Voltage acquisition circuit and device of voltage division network

Abstract

The utility model relates to the technical field of IC calibration voltage sampling, in particular to a voltage acquisition circuit and device of a voltage division network, comprising an acquisition module, the acquisition module comprises a first acquisition unit, a second acquisition unit, a third acquisition unit and a fourth acquisition unit, the input end of the first acquisition unit is connected with the positive end of a power supply, and the output end of the second acquisition unit is connected with the negative end of the power supply; the reference end of the first acquisition unit is connected with the input end of the second acquisition unit; the input end of the second acquisition unit is also connected with a high potential end, and the reference end of the second acquisition unit is connected with the input end of the third acquisition unit; the input end of the third acquisition unit is also connected with a middle potential end; the reference end of the third acquisition unit is connected with the input end of the fourth acquisition unit; the input end of the fourth acquisition unit is connected with the low-potential end. The reference end of the fourth acquisition unit is connected with the negative end of the power supply. The problem that the actual error between the electric quantity equally distributed to each battery cell and the battery cell is large due to the fact that the multiple battery cells are uneven when total voltage collection is adopted is solved.

Description

Technical Field

[0001] The present application relates to the technical field of IC calibration voltage sampling, and in particular to a voltage acquisition circuit and device of a voltage divider network. Background Art

[0002] IC calibration is a key step to ensure the performance of electronic systems, especially for the calibration of reference voltage, which directly affects the accuracy and stability of the system. By calibrating each string of ICs, it can be ensured that each unit can meet the same performance standards, thereby improving the performance and reliability of the entire system. A way to implement the reference voltage acquisition provided by the measurement IC calibration during the total voltage calibration can calibrate all ICs at the same time, reducing repetitive work and the number of equipment required for calibration, thereby reducing costs. Usually, direct acquisition after resistor voltage division is adopted, but there is a problem of low accuracy, which cannot meet the specific needs of each string of ICs, especially when the working conditions or performance requirements of each string of ICs are different, resulting in a large error in the estimated required power divided into each battery cell, and a large error will cause uneven batteries. Since it is difficult to ensure that the battery capacity is the same, some batteries will not be fully charged during use, and some batteries will not be used up, which will also have an impact on the service life of batteries that are frequently overcharged.

[0003] Based on the above scenarios, it can be seen that it is necessary to collect the reference voltage required for calibration of each battery cell to meet the increasing requirements for IC calibration accuracy and reliability in production and use. Utility Model Content

[0004] The embodiments of the present application provide a voltage collection circuit and device for a voltage divider network, which can avoid the problem of large error between the actual amount of electricity distributed to each battery cell and the battery cell due to unevenness between multiple battery cells when using total voltage collection.

[0005] In a first aspect, the present application provides a voltage collection circuit of a voltage divider network: a voltage collection circuit of a voltage divider network, applied to a voltage divider network, the voltage divider network includes a positive power supply terminal, a high potential terminal, a medium potential terminal, a low potential terminal and a negative power supply terminal, including a collection module, the collection module includes a first collection unit, a second collection unit, a third collection unit and a fourth collection unit,

[0006] The input end of the first acquisition unit is connected to the positive end of the power supply, and the reference end of the first acquisition unit is connected to the input end of the second acquisition unit, so as to use the high potential voltage output by the high potential end as the reference voltage of the first acquisition unit, and acquire the power supply voltage output by the positive end of the power supply according to the reference voltage of the first acquisition unit;

[0007] The input end of the second acquisition unit is also connected to the high potential end, and the reference end of the second acquisition unit is connected to the input end of the third acquisition unit, so as to use the middle potential voltage output by the middle potential end as the reference voltage of the second acquisition unit, and acquire the high potential voltage according to the reference voltage of the second acquisition unit;

[0008] The input end of the third acquisition unit is also connected to the middle potential end, and the reference end of the third acquisition unit is connected to the input end of the fourth acquisition unit, so as to use the low potential voltage output by the low potential end as the reference voltage of the third acquisition unit, and acquire the middle potential voltage according to the reference voltage of the third acquisition unit;

[0009] The input end of the fourth acquisition unit is also connected to the low potential end, and the reference end of the fourth acquisition unit is connected to the negative end of the power supply, so as to use the reference voltage output from the negative end of the power supply as the reference voltage of the fourth acquisition unit, and acquire the low potential voltage according to the reference voltage of the fourth acquisition unit.

