Battery partial voltage detection circuit

Abstract

The utility model relates to a battery partial voltage detection circuit, which comprises a thirty-eight decoder, and the Y0-Y5 ends of the output ends of the thirty-eight decoder are connected with the input end of a phase inverter; the output end of the phase inverter is connected with the driving integrated circuit; the J1-J6 ends in the output end of the driving integrated circuit are respectively connected with the primary sides of the two optocoupler relays, and six groups are provided; the input end of the secondary side of the first optocoupler relay in each group is connected with the positive electrode end of one battery, and the output end is connected with the positive phase input end of the operational amplifier, the third resistor and the first capacitor through the first resistor. The input end of the secondary side of the second optocoupler relay in each group is connected with the negative electrode end of one battery, and the output end is connected with the negative phase input end of the operational amplifier, a fourth resistor and a second capacitor through a second resistor; the output end of the operational amplifier, the other end of the fourth resistor and the other end of the second capacitor are connected with a fifth resistor; the other end of the fifth resistor is connected with the third capacitor and the A / D converter. According to the utility model, the accuracy of the collected partial voltage is ensured.

Description

Technical Field

[0001] This utility model relates to a battery voltage detection circuit. Background Technology

[0002] In battery pack testing, it's not enough to simply record the total voltage and current of the battery pack; the individual voltage of each battery cell must also be recorded simultaneously with the total voltage. This is crucial to understanding the overall battery pack's characteristics and consistency. Therefore, the accuracy of individual voltage detection is paramount. In typical designs, the total voltage and individual voltage acquisition are performed in the same circuit, using the same power supply and ground wire. This makes it difficult to effectively eliminate the common-mode voltage differences between the total voltage and the individual battery voltages, as well as between the individual battery voltages. Furthermore, each battery's voltage is acquired using its own independent acquisition circuit, which can lead to errors in the voltage acquisition between different circuits, affecting the accuracy of the test.

[0003] Therefore, a battery voltage detection circuit is provided. Utility Model Content

[0004] The purpose of this invention is to overcome the existing defects and provide a battery voltage detection circuit that ensures the accuracy of the collected voltage.

[0005] The technical solution to achieve the above objectives is:

[0006] A battery voltage detection circuit includes: a 3-to-8 decoder.

[0007] The Y0-Y5 terminals of the output of the 3-8 decoder are all connected to the input of the inverter.

[0008] The output of the inverter is connected to a driver integrated circuit.

[0009] The J1-J6 terminals in the output of the driver integrated circuit are respectively connected to the primary side of two optocoupler relays, for a total of six groups;

[0010] The input terminal of the secondary side of the first optocoupler relay in each group is connected to the positive terminal of a battery, and the output terminal is connected to the non-inverting input terminal of an operational amplifier, a third resistor, and a first capacitor through a first resistor.

[0011] The input terminal of the secondary side of the second optocoupler relay in each group is connected to the negative terminal of a battery, and the output terminal is connected to the negative phase input terminal of the operational amplifier, the fourth resistor, and the second capacitor respectively through the second resistor.

[0012] The output terminal of the operational amplifier, the other end of the fourth resistor, and the second capacitor are all connected to the fifth resistor.

[0013] The other end of the fifth resistor is connected to the third capacitor and the A / D converter, respectively.

[0014] The first capacitor, the third resistor, and the other end of the third capacitor are all grounded;

[0015] The output of the A / D converter is connected to an optocoupler isolator.

[0016] Preferably, the input terminals of the 3-to-8 decoder include terminals A, B, C, E1, E2, and E3. Terminals A, B, and C are respectively connected to the control signals of the microprocessor, terminals E1 and E2 are both grounded, and terminal E3 is connected to an external power supply voltage. The output terminal of the 3-to-8 decoder is also grounded through a fourth capacitor.

[0017] Preferably, the output terminal of the 3 / 8 decoder and the input terminal of the inverter are also connected to the input terminal of the driver integrated circuit; the output terminal of the driver integrated circuit is also grounded.

[0018] Preferably, one end of the operational amplifier is connected to the operating voltage and the fifth capacitor, and the other end of the fifth capacitor is grounded;

[0019] The other end of the operational amplifier is connected to the common ground voltage and the sixth capacitor, and the other end of the sixth capacitor is grounded.

[0020] Preferably, both the A / D converter and the optocoupler are connected to the operating voltage, and the optocoupler is also connected to the power supply voltage.

