Resistance detection circuit and resistance detector

Abstract

The embodiment of the utility model provides a resistance detection circuit and a resistance detector, and belongs to the technical field of resistance detection. The circuit comprises a detection module, a sampling module, a standard module, a power supply module and a main control module, the power supply module, the detection module and the standard module are sequentially connected in series to form a detection loop, and the power supply module is used for providing current for the detection module and the standard module; the sampling module is connected in parallel with the detection module and is used for acquiring a detection voltage value of the detection module; the sampling module is also connected in parallel with the standard module and is used for acquiring a standard voltage value of the standard module; and the main control module is electrically connected with the sampling module and is used for obtaining a target resistance value of the detection module according to the detection voltage value and the standard voltage value. Through the provided scheme, the detection precision of the measuring resistor is improved, and the detection cost is reduced.

Description

Technical Field

[0001] This application relates to the technical field of resistance detection, and particularly to a resistance detection circuit and a resistance detector. Background Art

[0002] Currently, the detection method of a source meter is often used to detect a resistance, that is, a set current output by the constant current source of the source meter is applied to the resistance to be measured, and then the voltage is detected across the two ends of the resistance to be measured, and the resistance value is calculated according to Ohm's law. The detection accuracy of this method depends on the accuracy of the current and the accuracy of the voltage. Since the source meter circuit is complex and there are many factors affecting the accuracy, especially when detecting small resistance values, the accuracy is difficult to guarantee. Utility Model Content

[0003] In order to solve the above technical problems, the embodiments of this application provide a resistance detection circuit and a resistance detector.

[0004] In a first aspect, the embodiments of this application provide a resistance detection circuit, and the resistance detection circuit includes: a detection module, a sampling module, a standard module, a power supply module, and a main control module;

[0005] The power supply module, the detection module, and the standard module are connected in series in sequence to form a detection loop, and the power supply module is configured to provide current to the detection module and the standard module;

[0006] The sampling module is connected in parallel with the detection module and is configured to obtain the detection voltage value of the detection module;

[0007] The sampling module is also connected in parallel with the standard module and is configured to obtain the standard voltage value of the standard module;

[0008] The main control module is electrically connected to the sampling module and is configured to obtain the target resistance value of the detection module according to the detection voltage value and the standard voltage value.

[0009] In an embodiment, the circuit further includes: a switch module:

[0010] The switch module includes: a switch unit;

[0011] The common end of the switch unit is electrically connected to the sampling module; the first access end of the switch unit is electrically connected to the detection module; the second access end of the switch unit is electrically connected to the standard module;

[0012] The control end of the switch unit is electrically connected to the main control module.

[0013] In an embodiment, the switch unit includes: a double-pole double-throw switch.

[0014] In one embodiment, the sampling module includes: a first sampling unit, a second sampling unit, a reference voltage, and a clock source;

[0015] The first sampling unit is electrically connected to the reference voltage, the clock source, the detection module, and the main control module respectively, and is configured to sample the detected voltage value and send the detected voltage value to the main control module;

[0016] The second sampling unit is electrically connected to the reference voltage, the clock source, the standard module, and the main control module respectively, and is configured to sample the standard voltage value and send the standard voltage value to the main control module.

[0017] In one embodiment, the circuit further includes: an amplification module;

[0018] The amplification module includes: a first amplification unit and a second amplification unit;

[0019] The first amplification unit is electrically connected to the detection module and the first sampling unit respectively;

[0020] The second amplification unit is electrically connected to the standard module and the second sampling unit respectively.

[0021] In one embodiment, the detection module includes: a to-be-tested resistor;

[0022] The first end of the to-be-tested resistor is connected in series with the first end of the power supply module;

[0023] The second end of the to-be-tested resistor is connected in series with the first end of the standard module.

[0024] In one embodiment, the standard module includes: a standard resistor;

[0025] The first end of the standard resistor is connected in series with the second end of the to-be-tested resistor;

[0026] The second end of the standard resistor is connected in series with the second end of the power supply module.

[0027] In one embodiment, the power supply module includes: a constant current source;

[0028] The first end of the constant current source is electrically connected to the first end of the to-be-tested resistor;

[0029] The second end of the constant current source is electrically connected to the second end of the standard resistor.

[0030] In one embodiment, the detection module includes: i to-be-tested resistors; i is greater than or equal to 2;

[0031] Each of the to-be-tested resistors is connected in series in sequence;

[0032] The first end of the i-th resistor to be measured is electrically connected to the first end of the power supply module;

[0033] The second end of the i-th resistor to be measured is electrically connected to the first end of the (i - 1)-th resistor to be measured;

[0034] The second end of the first resistor to be measured is connected in series with the first end of the standard module.

