Resistance measuring system and control method

Abstract

The invention provides a resistance measurement system and a control method, and the system comprises a voltage measurement module and an error calibration module. The voltage measurement module is used for connecting a resistor to be measured and outputting an actually measured voltage after the voltage measurement module is connected to the resistor to be measured; the error calibration module is connected with the voltage measurement module and is used for subtracting the error voltage from the actually measured voltage to determine a target voltage corresponding to the resistor to be measured and determining a target resistance value of the resistor to be measured based on the target voltage, and the error voltage is the voltage which is not added to the resistor to be measured in the actually measured voltage. According to the invention, the problem that the resistance value of a small-resistance-value resistor cannot be accurately measured in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the technical field of circuit design, and in particular to a resistance measurement system and a control method. Background Art

[0002] In the related art, a four-wire DMM (digital multimeter) or an LCR (L: inductance, C: capacitance, R: resistance) instrument is mostly used to measure the resistance value. However, when measuring a small resistance value of 1 to 100 mΩ by using the above measuring instruments, the measured value is not accurate enough and there is a deviation between the measured value and the ideal value.

[0003] Therefore, there is a technical problem in the related art that it is impossible to accurately measure the resistance of a small resistance resistor. Summary of the invention

[0004] The present application provides a resistance measurement system and a control method to at least solve the problem in the related art that it is impossible to accurately measure the resistance of a small resistance resistor.

[0005] In a first aspect, the present application provides a resistance measurement system, including: a voltage measurement module and an error calibration module;

[0006] The voltage measurement module is used to connect to the resistor to be measured and output the measured voltage after the voltage measurement module is connected to the resistor to be measured;

[0007] The error calibration module is connected to the voltage measurement module, and is used to determine a target voltage corresponding to the resistor to be measured by subtracting an error voltage from the actual measured voltage, and determine a target resistance value of the resistor to be measured based on the target voltage, wherein the error voltage is a voltage in the actual measured voltage that is not applied to the resistor to be measured.

[0008] Optionally, as in the aforementioned control system, the error calibration module comprises: an error calibration circuit and a resistance measurement circuit;

[0009] The error calibration circuit is connected to the voltage measurement module and is used to adjust and obtain a specified output voltage with the same magnitude as the error voltage, wherein the error voltage includes: a circuit voltage of a resistor access circuit, and an output terminal voltage of the voltage measurement module when the differential signal input to the voltage measurement module is 0, and the resistor access circuit is a circuit in the voltage measurement module used to access the resistor to be measured;

[0010] The resistance measurement circuit is connected to the error calibration circuit, and is used for obtaining the target voltage by subtracting the measured voltage from the specified output voltage, and determining the target resistance value of the resistor to be measured according to the target voltage.

[0011] Optionally, as in the aforementioned control system, the error calibration circuit comprises: a linear power supply, a voltage divider unit and an adder;

[0012] The linear power supply is used to output a first voltage, wherein the first voltage is the same as the output terminal voltage;

[0013] The voltage dividing unit is connected to the linear power supply and is used to output a second voltage according to the first voltage and an external DC power supply;

[0014] The adder is connected to the linear power supply and the voltage dividing unit respectively, and is used for adding the first voltage and the second voltage to obtain a third voltage.

[0015] Optionally, as in the aforementioned control system, the error calibration circuit further comprises: a voltage follower;

[0016] The voltage follower is arranged between the linear power supply and the voltage dividing unit, and is used for outputting the first voltage to the voltage dividing unit.

[0017] Optionally, as in the aforementioned control system, the voltage dividing unit comprises: a fixed resistor and a potentiometer connected in series;

[0018] The fixed resistor is connected to the voltage follower and is used to obtain the first voltage output by the voltage follower;

[0019] The first end of the potentiometer is connected to a fourth voltage and a ground end respectively, and the second end of the potentiometer is connected to the fixed resistor, which is used to adjust the resistance of the potentiometer so that the second end outputs the second voltage with the same magnitude as the circuit voltage.