[0021] The beneficial effects of this utility model are as follows: In this utility model, the optocoupler relay for battery time-sharing operation, the control of the A / D converter, and the data input / output lines all adopt optocoupler isolators, thereby ensuring the independence of voltage acquisition. At the same time, by controlling the optocoupler relay to connect only one battery to the integrated operational amplifier at a time, the common-mode voltage caused by connecting all batteries at the same time is eliminated. The operational amplifier only acquires the differential voltage of each battery, ensuring the accuracy of the acquired voltage. Attached Figure Description

[0022] Figure 1 This is a circuit diagram of a battery voltage detection circuit according to this utility model. Detailed Implementation

[0023] The technical solution of this utility model will now be clearly and completely described in conjunction with the accompanying drawings. In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, a battery voltage detection circuit includes: a 3x8 decoder U1, with Y0-Y5 terminals of the output of the 3x8 decoder U1 connected to the input of an inverter U2; the output of the inverter U2 connected to a driver integrated circuit U3; the J1-J6 terminals of the output of the driver integrated circuit U3 connected to the primary side of two optocoupler relays J, totaling six groups; the input of the secondary side of the first optocoupler relay J in each group is connected to the positive terminal of a battery, and its output is connected to the non-inverting input of an operational amplifier U4, a third resistor R3, and a first capacitor C1 via a first resistor R1. The input terminal of the secondary side of the second optocoupler relay J in each group is connected to the negative terminal of a battery, and the output terminal is connected to the negative phase input terminal of operational amplifier U4, the fourth resistor R4, and the second capacitor C2 through the second resistor R2. The output terminal of operational amplifier U4, the other end of the fourth resistor R4 and the second capacitor C2 are all connected to the fifth resistor R5. The other end of the fifth resistor R5 is connected to the third capacitor C3 and the A / D converter U5. The other ends of the first capacitor C1, the third resistor R3, and the third capacitor C3 are all grounded. The output terminal of A / D converter U5 is connected to optocoupler isolator U6.

[0026] In this embodiment, only one battery is sampled at a time, and all samples are ultimately input to the same operational amplifier U4 for acquisition and then to the A / D converter U5. The circuit for acquiring the voltage of each battery, the control circuit, and the circuit for the total voltage and current all use an optocoupler U6. Since only the voltage of one battery is acquired at a time, the optocoupler U6 and the A / D converter U5 are designed using a high-speed optocoupler relay and a high-speed A / D conversion integrated circuit, respectively. Considering the need to reduce the connection lines between the microprocessor and the battery voltage acquisition circuit, the A / D converter U5 uses a serially controlled A / D conversion integrated circuit, making the circuit practical and reliable.

[0027] In this embodiment, the input terminals of the 3-to-8 decoder U1 include terminals A, B, C, E1, E2, and E3. Terminals A, B, and C are respectively connected to the control signals of the microprocessor, terminals E1 and E2 are both grounded, and terminal E3 is connected to the external power supply voltage VCC. The output terminal of the 3-to-8 decoder U1 is also grounded through a fourth capacitor C4.

[0028] In this embodiment, the output of the 3 / 8 decoder U1 and the input of the inverter U2 are also connected to the input of the driver integrated circuit U3; the output of the driver integrated circuit U3 is also grounded.

[0029] In this embodiment, one end of the operational amplifier U4 is connected to the operating voltage VDD and the fifth capacitor C5, and the other end of the fifth capacitor C5 is grounded; the other end of the operational amplifier U4 is connected to the common ground voltage VSS and the sixth capacitor C6, and the other end of the sixth capacitor C6 is grounded.

[0030] In this embodiment, both the A / D converter U5 and the optocoupler U6 are connected to the operating voltage VDD, and the optocoupler U6 is also connected to the power supply voltage VCC.

[0031] The control signal from the microprocessor is decoded into six unique output signals by the 3 / 8 decoder U1. These signals are then inverted by the inverter U2 and input to the driver integrated circuit U3 to drive twelve optocoupler relays J. Each output of the driver integrated circuit U3 drives two optocoupler relays J. One optocoupler relay J is connected in series to the positive terminal of the battery, and the other is connected in series to the negative terminal. Because of the uniqueness of the output of the 3 / 8 decoder U1, it is ensured that only one set of optocoupler relays J with the same control terminal is connected for each control signal. This ensures that the voltage of only one battery is transmitted to the common operational amplifier U4. By adjusting the three input signals (A, B, and C) of the 3 / 8 decoder U1 in a time-division manner, the voltage of each battery can be acquired in a time-division manner.

