Large-current equipment detection circuit and method

Abstract

The invention discloses a detection circuit of large-current equipment. The detection circuit comprises a plurality of detection circuits, an aliasing operation circuit and a control circuit, each detection circuit comprises a sampling resistor, an operational amplifier and a matching resistor; the detection circuit collects voltage at two ends of the sampling resistor and is used for monitoring load current; the plurality of detection circuits are connected with the aliasing operation circuit, and the aliasing operation circuit is used for aliasing voltage signals of the plurality of detection circuits and obtaining a voltage average value; the control circuit is connected with the aliasing operation circuit, the voltage average value is input into the control circuit as a feedback signal, an actual current feedback value is obtained through conversion of the control circuit, and the feedback value is compared with a current set value set in the control circuit; a control circuit compares and judges and outputs a corresponding control signal, and the control signal is used for adjusting the load current, so that the load current is within the interval of the current set value. And the method is of great significance to stable operation of large-current equipment.

Description

Technical Field

[0001] The present invention relates to the field of detection circuits, and in particular to a high-current equipment detection circuit and method. Background Art

[0002] Recent years have seen remarkable breakthroughs in power battery technology, and at the same time, market demand for high-capacity, ultra-fast charging equipment has also seen rapid growth. In the new energy sector, high-current formation and capacity distribution equipment, limited by factors such as power component parameters, size, and cost, currently employs a topology that connects multiple low-current channels in parallel to achieve ultra-high current output. There are two main current detection methods: one is to use software to sample and sum the currents of each individual channel; the other is to add a high-capacity detection circuit to the overall circuit of the multiple parallel current channels. However, both detection methods have significant drawbacks. Due to the differences in parameters of the parallel low-current circuits, the load conditions vary with operating conditions, and the interference of other external factors, current imbalances can easily occur between the parallel circuits. During long-term operation, this current imbalance can cause overload stress on some circuit components, negatively impacting the service life of the electronic components.

[0003] The uneven current flow phenomenon is particularly pronounced during constant-voltage charging of power batteries. The principle of constant-voltage charging is to regulate the charging current so that the voltage at the battery's two poles remains stable at a set constant value. However, when a multi-channel low-current parallel topology is used for constant-voltage charging, the large parameter differences between the parallel low-current circuits can generate severe electromagnetic interference, leading to abnormal fluctuations in the charging current and, in turn, violent oscillations in the charging control loop, seriously affecting the stability and safety of the charging process. Furthermore, the method of adding up the detection results of multiple low-current circuits inevitably amplifies common-mode interference errors, significantly reducing the accuracy of total current detection. The method of using a single large-capacity detection circuit places higher demands on the capacity of power components, which not only increases power loss but also places more stringent requirements on performance indicators such as heat dissipation and temperature drift coefficient. This ultimately leads to an increase in product size and cost, hindering product market promotion and application.

[0004] In summary, the applicant has found through research that a technical problem that those skilled in the art urgently need to solve is: how to achieve high precision and high stability in multi-channel parallel large current measurement and control. Summary of the Invention

[0005] In order to overcome the technical defect that the above-mentioned multi-channel small current parallel topology structure will generate serious electromagnetic interference during operation, causing abnormal fluctuations in the charging current, and then triggering violent oscillations in the charging control loop, seriously affecting the stability and safety of the charging process, the present invention provides a high current device detection circuit and method.

[0006] In order to solve the above problems, the present invention is implemented according to the following technical solutions:

[0007] A detection circuit for a high-current device described in the first aspect of the present invention includes several detection circuits, an aliasing operation circuit and a control circuit; several of the detection circuits each include a sampling resistor, an operational amplifier and a matching resistor; the detection circuit collects voltage across the sampling resistor, and the sampling resistor is used to monitor the load current; several of the detection circuits are connected to the aliasing operation circuit, and the aliasing operation circuit is used to alias the voltage signals of several of the detection circuits and obtain a voltage average value; the control circuit is connected to the aliasing operation circuit, and the voltage average value is input into the control circuit as a feedback signal, and the actual current feedback value is obtained after conversion by the control circuit, and the feedback value is compared with the current set value set in the control circuit; the control circuit compares and judges and outputs a corresponding control signal, and the control signal is used to adjust the load current so that the load current is within the range of the current set value.