[0010] By adopting the above technical solution, the voltage divider network refers to the use of four series resistors to simulate the output of the battery pack, battery group, and battery string single cell voltage, and the acquisition module is divided into four acquisition units, each of which is used to collect a potential, namely the positive end of the power supply (for collecting the power supply voltage), the high potential end (for collecting the high potential voltage), the medium potential end (for collecting the medium potential voltage), and the low potential end (for collecting the low potential voltage). Each acquisition unit uses the potential of the next level as the reference voltage. For example, the first acquisition unit uses the high potential voltage as the reference voltage, and the fourth acquisition unit uses the 0V of the negative end of the power supply as the reference voltage. In this way, the reference voltage required for the calibration of each battery cell is collected, avoiding the problem of large errors between the power distributed to each battery cell and the actual power cell due to uneven cells between multiple batteries when using total voltage acquisition.

[0011] Optionally, it further includes an analog-to-digital conversion module, wherein the analog-to-digital conversion module includes a first input terminal, a second input terminal, a third input terminal, a fourth input terminal and an output terminal;

[0012] The first input end is connected to the output end of the first acquisition unit, the second input end is connected to the output end of the second acquisition unit, and the third input end is connected to the output end of the third acquisition unit;

[0013] The fourth input terminal is connected to the output terminal of the fourth acquisition unit, and the output terminal of the analog-to-digital conversion module is connected to an external single-chip microcomputer, which is used to perform analog-to-digital conversion on the power supply voltage, the high potential voltage, the medium potential voltage and the low potential voltage to generate and send a voltage acquisition digital signal to the single-chip microcomputer.

[0014] By adopting the above technical solution, the analog-to-digital conversion module receives the analog signals output by the four acquisition units, and performs analog-to-digital conversion based on the four analog signals received to obtain and send corresponding digital signals to the microcontroller for processing by the microcontroller.

[0015] Optionally, the voltage divider network includes a first resistor, a second resistor, a third resistor and a fourth resistor;

[0016] One end of the first resistor is connected to the positive end of the power supply and the input end of the first acquisition unit, and the other end is connected to one end of the second resistor and the input end of the second acquisition unit;

[0017] The other end of the second resistor is connected to one end of the third resistor and the input end of the third acquisition unit, the other end of the third resistor is connected to one end of the fourth resistor and the input end of the fourth acquisition unit, and one end of the fourth resistor is connected to the negative pole of the power supply and the reference end of the fourth acquisition unit.

[0018] By adopting the above technical solution, a first resistor, a second resistor, a third resistor and a fourth resistor are connected in series to perform step-by-step voltage division to generate multiple sampling points, and the sampling points correspond to the positive terminal, the high potential terminal, the medium potential terminal, the low potential terminal and the negative terminal of the power supply in sequence.

[0019] Optionally, the first acquisition unit includes a first follower and a first amplifier;

[0020] The input end of the first follower is connected to one end of the first resistor and the positive end of the power supply, and the output end of the first follower is connected to the non-inverting input end of the first amplifier;

[0021] An inverting input terminal of the first amplifier is connected to an input terminal of the second acquisition unit, and an output terminal of the first amplifier is connected to the first input terminal.

[0022] Optionally, the second acquisition unit includes a second follower and a second amplifier;

[0023] The input end of the second follower is connected to the connection point of the first resistor and the second resistor, and the output end of the second follower is connected to the non-inverting input end of the second amplifier;

[0024] An inverting input terminal of the second amplifier is connected to an input terminal of the third acquisition unit, and an output terminal of the second amplifier is connected to the second input terminal.