[0020] Optionally, as in the aforementioned control system, the resistance measurement circuit comprises: a subtractor;

[0021] The subtractor is used to determine the difference between the measured voltage and the specified output voltage, and to indicate that the resistance measurement system has been calibrated when the voltage measurement module is not connected to the resistor to be measured and the output end of the subtractor is adjusted to 0V by adjusting the error calibration circuit.

[0022] Optionally, the control system as described above further includes: a reference voltage circuit;

[0023] The voltage input terminal of the low voltage drop linear regulator of the reference voltage circuit is used to connect to an external DC power supply;

[0024] The voltage input terminal of the low voltage drop linear regulator is connected to the sleep terminal through a 100KΩ resistor;

[0025] The ground terminal of the low voltage drop linear regulator is connected to the sleep terminal through a 51KΩ resistor;

[0026] The output end of the reference voltage circuit is connected to the voltage measurement module and is used to output a 5V reference voltage to the voltage measurement module.

[0027] In a second aspect, the present application provides a control method for a resistance measurement system, comprising:

[0028] The measured voltage after the output voltage measurement module is connected to the resistor to be measured;

[0029] The target voltage corresponding to the resistor to be measured is determined by the error calibration module by subtracting the error voltage from the actual measured voltage, and the target resistance value of the resistor to be measured is determined based on the target voltage, wherein the error voltage is the voltage in the actual measured voltage that is not applied to the resistor to be measured.

[0030] Optionally, as in the aforementioned control method, before the output voltage measurement module is connected to the measured resistor to measure the actual voltage, the method further includes:

[0031] The error calibration circuit is used to adjust and obtain a specified output voltage having the same magnitude as the error voltage, wherein the error voltage includes: a circuit voltage of a resistor access circuit, and an output voltage of the voltage measurement module when the differential signal input to the voltage measurement module is 0, and the resistor access circuit is a circuit in the voltage measurement module for accessing the resistor to be measured;

[0032] The method of determining a target voltage corresponding to the resistor to be measured by subtracting an error voltage from the measured voltage includes: performing a difference operation on the measured voltage and the specified output voltage through a resistance measurement circuit to obtain a target voltage of the resistor to be measured, and determining a target resistance value of the resistor to be measured according to the target voltage.

[0033] Optionally, as in the aforementioned control method, the step of adjusting the error calibration circuit to obtain a specified output voltage having the same magnitude as the error voltage comprises:

[0034] When the voltage measurement module is not connected to the resistance to be measured, the error calibration circuit is adjusted until the output end of the resistance measurement circuit is 0V, and it is determined that the specified output voltage having the same magnitude as the error voltage is adjusted.

[0035] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art: the system provided by the embodiment of the present application, by setting a voltage measurement module and an error calibration module; the voltage measurement module is used to connect the resistor to be measured, and output the measured voltage after the voltage measurement module is connected to the resistor to be measured; the error calibration module is connected to the voltage measurement module, and is used to determine the target voltage corresponding to the resistor to be measured by subtracting the error voltage from the measured voltage, and determine the target resistance value of the resistor to be measured based on the target voltage, wherein the error voltage is the voltage in the measured voltage that is not added to the resistor to be measured. Therefore, in the case where the measured voltage measured by the voltage measurement module includes the voltage of other circuits other than the resistor to be measured, the error calibration module can still be used to eliminate the error voltage from the measured voltage to determine the target voltage corresponding to the resistor to be measured, and even if the target resistance is small, the target resistance value of the resistor to be measured can still be accurately determined based on the target voltage, and the problem that the resistance value of a small resistance value resistor cannot be accurately measured in the related art can be effectively solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0038] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0039] Figure 1 A structural block diagram of a resistance measurement system provided in an embodiment of the present application;

[0040] Figure 2 A schematic diagram of the circuit structure of a voltage measurement module provided in an embodiment of the present application;

[0041] Figure 3 A schematic diagram of a circuit structure of a resistor access circuit provided in an embodiment of the present application;

[0042] Figure 4 A schematic diagram of a circuit structure of a resistance measurement circuit provided in an embodiment of the present application;

[0043] Figure 5 A schematic diagram of a circuit structure of a reference voltage circuit provided in an embodiment of the present application;