[0008] Preferably, one end of the sampling resistor is connected to the inverting input terminal of the operational amplifier, and the other end of the sampling resistor is connected to the non-inverting input terminal of the operational amplifier; the output terminal of the operational amplifier is connected to one end of the matching resistor, and the other end of the matching resistor is connected to the aliasing operation circuit.

[0009] Preferably, the aliasing operation circuit includes a voltage follower, a first resistor and a second resistor; the non-phase input terminal of the voltage follower is connected to the matching resistor, the inverting input terminal of the voltage follower is connected to the output terminal of the voltage follower, and the output terminal of the voltage follower is connected to the controller through the first resistor, and is connected to the control circuit through the second resistor.

[0010] Preferably, the non-phase input terminal of the control circuit is connected to the second resistor, and the inverting input terminal of the control circuit is a set value input terminal.

[0011] Preferably, the control circuit is an analog circuit or a digital circuit.

[0012] The detection method for a large current device described in the second aspect of the present invention is based on the detection circuit for a large current device described in the first aspect of the present invention, wherein the plurality of detection circuits collect voltages at both ends of the sampling resistor to obtain a plurality of first voltages; the plurality of first voltages are differentially amplified to obtain a plurality of second voltages; the plurality of second voltages are obtained by the aliasing operation circuit to obtain a voltage average value; the voltage average value is input into the control circuit as a feedback signal, and the actual current feedback value is obtained after conversion by the control circuit, and the feedback value is compared with the current set value set in the control circuit; the control circuit compares and judges and outputs a corresponding control signal.

[0013] Preferably, when the resistance values ​​of the plurality of matching resistors are equal, the voltage at the input end obtained by the aliasing operation circuit is the average voltage value.

[0014] Preferably, the control circuit is used to adjust the load current and realize current closed-loop control among the plurality of detection circuits, arithmetic aliasing circuits and the control circuit.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] In a first aspect, the present application proposes a detection circuit designed for high-current equipment. Several detection circuits are used to collect the voltage across a sampling resistor to obtain a voltage signal reflecting the current magnitude. The detection circuits are connected to an aliasing operation circuit. The aliasing operation circuit, through a specific circuit design, performs comprehensive processing on the voltage signals from each detection circuit to ultimately obtain an average voltage value. The average voltage value is input into a control circuit. After corresponding conversion operations in the control circuit, the voltage signal is converted into an actual current feedback value, which is compared with a current set value preset in the control circuit. Based on the comparison result, a corresponding control signal is output to adjust the load current magnitude, thereby achieving precise control and monitoring of the high-current equipment. By aliasing the voltage signals from several detection circuits and taking their average value as the feedback signal, the detection circuit can effectively improve the accuracy and reliability of current detection while reducing the errors and interference caused by single-channel current sampling. This is of great significance for the stable operation and precise control of high-current equipment.

[0017] A second aspect of the present application provides a detection method based on the above-mentioned high-current device detection circuit. Several detection circuits collect voltages across a sampling resistor. When current flows, a voltage drop occurs across the resistor that is related to the current magnitude. The detection circuits sensitively detect these voltage drops, thereby obtaining several first voltage signals. These collected first voltages are differentially amplified. This effectively eliminates the effects of external factors such as common-mode interference on the voltage signal, improving signal accuracy and stability. After differential amplification, several second voltage signals are generated, resulting in a purer and more reliable signal. These second voltage signals are processed by a voltage follower. The voltage follower has high input impedance and low output impedance, effectively isolating the preceding and following circuits and preventing interference from the following circuits on the preceding circuit signals. Furthermore, the voltage follower integrates the several second voltage signals and outputs an average voltage value, which comprehensively and accurately reflects the overall current conditions of multiple channels. This average voltage value is input as a feedback signal into the control circuit. The control circuit compares this current feedback value with an internally preset current setpoint to ensure that the deviation between the actual current value and the setpoint is within an allowable range. The control circuit makes a comprehensive judgment based on the comparison results and outputs the corresponding control signal. Through this closed-loop control mechanism, the load current can be accurately adjusted to ensure the stable operation of high-current equipment.

