Multipath power sampling device

Abstract

The invention provides a multipath power sampling device, which relates to the technical field of power measurement and comprises a voltage source, a load, a voltage follower, a voltage amplifier, an MCU module and a data processing unit. The positive electrode of the voltage source is connected with one end of each of the plurality of groups of loads, and the other end of each of the plurality of groups of loads is connected with the sampling resistor; two ends of each group of loads are connected in parallel with a resistance voltage dividing module, and the resistance voltage dividing module is composed of two resistors which are connected in series; a connection node between every two series resistors is used as a voltage acquisition point, and the voltage acquisition points are correspondingly connected with the input ends of different voltage followers respectively; the output end of the voltage follower is connected with the MCU module; a connection node between each group of load and the sampling resistor is used as a current signal acquisition point, and the current signal acquisition points are correspondingly connected with the input ends of different voltage amplifiers respectively; and the output end of the voltage amplifier is connected with the MCU module. The test efficiency is greatly improved, and the micro-current sampling precision is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of power measurement technology, and more specifically, to a multi-channel power sampling device. Background Technology

[0002] With the rapid development of micro-motor technology, low-power fans are increasingly widely used in consumer electronics, industrial control, medical equipment, and other fields. These fans must undergo rigorous functional testing before leaving the factory, with operating power being one of the core indicators for determining product qualification. Abnormal power output typically reflects potential defects such as winding short circuits, magnet demagnetization, bearing jamming, and drive board failure. Current low-power fan production line testing equipment generally uses a single power supply + single power meter + manual line switching mode. Testing a single fan takes approximately 3-5 seconds. For production lines with a daily capacity of tens of thousands of units, the testing station becomes a bottleneck, requiring dozens of devices to operate in parallel, resulting in significant equipment investment and a large footprint. The rated current of low-power fans is often in the 0.1A-1.0A range, with the voltage drop across the current sampling resistor only in the millivolt range. Conventional operational amplifier circuits suffer from problems such as large input offset voltage, severe temperature drift, and sensitivity to common-mode interference, leading to low small-signal signal-to-noise ratios and power calculation errors exceeding ±10%. This results in both missed detection of defective products and false negatives of good products. Traditional resistor divider networks are directly connected to the MCU-ADC. When the input impedance of the fan under test fluctuates, the voltage division ratio shifts, the voltage sampling accuracy deteriorates, and the power calculation accuracy is further affected.

[0003] Therefore, the power sampling devices of existing low-power wind turbine production lines have problems such as low single-channel testing efficiency, insufficient accuracy of weak current sampling, and voltage sampling being affected by the load input impedance. Summary of the Invention

[0004] The present invention aims to solve the problems of low single-channel testing efficiency, insufficient accuracy of weak current sampling, and voltage sampling being affected by load input impedance in existing power sampling devices for low-power wind turbines.

[0005] To address the aforementioned problems, this invention provides a multi-channel power sampling device, comprising a voltage source, a load, a voltage follower, a voltage amplifier, an MCU module, and a data processing unit; the positive terminal of the voltage source is connected to one end of multiple loads, and the other end of the multiple loads is connected to a sampling resistor. Each load group has a resistor voltage divider module connected in parallel across its two ends. The resistor voltage divider module consists of two resistors connected in series. The connection node between each pair of series resistors serves as a voltage acquisition point. The voltage acquisition points are connected to the input terminals of different voltage followers one by one. The output terminal of the voltage follower is connected to the ADC input pin of the MCU module. The connection node between each load and the sampling resistor serves as a current signal acquisition point, and each current signal acquisition point is connected to the input terminal of a different voltage amplifier; the output terminal of the voltage amplifier is connected to the ADC input pin of the MCU module. The data output terminal of the MCU module is connected to the data processing unit; the MCU module integrates an ADC unit.