[0044] Figure 6 A schematic flow chart of a control method for a resistance measurement system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0046] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0047] In order to solve the technical problem that the existing technology cannot accurately measure the resistance of a small resistance resistor, the present application provides a resistance measurement system, including: a voltage measurement module and an error calibration module; the voltage measurement module is used to connect the resistor to be measured, and output the measured voltage after the voltage measurement module is connected to the resistor to be measured; the error calibration module is connected to the voltage measurement module, and is used to determine the target voltage corresponding to the resistor to be measured by subtracting the error voltage from the measured voltage, and determine the target resistance of the resistor to be measured based on the target voltage, wherein the error voltage is the voltage in the measured voltage that is not applied to the resistor to be measured. Therefore, in the case where the measured voltage measured by the voltage measurement module includes the voltage of other circuits other than the resistor to be measured, the error calibration module can still be used to eliminate the error voltage from the measured voltage to determine the target voltage corresponding to the resistor to be measured, and even if the target resistance is small, the target resistance of the resistor to be measured can still be accurately determined based on the target voltage, and the problem that the existing technology cannot accurately measure the resistance of a small resistance resistor can be effectively solved.

[0048] Figure 1 A resistance measurement system provided in an embodiment of the present application includes: a voltage measurement module 11 and an error calibration module 12;

[0049] The voltage measurement module 11 is used to connect to the resistor to be measured and output the measured voltage after the voltage measurement module is connected to the resistor to be measured;

[0050] The error calibration module 12 is connected to the voltage measurement module, and is used to determine the target voltage corresponding to the resistor to be measured by subtracting the error voltage from the actual measured voltage, and determine the target resistance value of the resistor to be measured based on the target voltage, wherein the error voltage is the voltage in the actual measured voltage that is not applied to the resistor to be measured.

[0051] In this embodiment, the voltage measurement module 11 may be a circuit structure that can be connected to a resistance to be measured and measure the actual voltage on the resistance to be measured.

[0052] In this embodiment, the resistor to be measured may be a small resistance with a resistance value less than 100 mΩ.

[0053] Since the circuit of the voltage measurement module 11 itself has a certain resistance value, when the voltage measurement module 11 is used to measure a small resistance, a large part of the actual voltage measured by the voltage measurement module 11 is added to the circuit of the voltage measurement module 11 itself, and the smaller the resistance of the resistor to be measured, the greater the voltage on the circuit of the voltage measurement module 11 itself, that is, the smaller the resistance to be measured, the greater the error voltage. Therefore, if the resistance of the resistor to be measured is directly determined based on the actual voltage, the accuracy of the measurement of the resistor to be measured will be low.

[0054] Since the method of this embodiment is mainly used to measure the resistance of small resistors, in order to more accurately calculate the resistance of the resistor to be measured, the voltage measurement module 11 can be a circuit structure or chip with gain that can amplify the voltage to a more processable level. Optionally, the gain can be 100, 200, etc.

[0055] In this embodiment, the target voltage applied to the resistor to be measured is determined by subtracting the error voltage from the measured voltage, and the current flowing through the resistor to be measured can be further determined, so that the actual voltage can be determined according to the target voltage and the gain Gain, and finally the target resistance value of the resistor to be measured can be determined according to the current and the actual voltage. The actual voltage V can be determined by the following formula: 实际 :V 实际 =(V 实际 -V 误差 ) / Gain.

[0056] Optionally, in order to facilitate the calculation of the target resistance, the current flowing through the resistor to be measured can be a constant current source I, and the size of the constant current source I can be 80mA, 90mA, etc. Further, the constant current source I can be fixed at 100mA to facilitate calculation.

[0057] Alternatively, if Figure 2As shown, a circuit structure diagram of an optional voltage measurement module 11 is provided:

[0058] The voltage measurement module 11 (ie, Figure 2 The Current Sense AMP IC U2 shown in the figure uses INA240A3, and its gain is Gain = 100. Probe1 and Probe2 are used to measure the two ends of the resistor, and the short resistance should be ensured to be less than 100mohm. Hooks Hook5 and Hook6 are used to connect to an external constant current source I, and the constant current source I is fixed at 100mA. Hook7 and Hook8 are used to debug the circuit.