[0018] The present invention abandons the traditional detection and control mode of sampling and controlling a single current and then adding them together. Instead, it adopts an operational amplifier to perform aliasing processing on multi-channel current sampling, and feeds back the analog value of the aliased output to the control circuit for current control. Since the interference to the current sampling after aliasing is the same as the interference to the single current sampling, but the interference will decrease with the aliasing result, the current detection accuracy is significantly improved, and multi-channel high-precision current detection is achieved. In addition, the present invention feeds back the analog value output after the operational amplifier aliasing operation method to the current control circuit, which can comprehensively consider the information of each current, effectively reduce the error between each current, and achieve equal current control of each channel. It successfully solves the technical difficulties of high-precision detection and high-stability control of multi-channel parallel connection, and provides solid technical support for the stable operation and precise control of large current equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0020] Figure 1 This is the circuit principle of a large current device detection circuit of the present invention Figure 1 ;

[0021] Figure 2 This is the circuit principle of a large current device detection circuit of the present invention Figure 2 ;

[0022] In the picture:

[0023] 1-Detection circuit, 2-Aliasing operation circuit, 3-Control circuit. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0025] Example 1:

[0026] like Figures 1 and 2 As shown, the detection circuit of a large current device described in the present invention includes: several detection circuits, an aliasing operation circuit and a control circuit; several of the detection circuits include a sampling resistor, an operational amplifier and a matching resistor; the detection circuit collects voltages at both ends of the sampling resistor, and the sampling resistor is used to monitor the load current; several of the detection circuits are connected to the aliasing operation circuit, and the aliasing operation circuit is used to alias the voltage signals of the several detection circuits and obtain a voltage average value; the control circuit is connected to the aliasing operation circuit, and the voltage average value is input into the control circuit as a feedback signal, and the actual current feedback value is obtained after conversion by the control circuit, and the feedback value is compared with the current set value set in the control circuit; the control circuit compares and judges and outputs a corresponding control signal, and the control signal is used to adjust the load current so that the load current is within the range of the current set value.

[0027] It is understood that the detection circuitry of high-current devices consists of several detection circuits, an aliasing operation circuit, and a control circuit. The detection circuits primarily collect voltages from several sampling resistors. The aliasing operation circuit, connected to the detection circuits, performs aliasing processing on the voltage signals from the detection circuits, which are related to the magnitude of multiple currents. The control circuit, connected to the aliasing operation circuit, primarily outputs a current control signal, thereby effectively regulating the load current.

[0028] Several detection circuits each include a sampling resistor, an operational amplifier, and a matching resistor, and are used to collect the voltage across the sampling resistor, thereby obtaining and reflecting a voltage signal related to the magnitude of the current flowing through the sampling resistor.

[0029] The aliasing operation circuit is connected to several detection circuits. It performs aliasing on the voltage signals corresponding to the currents collected by multiple detection circuits and calculates the average value of these voltage signals, known as the voltage average value. Specifically, the aliasing operation circuit uses a specific circuit design to comprehensively process the voltage signals from each detection circuit, ultimately obtaining a voltage average value that represents the overall level of the multiple currents.

[0030] The control circuit is connected to the aliasing operation circuit. The average voltage output by the aliasing operation circuit is input into the control circuit as a feedback signal. Within the control circuit, the voltage signal is converted into an actual current feedback value through appropriate conversion operations. This feedback value is then compared with the current set point preset within the control circuit. Based on the comparison result, the control circuit performs corresponding logical judgment and operation processing, and then outputs a corresponding control signal to adjust the load current and achieve precise control and monitoring of high-current equipment. By aliasing multiple current-related voltage signals and taking their average value as the feedback signal, this detection circuit can effectively improve the accuracy and reliability of current detection while reducing the errors and interference caused by single-channel current sampling. This is of great significance for the stable operation and precise control of high-current equipment.

[0031] Furthermore, one end of the sampling resistor is connected to the inverting input terminal of the operational amplifier, and the other end of the sampling resistor is connected to the non-inverting input terminal of the operational amplifier; the output terminal of the operational amplifier is connected to one end of the matching resistor, and the other end of the matching resistor is connected to the aliasing operation circuit.