[0035] In a second aspect, an embodiment of the present application provides a resistor detector, which includes: the resistor detection circuit of the first aspect.

[0036] For the above-mentioned resistor detection circuit and resistor detector provided by the present application, the circuit includes: a detection module, a sampling module, a standard module, a power supply module, and a main control module; the power supply module, the detection module, and the standard module are connected in series in sequence to form a detection loop, and the power supply module is used to provide current to the detection module and the standard module; the sampling module is connected in parallel with the detection module and is used to obtain the detection voltage value of the detection module; the sampling module is also connected in parallel with the standard module and is used to obtain the standard voltage value of the standard module; the main control module is electrically connected to the sampling module and is used to obtain the target resistance value of the detection module according to the detection voltage value and the standard voltage value. In this solution, by connecting the detection module in series with the standard module and connecting the power supply module and the sampling module, the target resistance value of the detection module can be obtained through simple voltage measurement and calculation, making the measurement result have high accuracy, relatively low use cost, and improving the stability of the measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the protection scope of the present application. In each drawing, similar components are numbered similarly.

[0038] Figure 1 Shows a schematic diagram of a module of the resistor detection circuit;

[0039] Figure 2 Shows a circuit schematic diagram of the resistor detection circuit;

[0040] Figure 3 Shows another schematic diagram of a module of the resistor detection circuit;

[0041] Figure 4 Shows another circuit schematic diagram of the resistor detection circuit;

[0042] Figure 5Shows another circuit schematic diagram of the resistance detection circuit;

[0043] Figure 6 Shows another module schematic diagram of the resistance detection circuit;

[0044] Figure 7 Shows yet another circuit schematic diagram of the resistance detection circuit.

[0045] Icons: 100 - Detection module; 200 - Sampling module; 300 - Main control module; 400 - Power supply module; 500 - Standard module; 600 - Amplification module; 700 - Switch module; 201 - First sampling unit; 202 - Second sampling unit; 203 - Clock source; 204 - Reference voltage; 601 - First amplification unit; 602 - Second amplification unit. Detailed implementation manners

[0046] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0047] Generally, the components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but merely represents the selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0048] In the following text, the terms "including", "having" and their cognates that can be used in various embodiments of the present application are only intended to represent specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or increasing the possibility of one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0049] In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of the present application pertain. The terms (such as those defined in a commonly used dictionary) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning, unless clearly defined in various embodiments of the present application.

[0051] Embodiment 1

[0052] An embodiment of the present application provides a resistance detection circuit. Refer to Figure 1 , the resistance detection circuit includes: a detection module 100, a sampling module 200, a standard module 500, a power supply module 400, and a main control module 300; the power supply module 400, the detection module 100, and the standard module 500 are connected in series in sequence to form a detection loop, and the power supply module 400 is used to supply current to the detection module 100 and the standard module 500; the sampling module 200 is connected in parallel with the detection module 100 and is used to obtain the detection voltage value of the detection module 100; the sampling module 200 is also connected in parallel with the standard module 500 and is used to obtain the standard voltage value of the standard module 500; the main control module 300 is electrically connected to the sampling module 200 and is used to obtain the target resistance value of the detection module 100 according to the detection voltage value and the standard voltage value.

[0053] It should be noted that in the present application, by connecting the detection module 100 in series with the standard module 500 and connecting the power supply module 400 and the sampling module 200, the target resistance value of the detection module 100 can be obtained through simple voltage measurement and calculation, making the measurement result have relatively high accuracy, and the cost used is relatively low, improving the stability of the measurement.

[0054] Furthermore, in other embodiments, the positions of the detection module and the standard module can be swapped, and the target resistance value of the detection module can still be obtained, reducing the detection cost.

[0055] In an embodiment, the circuit further includes: a switch module 700: the switch module 700 includes: a switch unit; the common end of the switch unit is electrically connected to the sampling module 200; the first access end of the switch unit is electrically connected to the detection module 100; the second access end of the switch unit is electrically connected to the standard module 500; the control end of the switch unit is electrically connected to the main control module 300. Optionally, the switch unit includes: a double-pole double-throw switch.

[0056] In this embodiment, as Figure 2As shown, by using a sampling module 200 to sample the voltage signals of the detection module 100 and the standard module 500 respectively, the two voltage signals are switched by a switch. Therefore, the ratio of the two sampling results is also independent of the accuracy of the reference voltage of the sampling module 200. When the analog signal of the sampling module 200 is converted once, one sampling is completed. The signal switching switch usually uses a relay or an analog switch device. Performing sampling and switching are both controlled by the main control module 300.