[0006] The multi-channel power sampling device provided by this invention has, but is not limited to, the following beneficial effects compared to the prior art: In this invention, the voltage source is the energy input layer of the system, serving as the power supply for the device under test; the load is the object under test, i.e., the low-power fan to be tested; the voltage follower is the buffer isolation layer for voltage sampling, acting as a high-impedance input buffer for analog signals; the voltage amplifier is the signal enhancement layer for current sampling, acting as a precision amplifier and level shifter for weak voltage signals; the MCU module is the data acquisition and computing center of the system, a digital converter for the analog world; and the data processing unit is the data application layer of the system, serving as a platform for the aggregation, storage, and display of test results.

[0007] This invention significantly improves testing efficiency. A single device supports parallel and synchronous testing of 8 fans. Combined with automated loading and unloading on the production line, the testing cycle time of the entire line is greatly shortened. The efficiency is 8 times higher than that of the traditional single-channel solution, and the number of equipment purchased and the production line floor space are greatly reduced.

[0008] The present invention greatly improves the micro-current sampling accuracy; it adopts a precision bias and reverse amplification topology to map weak differential signals, perfectly matching the sampling range of MCU-ADC; and completely solves the pain point of small signal sampling accuracy.

[0009] Furthermore, the voltage amplifier is an inverting proportional operational circuit with DC bias. The voltage amplifier includes an operational amplifier IC10A. The negative input terminal of the operational amplifier IC10A is connected to one end of a resistor R104, and the other end of the resistor R104 is connected to the voltage signal Ui collected by the sampling resistor. The positive input terminal of op-amp IC10A is connected to one end of resistor R105, and the other end of resistor R105 is grounded; A capacitor C62 is connected in parallel between the positive and negative input terminals of the operational amplifier IC10A; The positive input terminal of op-amp IC10A is connected to one end of resistor R103, and the other end of resistor R103 is connected to the reference power supply. The negative input terminal of op-amp IC10A is connected to one end of resistor R100, and the other end of resistor R100 is connected to the reference power supply. The power supply terminal of op-amp IC10A is connected to the reference power supply; the power supply terminal of op-amp IC10A is connected to one end of capacitor C60, and the other end of capacitor C60 is grounded; the ground terminal of op-amp IC10A is grounded. The output terminal of op-amp IC10A is connected to one end of resistor R86, the other end of resistor R86 is connected to one end of capacitor C56, and the other end of capacitor C56 is grounded. The signal between resistor R86 and capacitor C56 is the output signal Uo.

[0010] Furthermore, the voltage signal Ui input terminal is equipped with a clamping protection and power supply circuit; the clamping protection and power supply circuit includes a Zener diode ZD7, an energy storage element E10, a transistor Q7, a current-limiting resistor RS13, and a resistor R110; the voltage signal Ui is connected to one end of the third capacitor C66, the positive terminal of the Zener diode ZD7, and the negative terminal of the energy storage element E10; the positive terminal of the energy storage element E10 is connected to the emitter of the transistor Q7; the base of the transistor Q7 is connected to the negative terminal of the Zener diode ZD7; the collector of the transistor Q7 is connected to the power supply Vin through the current-limiting resistor RS13; the other end of the third capacitor C66 is connected to the power supply Vin through the resistor R110.

[0011] Furthermore, the voltage follower includes an operational amplifier IC10B; the positive input terminal of the operational amplifier IC10B is connected to one end of a resistor R101 and one end of a capacitor C63, respectively; the other end of the resistor R101 is connected to the negative terminal of a diode TVS8, and the other end of the capacitor C63 is connected to the positive terminal of a diode TVS8. A resistor R111 is connected in parallel to the high end of the next year's TVS8 diode; The positive terminal of diode TVS8 is grounded, and the negative terminal of diode TVS8 is connected to the power supply Vin through resistor R113. The inverting input and output terminals of op-amp IC10B are connected; The output terminal of op-amp IC10B is connected to one end of resistor R85, the other end of resistor R85 is connected to one end of capacitor C57, and the other end of capacitor C57 is grounded. The signal between resistor R85 and capacitor C57 is the output signal VS8.

