secondary mounting process to a voltage detection terminal provided on the shunt resistor to complete the current detection device; A method for manufacturing a current detection device, comprising:

12. The performing of the primary mounting includes further configuring a second adjustment circuit on the detection circuit board to adjust an offset of the voltage amplified by the amplifier circuit, the second adjustment circuit having a second amplifier and a second resistor circuit connected to a non-inverting input of the second amplifier and having a plurality of secondary mounting pads; deriving an optimal second combined resistance value of the second resistor circuit based on a result of the electrical continuity test; 12. The method for manufacturing a current detection device according to claim 11, further comprising: calculating a combination of selecting whether to mount a secondary adjustment resistor, mount a jumper, or not mount a secondary adjustment resistor on each of the plurality of secondary mounting pads provided in the second resistance circuit based on the second combined resistance value, and selecting a resistance value of the secondary adjustment resistor.

13. 13. The method for manufacturing a current detection device according to claim 12, wherein the secondary adjustment resistor is a thin film chip resistor having a resistance tolerance of ±0.5% and is selected from any resistance value in the E12 series.

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