CN219085028U - Resistance measuring device and source meter - Google Patents
Resistance measuring device and source meter Download PDFInfo
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- CN219085028U CN219085028U CN202223317813.2U CN202223317813U CN219085028U CN 219085028 U CN219085028 U CN 219085028U CN 202223317813 U CN202223317813 U CN 202223317813U CN 219085028 U CN219085028 U CN 219085028U
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Abstract
The utility model discloses a resistance measuring device and a source meter, which comprises a power supply, an output adjusting module, a measured terminal, a control unit and a sampling unit, wherein the sampling unit comprises a voltage sampling unit and a current sampling unit.
Description
Technical Field
The utility model relates to the field of measuring equipment, in particular to a resistance measuring device and a source meter.
Background
The source meter is a common instrument in the measurement and control technology, combines the achievements of the electronic technology and the computing technology with the measurement and control technology, has the advantages of wide application, convenient operation, accurate reading, small volume, convenient carrying and the like, becomes an indispensable instrument in modern measurement, can output a voltage source, a current source, an electronic load, measure voltage, current, resistance, diodes and the like, and replaces a plurality of power supplies, loads and measuring instruments in a plurality of fields. The method has the advantages of convenient use, high measurement speed, wide measuring range, strong overload capacity, high impedance of the transfusion, objectivity of the indicated value, strong expansion capacity and the like, and is widely applied to the scientific and technological measurement fields such as material measurement, semiconductor measurement, photoelectric device measurement and the like.
The principle of measuring the resistor by the source meter is that the resistor is measured by a common universal meter by using a constant current source method according to ohm law, the reading value of the resistor is actually a voltage reading value, and the electronic components have time drift and zero drift, so that the error between the measured value and the true value of the resistor is larger, and the precision of the resistor measurement is lower.
Disclosure of Invention
The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, the utility model provides a resistance measuring device and a source meter, which can solve the problem that the accuracy of measuring resistance is low because of time drift and zero drift of electronic components in the existing source meter.
An electrical resistance measuring device according to an embodiment of the first aspect of the present utility model includes: the power supply is used for supplying power; the power supply is connected with the input end of the output adjustment module; the output end of the output adjustment module is connected with the tested terminal; the output end of the control unit is connected with the control end of the output adjustment module; the sampling unit comprises a voltage sampling unit and a current sampling unit, wherein the sampling end of the current sampling unit is connected with the output end of the output adjustment module, the sampling end of the voltage sampling unit is connected with the two ends of the tested terminal, the data processing module is arranged on the sampling unit, the output end of the current sampling unit is connected with the first input end of the data processing module, and the output end of the voltage sampling unit is connected with the second input end of the data processing module.
The resistance measuring device according to the embodiment of the first aspect of the present utility model has at least the following advantages:
according to the embodiment of the utility model, the power supply supplies power to the tested device through the output adjustment module, the voltage sampling unit and the current sampling unit respectively acquire the voltage and the current of the tested device and feed the voltage and the current back to the data processing module, the control unit can adjust the voltage and the current at two ends of the tested device through the output adjustment module, the data processing module can calculate the real resistance of the tested device according to multiple groups of voltage and current data, the problem that the accuracy is reduced due to time drift and zero drift of the source table when the resistance is measured is solved, and the measurement accuracy is improved.
According to some embodiments of the utility model, the control unit includes an output control module, a digital-to-analog conversion module, a mode control module and a signal processing and amplifying module, where the output control module is connected to an input end of the digital-to-analog conversion module, an output end of the digital-to-analog conversion module is connected to an input end of the signal processing and amplifying module, an output end of the signal processing and amplifying module is connected to a control end of the output adjustment module, and the mode control module is connected to a control end of the signal processing and amplifying module.
According to some embodiments of the utility model, the voltage sampling unit is connected to the first feedback end of the signal processing and amplifying module through the signal amplifying module, and the current sampling unit is connected to the second feedback end of the signal processing and amplifying module through the signal amplifying module.
According to some embodiments of the utility model, the control unit includes an output control module, a digital-to-analog conversion module, a mode control module and a signal processing and amplifying module, where the output control module is connected to an input end of the digital-to-analog conversion module, an output end of the digital-to-analog conversion module is connected to an input end of the signal processing and amplifying module, an output end of the signal processing and amplifying module is connected to a control end of the output adjustment module, and the mode control module is connected to a control end of the signal processing and amplifying module.
According to some embodiments of the utility model, the signal processing and amplifying module includes a first switch chip U3B, a second switch chip U4B and an amplifier U2A, the mode control module is respectively connected to the control ends of the first switch chip U3B and the second switch chip U4B, the output end of the digital-to-analog conversion module is respectively connected to the input ends of the first switch chip U3B and the second switch chip U4B, the voltage sampling unit is connected to the feedback end of the first switch chip U3B through the signal amplifying module, the current sampling unit is connected to the feedback end of the second switch chip U4B through the signal amplifying module, the first switch chip U3B and the second switch chip U4B are both connected to the input end of the amplifier U2A, and the output end of the amplifier U2A is connected to the control end of the output adjusting module.