[0025] Optionally, the third acquisition unit includes a third follower and a third amplifier;

[0026] The input end of the third follower is connected to the connection point of the second resistor and the third resistor, and the output end of the third follower is connected to the non-inverting input end of the third amplifier;

[0027] The inverting input terminal of the third amplifier is connected to the input terminal of the fourth acquisition unit, and the output terminal of the third amplifier is connected to the third input terminal.

[0028] Optionally, the fourth acquisition unit includes a fourth follower and a fourth amplifier;

[0029] The input end of the fourth follower is connected to the connection point of the third resistor and the fourth resistor, and the output end of the fourth follower is connected to the non-inverting input end of the fourth amplifier;

[0030] An inverting input terminal of the fourth amplifier is connected to the other end of the fourth resistor, and an output terminal of the fourth amplifier is connected to the fourth input terminal.

[0031] By adopting the above technical solution, the amplifier in each level of the acquisition unit is connected to the follower output terminal in the next acquisition unit to ensure the reference potential and avoid the damage to the back-end circuit caused by the excessive output of the operational amplifier. Taking the first acquisition unit as an example, the first follower is used to avoid damage to the first acquisition unit due to impedance mismatch. The first follower inputs the power supply voltage collected from the positive end of the power supply to the non-phase input terminal of the first amplifier, and the inverting input terminal of the first amplifier is connected to the output terminal of the second follower in the second acquisition unit, that is, a high potential voltage is used as the reference voltage to ensure that the positive and negative voltage difference of the first amplifier is not too large, which will cause the output voltage to be too large, thereby improving the acquisition reliability.

[0032] Optionally, the analog-to-digital conversion module includes an analog-to-digital converter, and the analog-to-digital converter includes a first acquisition terminal, a second acquisition terminal, a third acquisition terminal, a fourth acquisition terminal and a digital output terminal;

[0033] The first acquisition terminal is connected to the output terminal of the first amplifier, the second acquisition terminal is connected to the output terminal of the second amplifier, the third acquisition terminal is connected to the output terminal of the third amplifier, the fourth acquisition terminal is connected to the output terminal of the fourth amplifier, and the digital output terminal is connected to the single chip microcomputer.

[0034] A second aspect of the present application provides a voltage collection device for a voltage divider network, which is equipped with the voltage collection circuit of the voltage divider network described above.

[0035] In summary, the beneficial effects of the present application are as follows: the acquisition module is divided into four acquisition units, each acquisition unit is for collecting a potential, namely the positive end of the power supply (for collecting the power supply voltage), the high potential end (for collecting the high potential voltage), the medium potential end (for collecting the medium potential voltage), and the low potential end (for collecting the low potential voltage). Each acquisition unit uses the potential of the next level as a reference voltage. For example, the first acquisition unit uses the high potential voltage as a reference voltage, and the fourth acquisition unit uses 0V at the negative end of the power supply as a reference voltage. In order to collect the reference voltage required for calibration of each battery cell, the problem of large error between the actual power distributed to each battery cell and the battery cell due to unevenness between multiple battery cells caused by total voltage collection is avoided. The amplifier in each level of collection unit is connected to the follower output end of the next collection unit to ensure the reference potential and avoid damage to the back-end circuit caused by excessive output of the operational amplifier. Taking the first collection unit as an example, the first follower is used to avoid damage to the first collection unit due to impedance mismatch. The first follower inputs the power supply voltage collected from the positive end of the power supply to the non-phase input end of the first amplifier, and the inverting input end of the first amplifier is connected to the output end of the second follower in the second collection unit, that is, a high potential voltage is used as the reference voltage to ensure that the positive and negative voltage difference of the first amplifier is not too large, which will cause excessive output voltage, thereby improving the collection reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a module schematic diagram of a voltage collection circuit of a voltage divider network provided in an embodiment of the present application;

[0037] Figure 2 is a circuit schematic diagram of a voltage collection circuit of a voltage divider network provided in an embodiment of the present application;

[0038] Figure 3 It is a circuit schematic diagram of the analog-to-digital conversion module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The following examples will help those skilled in the art to further understand the effects of the present application, but are not intended to limit the present application in any form. It should be noted that, for those of ordinary skill in the art, several modifications and improvements may be made without departing from the concept of the present application. These all fall within the scope of protection of the present application.

