CN214097610U - System for automatically switching measuring range to measure current - Google Patents
System for automatically switching measuring range to measure current Download PDFInfo
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- CN214097610U CN214097610U CN202022900781.3U CN202022900781U CN214097610U CN 214097610 U CN214097610 U CN 214097610U CN 202022900781 U CN202022900781 U CN 202022900781U CN 214097610 U CN214097610 U CN 214097610U
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Abstract
The utility model discloses an automatic switch range measurement current's system, the both ends at diode D1 and sampling resistor R1 are connected to first range measurement modulate circuit's measurement end, sampling resistor R2's both ends are connected to second range test modulate circuit's measurement end, parallelly connected back and sampling resistor R2 of diode D1 and sampling resistor R1, power and load resistance RL establish ties and form two-range current test return circuit, MCU control circuit links to each other with first range measurement modulate circuit and second range measurement modulate circuit control, regard as control display device when being used for measuring current. The utility model has simple circuit, low cost and easy calculation and design; the measurement reading in the range switching process of the utility model and the current passing through the load device are all in seamless connection, and the influence on the work of the load device is very small; the utility model discloses the continuous accurate measurement that is particularly suitable for load current dynamic state change, no matter how violent the current change, the current value at big or small both ends all ensures measurement accuracy easily.
Description
Technical Field
The utility model relates to a measure electric current technical field, concretely relates to automatic switch-over range measuring current's system.
Background
As is well known, current measurement is usually performed by connecting a sampling resistor in a current loop, obtaining a voltage across the sampling resistor through measurement, and then converting the current into a loop current. Because the current in the loop has a large variation range, and because of the limitation of the performance of the components of the existing measuring system, the precise measurement can be completed only by switching the measuring range, namely, different sampling resistors are changed to obtain a voltage signal suitable for the test. A typical circuit is shown in fig. 1, and span switching is usually pre-estimated and then manually completed, which is not intelligent and automatic enough. In addition, there is a method for automatically switching the range when the measured value cannot be estimated, or for the convenience of measurement, which is usually accomplished by controlling an electronic switch through a comparison circuit, as shown in fig. 2: however, this method has obvious disadvantages: (1) the circuit design is complex, a plurality of comparison control circuits are needed to complete the control logic of range switching, and the cost is high; (2) the semiconductor electronic switch is not completely closed when being closed, and a small leakage current influences the measurement result of the small current of uA or even lower magnitude; (3) the mechanical electronic switches such as relays and the like have the problems of slow switching, influence on the normal work of loads and measurement failure.
Based on this, there is an urgent need for a system for automatically switching the measuring range and measuring the current, which has a simple structure and is easy to implement.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problem that a system for automatically switching range measuring current is provided, realize the seamless switching of current range measurement through utilizing the suitable diode cooperation sampling resistance of conduction current.
In order to achieve the above purpose, the technical scheme of the utility model is realized like this:
a method of automatically switching a range measurement current, comprising the steps of:
debugging a first measuring range measuring and conditioning circuit and a second measuring range measuring and conditioning circuit;
connecting the measuring end of the first range measurement conditioning circuit to two ends of a diode D1 and a sampling resistor R1;
connecting the measuring end of the second measuring range testing conditioning circuit with two ends of a sampling resistor R2;
finally, the diode D1 and the sampling resistor R1 are connected in parallel and then connected in series with the sampling resistor R2, the power supply and the load resistor RL to form a double-range current test loop.
Further: the MCU control circuit is connected with the first range measurement conditioning circuit and the second range measurement conditioning circuit in a control mode and is used for controlling the display device when measuring current.
Further: a diode D2 is also included, and a diode D2 is connected in anti-parallel with the diode D1 for measuring the alternating current.
Further: the three-range current testing circuit further comprises a third-range measuring and conditioning circuit, a diode D3, a diode D4 and a sampling resistor R3, the diode D3, the diode D4 and the sampling resistor R3 are connected in parallel, the diode D3 and the diode D4 are connected in reverse to be used for measuring alternating current, the measuring end of the third-range measuring and conditioning circuit is connected to two ends of the diode D3, the diode D4 and the sampling resistor R3, and finally the diode D3, the diode D4 and the sampling resistor R3 are connected in parallel and then connected with the sampling resistor R2, the sampling resistor R1, a power supply and a load resistor RL in series to form a three-range current testing loop.
