Current metering circuit of protection plate

Abstract

The utility model discloses a current metering circuit for a protection board, which comprises a charging and discharging protection circuit, a current acquisition circuit and a controller circuit, and is characterized in that the charging and discharging protection circuit is used for carrying out charging and discharging protection control on a battery; the current acquisition circuit comprises a current sampling resistor R39 and a current signal processing circuit, the current sampling resistor R39 is used for sampling current, and a signal input end of the current signal processing circuit is connected with the current sampling resistor R39 so as to output the sampled current after processing the sampled current; and the controller circuit carries out overcurrent protection control and / or carries out flow statistics output on the current through the charging and discharging protection circuit according to the sampling current. Therefore, a special metering chip is replaced by the independent current signal processing circuit and the controller circuit, so that the implementation of the whole metering function is cheaper, the controller circuit can transmit current metering signals to the outside in a wired or wireless mode, and the application is more flexible.

Description

Technical Field

[0001] The utility model relates to the technical field of battery full charge protection, in particular to a current measurement circuit for a protection board. Background Art

[0002] Lithium (Li)-ion batteries are being used more and more widely as energy storage and power supply batteries. During the use of lithium (Li)-ion batteries, various charge and discharge protections need to be carried out on the lithium batteries to manage the charge and discharge of the lithium batteries and ensure the safety and reliability of the lithium batteries during use.

[0003] The existing charge and discharge measurement of lithium batteries is generally realized through a dedicated chip, and usually the dedicated current measurement chip is integrated in the lithium battery charge and discharge protection module. On the one hand, it causes the high price of the full charge protection module, and on the other hand, it causes inflexible and inconvenient use. Summary of the Utility Model

[0004] The utility model aims to at least solve one of the technical problems in the related technologies to some extent. For this purpose, an object of the utility model is to propose a current measurement circuit for a protection board.

[0005] To achieve the above object, according to an embodiment of the utility model, the current measurement circuit for a protection board includes:

[0006] A charge and discharge protection circuit for controlling the charge and discharge protection of the battery;

[0007] A current acquisition circuit, the current acquisition circuit includes a current sampling resistor R39 and a current signal processing circuit. The current sampling resistor R39 is arranged on the loop of the battery to sample the current, and the signal input end of the current signal processing circuit is connected to the current sampling resistor R39 to output the sampled current after processing;

[0008] A controller circuit, the current detection input end of the controller circuit is connected to the signal output end of the current acquisition circuit, and the controller circuit is also connected to the charge and discharge protection circuit to perform overcurrent protection control through the charge and discharge protection circuit according to the sampled current and / or output the current flow statistics.

[0009] Further, according to an embodiment of the utility model, the current acquisition circuit includes:

[0010] Amplifier A1, the non-inverting input terminal of the amplifier A1 is connected to one end of the current sampling resistor R39 through a resistor R35, the inverting input terminal of the amplifier A1 is connected to the other end of the current sampling resistor R39 through a resistor R37, the inverting input terminal of the amplifier A1 is also connected to one end of a resistor R41, the other end of the resistor R41 is connected to the output terminal of the amplifier A1, and the output terminal of the amplifier A1 is connected to the current detection input terminal of the controller circuit through a resistor R36.

[0011] Further, according to an embodiment of the present invention, the current acquisition circuit further includes:

[0012] Capacitor C21, one end of the capacitor C21 is connected to the inverting input terminal of the amplifier A1, and the other end of the capacitor C21 is connected to the output terminal of the amplifier A1.

[0013] Further, according to an embodiment of the present invention, the current acquisition circuit further includes:

[0014] Transient diode T1, one end of the transient diode T1 is connected to one end of the current sampling resistor R39, and the other end of the transient diode T1 is connected to the reference ground;

[0015] Transient diode T2, one end of the transient diode T2 is connected to the other end of the current sampling resistor R39, and the other end of the transient diode T2 is connected to the reference ground;

[0016] Transient diode T3, one end of the transient diode T3 is connected to the non-inverting input terminal of the amplifier A1, and the other end of the transient diode T3 is connected to the inverting input terminal of the amplifier A1.