[0040] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0041] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0042] It should also be understood that the term “and / or” used in the specification and appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0043] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0044] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0045] The present application is further described in detail below in conjunction with the accompanying drawings.

[0046] Reference Figure 1 , which is a module schematic diagram of a voltage acquisition circuit of a voltage divider network provided in an embodiment of the present application, including a voltage divider network, an acquisition module 1 and an analog-to-digital conversion module 2. Each module is specifically described below:

[0047] About the voltage divider network: The voltage divider network is formed by four resistors connected in series to simulate and generate multiple sampling points. The sampling points correspond to the positive end of the power supply, the high potential end, the medium potential end, the low potential end and the negative end of the power supply. For specific connections and sampling point locations, please refer to Figure 1 , the following is a detailed description:

[0048] The voltage dividing network includes a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4;

[0049] One end of the first resistor R1 is connected to the positive end of the power supply and the input end of the first acquisition unit, and the other end is connected to one end of the second resistor R2 and the input end of the second acquisition unit;

[0050] The other end of the second resistor R2 is connected to one end of the third resistor R3 and the input end of the third acquisition unit, the other end of the third resistor R3 is connected to one end of the fourth resistor R4 and the input end of the fourth acquisition unit, and one end of the fourth resistor R4 is connected to the negative electrode of the power supply and the reference end of the fourth acquisition unit.

[0051] Specifically, the four resistors connected in series have the same resistance value and are used to simulate the output voltage of the battery pack, battery group, and battery string single cell. In this embodiment, four resistors with a resistance value of 1K are used for voltage division. One end of the first resistor R1 can be sampled to obtain the power supply voltage BAT+ (16V in this embodiment), and the connection between the first resistor R1 and the second resistor R2 can obtain the high potential voltage VH (12V in this embodiment). The connection between the second resistor R2 and the third resistor R3 can be sampled to obtain the medium potential voltage VM (8V in this embodiment), and the connection between the third resistor R3 and the fourth resistor R4 can be sampled to obtain the low potential voltage VL (4V in this embodiment). The potential difference of a certain position relative to the potential of the next stage is 4V to avoid damage to the operational amplifier due to excessive voltage difference, and to avoid excessive proportional amplification output of the operational amplifier to damage the back-end circuit.

[0052] Regarding the acquisition module 1: it includes a first acquisition unit, a second acquisition unit, a third acquisition unit and a fourth acquisition unit,

[0053] The input end of the first acquisition unit is connected to the positive end of the power supply, and the reference end of the first acquisition unit is connected to the input end of the second acquisition unit, so as to use the high potential voltage VH output by the high potential end as the reference voltage of the first acquisition unit, and acquire the power supply voltage BAT+ output by the positive end of the power supply according to the reference voltage of the first acquisition unit;

[0054] The input end of the second acquisition unit is also connected to the high potential end, and the reference end of the second acquisition unit is connected to the input end of the third acquisition unit, so as to use the middle potential voltage VM output by the middle potential end as the reference voltage of the second acquisition unit, and acquire the high potential voltage VH according to the reference voltage of the second acquisition unit;

[0055] The input end of the third acquisition unit is also connected to the middle potential end, and the reference end of the third acquisition unit is connected to the input end of the fourth acquisition unit, so as to use the low potential voltage VL output by the low potential end as the reference voltage of the third acquisition unit, and acquire the middle potential voltage VM according to the reference voltage of the third acquisition unit;

[0056] The input end of the fourth acquisition unit is also connected to the low potential end, and the reference end of the fourth acquisition unit is connected to the negative end of the power supply, so as to use the reference voltage output from the negative end of the power supply as the reference voltage of the fourth acquisition unit, and acquire the low potential voltage VL according to the reference voltage of the fourth acquisition unit.