Further: the three-range current testing circuit further comprises a fourth-range measuring and conditioning circuit, a diode D5 and a sampling resistor R4, the diode D5 and the sampling resistor R4 are connected in parallel, the measuring end of the fourth-range measuring and conditioning circuit is connected to the two ends of the diode D5 and the two ends of the sampling resistor R4, and finally the diode D5 and the sampling resistor R4 are connected in parallel and then connected with the sampling resistor R1, the sampling resistor R2, a power supply and a load resistor RL in series to form a three-range current testing circuit.
In order to realize the above object, the utility model also provides an automatic switch range measurement current's system, including MCU control circuit, first range measurement modulate circuit, second range measurement modulate circuit, diode D1, sampling resistor R1, sampling resistor R2, power and load resistance RL, the both ends at diode D1 and sampling resistor R1 are connected to the measuring end of first range measurement modulate circuit, the both ends of sampling resistor R2 are connected to the measuring end of second range measurement modulate circuit, diode D1 and sampling resistor R1 establish ties with sampling resistor R2, power and load resistance RL after connecting in parallel and form dual-range current test circuit, MCU control circuit links to each other with first range measurement modulate circuit and second range measurement modulate circuit control for as control display device when measuring current.
In order to achieve the above object, the present invention further provides a system for automatically switching range measurement current, which comprises an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a diode D1, a diode D2, a sampling resistor R1, a sampling resistor R2, a power supply and a load resistor RL, wherein the measurement end of the first range measurement conditioning circuit is connected to two ends of the diode D1, the diode D2 and the sampling resistor R1, the measurement end of the second range measurement conditioning circuit is connected to two ends of the sampling resistor R2, the diode D2 and the diode D1 are connected in parallel in reverse direction for measuring ac current, the diode D1, the diode D2 and the sampling resistor R1 are connected in parallel and then connected in series with the sampling resistor R2, the power supply and the load resistor RL to form a dual-range current test loop, the MCU control circuit is connected to the first range measurement conditioning circuit and the second range measurement conditioning circuit, for use in measuring current as a control display device.
In order to achieve the above object, the present invention further provides a system for automatically switching range measurement current, which comprises an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a third range measurement conditioning circuit, a diode D1, a diode D2, a diode D3, a diode D4, a sampling resistor R1, a sampling resistor R2, a sampling resistor R3, a power supply, and a load resistor RL, wherein the measurement end of the first range measurement conditioning circuit is connected to both ends of the diode D1, the diode D2, and the sampling resistor R1, the measurement end of the second range measurement conditioning circuit is connected to both ends of the sampling resistor R2, the diode D2 is connected in reverse parallel with the diode D1 for measuring ac current, the diode D3, the diode D4, the sampling resistor R3 are connected in parallel, the diode D3, the diode D4 are connected in reverse for measuring ac current, the measuring end of the third range measuring and conditioning circuit is connected with two ends of a diode D3, a diode D4 and a sampling resistor R3, the diode D3, the diode D4 and the sampling resistor R3 are connected in parallel and then connected with a sampling resistor R2, a sampling resistor R1, a power supply and a load resistor RL in series to form a three-range current testing loop, and the MCU control circuit is connected with the first range measuring and conditioning circuit, the second range measuring and conditioning circuit and the third range measuring and conditioning circuit in a control mode and used as a control display device when measuring current.
In order to achieve the above object, the present invention further provides a system for automatically switching range measurement current, which comprises an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a fourth range measurement conditioning circuit, a diode D1, a diode D5, a sampling resistor R1, a sampling resistor R2, a sampling resistor R4, a power supply and a load resistor RL, wherein the measurement end of the first range measurement conditioning circuit is connected to both ends of the diode D1 and the sampling resistor R1, the measurement end of the second range measurement conditioning circuit is connected to both ends of the sampling resistor R2, the diode D1 is connected in parallel to the sampling resistor R1, the measurement end of the fourth range measurement conditioning circuit is connected to both ends of the diode D5 and the sampling resistor R4, the diode D5 and the sampling resistor R4 are connected in parallel, the sampling resistor R1, the sampling resistor R2, the power supply and the load resistor RL are connected in series to form a three-range current test loop, the MCU control circuit is in control connection with the first range measurement conditioning circuit, the second range measurement conditioning circuit and the fourth range measurement conditioning circuit and is used as control display equipment when measuring current.