[0032] It is understandable that in each detection circuit, the sampling resistor converts the current signal into a voltage signal, one end of which is connected to the inverting input of the operational amplifier, and the other end is connected to the non-inverting input of the operational amplifier. As a core component, the operational amplifier can amplify the weak signal converted by the sampling resistor to ensure that the signal has sufficient strength for subsequent processing. The output end of the operational amplifier is connected to one end of the matching resistor, and the other end of the matching resistor is connected to the aliasing operation circuit, thereby realizing effective transmission and conversion of the signal. This design effectively ensures the accuracy and stability of current sampling, and provides a reliable foundation for subsequent aliasing operations and load current regulation.

[0033] Furthermore, the aliasing operation circuit includes a voltage follower, a first resistor and a second resistor; the non-phase input terminal of the voltage follower is connected to the matching resistor, the inverting input terminal of the voltage follower is connected to the output terminal of the voltage follower, and the output terminal of the voltage follower is connected to the controller through the first resistor and connected to the control circuit through the second resistor.

[0034] The design of the aliasing operation circuit is to integrate and convert the signals of multiple currents so that the control circuit can accurately adjust the load current. The aliasing operation circuit is mainly composed of a voltage follower, a first resistor and a second resistor. Specifically, the positive input terminal of the voltage follower is connected to the matching resistor, and its negative input terminal and output terminal are connected to each other to form a closed-loop structure, thereby realizing high-impedance input and low-impedance output of the input signal, ensuring stable transmission of the signal. In addition, the output terminal of the voltage follower is connected to the controller through the first resistor, and is connected to the control circuit through the second resistor, thereby realizing further adjustment and matching of the signal. Such a design not only improves the stability and reliability of the entire circuit, but also enables the multi-channel current signals to be effectively aliased and converted, providing accurate feedback information for the control circuit, and thus realizing effective control of the load current.

[0035] Furthermore, the non-phase input terminal of the control circuit is connected to the second resistor, and the inverting input terminal of the control circuit is a set value input terminal.

[0036] The control circuit's non-inverting input is connected to the second resistor to receive the signal from the aliasing operation circuit. Meanwhile, the control circuit's inverting input is designed as a setpoint input for introducing a preset current target value or reference signal. This design enables the control circuit to compare the difference between the actual current signal and the setpoint, and then output a corresponding current control signal, achieving precise regulation of the load current to meet the operational requirements and safety regulations of high-current equipment.

[0037] Furthermore, the control circuit is an analog circuit or a digital circuit.

[0038] When the control circuit is analog, it includes operational amplifiers, comparators, and other analog components to directly process analog signals. When the control circuit is digital, it includes an analog-to-digital converter (ADC) to convert analog feedback signals into digital signals for digital processing.

[0039] In the case of analog circuits, the control signal may be a continuous voltage or current used to directly adjust the load current. In the case of digital circuits, the control signal may be a pulse width modulation (PWM) signal or other digital signal used to adjust the load current through a digital-to-analog converter (DAC) or directly drive the circuit.

[0040] Example 2:

[0041] like Figure 2As shown, a detection method for a large current device described in the second aspect of the present invention is implemented based on the detection circuit in the first embodiment of the present invention, wherein the plurality of detection circuits collect voltages at both ends of the sampling resistor to obtain a plurality of first voltages; the plurality of first voltages are differentially amplified to obtain a plurality of second voltages; the plurality of second voltages obtain a voltage average value through the aliasing operation circuit; the voltage average value is input into the control circuit as a feedback signal, and the actual current feedback value is obtained after conversion by the control circuit, and the feedback value is compared with the current set value set in the control circuit; the control circuit compares and judges and outputs a corresponding control signal.

[0042] It is understandable that, first, the several detection circuits respectively collect voltages at both ends of the respective sampling resistors, thereby obtaining several first voltages. Next, the several first voltages are differentially amplified to obtain several second voltages. Afterwards, the voltage follower in the aliasing operation circuit processes the several second voltages and outputs the voltage average value. This voltage average value is input into the control circuit as a feedback signal. In the control circuit, the feedback signal is converted to obtain the actual current feedback value. Subsequently, the feedback value is compared with the current setting value preset in the control circuit. Based on the comparison result, the control circuit performs corresponding comparison and judgment, and outputs the corresponding control signal, thereby achieving accurate detection and control of high-current equipment.

[0043] In an optional embodiment, when the resistance values ​​of the plurality of matching resistors are equal, the voltage at the input end of the aliasing operation circuit is the average voltage value.