[0032] from Figure 1 As can be seen, the voltage of all six batteries was collected using the same operational amplifier U4, which effectively solved the problem of consistency and accuracy of the collected voltage.

[0033] A detection circuit is used to collect the voltages of six batteries. The A / D converter U5 used for acquisition must be high-speed. Considering the need for isolation from the microprocessor circuit, this design uses the high-speed data control and serial A / D conversion integrated circuit TLC2543CN with fewer input and output lines. Utilizing its high-speed conversion characteristics, it ensures that the voltage of each battery is collected once within 300 milliseconds when collecting the voltage of each battery in a time-division multiplexing manner. This visually maintains the effect of simultaneous voltage acquisition. Since the TLC2543CN has fewer data input and output lines for control acquisition, it also meets the challenge of having fewer isolated signal lines in the design.

[0034] The operating voltage VDD, common ground voltage VSS, and ground wire of the battery voltage detection circuit are different from the power supply voltage VCC and ground wire of the microprocessor. The control and data input / output lines of the optocoupler relay J and the A / D converter U5 for battery time-sharing operation all use optocoupler isolators U6, thus ensuring the independence of voltage acquisition. At the same time, by controlling the optocoupler relay J to connect only one battery to the integrated operational amplifier at a time, the common-mode voltage caused by connecting all batteries at the same time is eliminated. The operational amplifier only acquires the differential voltage of each battery, ensuring the accuracy of the acquired voltage.

[0035] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A battery voltage detection circuit, characterized in that, include: 3-8 decoder (U1). The Y0-Y5 terminals of the output of the 3-8 decoder (U1) are all connected to the input of the inverter (U2); The output of the inverter (U2) is connected to the driver integrated circuit (U3). The J1-J6 terminals of the output of the driver integrated circuit (U3) are respectively connected to the primary side of two optocoupler relays (J), for a total of six groups; The input terminal of the secondary side of the first optocoupler relay (J) in each group is connected to the positive terminal of a battery, and the output terminal is connected to the non-inverting input terminal of the operational amplifier (U4), the third resistor (R3), and the first capacitor (C1) through the first resistor (R1). The input terminal of the second optocoupler relay (J) in each group is connected to the negative terminal of a battery, and the output terminal is connected to the negative phase input terminal of the operational amplifier (U4), the fourth resistor (R4), and the second capacitor (C2) through the second resistor (R2). The output terminal of the operational amplifier (U4), the other end of the fourth resistor (R4) and the second capacitor (C2) are all connected to the fifth resistor (R5). The other end of the fifth resistor (R5) is connected to the third capacitor (C3) and the A / D converter (U5). The other ends of the first capacitor (C1), the third resistor (R3), and the third capacitor (C3) are all grounded; The output of the A / D converter (U5) is connected to the optocoupler isolator (U6).

2. The battery voltage detection circuit according to claim 1, characterized in that, The input terminals of the 3-to-8 decoder (U1) include terminals A, B, C, E1, E2, and E3. Terminals A, B, and C are respectively connected to the control signals of the microprocessor, terminals E1 and E2 are both grounded, and terminal E3 is connected to the external power supply voltage (VCC). The output terminal of the 3-to-8 decoder (U1) is also grounded through a fourth capacitor (C4).

3. The battery voltage detection circuit according to claim 1, characterized in that, The output of the 3 / 8 decoder (U1) and the input of the inverter (U2) are also connected to the input of the driver integrated circuit (U3); the output of the driver integrated circuit (U3) is also grounded.

4. The battery voltage detection circuit according to claim 2, characterized in that, One end of the operational amplifier (U4) is connected to the operating voltage (VDD) and the fifth capacitor (C5), and the other end of the fifth capacitor (C5) is grounded. The other end of the operational amplifier (U4) is connected to the common ground voltage (VSS) and the sixth capacitor (C6), and the other end of the sixth capacitor (C6) is grounded.

5. A battery voltage detection circuit according to claim 4, characterized in that, The A / D converter (U5) and the optocoupler (U6) are both connected to the operating voltage (VDD), and the optocoupler (U6) is also connected to the power supply voltage (VCC).

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