[0059] In the system of this embodiment, when the actual voltage measured by the voltage measurement module 11 includes the voltage of other circuits except the resistor to be measured, the error calibration module can still eliminate the error voltage from the actual voltage to determine the target voltage corresponding to the resistor to be measured, and even if the target resistance is small, the target resistance of the resistor to be measured can still be accurately determined based on the target voltage, thereby effectively solving the problem in the related art that it is impossible to accurately measure the resistance of a small resistance resistor.

[0060] As an optional implementation, as in the aforementioned control system, the error calibration module 12 includes: an error calibration circuit and a resistance measurement circuit;

[0061] The error calibration circuit is connected to the voltage measurement module 11 and is used to adjust and obtain a specified output voltage of the same magnitude as the error voltage, wherein the error voltage includes: a circuit voltage of the resistor access circuit and an output voltage of the voltage measurement module 11 when the differential signal of the input voltage measurement module 11 is 0, and the resistor access circuit is a circuit in the voltage measurement module 11 for accessing the resistor to be measured;

[0062] The resistance measurement circuit is connected to the error calibration circuit, and is used to obtain a target voltage by subtracting the actual measured voltage from the specified output voltage, and to determine a target resistance value of the resistor to be measured according to the target voltage.

[0063] Specifically, in this embodiment, the error calibration module 12 includes: an error calibration circuit and a resistance measurement circuit. The error calibration circuit is used to adjust to obtain a specified output voltage of the same magnitude as the error voltage, and then output the specified output voltage to the resistance measurement circuit, and the resistance measurement circuit can obtain the aforementioned measured voltage, so that the resistance measurement circuit can obtain the target voltage actually applied to the resistor to be measured by subtracting the measured voltage from the specified output voltage, and then determine the target resistance value of the resistor to be measured according to the current flowing through the resistor to be measured and the target voltage.

[0064] In the present disclosure, the error voltage includes: the circuit voltage of the resistor access circuit, the resistor access circuit is a circuit in the voltage measurement module 11 for accessing the resistor to be measured, such as Figure 3 As shown, the resistor access circuit may include Probe1 and Probe2 for connecting the two ends of the resistor to be measured, and in order to ensure the measurement accuracy, it should be ensured that the short-circuit resistance of Probe1 and Probe2 is less than 100mΩ. In addition, the error voltage also includes: the output voltage of the voltage measurement module 11 when the differential signal of the input voltage measurement module 11 is 0, for example, when Figure 3 As shown, when the VS terminal of the Current Sense AMP IC U2 is pressurized to VS_5V0 and the differential signal of the input voltage measurement module 11 is 0, the output voltage is 2V5. It can be seen that the error calibration circuit is a circuit used to eliminate the voltage causing the above error in the process of finally calculating the target resistance value of the resistor to be measured.

[0065] As an optional implementation, as in the aforementioned control system, the error calibration circuit includes: a linear power supply, a voltage divider unit and an adder;

[0066] A linear power supply is used to output a first voltage, wherein the first voltage is the same as the output terminal voltage. Specifically, the linear power supply can be a linear power supply of ADR441-EP, which is used to output a reference voltage source VREF_2V5, that is, the first voltage is 2.5V, and Figure 3 As shown, the V of the linear power supply LDO IC U3 in The terminal is connected to the reference voltage source VS_5V0, and the GND terminal is grounded.

[0067] The voltage divider unit is connected to the linear power supply, and is used to output a second voltage according to the first voltage and the external DC power supply. Specifically, the voltage divider unit is connected to the linear power supply to obtain the first voltage. In addition, the voltage divider unit is also connected to the external DC power supply, so that the voltage divider unit can generate a second voltage VCOMP_DIV according to the first voltage and the external DC power supply, and output it externally.