[0044] It is understandable that when the resistance values ​​of the matching resistors are equal, the voltage follower in the aliasing operation circuit can achieve average processing of the output voltages of each detection circuit. Since the input current of the voltage follower is almost zero and the resistance values ​​of the matching resistors are the same, according to Kirchhoff's current law, the current in each branch is equal. Therefore, the input voltage of the operational amplifier (i.e., the non-inverting input voltage of the voltage follower) is equal to the average value of the output voltages of each detection circuit. In this way, the voltage at the input of the operational amplifier is the voltage average, thereby simplifying the circuit design and improving the accuracy of signal processing.

[0045] In an optional embodiment, the control circuit is used to regulate the load current, implementing closed-loop current control among the plurality of detection circuits, the arithmetic aliasing circuit, and the control circuit. Specifically, when the control circuit compares the actual current feedback value with the preset current set value, if there is a difference between the two, the control circuit generates a corresponding control signal based on this difference. This control signal is sent to the load's drive circuit or related actuator to adjust the load current. For example, the control signal may be used to adjust the on-time or conduction degree of a power transistor, thereby controlling the magnitude of the load current. In this way, the control circuit can dynamically adjust the load current so that the actual current value gradually approaches or reaches the preset value, thereby achieving precise current control. The implementation of closed-loop control improves the stability and reliability of the system, ensuring that high-current equipment operates within a safe and efficient current range. This closed-loop control system can promptly respond to current changes and make rapid adjustments, which is of great significance for the stable operation and fault prevention of high-current equipment.

[0046] In an optional embodiment, the closed-loop control is used to eliminate loop oscillations caused by uneven current during constant voltage charging. The closed-loop control system dynamically adjusts the control signal by monitoring the difference between the current feedback value and the preset current set value in real time, thereby stabilizing the load current. When there is uneven current flow, the closed-loop control system can detect the current fluctuation in time and suppress the loop oscillation by adjusting the control signal. This closed-loop control mechanism improves the stability and reliability of the system and ensures the uniformity and stability of the current during constant voltage charging.

[0047] Example 3:

[0048] Optionally, the detection circuit includes at least two or more detection circuits, and the principles of each detection circuit are basically the same.

[0049] like Figure 2 As shown, one end of the sampling resistors (RL-1, RL-2, ... RL-N) is directly or indirectly connected to the BUS bus, and the other end is directly or indirectly connected to the load resistor RL, while the other end of the load resistor RL is directly or indirectly connected to PGND (power ground or the negative pole of the BUS bus).

[0050] Specifically, taking the sampling resistor RL-1 as an example, one end thereof is directly or indirectly connected to BUS, and the other end is directly or indirectly connected to the load resistor RL. One end of RL-1 is also connected to the inverting input of the operational amplifier U-1, and the other end is connected to the non-inverting input of the operational amplifier U-1. The output of the operational amplifier U-1 is connected to one end of the matching resistor R-1, and the other end of the matching resistor R-1 is connected to the non-inverting input of the voltage follower A1. The inverting input and output of the voltage follower A1 are connected to form a closed-loop structure, enabling it to output voltage stably. The output of the voltage follower A1 is connected to the AD port of the controller through the first resistor RAD, and is connected to the non-inverting input of the control circuit through the second resistor R. The inverting input of the control circuit serves as a set value input for receiving a preset current set value.

[0051] When the load circuit is operating, current flows through sampling resistor RL-1, generating a voltage across it. Operational amplifier U-1 performs a differential operation on the voltage difference between 1-IS+ and 1-IS- across the sampling resistor, amplifying it and outputting voltage V1. Output voltage V1 is fed through matching resistor R-1 to the non-inverting input of voltage follower A1. Similarly, the corresponding sampled voltage V2 of sampling resistor RL-2 is fed through matching resistor R-2 to the non-inverting input of voltage follower A1; the corresponding sampled voltage VN of sampling resistor RL-N is fed through matching resistor RN to the non-inverting input of voltage follower A1.

[0052] Voltages V1, V2, ..., and VN are fed into the non-inverting input of voltage follower A1 through matching resistors R-1, R-2, ..., and RN, respectively, for aliasing. When the resistances of R-1, R-2, ..., and RN are equal, the voltage at the input of voltage follower A1 is the average of the voltages V1, V2, ..., and VN. Because voltage follower A1 is designed as a voltage follower, its output voltage Vo is equal to the average of the voltages V1, V2, ..., and VN.