[0057] Specifically, each acquisition unit is used to acquire a potential, which are the positive end of the power supply (used to acquire the power supply voltage BAT+), the high potential end (used to acquire the high potential voltage VH), the medium potential end (used to acquire the medium potential voltage VM), and the low potential end (used to acquire the low potential voltage VL). Each acquisition unit uses the potential of the next level as the reference voltage. For example, the first acquisition unit uses the high potential voltage VH as the reference voltage, and the fourth acquisition unit uses the 0V of the negative end of the power supply as the reference voltage. In this way, the reference voltage required for calibration of each battery cell is acquired, avoiding the problem of large error between the power distributed to each battery cell and the actual power of the battery cell due to unevenness between multiple batteries when using total voltage acquisition.

[0058] More specifically, please refer to Figure 2 , Figure 2 1 is a circuit schematic diagram of a voltage acquisition circuit of a voltage divider network provided in an embodiment of the present application, including a specific circuit implementation structure of a voltage divider network and an acquisition module 1, which is specifically described below:

[0059] The first acquisition unit includes a first follower U11 and a first amplifier U12;

[0060] The input end of the first follower U11 is connected to one end of the first resistor R1 and the positive end of the power supply, and the output end of the first follower U11 is connected to the non-inverting input end of the first amplifier U12;

[0061] An inverting input terminal of the first amplifier U12 is connected to an input terminal of the second acquisition unit, and an output terminal CELL1 of the first amplifier U12 is connected to the first input terminal.

[0062] The second acquisition unit includes a second follower U21 and a second amplifier U22;

[0063] The input end of the second follower U21 is connected to the connection point of the first resistor R1 and the second resistor R2, and the output end of the second follower U21 is connected to the non-inverting input end of the second amplifier U22;

[0064] An inverting input terminal of the second amplifier U22 is connected to an input terminal of the third acquisition unit, and an output terminal CELL2 of the second amplifier U22 is connected to the second input terminal.

[0065] The third acquisition unit includes a third follower U31 and a third amplifier U32;

[0066] The input end of the third follower U31 is connected to the connection point of the second resistor R2 and the third resistor R3, and the output end of the third follower U31 is connected to the non-inverting input end of the third amplifier U32;

[0067] The inverting input terminal of the third amplifier U32 is connected to the input terminal of the fourth acquisition unit, and the output terminal CELL3 of the third amplifier U32 is connected to the third input terminal.

[0068] The fourth acquisition unit includes a fourth follower U41 and a fourth amplifier U42;

[0069] The input end of the fourth follower U41 is connected to the connection point of the third resistor R3 and the fourth resistor R4, and the output end of the fourth follower U41 is connected to the non-inverting input end of the fourth amplifier U42;

[0070] An inverting input terminal of the fourth amplifier U42 is connected to the other end of the fourth resistor R4 , and an output terminal CELL4 of the fourth amplifier U42 is connected to the fourth input terminal.

[0071] Specifically, the amplifier in each level of the acquisition unit is connected to the follower output terminal in the next acquisition unit to ensure the reference potential and avoid the damage to the back-end circuit caused by the excessive output of the operational amplifier. Taking the first acquisition unit as an example, the first follower U11 is used to avoid damage to the first acquisition unit due to impedance mismatch. The first follower U11 inputs the power supply voltage BAT+ collected from the positive end of the power supply to the non-phase input terminal of the first amplifier U12, and the inverting input terminal of the first amplifier U12 is connected to the output terminal of the second follower U21 in the second acquisition unit, that is, the high potential voltage VH is used as the reference voltage to ensure that the positive and negative voltage difference of the first amplifier U12 is not too large, which will cause the output voltage to be too large, thereby improving the acquisition reliability.

[0072] More specifically, the positive input terminal of the op amp of each sampling unit is connected to the follower output of the corresponding unit, and its negative input terminal is connected to the follower output of the next level unit, thereby ensuring that the positive and negative input terminals of the op amp in each unit are at a fixed voltage difference, which is 4V in this embodiment. The voltage difference value depends on the properties of the op amp and can be adjusted according to actual conditions.