[0068] like Figure 3 As shown, a schematic diagram of the circuit structure of an optional error calibration circuit is provided in this embodiment. The adder is connected to the linear power supply and the voltage divider unit respectively, and is used to add the first voltage and the second voltage to obtain a third voltage. Specifically, an adder of INA105 (ie, Figure 3The SUM AMP IC U5 is shown in the figure, and the adder is connected to the linear power supply and the voltage divider unit respectively, so that the adder can obtain the first voltage VREF_2V5 and the second voltage VCOMP_DIV, and then add the first voltage VREF_2V5 and the second voltage VCOMP_DIV to obtain the third voltage VCAL. Figure 2 As shown, the 1_REF terminal of the adder is used to input the first voltage VREF_2V5, the 3_IN+ terminal is used to input the second voltage VCOMP_DIV, the 7_V+ terminal is used to connect to the external DC power supply VS_15V 0, and the output VCAL=VCOMP_DIV+VREF_2V5.

[0069] As an optional implementation, as in the aforementioned control system, the error calibration circuit further includes: a voltage follower;

[0070] The voltage follower is provided between the linear power supply and the voltage divider unit, and is used to output the first voltage to the voltage divider unit. Specifically, in order to avoid the mutual influence between VREF_2V5 and VCOMP_DIV, a voltage follower is further added in this embodiment. The voltage follower (ie, Figure 3 The voltage follower IC U4 shown in the figure uses INA105 and is set between the linear power supply (ie, LDO ICU3) and the voltage divider unit to isolate VREF_2V5 from VCOMP_DIV. In addition, the voltage follower is connected to an external DC power supply VS-15V0 through HOOK9, and the port 7_V+ of the voltage follower is connected to an external DC power supply VS_15V0.

[0071] As an optional implementation, as in the aforementioned control system, the voltage dividing unit includes: a fixed resistor and a potentiometer connected in series;

[0072] The fixed resistor is connected to the voltage follower to obtain a first voltage output by the voltage follower;

[0073] The first end of the potentiometer is connected to the fourth voltage and the ground end respectively, and the second end of the potentiometer is connected to a fixed resistor, which is used to adjust the resistance of the potentiometer so that the second end outputs a second voltage with the same magnitude as the circuit voltage.

[0074] Specifically, Figure 3As shown, the fixed resistor R4 can adopt a 10KΩ resistor with an error within the range of 1%. The potentiometer can adopt a variable resistor with a maximum resistance of 10KΩ within the range of 1%. And the fixed resistor can be connected to the output end of the voltage follower, so that the first voltage output by the voltage follower can be obtained. The first end of the potentiometer is respectively connected to a fourth voltage and a ground terminal, and the fourth voltage can be obtained through the HOOK10 external DC power supply VS-15V0. The second end of the potentiometer is connected to a fixed resistor, so that the voltage VCOMP_DIV outputted from the second end can be adjusted by adjusting the resistance value of the potentiometer, and the second voltage can be compared with the circuit voltage to determine whether the second voltage is the same as the circuit voltage.

[0075] By setting the voltage dividing unit in this embodiment, the purpose of generating a second voltage having the same magnitude as the circuit voltage can be achieved, thereby providing a basis for accurately determining the target voltage of the resistor to be measured later.

[0076] As an optional implementation, as in the aforementioned control system, the resistance measurement circuit includes: a subtractor;

[0077] The subtractor is used to determine the difference between the measured voltage and the specified output voltage, and indicates that the resistance measurement system has been calibrated when the voltage measurement module 11 is not connected to the resistor to be measured and the output end of the subtractor is 0V by adjusting the error calibration circuit.

[0078] Specifically, the subtractor (ie, Figure 4 The Difference AMP IC U6 shown in the figure can adopt a subtractor of model INA105, through which the measured voltage V_RES_AMP_OUT mentioned above can be subtracted from the specified output voltage VCAL, so as to obtain the target voltage VEND equivalent to that after removing the error voltage, as shown in the following formula:

[0079] VEND=V_RES_AMP_OUT-VCAL.

[0080] Furthermore, the 6_OUT terminal and the 1_REF terminal of the subtractor are respectively connected to Hook11 and Hook12 for measuring the target voltage.