[0057] For example, if it is determined to sample the voltage signal of the detection module 100, the corresponding moving end of the double - pole double - throw switch is controlled to be electrically connected to the detection module 100, so that the detection module 100 can be connected in parallel with the sampling module 200, thereby controlling the sampling module 200 to sample the detected voltage value of the detection module 100.

[0058] In one embodiment, as Figure 3 shown, the sampling module 200 further includes: a first sampling unit 201, a second sampling unit 202, a reference voltage 204, and a clock source 203; the first sampling unit 201 is electrically connected to the reference voltage 204, the clock source 203, the detection module 100, and the main control module 300 respectively, and is used to sample the detected voltage value and send the detected voltage value to the main control module; the second sampling unit 202 is electrically connected to the reference voltage 204, the clock source 203, the standard module 500, and the main control module 300 respectively, and is used to sample the standard voltage value and send the standard voltage value to the main control module.

[0059] As Figure 4 shown, the two sampling units use the same reference voltage Ref. Therefore, the numerical ratio output by the two sampling units is independent of the accuracy of the reference voltage. The main control module 300 controls the two sampling units to start sampling simultaneously, and the two sampling units use the same clock source Clk.

[0060] The same clock source Clk means that the two sampling units are synchronous when counting clock pulses. By completing the sampling operation within the same clock cycle, no matter how the current fluctuates, the two sampling units can capture the voltage values at almost the same time point, thereby greatly reducing the error introduced by current fluctuations.

[0061] In one embodiment, as Figure 5As shown, the circuit further includes: an amplification module 600; the amplification module 600 includes: a first amplification unit 601 and a second amplification unit 602; the first amplification unit 601 is electrically connected to the detection module 100 and the first sampling unit 201 respectively; the second amplification unit 602 is electrically connected to the standard module 500 and the second sampling unit 202 respectively.

[0062] Among them, the sampling module is an analog-to-digital converter (ADC), represented by ADC herein, the main control module is an MCU, the first amplification unit is a first amplifier D1, and the second amplification unit is a second amplifier D2. Figure 5 Among them, the sampling module is an analog-to-digital converter (ADC), represented by ADC herein, the main control module is an MCU, the first amplification unit is a first amplifier D1, and the second amplification unit is a second amplifier D2.

[0063] Exemplarily, as Figure 6 shown, when detecting a small resistance value, the voltage drop generated on the resistor is relatively small. Therefore, an amplifier is added before the sampling module 200 to amplify the voltage signal first, and then the sampling module 200 performs sampling. By amplifying the weak voltage signal to a range that the sampling module 200 can accurately detect and selecting an appropriate amplification factor, it is ensured that even the tiny voltage drop generated on the small-resistance resistor can be clearly captured and measured, further increasing the accuracy of resistance measurement.

[0064] In one embodiment, the detection module 100 includes: a resistor to be measured; the first end of the resistor to be measured is connected in series with the first end of the power supply module 400; the second end of the resistor to be measured is connected in series with the first end of the standard module 500.

[0065] Since the voltage detection circuit itself may have zero drift, when the input voltage of the amplifier is zero, the value converted and output by the sampling module 200 is not zero, but has an offset. In addition, since there may be thermoelectric potential at the connection points of the resistor and the circuit, when the current on the resistor is zero, there is still a certain voltage at the input end of the amplifier, which is not zero, and this will also cause the value converted and output by the sampling module 200 not to be zero, and there is also an offset.

[0066] To solve the problem of the offset of the detected voltage, different currents I are used for detection respectively, and the main control module 300 takes the difference for calculation. By this method, the offset can be effectively canceled.

[0067] Assume that the amplification factors of the two amplifiers are equal, and the parameters of the two sampling modules 200 are the same. The difference between the output values of the sampling module 200 for the resistor R to be measured measured twice before and after is △D, and the difference between the output values of the sampling module 200 for the standard resistor Rs is △Ds. Then the main control module 300 can calculate the measured resistor R = Rs·△D / △Ds.

[0068] In one embodiment, the standard module 500 includes: a standard resistor; a first end of the standard resistor is connected in series with a second end of the resistor under test; a second end of the standard resistor is connected in series with a second end of the power supply module 400.