Further: the forward conducting voltage of the diodes D1, D2, D3 and D4 is about 0.6V, and when the forward voltage is 0.1V, the forward current is 60 nA.
The beneficial effects of the utility model are embodied in: the utility model has simple circuit, low cost and easy calculation and design; the measurement reading in the range switching process of the utility model and the current passing through the load device are all in seamless connection, and the influence on the work of the load device is very small; the utility model discloses the continuous accurate measurement that is particularly suitable for load current dynamic state change, no matter how violent the current change, the current value at big or small both ends all ensures measurement accuracy easily.
Drawings
The accompanying drawings, which form a part hereof, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without undue limitation. In the drawings:
FIG. 1 is a circuit diagram of a manual switching range in the prior art;
FIG. 2 is a diagram of an automatic switching range circuit in the prior art;
fig. 3 is a schematic structural diagram of a system for automatically switching a span measurement current in embodiment 2 (direct current double span);
fig. 4 is a schematic structural diagram of a system for automatically switching a span measurement current (ac double span) in embodiment 3;
fig. 5 is a schematic structural view (ac three-range) of a system for automatically switching a range measurement current according to embodiment 4;
fig. 6 is a schematic structural diagram (dc three-range) of a system for automatically switching a range measurement current in embodiment 4.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. The embodiments and features of the embodiments in the present application may be combined with each other without conflict. Based on the embodiments in the utility model, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the utility model.
In addition, if there is a description relating to "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" appearing throughout includes three juxtapositions, exemplified by "A and/or B" including either A or B or both A and B. In addition, "a plurality" means two or more. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the utility model.
See fig. 3-6.
Example 1
A method of automatically switching a range measurement current, comprising the steps of:
debugging a first measuring range measuring and conditioning circuit and a second measuring range measuring and conditioning circuit;
connecting the measuring end of the first range measurement conditioning circuit to two ends of a diode D1 and a sampling resistor R1;
connecting the measuring end of the second measuring range testing conditioning circuit with two ends of a sampling resistor R2;
finally, the diode D1 and the sampling resistor R1 are connected in parallel and then connected in series with the sampling resistor R2, the power supply and the load resistor RL to form a double-range current test loop.
In the case where the forward voltage of the diode of this embodiment is not sufficiently high, the forward current is extremely low, and the diode can be regarded as an off state. When the voltage is much lower than the turn-on voltage, and the forward voltage is further reduced, the reduction amplitude of the forward current is larger and can be ignored when being far lower than the measured current.
As shown in fig. 3, R1 and R2 are sampling resistors for two measuring ranges of small current and large current, respectively. When the measured current is small, the voltage on the large current range sampling resistor R2 is very low and is difficult to measure, but the voltage on the small current range R1 is large enough to make accurate measurement. When the measured current is large enough, the diode is conducted, the load current is ensured to be continuous, and the voltage on the R2 is large enough, so that the accurate measurement can be completed by using a large current range. Thus, seamless switching of two ranges is realized.
Through practical tests, the forward conduction voltage of a diode is about 0.6V, and the forward current is only 60nA when the forward voltage is 0.1V. This is a typical characteristic of a diode. Most diodes are commonly of this nature. When small current is measured, a proper sampling resistor can be selected to ensure that the current mainly flows through the resistor and the leakage current flowing through the diode can be ignored. For example, when the voltage is 0.1V, I is V/R, the current flowing through the resistor is 0.1/10, 0.01A is 10mA, and the forward current of 60nA is taken as an example when the upper diode is 0.1V, the error introduced is 60nA/10mA is 0.006%, which is completely negligible.
When the tested current is lower, the voltage at two ends of the diode is also lower, the amplitude of the reduction of the leakage current is larger due to the characteristics of the diode, and the test result is not influenced. And by selecting a larger sampling resistor resistance value, in the current measurement of uA, nA and even pA magnitude, the current is always ensured to mainly pass through the resistor, and the leakage current of the diode in the measuring range can be ignored all the time.
When the current is larger, the voltage across the resistor increases, and when the current approaches or exceeds the turn-on voltage of the diode, the current mainly flows through the diode. At this point, the voltage reading across the first gear R1 is not meaningful, but the current through the second gear sampling resistor R2 is large enough, and the voltage is high enough, to make a measurement reading. The size of the sampling resistor of two gears can be calculated and designed, so that the two measuring range measuring ranges have an overlapping area, continuous reading of two-gear measurement can be guaranteed, and seamless switching is achieved.