[0081] The specific principle of error calibration is as described in step 1 below:

[0082] Short-circuit Probe1 and Probe2, that is, the voltage measurement module 11 is not connected to the resistor to be measured. At this time, the resistance measured in the voltage measurement module 11 only includes the resistance corresponding to the circuit connected to its own resistance;

[0083] Since V_RES_AMP_OUT=(I×(Rreal+Rerror))×Gain+2V5, and Rreal=0Ω, Rreal is the resistance value of the resistor to be measured, Rerror is the resistance value of the resistor connected to the circuit, I is the current value of the constant current source, and 2V5 is the output voltage of the voltage measurement module 11 when the differential signal of the input voltage measurement module 11 is 0 and the VS terminal of the Current Sense AMP IC U2 is pressurized to VS_5V0;

[0084] It can be obtained that when Probe1 and Probe2 are short-circuited, V_RES_AMP_OUT=(I×Rerror)×Gain+2V5;

[0085] Adjust potentiometer RP1 so that (I×Rerror)×Gain=VCOMP_DIV;

[0086] Since VCAL=VCOMP_DIV+VREF_2V5, and VREF_2V5=2V5;

[0087] Therefore, when V_RES_AMP_OUT=VCAL, that is, V_RES_AMP_OUT-VCAL=VEND=0V, that is, when the error calibration circuit makes the output end of the subtractor 0V, the resistance measurement system has been calibrated.

[0088] Calibration standard: When the DMM (digital multimeter) measures 0V between Hook11 and Hook12, the calibration is successful.

[0089] As an optional implementation, the control system as described above further includes: a reference voltage circuit;

[0090] The voltage input terminal of the low voltage difference linear regulator of the reference voltage circuit is used to connect an external DC power supply;

[0091] The voltage input terminal of the low-dropout linear regulator is connected to the sleep terminal through a 100KΩ resistor;

[0092] The ground terminal of the low-dropout linear regulator is connected to the sleep terminal through a 51KΩ resistor;

[0093] The output end of the reference voltage circuit is connected to the voltage measurement module 11 for outputting a 5V reference voltage to the voltage measurement module 11 .

[0094] Take the reference voltage circuit as an example to generate a 5V0 reference voltage circuit. Figure 5 As shown, the reference voltage circuit is as follows: the low voltage dropout linear regulator (ie, Figure 5The LDO IC U1 shown in the figure adopts a regulator of model REF195, which is used to output a reference voltage source VS_5V0. The output end of the reference voltage circuit is connected to the voltage measurement module 11 so that the voltage measurement module 11 (ie, Figure 2 The INA240A3 IC shown) is powered by the 5V0 reference voltage. The voltage input terminals of REF195 (i.e., Figure 5 The VS terminal shown in the figure is connected to the sleep terminal through a 100KΩ resistor with an error within 1%; the ground terminal of REF195 (i.e., Figure 5 The GND terminal shown in the figure is connected to the sleep terminal through a 51KΩ resistor with an error within 1%. Further, Hook1 (connected to the VS terminal) and Hook2 (connected to the GND terminal) are used to connect an external DC power supply 15V0. Hook3 (connected to the OUT terminal) and Hook4 (connected to the GND terminal) are used to debug the circuit.

[0095] As described below, an embodiment of using the resistance measurement system of any of the above embodiments to calculate resistance is provided:

[0096] VEND=V_RES_AMP_OUT-VCAL

[0097] =[(I×(Rreal+Rerror))×Gain+2V5]-[VCOMP_DIV+VREF_2V5];

[0098] In step 1, the potentiometer RP1 has been adjusted so that (I×Rerror)×Gain=VCOMP_DIV;

[0099] Therefore, VEND = (I × Rreal) × Gain; that is, Rreal = VEND / (I × Gain);

[0100] Since I=100mA, Gain=100, so Rreal=VEND / 10;

[0101] When I = 100mA and Gain = 100, calculate the following example using Rreal = VEND / 10:

[0102] If VEND=1V, then Rreal=100mΩ; if VEND=0.1V, Rreal=10mΩ; if VEND=0.01V, Rreal=1mΩ; in general, DMM can accurately measure 0.01V voltage, so the system of this embodiment can accurately measure 1mΩ resistance.