[0069] In this embodiment, by way of example, as Figure 7 shown, by connecting the determined standard module in series with the resistor under test, the internal constant current source outputs a set current I which is applied to the resistor under test and the standard resistor, and then the voltage U across the resistor under test R and the voltage Us across the standard resistor RS are measured respectively. Since the current in a series circuit is equal, the resistance ratio of the two resistors is equal to the voltage ratio, that is, R / Rs = U / Us, so R = Rs·U / Us.

[0070] In one embodiment, the power supply module 400 includes: a constant current source; a first end of the constant current source is electrically connected to a first end of the resistor under test; a second end of the constant current source is electrically connected to a second end of the standard resistor.

[0071] In one embodiment, the detection module 100 includes: i resistors under test; i is greater than or equal to 2; the resistors under test are connected in series in sequence; a first end of the i-th resistor under test is electrically connected to a first end of the power supply module; a second end of the i-th resistor under test is electrically connected to a first end of the (i - 1)-th resistor under test; a second end of the first resistor under test is connected in series with a first end of the standard module.

[0072] In this embodiment, the sampling module 200 is used to detect the voltage values of the resistors under test, and the target resistance values of the resistors under test can be calculated respectively according to the ratio of the voltage values of the resistors under test to the voltage value of the standard resistor.

[0073] The resistance detection circuit provided in this embodiment includes: a detection module 100, a sampling module 200, a standard module 500, a power supply module 400, and a main control module 300; the power supply module 400, the detection module 100, and the standard module 500 are connected in series in sequence to form a detection loop, and the power supply module 400 is used to provide current to the detection module 100 and the standard module 500; the sampling module 200 is connected in parallel with the detection module 100 and is used to obtain the detection voltage value of the detection module 100; the sampling module 200 is also connected in parallel with the standard module 500 and is used to obtain the standard voltage value of the standard module 500; the main control module 300 is electrically connected to the sampling module 200 and is used to obtain the target resistance value of the detection module 100 according to the detection voltage value and the standard voltage value. In this solution, by connecting the detection module 100 in series with the standard module 500 and connecting the power supply module 400 and the sampling module 200, the target resistance value of the detection module 100 can be obtained through simple voltage measurement and calculation, making the measurement result have relatively high precision, and the cost used is relatively low, improving the stability of the measurement.

[0074] Embodiment 2

[0075] This embodiment provides a resistance detector, including the resistance detection circuit provided in Embodiment 1.

[0076] The embodiment of the present application provides a resistance detection circuit, including: a detection module, a sampling module, a standard module, a power supply module, and a main control module; the power supply module, the detection module, and the standard module are connected in series in sequence to form a detection loop, and the power supply module is used to provide current to the detection module and the standard module; the sampling module is connected in parallel with the detection module and is used to obtain the detection voltage value of the detection module; the sampling module is also connected in parallel with the standard module and is used to obtain the standard voltage value of the standard module; the main control module is electrically connected to the sampling module and is used to obtain the target resistance value of the detection module according to the detection voltage value and the standard voltage value.

[0077] In an implementation manner, the circuit further includes: a switch module: the switch module includes: a switch unit; the common end of the switch unit is electrically connected to the sampling module; the first access end of the switch unit is electrically connected to the detection module; the second access end of the switch unit is electrically connected to the standard module; the control end of the switch unit is electrically connected to the main control module.

[0078] In an implementation manner, the switch unit includes: a double-pole double-throw switch.

[0079] In one embodiment, the first sampling unit is electrically connected to the reference voltage, the clock source, the detection module, and the main control module respectively, and is configured to sample the detected voltage value and send the detected voltage value to the main control module; the second sampling unit is electrically connected to the reference voltage, the clock source, the standard module, and the main control module respectively, and is configured to sample the standard voltage value and send the standard voltage value to the main control module.

[0080] In one embodiment, the circuit further includes an amplification module; the amplification module includes a first amplification unit and a second amplification unit; the first amplification unit is electrically connected to the detection module and the first sampling unit respectively; the second amplification unit is electrically connected to the standard module and the second sampling unit respectively.

[0081] In one embodiment, the detection module includes a to-be-detected resistor; the first end of the to-be-detected resistor is connected in series with the first end of the power supply module; the second end of the to-be-detected resistor is connected in series with the first end of the standard module.

[0082] In one embodiment, the standard module includes a standard resistor; the first end of the standard resistor is connected in series with the second end of the to-be-detected resistor; the second end of the standard resistor is connected in series with the second end of the power supply module.

[0083] In one embodiment, the power supply module includes a constant current source; the first end of the constant current source is electrically connected to the first end of the to-be-detected resistor; the second end of the constant current source is electrically connected to the second end of the standard resistor.