[0012] Furthermore, the reference power supply voltage is 3.3V; the resistance values ​​of resistors R103 and R105 are equal, and the ratio of resistor R87 to resistor R104 is ≥10.

[0013] Furthermore, resistor R113 and resistor R111 form a series voltage divider network.

[0014] Furthermore, the multiple loads are in an 8-way independent parallel structure.

[0015] Furthermore, the MCU module integrates a 12-bit or higher successive approximation ADC; the MCU module also has a built-in power calculation module.

[0016] Furthermore, the data processing unit is an industrial computer, a programmable logic controller, or a cloud server.

[0017] Furthermore, the voltage source is an external programmable DC power supply, with the positive terminal connected to the power input node Vin of each load and the negative terminal connected to system ground GND. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the frame of the multi-channel power sampling device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the voltage amplifier circuit in the multi-channel power sampling device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the voltage follower circuit in the multi-channel power sampling device according to an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings showing multiple embodiments according to this application. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," etc., in the specification, claims, and accompanying drawings of this application are open-ended terms. Therefore, "comprising," "including," or "having" refers to, for example, a method or apparatus having one or more steps or elements, but is not limited to having only these one or more elements. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] It should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, parts, or groups of features, integers, steps, or parts.

[0024] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0025] See Figures 1-3 An embodiment of the present invention provides a multi-channel power sampling device, comprising a voltage source, a load, a voltage follower, a voltage amplifier, an MCU module, and a data processing unit; the positive terminal of the voltage source is connected to one end of multiple loads, and the other end of the multiple loads is connected to a sampling resistor; Each load group has a resistor voltage divider module connected in parallel across its two ends. The resistor voltage divider module consists of two resistors connected in series. The connection node between each pair of series resistors serves as a voltage acquisition point. The voltage acquisition points are connected to the input terminals of different voltage followers one by one. The output terminal of the voltage follower is connected to the ADC input pin of the MCU module. The connection node between each load and the sampling resistor serves as a current signal acquisition point, and each current signal acquisition point is connected to the input terminal of a different voltage amplifier; the output terminal of the voltage amplifier is connected to the ADC input pin of the MCU module. The data output terminal of the MCU module is connected to the data processing unit; the MCU module integrates an ADC unit, which is used to convert analog voltage signals into digital quantities.

[0026] In this invention, the voltage source serves as the system's energy input layer, acting as the power supply for the device under test; the load represents the object under test, i.e., the low-power fan being tested; the voltage follower acts as a buffer and isolation layer for voltage sampling, a high-impedance input buffer for analog signals; the voltage amplifier serves as a signal enhancement layer for current sampling, a precision amplification and level shifter for weak voltage signals; the MCU module is the system's data acquisition and computing center, a digital converter for the analog world; and the data processing unit is the system's data application layer, a platform for the aggregation, storage, and display of test results.

[0027] This invention significantly improves testing efficiency. A single device supports parallel and synchronous testing of 8 fans. Combined with automated loading and unloading on the production line, the testing cycle time of the entire line is greatly shortened. The efficiency is 8 times higher than that of the traditional single-channel solution, and the number of equipment purchased and the production line floor space are greatly reduced.

[0028] The present invention greatly improves the micro-current sampling accuracy; it adopts a precision bias and reverse amplification topology to map weak differential signals, perfectly matching the sampling range of MCU-ADC; and completely solves the pain point of small signal sampling accuracy.

[0029] The voltage sampling of this invention has no load effect, the voltage follower input impedance is >100MΩ, the voltage divider network has a no-load voltage division ratio and a voltage division ratio after load connection with a deviation of <0.01%, and the voltage sampling accuracy is improved by two orders of magnitude compared with the traditional direct ADC scheme.

[0030] The present invention integrates power supply sampling, with an integrated 5V voltage regulator circuit on the board, which can directly power the 5V fan without the need for an external independent power supply; the single board hardware is compatible with testing of multiple specifications of fans such as 5V / 12V / 24V, which greatly improves the efficiency of production line changeover.