The source meter according to an embodiment of the second aspect of the present utility model includes the resistance measuring device described above.
The source table according to the embodiment of the second aspect of the present utility model has at least the following advantages:
according to the embodiment of the utility model, the power supply supplies power to the tested device through the output adjustment module, the voltage sampling unit and the current sampling unit respectively acquire the voltage and the current of the tested device and feed the voltage and the current back to the data processing module, the control unit can adjust the voltage and the current at two ends of the tested device through the output adjustment module, the data processing module can calculate the real resistance of the tested device according to multiple groups of voltage and current data, the problem that the accuracy is reduced due to time drift and zero drift of the source table when the resistance is measured is solved, and the measurement accuracy is improved.
Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.
Drawings
The utility model is further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a schematic block diagram of a resistance measuring device according to an embodiment of the present utility model;
fig. 2 is a schematic circuit diagram of a signal processing and amplifying module, an output adjusting module, a sampling unit and a signal amplifying module according to an embodiment of the present utility model.
Detailed Description
Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.
In the description of the present utility model, it should be understood that the direction or positional relationship indicated with respect to the description of the orientation, such as up, down, etc., is based on the direction or positional relationship shown in the drawings, is merely for convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the apparatus or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model.
In the description of the present utility model, plural means two or more. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.
In the description of the present utility model, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present utility model can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.
Referring to fig. 1, a resistance measuring apparatus includes: the device comprises a power supply, an output adjusting module, a tested terminal, a control unit and a sampling unit. The power supply is connected with the input end of the output adjustment module, the output end of the output adjustment module is connected with the tested terminal, and the tested terminal is connected with the two ends of the tested device so as to supply power to the tested device. The output end of the control unit is connected with the control end of the output adjustment module, the sampling unit comprises a voltage sampling unit and a current sampling unit, the sampling end of the current sampling unit is connected with the output end of the output adjustment module, the sampling end of the voltage sampling unit is connected with two ends of a tested terminal, the output end of the current sampling unit is connected with the first input end of the data processing module, and the output end of the voltage sampling unit is connected with the second input end of the data processing module.
According to the embodiment of the utility model, the power supply supplies power to the tested device through the output adjustment module, the voltage sampling unit and the current sampling unit respectively acquire the voltage and the current of the tested device and feed the voltage and the current back to the data processing module, the control unit can adjust the voltage and the current at two ends of the tested device through the output adjustment module, the data processing module can calculate the real resistance of the tested device according to multiple groups of voltage and current data, the problem that the accuracy is reduced due to time drift and zero drift of the source table when the resistance is measured is solved, and the measurement accuracy is improved.
Specifically, the control unit comprises an output control module, a digital-to-analog conversion module, a mode control module and a signal processing and amplifying module, wherein the output control module is connected with the input end of the digital-to-analog conversion module, the output end of the digital-to-analog conversion module is connected with the input end of the signal processing and amplifying module, the output end of the signal processing and amplifying module is connected with the control end of the output adjustment module, and the mode control module is connected with the control end of the signal processing and amplifying module.
The voltage sampling unit is connected with the analog-to-digital conversion module through the signal amplification module, and is input to the data processing module after analog-to-digital conversion through the analog-to-digital conversion module.
The measuring principle of the embodiment of the utility model is as follows:
after power-on, the power supply is connected to the tested device through the current sampling unit after being regulated and output by the output regulating module. When the test starts, the mode control module outputs a mode control signal to the signal processing and amplifying module to switch the constant voltage output mode and the constant current output mode, wherein a constant current mode is generally adopted when the resistance value of the tested device is smaller, and a constant voltage mode is generally adopted when the resistance value is smaller, and the two output modes can be mutually used.
The output control module outputs a digital signal 1, a fixed analog signal is obtained through the digital-to-analog conversion module, meanwhile, a feedback signal is obtained after the current voltage signals obtained by the voltage sampling unit and the current sampling unit are processed by the signal amplifying module for calculation and amplification, the signal processing and amplifying module adjusts the output adjusting unit through the analog signal and the feedback signal to form a first stable constant voltage or constant current power supply 1, the first stable constant voltage or constant current power supply 1 is applied to two ends of a tested device, and meanwhile, the voltage sampling signal and the current sampling signal which are amplified by the signals are sent to the data processing module to obtain voltage data U1 and current data I1.
When the output control module outputs another digital signal 2, a second constant voltage or constant current power supply 2 is obtained through the steps, and because the power supplies are different in size, the current of the tested device and the voltage at two ends are also different, and therefore a group of new voltage data U2 and current data I2 can be obtained.