In one specific example: the MCU control circuit is connected with the first range measurement conditioning circuit and the second range measurement conditioning circuit in a control mode and is used for controlling the display device when measuring current.
Generally, a modern measurement system has a single chip Microcomputer (MCU) or a computer as control display equipment, when measurement is carried out, the control equipment (MCU) reads data of two gears, and when the reading of a large current gear is too small, the reading of a small current gear is adopted. The reading of the high-current gear can be used when the reading of the high-current gear is large enough, that is, the current to be measured is large enough. Therefore, the present embodiment adopts the MCU control circuit, and the automatic seamless switching of the measurement range can be realized by reading the parameters of the MCU control circuit.
In one specific example: a diode D2 is also included, and a diode D2 is connected in anti-parallel with the diode D1 for measuring the alternating current.
The test method of the embodiment can be used for measuring direct current and also can be applied to measurement of alternating current.
In a specific example, the three-range current testing circuit further comprises a third-range measurement conditioning circuit, a diode D3, a diode D4 and a sampling resistor R3, the diode D3, the diode D4 and the sampling resistor R3 are connected in parallel, the diode D3 and the diode D4 are reversely connected for measuring alternating current, the measuring end of the third-range measurement conditioning circuit is connected to two ends of the diode D3, the diode D4 and the sampling resistor R3, and finally the diode D3, the diode D4 and the sampling resistor R3 are connected in parallel and then connected with the sampling resistor R2, the sampling resistor R1, a power supply and a load resistor RL in series to form a three-range current testing circuit.
The embodiment is easy to expand the measuring range and can realize three-measuring-range alternating current measurement.
In a specific example, the three-range current testing circuit further comprises a fourth-range measurement conditioning circuit, a diode D5 and a sampling resistor R4, wherein the diode D5 and the sampling resistor R4 are connected in parallel, a measuring end of the fourth-range measurement conditioning circuit is connected to two ends of the diode D5 and two ends of the sampling resistor R4, and finally the diode D5 and the sampling resistor R4 are connected in parallel and then connected with the sampling resistor R1, the sampling resistor R2, a power supply and a load resistor RL in series to form the three-range current testing circuit.
The embodiment is easy to expand the range, and can realize three-range direct current measurement.
Example 2
To achieve the above object, see fig. 3: the embodiment also provides a system for automatically switching the range measurement current, which comprises an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a diode D1, a sampling resistor R1, a sampling resistor R2, a power supply and a load resistor RL, wherein the measurement end of the first range measurement conditioning circuit is connected to two ends of the diode D1 and the sampling resistor R1, the measurement end of the second range measurement conditioning circuit is connected to two ends of the sampling resistor R2, the diode D1 and the sampling resistor R1 are connected in parallel and then connected in series with the sampling resistor R2, the power supply and the load resistor RL to form a dual-range current test loop, and the MCU control circuit is connected with the first range measurement conditioning circuit and the second range measurement conditioning circuit in a control manner and used for controlling a display device during current measurement.
The beneficial effects of this embodiment are similar to the beneficial effects of the automatic switching range measurement current of embodiment 1 with respect to the prior art, and are not described herein again.
Example 3
In order to achieve the above object, this embodiment further provides a system for automatically switching a range measurement current, including an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a diode D1, a diode D2, a sampling resistor R1, a sampling resistor R2, a power supply, and a load resistor RL, where a measurement end of the first range measurement conditioning circuit is connected to two ends of the diode D1, the diode D2, and the sampling resistor R1, a measurement end of the second range measurement conditioning circuit is connected to two ends of the sampling resistor R2, the diode D2 and the diode D1 are connected in reverse parallel for measuring an ac current, the diode D1, the diode D2, and the sampling resistor R1 are connected in parallel and then connected in series with the sampling resistor R2, the power supply, and the load resistor RL to form a dual-range current test loop, the MCU control circuit is connected to the first range measurement conditioning circuit and the second range measurement conditioning circuit in a control manner, for use in measuring current as a control display device.
The beneficial effects of this embodiment are similar to the beneficial effects of the automatic switching range measurement current of embodiment 1 with respect to the prior art, and are not described herein again.