[0031] The present invention enables full-process quality traceability. The measured values ​​of voltage, current and power of each wind turbine are uploaded to the data processing unit to form a complete database with timestamp + batch number + workstation number. It supports SPC statistical analysis and precise traceability of individual machines, providing data-driven decision-making basis for production process optimization.

[0032] Furthermore, the voltage amplifier is an inverting proportional operational circuit with DC bias. The voltage amplifier includes an operational amplifier IC10A. The negative input terminal of the operational amplifier IC10A is connected to one end of a resistor R104, and the other end of the resistor R104 is connected to the voltage signal Ui collected by the sampling resistor. The positive input terminal of op-amp IC10A is connected to one end of resistor R105, and the other end of resistor R105 is grounded; A capacitor C62 is connected in parallel between the positive and negative input terminals of the operational amplifier IC10A; The positive input terminal of op-amp IC10A is connected to one end of resistor R103, and the other end of resistor R103 is connected to the reference power supply. The negative input terminal of op-amp IC10A is connected to one end of resistor R100, and the other end of resistor R100 is connected to the reference power supply. The power supply terminal of op-amp IC10A is connected to the reference power supply; the power supply terminal of op-amp IC10A is connected to one end of capacitor C60, and the other end of capacitor C60 is grounded; the ground terminal of op-amp IC10A is grounded. The output terminal of op-amp IC10A is connected to one end of resistor R86, the other end of resistor R86 is connected to one end of capacitor C56, and the other end of capacitor C56 is grounded. The signal between resistor R86 and capacitor C56 is the output signal Uo.

[0033] The voltage amplifier amplifies the millivolt differential voltage Ui across the sampling resistor to a volt-level single-ended signal Uo, matching the ADC input range; a 1.65V DC bias is superimposed to map the bipolar current signal (i.e., forward and reverse rotation) to the ADC's forward linear region; inverse proportional operation is performed, with the gain precisely set by R87 / R104; low-pass filtering: R86+C56 suppresses switching noise and high-frequency interference.

[0034] Furthermore, the voltage signal Ui input terminal is equipped with a clamping protection and power supply circuit; the clamping protection and power supply circuit includes a Zener diode ZD7, an energy storage element E10, a transistor Q7, a current-limiting resistor RS13, and a resistor R110; the voltage signal Ui is connected to one end of the third capacitor C66, the positive terminal of the Zener diode ZD7, and the negative terminal of the energy storage element E10; the positive terminal of the energy storage element E10 is connected to the emitter of the transistor Q7; the base of the transistor Q7 is connected to the negative terminal of the Zener diode ZD7; the collector of the transistor Q7 is connected to the power supply Vin through the current-limiting resistor RS13; the other end of the third capacitor C66 is connected to the power supply Vin through the resistor R110.

[0035] The integrated clamping protection and power supply sampling circuit completely eliminates ground loop interference. Active clamping protection reduces the potentially fatal high voltage of 12V / 24V to <6V, within the operational amplifier's tolerance range. Combined with the operational amplifier's internal clamping diodes, this achieves effective protection in engineering terms. It suppresses inrush current and protects the contacts; the E10 chip acts as a virtual battery, improving the dynamic response of the voltage regulation.

[0036] Furthermore, the voltage follower includes an operational amplifier IC10B; the positive input terminal of the operational amplifier IC10B is connected to one end of a resistor R101 and one end of a capacitor C63, respectively; the other end of the resistor R101 is connected to the negative terminal of a diode TVS8, and the other end of the capacitor C63 is connected to the positive terminal of a diode TVS8. A resistor R111 is connected in parallel to the high end of the next year's TVS8 diode; The positive terminal of diode TVS8 is grounded, and the negative terminal of diode TVS8 is connected to the power supply Vin through resistor R113. The inverting input and output terminals of op-amp IC10B are connected; The output terminal of op-amp IC10B is connected to one end of resistor R85, the other end of resistor R85 is connected to one end of capacitor C57, and the other end of capacitor C57 is grounded. The signal between resistor R85 and capacitor C57 is the output signal VS8.