[0017] Further, according to an embodiment of the present invention, the charge and discharge protection circuit includes:

[0018] Protection controller U1, the voltage detection terminal of the protection controller U1 is respectively connected to each battery cell to perform charge and discharge voltage detection on each battery cell;

[0019] Charge and discharge switch, the charge and discharge switch is arranged on the charge and discharge loop of the battery;

[0020] Charge drive circuit, the protection controller U1 is connected to the charge control terminal of the charge and discharge switch through the charge drive circuit to perform charge switch drive under the control of the protection controller U1;

[0021] Discharge drive circuit, the protection controller U1 is connected to the discharge control terminal of the charge and discharge switch through the discharge drive circuit to perform discharge switch drive under the control of the protection controller U1.

[0022] Further, according to an embodiment of the present invention, the charging drive circuit includes:

[0023] A triode Q4, the emitter of the triode Q4 is connected to the charging signal output terminal of the protection controller U1 through a resistor R15, and the base of the triode Q4 is connected to the reference ground through a resistor R17;

[0024] A diode D4, the anode of the diode D4 is connected to the collector of the triode Q4, and the cathode of the diode D4 is connected to the charging control terminal of the charge-discharge switch through a resistor R48.

[0025] Further, according to an embodiment of the present invention, the discharging drive circuit includes:

[0026] A diode D2, the anode of the diode D2 is connected to the discharging signal output terminal of the protection controller U1 through a resistor R16, and the cathode of the diode D2 is connected to the discharging control terminal of the charge-discharge switch through a resistor R47;

[0027] A triode Q5, the base of the triode Q5 is connected to the anode of the diode D2, the base of the triode Q5 is also connected to the reference ground through a resistor R21, the collector of the triode Q5 is also connected to the reference ground terminal through a resistor R22, and the emitter of the triode Q5 is connected to the cathode of the diode D2.

[0028] Further, according to an embodiment of the present invention, the charge-discharge protection circuit further includes:

[0029] A current sampling resistor R30, the current sampling resistor R30 is connected in series on the charge-discharge loop of the battery to detect the current of the charge-discharge loop, and the current detection output terminal of the current sampling resistor R30 is connected to the current detection terminal of the protection controller U1;

[0030] A capacitor C6, one end of the capacitor C6 is connected to the current detection terminal of the protection controller U1, and the other end of the capacitor C6 is connected to the reference ground.

[0031] Further, according to an embodiment of the present invention, the charge-discharge protection circuit further includes a battery terminal protection circuit, and the battery terminal protection circuit includes:

[0032] Triode Q6, the collector of the triode Q6 is connected to the negative terminal of the first battery through a resistor R26, the emitter of the triode Q6 is connected to the positive terminal of the first battery, the base of the triode Q6 is connected to the first detection terminal of the protection controller U1 through a resistor R24, and the emitter of the triode Q6 is also connected to the first detection terminal of the protection controller U1 through a resistor R20;

[0033] Triode Q3, the collector of the triode Q3 is connected to the negative terminal of the second battery through a resistor R19, the emitter of the triode Q3 is connected to the positive terminal of the second battery, the base of the triode Q3 is connected to the second detection terminal of the protection controller U1 through a resistor R18, and the emitter of the triode Q3 is also connected to the second detection terminal of the protection controller U1 through a resistor R14;

[0034] Triode Q2, the collector of the triode Q2 is connected to the negative terminal of the third battery through a resistor R13, the emitter of the triode Q2 is connected to the positive terminal of the third battery, the base of the triode Q2 is connected to the third detection terminal of the protection controller U1 through a resistor R10, and the emitter of the triode Q2 is also connected to the third detection terminal of the protection controller U1 through a resistor R7;

[0035] Triode Q1, the collector of the triode Q1 is connected to the negative terminal of the fourth battery through a resistor R6, the emitter of the triode Q1 is connected to the positive terminal of the fourth battery, the base of the triode Q1 is connected to the fourth detection terminal of the protection controller U1 through a resistor R3, and the emitter of the triode Q1 is also connected to the fourth detection terminal of the protection controller U1 through a resistor R2.

[0036] Furthermore, according to an embodiment of the present invention, the charge and discharge protection circuit further includes an interface terminal protection circuit, and the interface terminal protection circuit includes:

[0037] Zener diode D3, the cathode of the Zener diode D3 is connected to the positive terminal of the charge and discharge interface, and the anode of the Zener diode D3 is connected to the negative terminal of the charge and discharge interface;

[0038] Capacitor C8, one end of the capacitor C8 is connected to the positive terminal of the charge and discharge interface;

[0039] Capacitor C10, one end of the capacitor C10 is connected to the other end of the capacitor C8, and the other end of the capacitor C10 is connected to the negative terminal of the charge and discharge interface.