[0103] like Figure 6According to another aspect of the present disclosure, a control method for a resistance measurement system is provided, comprising the following steps:

[0104] Step S202, outputting the measured voltage after the voltage measurement module is connected to the resistor to be measured;

[0105] Step S204, the error calibration module determines a target voltage corresponding to the resistor to be measured by subtracting the error voltage from the actual voltage, and determines a target resistance value of the resistor to be measured based on the target voltage, wherein the error voltage is the voltage of the actual voltage that is not applied to the resistor to be measured.

[0106] The specific implementation of the control method of the resistance measurement system in this embodiment can refer to the description of the relevant embodiments of the resistance measurement system mentioned above, and will not be described again here.

[0107] As an optional implementation, as in the aforementioned control method, before the output voltage measurement module is connected to the measured resistor and the actual voltage is measured, the method further includes:

[0108] The error calibration circuit is used to adjust and obtain a specified output voltage having the same magnitude as the error voltage, wherein the error voltage includes: a circuit voltage of the resistor access circuit and an output voltage of the voltage measurement module when the differential signal of the input voltage measurement module is 0, and the resistor access circuit is a circuit in the voltage measurement module for accessing the resistor to be measured;

[0109] Determining a target voltage corresponding to the resistor to be measured from the measured voltage includes: subtracting the measured voltage from a specified output voltage through a resistance measurement circuit to obtain a target voltage of the resistor to be measured, and determining a target resistance value of the resistor to be measured based on the target voltage.

[0110] The specific implementation of the control method of the resistance measurement system in this embodiment can refer to the description of the relevant embodiments of the resistance measurement system mentioned above, and will not be described again here.

[0111] As an optional implementation, as in the aforementioned control method, adjusting the error calibration circuit to obtain a specified output voltage having the same magnitude as the error voltage includes:

[0112] When the voltage measurement module is not connected to the resistance to be measured, the error calibration circuit is adjusted until the output end of the resistance measurement circuit is 0V, and it is determined that the specified output voltage having the same magnitude as the error voltage is adjusted.

[0113] The specific implementation of the control method of the resistance measurement system in this embodiment can refer to the description of the relevant embodiments of the resistance measurement system mentioned above, and will not be described again here.

[0114] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art: the system provided by the embodiment of the present application, by setting a voltage measurement module and an error calibration module; the voltage measurement module is used to connect the resistor to be measured, and output the measured voltage after the voltage measurement module is connected to the resistor to be measured; the error calibration module is connected to the voltage measurement module, and is used to determine the target voltage corresponding to the resistor to be measured in the measured voltage, and determine the target resistance value of the resistor to be measured based on the target voltage. Therefore, in the case where the measured voltage measured by the voltage measurement module includes the voltage of other circuits other than the resistor to be measured, the target voltage corresponding to the resistor to be measured can still be determined in the measured voltage through the error calibration module, and then the target resistance value of the resistor to be measured can be accurately determined based on the target voltage, and then the problem that the resistance value of small resistance value resistors cannot be accurately measured in the related art can be effectively solved.

[0115] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0116] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a general hardware platform, and of course, by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the relevant technology can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0117] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0118] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A resistance measurement system, characterized in that: include: Voltage measurement module and error calibration module; The voltage measurement module is used to connect to the resistor to be measured and output the measured voltage after the voltage measurement module is connected to the resistor to be measured; The error calibration module is connected to the voltage measurement module, and is used to determine a target voltage corresponding to the resistor to be measured by subtracting an error voltage from the actual measured voltage, and determine a target resistance value of the resistor to be measured based on the target voltage, wherein the error voltage is a voltage in the actual measured voltage that is not applied to the resistor to be measured.