[0037] The voltage follower performs impedance transformation on the attenuated voltage signal output from the voltage divider network: input impedance > 100MΩ, output impedance < 100Ω; it isolates the voltage divider network from the MCU-ADC, eliminating the load effect of the ADC input impedance on the voltage division ratio; low-pass filtering: R85+C57 form an anti-aliasing filter to suppress high-frequency noise; overvoltage protection: TVS8 clamps the input to 3.6V to prevent surge damage to the MCU.

[0038] Furthermore, the reference power supply voltage is 3.3V; the resistance values ​​of resistors R103 and R105 are equal, and the ratio of resistor R87 to resistor R104 is ≥10.

[0039] Resistors R103 and R105 have equal resistance values, making the voltage at the positive input terminal of the operational amplifier 1.65V; the ratio of resistors R87 to R104 is ≥10, achieving a signal inverse amplification of ≥10 times; preferably, the feedback resistor (R87) is 105kΩ, the first resistor (R104) is 10kΩ, and the closed-loop gain is -10.5 times.

[0040] Furthermore, resistor R113 and resistor R111 form a series voltage divider network.

[0041] The series voltage divider network attenuates the input voltage Vin to the full-scale range of the ADC of the MCU module; the op-amp IC10B forms a voltage follower with an input impedance ≥100MΩ, eliminating the influence of the downstream load on the voltage divider network.

[0042] Furthermore, the multiple loads are in an 8-way independent parallel structure.

[0043] It can connect to 8 devices under test at the same time; each load is independently configured with a voltage sampling channel and a current sampling channel to achieve 8-channel parallel synchronous sampling.

[0044] Furthermore, the MCU module integrates a 12-bit or higher successive approximation ADC; the MCU module also has a built-in power calculation module.

[0045] The power calculation module calculates the active power in real time based on the voltage and current sampling values, compares the power value with the preset qualified threshold, generates a qualified / unqualified judgment signal, and uploads it to the processing data unit through the communication interface.

[0046] Furthermore, the data processing unit is an industrial computer, a programmable logic controller, or a cloud server.

[0047] The data processing unit receives multiple real-time power data and judgment results uploaded by the MCU module, performs data storage, statistical analysis and visualization, and supports quality traceability by production batch or single unit serial number.

[0048] Furthermore, the voltage source is an external programmable DC power supply, with the positive terminal connected to the power input node Vin of each load and the negative terminal connected to system ground GND.

[0049] The voltage source provides the rated operating voltage required by the device under test; the device can be adapted to devices under test with various voltage specifications such as 5V, 12V, and 24V by changing the ratio of the voltage divider resistors R113 and R111.

[0050] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A multi-channel power sampling device, characterized in that, It includes a voltage source, a load, a voltage follower, a voltage amplifier, an MCU module, and a data processing unit; the positive terminal of the voltage source is connected to one end of multiple sets of loads, and the other end of the multiple sets of loads is connected to a sampling resistor; Each load group has a resistor voltage divider module connected in parallel across its two ends. The resistor voltage divider module consists of two resistors connected in series. The connection node between each pair of series resistors serves as a voltage acquisition point. The voltage acquisition points are connected to the input terminals of different voltage followers one by one. The output terminal of the voltage follower is connected to the ADC input pin of the MCU module. The connection node between each load and the sampling resistor serves as a current signal acquisition point, and each current signal acquisition point is connected to the input terminal of a different voltage amplifier; the output terminal of the voltage amplifier is connected to the ADC input pin of the MCU module. The data output terminal of the MCU module is connected to the data processing unit; the MCU module integrates an ADC unit.