[0040] The current measurement circuit of the protection board provided by the embodiment of the present utility model uses a charge and discharge protection circuit to control the charge and discharge protection of the battery; a current sampling resistor R39 and a current signal processing circuit. The current sampling resistor R39 is arranged on the loop of the battery to sample the current. The signal input end of the current signal processing circuit is connected to the current sampling resistor R39 to process the sampled current and then output it. The current detection input end of the controller circuit is connected to the signal output end of the current acquisition circuit, and the controller circuit is also connected to the charge and discharge protection circuit to perform overcurrent protection control through the charge and discharge protection circuit according to the sampled current and / or output the current flow statistics. In this way, by replacing the dedicated metering chip with a separate current signal processing circuit and a controller circuit, the realization of the overall metering function is cheaper, and the controller circuit can select wired or wireless methods to transmit the current measurement signal externally, making the application more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a schematic structural diagram of the charge and discharge protection circuit provided by the present utility model;

[0042] Figure 2 is a schematic structural diagram of the current acquisition circuit provided by the present utility model;

[0043] Figure 3 is a schematic structural diagram of the controller circuit provided by the present utility model.

[0044] The realization, functional characteristics and advantages of the object of the present utility model will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] In order to enable those skilled in the art of this technology to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present utility model belongs. The terms used in the specification of the present utility model herein are only for the purpose of describing specific embodiments and are not intended to limit the present utility model.

[0046] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present utility model. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0047] Refer to Figures 1 to 3, an embodiment of the present utility model provides a protection board current measurement circuit, including: a charge and discharge protection circuit, a current acquisition circuit, and a controller circuit. The charge and discharge protection circuit is used to control the charge and discharge protection of the battery, so as to avoid overcharging or over-discharging of the lithium battery and ensure the service life of the lithium battery.

[0048] The current acquisition circuit includes a current sampling resistor R39 and a current signal processing circuit. The current sampling resistor R39 is arranged on the loop of the battery to sample the current. The signal input end of the current signal processing circuit is connected to the current sampling resistor R39 to process the sampled current and then output it. The current detection input end of the controller circuit is connected to the signal output end of the current acquisition circuit. The controller circuit is also connected to the charge and discharge protection circuit to perform overcurrent protection control through the charge and discharge protection circuit according to the sampled current and / or output the current for flow statistics.

[0049] Specifically, the current sampling resistor R39 is arranged on the charge and discharge loop of the battery. The current sampling resistor R39 is connected to the current signal processing circuit to output the current signal to the current signal processing circuit. After being processed by the current signal processing circuit, the current sampling value is output to the controller circuit. The controller circuit is also used to perform overcurrent protection control according to the current signal and / or output the current for flow statistics. Through the current sampling resistor R39, the current value of the charge and discharge loop can be obtained in real time. The controller circuit calculates the current flow according to the current value of the charge and discharge loop and outputs the current flow in a wired or wireless manner to display the battery current flow through a display device. Since directly sampling the signal through the current sampling resistor R39 may contain interference signals or cannot meet the voltage sampling requirements of the controller circuit, the current signal processing circuit can filter and perform signal operations on the current sampling signal of the current sampling resistor R39 and then output it to the controller circuit. Among them, as Figure 3 shown in the figure, the controller circuit may include a single-chip microcomputer controller U2. The single-chip microcomputer controller U2 is connected to the signal output end of the current signal processing circuit through the I_BAT signal terminal. In this way, the single-chip microcomputer controller U2 can obtain the current flow of the charge and discharge loop through the I_BAT signal terminal. In this way, by using a separate current signal processing circuit and controller circuit to replace the dedicated metering chip, the realization of the overall metering function is cheaper, and the controller circuit can select a wired or wireless method to externally transmit the current metering signal, making the application more flexible.

[0050] Refer to Figure 2, the current acquisition circuit includes: an amplifier A1. The non-inverting input terminal of the amplifier A1 is connected to one end of the current sampling resistor R39 through a resistor R35. The inverting input terminal of the amplifier A1 is connected to the other end of the current sampling resistor R39 through a resistor R37. The inverting input terminal of the amplifier A1 is also connected to one end of a resistor R41, and the other end of the resistor R41 is connected to the output terminal of the amplifier A1. The output terminal of the amplifier A1 is connected to the current detection input terminal of the controller circuit through a resistor R36.