Example 4
In order to achieve the above object, this embodiment further provides a system for automatically switching a range measurement current, including an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a third range measurement conditioning circuit, a diode D1, a diode D2, a diode D3, a diode D4, a sampling resistor R1, a sampling resistor R2, a sampling resistor R3, a power supply, and a load resistor RL, wherein a measurement end of the first range measurement conditioning circuit is connected to two ends of the diode D1, the diode D2, and the sampling resistor R1, a measurement end of the second range measurement conditioning circuit is connected to two ends of the sampling resistor R2, the diode D2 is connected in reverse parallel with the diode D1 for measuring an ac current, the diode D3, the diode D4, and the sampling resistor R3 are connected in parallel, the diode D3 and the diode D4 are connected in reverse for measuring an ac current, the measuring end of the third range measuring and conditioning circuit is connected with two ends of a diode D3, a diode D4 and a sampling resistor R3, the diode D3, the diode D4 and the sampling resistor R3 are connected in parallel and then connected with a sampling resistor R2, a sampling resistor R1, a power supply and a load resistor RL in series to form a three-range current testing loop, and the MCU control circuit is connected with the first range measuring and conditioning circuit, the second range measuring and conditioning circuit and the third range measuring and conditioning circuit in a control mode and used as a control display device when measuring current.
The beneficial effects of this embodiment are similar to the beneficial effects of the automatic switching range measurement current of embodiment 1 with respect to the prior art, and are not described herein again.
Example 5
In order to achieve the above object, this embodiment further provides a system for automatically switching a range measurement current, including an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a fourth range measurement conditioning circuit, a diode D1, a diode D5, a sampling resistor R1, a sampling resistor R2, a sampling resistor R4, a power supply, and a load resistor RL, where a measurement end of the first range measurement conditioning circuit is connected to two ends of the diode D1 and the sampling resistor R1, a measurement end of the second range measurement conditioning circuit is connected to two ends of the sampling resistor R2, the diode D1 is connected in parallel with the sampling resistor R1, a measurement end of the fourth range measurement conditioning circuit is connected to two ends of the diode D5 and the sampling resistor R4, the diode D5 and the sampling resistor R4 are connected in parallel, and then connected to the sampling resistor R1, the sampling resistor R2, the power supply, and the load resistor RL are connected in series to form a three-range current test loop, the MCU control circuit is in control connection with the first range measurement conditioning circuit, the second range measurement conditioning circuit and the fourth range measurement conditioning circuit and is used as control display equipment when measuring current.
The beneficial effects of this embodiment are similar to the beneficial effects of the automatic switching range measurement current of embodiment 1 with respect to the prior art, and are not described herein again.
Specifically, the method comprises the following steps: the forward conducting voltage of the diodes D1, D2, D3 and D4 is about 0.6V, and when the forward voltage is 0.1V, the forward current is 60 nA.
In summary, the basic principle of the expansion of the embodiments 3, 4, and 5 is consistent with the foregoing analysis and description (embodiment 1), only the diode with the appropriate conduction current needs to be selected according to the design range, and the value of the sampling resistor of the design range needs to be simply calculated and selected, that is, the test voltage signal is conveniently and accurately obtained within the design range, and the leakage current passing through the diode can be ignored within the range. The simple calculation can be easily completed by electronic related engineering personnel. Compare with current manual, the method of automatic gear shift measuring current, the utility model has the advantages of it is following: the circuit is simple, the cost is low, and the calculation design is easy; the measurement reading in the range switching process and the current passing through the load equipment are in seamless connection, and the influence on the work of the load equipment is extremely small; the load current dynamic change measuring device is very suitable for continuous and accurate measurement of load current dynamic change, and the current values at the large end and the small end can easily guarantee the measurement accuracy no matter how violent the current change is.
The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (5)
1. A system for automatically switching range measurement current is characterized in that: the device comprises an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a diode D1, a sampling resistor R1, a sampling resistor R2, a power supply and a load resistor RL, wherein the measurement end of the first range measurement conditioning circuit is connected with the two ends of the diode D1 and the sampling resistor R1, the measurement end of the second range measurement conditioning circuit is connected with the two ends of the sampling resistor R2, the diode D1 and the sampling resistor R1 are connected in parallel and then connected in series with the sampling resistor R2, the power supply and the load resistor RL to form a double-range current test loop, and the MCU control circuit is in control connection with the first range measurement conditioning circuit and the second range measurement conditioning circuit and is used as a control display device when measuring current.