2. The multi-channel power sampling device according to claim 1, characterized in that, The voltage amplifier is an inverting proportional operational circuit with DC bias. The voltage amplifier includes operational amplifier IC10A. The negative input terminal of operational amplifier IC10A is connected to one end of resistor R104, and the other end of resistor R104 is connected to the voltage signal Ui collected by the sampling resistor. The positive input terminal of op-amp IC10A is connected to one end of resistor R105, and the other end of resistor R105 is grounded; A capacitor C62 is connected in parallel between the positive and negative input terminals of the operational amplifier IC10A; The positive input terminal of op-amp IC10A is connected to one end of resistor R103, and the other end of resistor R103 is connected to the reference power supply. The negative input terminal of op-amp IC10A is connected to one end of resistor R100, and the other end of resistor R100 is connected to the reference power supply. The power supply terminal of op-amp IC10A is connected to the reference power supply; the power supply terminal of op-amp IC10A is connected to one end of capacitor C60, and the other end of capacitor C60 is grounded; the ground terminal of op-amp IC10A is grounded. The output terminal of op-amp IC10A is connected to one end of resistor R86, the other end of resistor R86 is connected to one end of capacitor C56, and the other end of capacitor C56 is grounded. The signal between resistor R86 and capacitor C56 is the output signal Uo.

3. The multi-channel power sampling device according to claim 2, characterized in that, The voltage signal Ui input terminal is equipped with a clamping protection and power supply circuit; the clamping protection and power supply circuit includes a Zener diode ZD7, an energy storage element E10, a transistor Q7, a current-limiting resistor RS13, and a resistor R110; the voltage signal Ui is connected to one end of the third capacitor C66, the positive terminal of the Zener diode ZD7, and the negative terminal of the energy storage element E10; the positive terminal of the energy storage element E10 is connected to the emitter of the transistor Q7; the base of the transistor Q7 is connected to the negative terminal of the Zener diode ZD7; the collector of the transistor Q7 is connected to the power supply Vin through the current-limiting resistor RS13; the other end of the third capacitor C66 is connected to the power supply Vin through the resistor R110.

4. The multi-channel power sampling device according to claim 3, characterized in that, The voltage follower includes an operational amplifier IC10B; the positive input terminal of the operational amplifier IC10B is connected to one end of a resistor R101 and one end of a capacitor C63, respectively; the other end of the resistor R101 is connected to the negative terminal of a diode TVS8, and the other end of the capacitor C63 is connected to the positive terminal of a diode TVS8. A resistor R111 is connected in parallel to the high end of the next year's TVS8 diode; The positive terminal of diode TVS8 is grounded, and the negative terminal of diode TVS8 is connected to the power supply Vin through resistor R113. The inverting input and output terminals of op-amp IC10B are connected; The output terminal of op-amp IC10B is connected to one end of resistor R85, the other end of resistor R85 is connected to one end of capacitor C57, and the other end of capacitor C57 is grounded. The signal between resistor R85 and capacitor C57 is the output signal VS8.

5. The multi-channel power sampling device according to claim 4, characterized in that, The reference power supply voltage is 3.3V; the resistance values ​​of resistors R103 and R105 are equal, and the ratio of resistor R87 to resistor R104 is ≥10.

6. The multi-channel power sampling device according to claim 5, characterized in that, The resistors R113 and R111 form a series voltage divider network.

7. The multi-channel power sampling device according to claim 6, characterized in that, Multiple loads are configured as 8 independent parallel connections.

8. The multi-channel power sampling device according to claim 7, characterized in that, The MCU module integrates a 12-bit or higher successive approximation ADC; the MCU module also has a built-in power calculation module.

9. The multi-channel power sampling device according to claim 8, characterized in that, The data processing unit is an industrial computer, a programmable logic controller, or a cloud server.

10. The multi-channel power sampling device according to claim 9, characterized in that, The voltage source is an external programmable DC power supply. The positive terminal of the voltage source is connected to the power input node Vin of each load, and the negative terminal is connected to the system ground GND.

Images