From ohm's law, derive
ΔU＝U1–U2；ΔI＝I1–I2。
When a resistance of 0.1 Ω is measured, when the mode is adjusted to the constant current source output mode, the measurement results of the output control outputs constant currents 1A and 0.5A are:
according to ohm's law, the voltage across the resistor: u=0.1V and 0.05V
Current I1:1 (a) × (1+0.05%) +500 μa=1.001 (a)
Current I2:0.1 (a) × (1+0.05%) +500 μa= 0.50075 (a)
Measurement error of current difference: (1.001-0.50075-0.5)/0.5=0.05%
Voltage U1:0.1 (V) × (1+0.02%) +100 μv= 0.10012 (V)
Voltage U2:0.05 (V) × (1+0.02%) +100 μv= 0.05011 (V)
Voltage difference measurement error: (0.10012-0.05011-0.05)/0.05=0.02%
The calculated resistance error is 0.05% +0.02% = 0.07%.
From the data, the measuring precision is very high, and the resistance measuring device can greatly improve the resistance measuring precision. This is because the time drift and zero drift are almost constant in a short time in the two sets of measured values, because the temperature drift caused by the thermal stability of the device and the zero drift caused by the time are very small in a relatively short time, and the error of the measurement is larger and larger along with the heating and the time, and the difference value measurement is adopted to measure twice in a very short time, and the same difference value caused by the drift is subtracted in the subtracting way to obtain a more accurate result. Therefore, the resistance measuring device can measure the resistance by using two difference values, and the measuring precision of the resistance is effectively improved.
Specifically, referring to fig. 2, in the embodiment of the present utility model, the signal processing and amplifying module includes a first switch chip U3B, a second switch chip U4B and an amplifier U2A, in this embodiment, the types of the first switch chip U3B and the second switch chip U4B are DG444, other switch chips may also be adopted, the signal amplifying module includes an amplifier U1 and an amplifier U10, the mode control module is connected to the control ends of the first switch chip U3B and the second switch chip U4B, the output end of the digital-to-analog conversion module is connected to the input ends of the first switch chip U3B and the second switch chip U4B, the voltage sampling unit is connected to the feedback end of the first switch chip U3B through the amplifier U10, the current sampling unit is connected to the feedback end of the second switch chip U4B through the amplifier U1, the first switch chip U3B and the second switch chip U4B are both connected to the input end of the amplifier U2A, the output end of the amplifier U2A is connected to the control end of the output adjustment module, and the output adjustment module is formed by a MOS transistor Q1 and a MOS transistor Q2.
The utility model further comprises a source meter comprising the resistance measuring device of the embodiment.
The embodiments of the present utility model have been described in detail with reference to the accompanying drawings, but the present utility model is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present utility model.
Claims (5)
1. A resistance measurement device, comprising:
the power supply is used for supplying power;
the power supply is connected with the input end of the output adjustment module;
the output end of the output adjustment module is connected with the tested terminal;
the output end of the control unit is connected with the control end of the output adjustment module;
the sampling unit comprises a voltage sampling unit and a current sampling unit, the sampling end of the current sampling unit is connected with the output end of the output adjustment module, the sampling end of the voltage sampling unit is connected with the two ends of the tested terminal,
and the output end of the voltage sampling unit is connected with the second input end of the data processing module.
2. The resistance measurement device according to claim 1, wherein the control unit includes an output control module, a digital-to-analog conversion module, a mode control module, and a signal processing and amplifying module, the output control module is connected to an input end of the digital-to-analog conversion module, an output end of the digital-to-analog conversion module is connected to an input end of the signal processing and amplifying module, an output end of the signal processing and amplifying module is connected to a control end of the output adjustment module, and the mode control module is connected to a control end of the signal processing and amplifying module.
3. The resistance measurement device of claim 2, further comprising a signal amplification module, wherein the voltage sampling unit is connected to the first feedback terminal of the signal processing and amplification module through the signal amplification module, and wherein the current sampling unit is connected to the second feedback terminal of the signal processing and amplification module through the signal amplification module.
4. The resistance measurement device according to claim 3, wherein the signal processing and amplifying module includes a first switch chip U3B, a second switch chip U4B and an amplifier U2A, the mode control module is respectively connected to the control ends of the first switch chip U3B and the second switch chip U4B, the output end of the digital-to-analog conversion module is respectively connected to the input ends of the first switch chip U3B and the second switch chip U4B, the voltage sampling unit is connected to the feedback end of the first switch chip U3B through the signal amplifying module, the current sampling unit is connected to the feedback end of the second switch chip U4B through the signal amplifying module, the first switch chip U3B and the second switch chip U4B are both connected to the input end of the amplifier U2A, and the output end of the amplifier U2A is connected to the control end of the output adjustment module.
5. A source meter comprising the resistance measuring device according to any one of claims 1 to 4.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202223317813.2U CN219085028U (en) | 2022-12-09 | 2022-12-09 | Resistance measuring device and source meter |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202223317813.2U CN219085028U (en) | 2022-12-09 | 2022-12-09 | Resistance measuring device and source meter |
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| CN219085028U true CN219085028U (en) | 2023-05-26 |
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| CN202223317813.2U Active CN219085028U (en) | 2022-12-09 | 2022-12-09 | Resistance measuring device and source meter |
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