[0084] In one embodiment, the detection module includes i to-be-detected resistors; i is greater than or equal to 2; the to-be-detected resistors are connected in series in sequence; the first end of the i-th to-be-detected resistor is electrically connected to the first end of the power supply module; the second end of the i-th to-be-detected resistor is electrically connected to the first end of the (i - 1)-th to-be-detected resistor; the second end of the first to-be-detected resistor is connected in series with the first end of the standard module.

[0085] The resistance detector provided in this embodiment includes the resistance detection circuit provided in Embodiment 1. Among them, the circuit includes: a detection module, a sampling module, a standard module, a power supply module, and a main control module; the power supply module, the detection module, and the standard module are connected in series in sequence to form a detection loop. The power supply module is used to provide current to the detection module and the standard module; the sampling module is connected in parallel with the detection module and is used to obtain the detection voltage value of the detection module; the sampling module is also connected in parallel with the standard module and is used to obtain the standard voltage value of the standard module; the main control module is electrically connected to the sampling module and is used to obtain the target resistance value of the detection module according to the detection voltage value and the standard voltage value. In this solution, by connecting the detection module and the standard module in series and connecting the power supply module and the sampling module, the target resistance value of the detection module can be obtained through simple voltage measurement and calculation, making the measurement result have high accuracy, relatively low use cost, and improving the stability of the measurement.

[0086] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or terminal. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or terminal including that element.

[0087] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all belong to the protection scope of the present application.

Claims

1. A resistance detection circuit, characterized in that, The circuit includes: a detection module, a sampling module, a standard module, a power supply module, and a main control module; The power supply module, the detection module, and the standard module are connected in series in sequence to form a detection loop. The power supply module is used to provide current to the detection module and the standard module; The sampling module is connected in parallel with the detection module and is used to obtain the detection voltage value of the detection module; The sampling module is also connected in parallel with the standard module and is used to obtain the standard voltage value of the standard module; The main control module is electrically connected to the sampling module and is used to obtain the target resistance value of the detection module according to the detection voltage value and the standard voltage value.

2. The resistance detection circuit according to claim 1, wherein The circuit further includes: a switch module: The switch module includes: a switch unit; The common terminal of the switch unit is electrically connected to the sampling module; the first access terminal of the switch unit is electrically connected to the detection module; the second access terminal of the switch unit is electrically connected to the standard module; The control terminal of the switch unit is electrically connected to the main control module.

3. The resistance detection circuit according to claim 2, wherein, The switch unit includes: a double-pole double-throw switch.

4. The resistance detection circuit according to claim 1, wherein, The sampling module includes: a first sampling unit, a second sampling unit, a reference voltage, and a clock source; The first sampling unit is electrically connected to the reference voltage, the clock source, the detection module, and the main control module respectively, and is used to sample the detection voltage value and send the detection voltage value to the main control module; The second sampling unit is electrically connected to the reference voltage, the clock source, the standard module, and the main control module respectively, and is used to sample the standard voltage value and send the standard voltage value to the main control module.

5. The resistance detection circuit according to claim 4, wherein, The circuit further includes: an amplification module; The amplification module includes: a first amplification unit and a second amplification unit; The first amplification unit is electrically connected to the detection module and the first sampling unit respectively; The second amplification unit is electrically connected to the standard module and the second sampling unit respectively.

6. The resistance detection circuit according to claim 1, wherein, The detection module includes: a to-be-detected resistor; The first end of the to-be-detected resistor is connected in series with the first end of the power supply module; The second end of the to-be-detected resistor is connected in series with the first end of the standard module.

7. The resistance detection circuit according to claim 6, wherein The standard module includes: a standard resistor; The first end of the standard resistor is connected in series with the second end of the to-be-detected resistor; The second end of the standard resistor is connected in series with the second end of the power supply module.

8. The resistance detection circuit according to claim 7, wherein, The power supply module includes: a constant current source; The first end of the constant current source is electrically connected to the first end of the to-be-detected resistor; The second end of the constant current source is electrically connected to the second end of the standard resistor.

9. The resistance detection circuit according to claim 1, wherein The detection module includes: i to-be-detected resistors; i is greater than or equal to 2; Each of the to-be-detected resistors is connected in series in sequence; The first end of the i-th to-be-detected resistor is electrically connected to the first end of the power supply module; The second end of the i-th to-be-detected resistor is electrically connected to the first end of the (i - 1)-th to-be-detected resistor; The second end of the first to-be-detected resistor is connected in series with the first end of the standard module.

10. A resistance detector, characterized in that, Including the resistance detection circuit according to any one of claims 1-9.

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