[0073] Regarding the analog-to-digital conversion module 2: the analog-to-digital conversion module 2 includes a first input terminal, a second input terminal, a third input terminal, a fourth input terminal and an output terminal;

[0074] The first input end is connected to the output end of the first acquisition unit, the second input end is connected to the output end of the second acquisition unit, and the third input end is connected to the output end of the third acquisition unit;

[0075] The fourth input terminal is connected to the output terminal of the fourth acquisition unit, and the output terminal of the analog-to-digital conversion module 2 is connected to the external single-chip microcomputer MCU, and is used to perform analog-to-digital conversion on the power supply voltage BAT+, the high potential voltage VH, the medium potential voltage VM and the low potential voltage VL to generate and send a voltage acquisition digital signal to the single-chip microcomputer MCU.

[0076] Specifically, the analog-to-digital conversion module 2 receives the analog signals output by the four acquisition units, and performs analog-to-digital conversion according to the received four analog signals to obtain and send the corresponding digital signals to the single-chip microcomputer MCU for processing by the single-chip microcomputer MCU. Figure 3 , Figure 3 1 is a circuit schematic diagram of the analog-to-digital conversion module 2 provided in an embodiment of the present application, showing a specific design of an embodiment of the analog-to-digital conversion module 2, which is specifically described below:

[0077] The analog-to-digital conversion module 2 includes an analog-to-digital converter U5, and the analog-to-digital converter U5 includes a first acquisition terminal AIN0, a second acquisition terminal AIN1, a third acquisition terminal AIN2, a fourth acquisition terminal AIN3 and a digital output terminal;

[0078] The first acquisition terminal AIN0 is connected to the output terminal CELL1 of the first amplifier U12, the second acquisition terminal AIN1 is connected to the output terminal CELL2 of the second amplifier U22, the third acquisition terminal AIN2 is connected to the output terminal CELL3 of the third amplifier U32, the fourth acquisition terminal AIN3 is connected to the output terminal CELL4 of the fourth amplifier U42, and the digital output terminal is connected to the single-chip computer MCU.

[0079] Specifically, the analog-to-digital converter U5 includes four acquisition terminals, corresponding to the four input terminals of the above-mentioned analog-to-digital conversion module 2. After receiving the analog signals sent by the four acquisition units, it is sent to the microcontroller MCU through two digital output terminals SCL and SDA, and the microcontroller MCU performs subsequent processing.

[0080] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A voltage acquisition circuit of a voltage divider network, applied to a voltage divider network, wherein the voltage divider network comprises a positive power supply terminal, a high potential terminal, a medium potential terminal, a low potential terminal and a negative power supply terminal, and is characterized in that: The acquisition module includes a first acquisition unit, a second acquisition unit, a third acquisition unit and a fourth acquisition unit. The input end of the first acquisition unit is connected to the positive end of the power supply, and the reference end of the first acquisition unit is connected to the input end of the second acquisition unit, so as to use the high potential voltage output by the high potential end as the reference voltage of the first acquisition unit, and acquire the power supply voltage output by the positive end of the power supply according to the reference voltage of the first acquisition unit; The input end of the second acquisition unit is also connected to the high potential end, and the reference end of the second acquisition unit is connected to the input end of the third acquisition unit, so as to use the middle potential voltage output by the middle potential end as the reference voltage of the second acquisition unit, and acquire the high potential voltage according to the reference voltage of the second acquisition unit; The input end of the third acquisition unit is also connected to the middle potential end, and the reference end of the third acquisition unit is connected to the input end of the fourth acquisition unit, so as to use the low potential voltage output by the low potential end as the reference voltage of the third acquisition unit, and acquire the middle potential voltage according to the reference voltage of the third acquisition unit; The input end of the fourth acquisition unit is also connected to the low potential end, and the reference end of the fourth acquisition unit is connected to the negative end of the power supply, so as to use the reference voltage output from the negative end of the power supply as the reference voltage of the fourth acquisition unit, and acquire the low potential voltage according to the reference voltage of the fourth acquisition unit.