[0051] Specifically, the amplifier A1 forms a differential amplifier circuit, which can perform differential operation and signal isolation on the acquisition signals at both ends of the current sampling resistor R39 and then output them to the signal acquisition terminal of the controller circuit. In this way, the voltage sampling requirements of the controller circuit can be met.

[0052] Refer to Figure 2 , the current acquisition circuit further includes: a capacitor C21. One end of the capacitor C21 is connected to the inverting input terminal of the amplifier A1, and the other end of the capacitor C21 is connected to the output terminal of the amplifier A1. An active low-pass filter circuit can be formed between the capacitor C21 and the amplifier A1, which can filter out high-frequency interference signals and reduce the influence of interference signals on the current signal, thereby ensuring the stability and reliability of the output signal of the amplifier A1.

[0053] Refer to Figure 2 , the current acquisition circuit further includes: transient diodes T1, T2, and T3. One end of the transient diode T1 is connected to one end of the current sampling resistor R39, and the other end of the transient diode T1 is connected to the reference ground; one end of the transient diode T2 is connected to the other end of the current sampling resistor R39, and the other end of the transient diode T2 is connected to the reference ground; one end of the transient diode T3 is connected to the non-inverting input terminal of the amplifier A1, and the other end of the transient diode T3 is connected to the inverting input terminal of the amplifier A1.

[0054] Specifically, the transient diodes T2 and T3 can filter out the pulse signals at both ends of the current sampling resistor R39. At the same time, the transient diode T1 can filter out the pulse signals at both input terminals of the amplifier A1, thereby ensuring the stability of the signals input to both ends of the amplifier A1. In addition, it can avoid damage to the amplifier A1 caused by strong signals and protect the amplifier A1.

[0055] Refer to Figure 1, the charge and discharge protection circuit includes: a protection controller U1, a charge and discharge switch, a charge drive circuit, and a discharge drive circuit. The voltage detection terminals of the protection controller U1 are respectively connected to each battery cell to detect the charge and discharge voltages of each battery cell; as Figure 1 shown in

[0056] the voltage detection terminals (VC0~VC4) of the protection controller U1 are respectively connected to four lithium battery cells to detect the charge and discharge voltages of each battery cell.

[0057] The charge and discharge switch is arranged on the charge and discharge loop of the battery; the charge and discharge switch includes a charge switch and a discharge switch. The charge switch may include multiple parallel MOS transistors (Q8 and Q10), and the discharge switch may include multiple parallel MOS transistors (Q9 and Q11). Figure 1 The protection controller U1 is connected to the charge control terminal of the charge and discharge switch through the charge drive circuit to drive the charge switch under the control of the protection controller U1; as

[0058] shown in

[0059] the charge drive circuit includes: a triode Q4 and a diode D4. The emitter of the triode Q4 is connected to the charge signal output terminal of the protection controller U1 through a resistor R15, and the base of the triode Q4 is connected to the reference ground through a resistor R17; the anode of the diode D4 is connected to the collector of the triode Q4, and the cathode of the diode D4 is connected to the charge control terminal of the charge and discharge switch through a resistor R48. Figure 1As shown in the figure, the discharge drive circuit includes: a diode D2 and a triode Q5. The anode of the diode D2 is connected to the discharge signal output terminal of the protection controller U1 through a resistor R16, and the cathode of the diode D2 is connected to the discharge control terminal of the charge and discharge switch through a resistor R47. The base of the triode Q5 is connected to the anode of the diode D2, the base of the triode Q5 is also connected to the reference ground through a resistor R21, the collector of the triode Q5 is also connected to the reference ground terminal through a resistor R22, and the emitter of the triode Q5 is connected to the cathode of the diode D2.

[0060] Specifically, the working process of this discharge drive circuit is as follows. When the protection controller U1 needs to conduct the discharge loop, it can output a high-level signal through the DO terminal. This high-level signal acts on the gates of the discharge switches (MOS transistors Q9 and Q11) through the diode D2, thereby enabling the discharge switches to conduct. On the contrary, when the protection controller U1 outputs a low-level signal through the DO terminal, the gates of the discharge switches (MOS transistors Q9 and Q11) can be quickly discharged through the triode Q5, thereby causing the discharge switches (MOS transistors Q9 and Q11) to be cut off, thus disconnecting the discharge loop and further protecting the lithium battery from discharging.