[0053] The output voltage Vo is connected to the controller's AD port via a first resistor RAD and to the control circuit's feedback input via a second resistor R. The control circuit's setpoint input receives a preset current setpoint and compares the feedback value with the setpoint. After performing internal logic operations, the control circuit outputs a PWM control signal to control the current flowing through the load, thereby completing closed-loop current control.

[0054] This circuit uses a voltage follower to alias multiple current samples. Since the interference experienced by the aliased current samples is consistent with that experienced by a single current sample, the interference is reduced with the aliasing result, thus achieving high-precision current detection. By feeding the analog value output by the voltage follower after aliasing back to the current control circuit, this solves the problems of uneven current distribution between channels and current oscillation during constant-voltage battery charging when using conventional single-channel current sampling detection methods, achieving current sharing control and high-precision detection between channels.

[0055] In summary, the detection circuit described in the present invention effectively improves the detection accuracy and stability of high-current equipment through multi-channel current sampling, aliasing operation and closed-loop control, ensures the current uniformity and stability of the equipment during constant voltage charging, avoids loop oscillation caused by uneven current flow, and thus ensures the safe operation of high-current equipment.

[0056] For other structures of the high current device detection circuit and method described in this embodiment, refer to the prior art.

[0057] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Therefore, any modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A detection circuit for a high current device, characterized in that: include: Several detection circuits, aliasing operation circuits and control circuits; Several of the detection circuits include a sampling resistor, an operational amplifier, and a matching resistor; The detection circuit collects voltage across the sampling resistor, and the sampling resistor is used to monitor the load current; The plurality of detection circuits are connected to the aliasing operation circuit, and the aliasing operation circuit is used to alias the voltage signals of the plurality of detection circuits and obtain a voltage average value; The control circuit is connected to the aliasing operation circuit, and the voltage average value is input into the control circuit as a feedback signal. The actual current feedback value is obtained after conversion by the control circuit, and the feedback value is compared with the current set value set in the control circuit; Comparing and judging through the control circuit and outputting corresponding control signals; The control signal is used to adjust the load current so that the load current is within the range of the current setting value.

2. The detection circuit for a high current device according to claim 1, wherein: One end of the sampling resistor is connected to the inverting input terminal of the operational amplifier, and the other end of the sampling resistor is connected to the non-inverting input terminal of the operational amplifier; The output end of the operational amplifier is connected to one end of the matching resistor, and the other end of the matching resistor is connected to the aliasing operation circuit.

3. The detection circuit for a high current device according to claim 2, wherein: The aliasing operation circuit includes a voltage follower, a first resistor and a second resistor; The non-phase input terminal of the voltage follower is connected to the matching resistor, the inverting input terminal of the voltage follower is connected to the output terminal of the voltage follower, the output terminal of the voltage follower is connected to the controller through a first resistor, and is connected to the control circuit through a second resistor.

4. The detection circuit for a high current device according to claim 3, wherein: The non-phase input terminal of the control circuit is connected to the second resistor, and the inverting input terminal of the control circuit is a set value input terminal.

5. The method for detecting a high current device according to claim 4, wherein: The control circuit is an analog circuit or a digital circuit.

6. A method for detecting a high current device, based on a detection circuit for a high current device according to any one of claims 1 to 5, characterized in that : The plurality of detection circuits collect voltages at both ends of the sampling resistor to obtain a plurality of first voltages; performing differential operational amplification on the first voltages to obtain second voltages; The plurality of second voltages are obtained by the aliasing operation circuit to obtain a voltage average value; Inputting the voltage average value into the control circuit as a feedback signal, converting the actual current feedback value through the control circuit, and comparing the feedback value with the current set value set in the control circuit; The control circuit compares and judges and outputs a corresponding control signal.

7. The method for detecting a high current device according to claim 6, wherein: When the resistance values ​​of the matching resistors are equal, the voltage at the input end of the aliasing operation circuit is the average voltage.

8. The method for detecting a high current device according to claim 6, wherein: The control circuit is used to adjust the load current and realize the current closed-loop control among the plurality of detection circuits, the operation aliasing circuit and the control circuit.

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