2. The system according to claim 1, characterized in that The error calibration module includes: an error calibration circuit and a resistance measurement circuit; The error calibration circuit is connected to the voltage measurement module and is used to adjust and obtain a specified output voltage with the same magnitude as the error voltage, wherein the error voltage includes: a circuit voltage of a resistor access circuit, and an output terminal voltage of the voltage measurement module when the differential signal input to the voltage measurement module is 0, and the resistor access circuit is a circuit in the voltage measurement module used to access the resistor to be measured; The resistance measurement circuit is connected to the error calibration circuit, and is used for obtaining the target voltage by subtracting the measured voltage from the specified output voltage, and determining the target resistance value of the resistor to be measured according to the target voltage.

3. The system according to claim 2, characterized in that The error calibration circuit comprises: a linear power supply, a voltage divider unit and an adder; The linear power supply is used to output a first voltage, wherein the first voltage is the same as the output terminal voltage; The voltage dividing unit is connected to the linear power supply and is used to output a second voltage according to the first voltage and an external DC power supply; The adder is connected to the linear power supply and the voltage dividing unit respectively, and is used for adding the first voltage and the second voltage to obtain a third voltage.

4. The system according to claim 3, characterized in that The error calibration circuit further comprises: a voltage follower; The voltage follower is arranged between the linear power supply and the voltage dividing unit, and is used for outputting the first voltage to the voltage dividing unit.

5. The system according to claim 4, characterized in that The voltage dividing unit comprises: a fixed resistor and a potentiometer connected in series; The fixed resistor is connected to the voltage follower and is used to obtain the first voltage output by the voltage follower; The first end of the potentiometer is connected to a fourth voltage and a ground end respectively, and the second end of the potentiometer is connected to the fixed resistor, which is used to adjust the resistance of the potentiometer so that the second end outputs the second voltage with the same magnitude as the circuit voltage.

6. The system according to claim 2, characterized in that The resistance measurement circuit comprises: a subtractor; The subtractor is used to determine the difference between the measured voltage and the specified output voltage, and to indicate that the resistance measurement system has been calibrated when the voltage measurement module is not connected to the resistor to be measured and the output end of the subtractor is 0V by adjusting the error calibration circuit.

7. The system according to claim 1, characterized in that Also includes: Reference voltage circuit; The voltage input terminal of the low voltage drop linear regulator of the reference voltage circuit is used to connect to an external DC power supply; The voltage input terminal of the low voltage drop linear regulator is connected to the sleep terminal through a 100KΩ resistor; The ground terminal of the low voltage drop linear regulator is connected to the sleep terminal through a 51KΩ resistor; The output end of the reference voltage circuit is connected to the voltage measurement module and is used to output a 5V reference voltage to the voltage measurement module.

8. A control method for a resistance measurement system, characterized in that: include: The measured voltage after the output voltage measurement module is connected to the resistor to be measured; The target voltage corresponding to the resistor to be measured is determined by the error calibration module by subtracting the error voltage from the actual measured voltage, and the target resistance value of the resistor to be measured is determined based on the target voltage, wherein the error voltage is the voltage in the actual measured voltage that is not applied to the resistor to be measured.

9. The control method according to claim 8, characterized in that: Before measuring the actual voltage after the output voltage measurement module is connected to the resistor to be measured, the method further includes: The error calibration circuit is used to adjust and obtain a specified output voltage having the same magnitude as the error voltage, wherein the error voltage includes: a circuit voltage of a resistor access circuit, and an output voltage of the voltage measurement module when the differential signal input to the voltage measurement module is 0, and the resistor access circuit is a circuit in the voltage measurement module for accessing the resistor to be measured; The method of determining a target voltage corresponding to the resistor to be measured by subtracting an error voltage from the measured voltage includes: performing a difference operation on the measured voltage and the specified output voltage through a resistance measurement circuit to obtain a target voltage of the resistor to be measured, and determining a target resistance value of the resistor to be measured according to the target voltage.

10. The control method according to claim 9, characterized in that: The step of adjusting the error calibration circuit to obtain a specified output voltage having the same magnitude as the error voltage comprises: When the voltage measurement module is not connected to the resistance to be measured, the error calibration circuit is adjusted until the output end of the resistance measurement circuit is 0V, and it is determined that the specified output voltage having the same magnitude as the error voltage is adjusted.

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