2. A system for automatically switching range measurement current is characterized in that: comprises an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a diode D1, a diode D2, a sampling resistor R1, a sampling resistor R2, a power supply and a load resistor RL, the measuring end of the first range measurement conditioning circuit is connected to two ends of the diode D1, the diode D2 and the sampling resistor R1, the measuring end of the second measuring range measuring and conditioning circuit is connected with two ends of a sampling resistor R2, the diode D2 and the diode D1 are connected in reverse parallel for measuring alternating current, the diode D1, the diode D2 and the sampling resistor R1 are connected in parallel and then are connected in series with the sampling resistor R2, the power supply and the load resistor RL to form a double-range current test loop, the MCU control circuit is in control connection with the first range measurement conditioning circuit and the second range measurement conditioning circuit and is used as control display equipment when measuring current.
3. A system for automatically switching range measurement current is characterized in that: the device comprises an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a third range measurement conditioning circuit, a diode D1, a diode D2, a diode D3, a diode D4, a sampling resistor R1, a sampling resistor R2, a sampling resistor R3, a power supply and a load resistor RL, wherein the measurement end of the first range measurement conditioning circuit is connected with two ends of the diode D1, the diode D2 and the sampling resistor R1, the measurement end of the second range measurement conditioning circuit is connected with two ends of the sampling resistor R2, the diode D2 and the diode D1 are connected in parallel in an inverse direction for measuring alternating current, the diode D3, the diode D4 and the sampling resistor R3 are connected in parallel in a parallel direction, the diode D3 and the diode D4 are connected in the inverse direction for measuring alternating current, and the measurement end of the third range measurement conditioning circuit is connected with the diode D3, the diode 539D 2, the diode D4 and the sampling resistor R3, The two ends of the sampling resistor R3 are connected in parallel with the diode D3, the diode D4 and the sampling resistor R3, and then connected with the sampling resistor R2, the sampling resistor R1, the power supply and the load resistor RL to form a three-range current test loop in series, and the MCU control circuit is in control connection with the first range measurement conditioning circuit, the second range measurement conditioning circuit and the third range measurement conditioning circuit and is used as a control display device when measuring current.
4. A system for automatically switching range measurement current is characterized in that: the device comprises an MCU control circuit, a first range measurement conditioning circuit, a second range measurement conditioning circuit, a fourth range measurement conditioning circuit, a diode D1, a diode D5, a sampling resistor R1, a sampling resistor R2, a sampling resistor R4, a power supply and a load resistor RL, wherein the measurement end of the first range measurement conditioning circuit is connected with two ends of a diode D1 and a sampling resistor R1, the measurement end of the second range measurement conditioning circuit is connected with two ends of a sampling resistor R2, the diode D1 is connected with the sampling resistor R1 in parallel, the measurement end of the fourth range measurement conditioning circuit is connected with two ends of a diode D5 and a sampling resistor R4, the diode D5 and the sampling resistor R4 are connected with the sampling resistor R1, the sampling resistor R2, the power supply and the load resistor RL in series to form a three-range current test loop, and the MCU control circuit is connected with the first range measurement conditioning circuit, the second range measurement conditioning circuit, the sampling resistor R3583, the sampling resistor R2, the power supply and the load resistor RL in series to form a three-range current test loop, The second range measurement conditioning circuit and the fourth range measurement conditioning circuit are connected in a control mode and used for being used as control display equipment when measuring current.
5. The system for automatically switching span measurement current according to any of claims 1-4, wherein: the forward conduction voltage of the diodes D1, D2, D3 and D4 is 0.6V, and when the forward voltage is 0.1V, the forward current is 60 nA.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116593769A (en) * | 2023-07-17 | 2023-08-15 | 烟台东方威思顿电气有限公司 | High-precision electric energy calculation method with wide dynamic range |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116593769A (en) * | 2023-07-17 | 2023-08-15 | 烟台东方威思顿电气有限公司 | High-precision electric energy calculation method with wide dynamic range |
| CN116593769B (en) * | 2023-07-17 | 2023-10-27 | 烟台东方威思顿电气有限公司 | High-precision electric energy calculation method with wide dynamic range |
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