2. The voltage acquisition circuit of the voltage divider network according to claim 1, characterized in that: Also includes an analog-to-digital conversion module, the analog-to-digital conversion module includes a first input terminal, a second input terminal, a third input terminal, a fourth input terminal and an output terminal; The first input end is connected to the output end of the first acquisition unit, the second input end is connected to the output end of the second acquisition unit, and the third input end is connected to the output end of the third acquisition unit; The fourth input terminal is connected to the output terminal of the fourth acquisition unit, and the output terminal of the analog-to-digital conversion module is connected to an external single-chip microcomputer, which is used to perform analog-to-digital conversion on the power supply voltage, the high potential voltage, the medium potential voltage and the low potential voltage to generate and send a voltage acquisition digital signal to the single-chip microcomputer.

3. The voltage acquisition circuit of the voltage divider network according to claim 2, characterized in that: The voltage divider network includes a first resistor, a second resistor, a third resistor and a fourth resistor; One end of the first resistor is connected to the positive end of the power supply and the input end of the first acquisition unit, and the other end is connected to one end of the second resistor and the input end of the second acquisition unit; The other end of the second resistor is connected to one end of the third resistor and the input end of the third acquisition unit, the other end of the third resistor is connected to one end of the fourth resistor and the input end of the fourth acquisition unit, and one end of the fourth resistor is connected to the negative end of the power supply and the reference end of the fourth acquisition unit.

4. The voltage acquisition circuit of the voltage divider network according to claim 3, characterized in that: The first acquisition unit includes a first follower and a first amplifier; The input end of the first follower is connected to one end of the first resistor and the positive end of the power supply, and the output end of the first follower is connected to the non-inverting input end of the first amplifier; An inverting input terminal of the first amplifier is connected to an input terminal of the second acquisition unit, and an output terminal of the first amplifier is connected to the first input terminal.

5. The voltage acquisition circuit of the voltage divider network according to claim 4, characterized in that: The second acquisition unit includes a second follower and a second amplifier; The input end of the second follower is connected to the connection point of the first resistor and the second resistor, and the output end of the second follower is connected to the non-inverting input end of the second amplifier; An inverting input terminal of the second amplifier is connected to an input terminal of the third acquisition unit, and an output terminal of the second amplifier is connected to the second input terminal.

6. The voltage acquisition circuit of the voltage divider network according to claim 5, characterized in that: The third acquisition unit includes a third follower and a third amplifier; The input end of the third follower is connected to the connection point of the second resistor and the third resistor, and the output end of the third follower is connected to the non-inverting input end of the third amplifier; The inverting input terminal of the third amplifier is connected to the input terminal of the fourth acquisition unit, and the output terminal of the third amplifier is connected to the third input terminal.

7. The voltage acquisition circuit of the voltage divider network according to claim 6, characterized in that: The fourth acquisition unit includes a fourth follower and a fourth amplifier; The input end of the fourth follower is connected to the connection point of the third resistor and the fourth resistor, and the output end of the fourth follower is connected to the non-inverting input end of the fourth amplifier; An inverting input terminal of the fourth amplifier is connected to the other end of the fourth resistor, and an output terminal of the fourth amplifier is connected to the fourth input terminal.

8. The voltage acquisition circuit of the voltage divider network according to claim 7, characterized in that: The analog-to-digital conversion module includes an analog-to-digital converter, and the analog-to-digital converter includes a first acquisition terminal, a second acquisition terminal, a third acquisition terminal, a fourth acquisition terminal and a digital output terminal; The first acquisition terminal is connected to the output terminal of the first amplifier, the second acquisition terminal is connected to the output terminal of the second amplifier, the third acquisition terminal is connected to the output terminal of the third amplifier, the fourth acquisition terminal is connected to the output terminal of the fourth amplifier, and the digital output terminal is connected to the single chip microcomputer.

9. A voltage collection device for a voltage divider network, characterized in that: A voltage acquisition circuit equipped with a voltage divider network as claimed in any one of claims 1 to 8.

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