[0061] Refer to Figure 1 The charge and discharge protection circuit further includes: a current sampling resistor R30 and a capacitor C6. The current sampling resistor R30 is connected in series on the charge and discharge loop of the battery to detect the current in the charge and discharge loop. The current detection output terminal of the current sampling resistor R30 is connected to the current detection terminal of the protection controller U1. One end of the capacitor C6 is connected to the current detection terminal of the protection controller U1, and the other end of the capacitor C6 is connected to the reference ground.

[0062] The current sampling resistor R30 is arranged on the charge and discharge loop of the battery. The current sampling resistor R30 is connected to the charge and discharge protection circuit to output a current signal to the charge and discharge protection circuit. The charge and discharge protection circuit is also used to perform overcurrent protection control according to the current signal. The current value of the charge and discharge loop can be obtained in real time through the current sampling resistor R30, and the charge and discharge protection circuit performs overcurrent protection when the real-time current value exceeds the set value.

[0063] Refer to Figure 1, the charge and discharge protection circuit further includes a battery terminal protection circuit, and the battery terminal protection circuit includes: triode Q6, triode Q3, triode Q2, and triode Q1. The collector of triode Q6 is connected to the negative terminal of the first battery through resistor R26, the emitter of triode Q6 is connected to the positive terminal of the first battery, the base of triode Q6 is connected to the first detection terminal of the protection controller U1 through resistor R24, and the emitter of triode Q6 is also connected to the first detection terminal of the protection controller U1 through resistor R20; The collector of triode Q3 is connected to the negative terminal of the second battery through resistor R19, the emitter of triode Q3 is connected to the positive terminal of the second battery, the base of triode Q3 is connected to the second detection terminal of the protection controller U1 through resistor R18, and the emitter of triode Q3 is also connected to the second detection terminal of the protection controller U1 through resistor R14; The collector of triode Q2 is connected to the negative terminal of the third battery through resistor R13, the emitter of triode Q2 is connected to the positive terminal of the third battery, the base of triode Q2 is connected to the third detection terminal of the protection controller U1 through resistor R10, and the emitter of triode Q2 is also connected to the third detection terminal of the protection controller U1 through resistor R7; The collector of triode Q1 is connected to the negative terminal of the fourth battery through resistor R6, the emitter of triode Q1 is connected to the positive terminal of the fourth battery, the base of triode Q1 is connected to the fourth detection terminal of the protection controller U1 through resistor R3, and the emitter of triode Q1 is also connected to the fourth detection terminal of the protection controller U1 through resistor R2.

[0064] Specifically, by providing a protection circuit at the signal acquisition terminal of each battery and the protection controller U1, the protection controller U1 can be protected to avoid damage to the protection controller U1 by strong current signals. Here, the working process is described by taking the protection circuit of the first lithium battery as an example. When a large current is generated in the first lithium battery, the voltage across resistor R20 can be increased, causing triode Q6 to conduct, and then releasing the current to prevent strong current from entering the signal detection terminal of the protection controller U1, thereby protecting the protection controller U1. The working principles of the protection circuits of the other lithium batteries are the same as that of the protection circuit of the first lithium battery and will not be repeated here.

[0065] Refer to Figure 1, the charge and discharge protection circuit further includes an interface terminal protection circuit, and the interface terminal protection circuit includes: a voltage stabilizing diode D3, a capacitor C8, and a capacitor C10. The cathode of the voltage stabilizing diode D3 is connected to the positive terminal of the charge and discharge interface, and the anode of the voltage stabilizing diode D3 is connected to the negative terminal of the charge and discharge interface; one end of the capacitor C8 is connected to the positive terminal of the charge and discharge interface; one end of the capacitor C10 is connected to the other end of the capacitor C8, and the other end of the capacitor C10 is connected to the negative terminal of the charge and discharge interface. The voltage stabilizing diode D3, the capacitor C8, and the capacitor C10 can form a filtering circuit, which can filter out or stabilize high-frequency and high-voltage pulse signals to protect the subsequent circuit.

[0066] The above are only the embodiments of the present invention, but do not limit the patent scope of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing specific embodiments, or perform equivalent replacements for some of the technical features. Any equivalent structure directly or indirectly using the content of the specification and drawings of the present invention in other related technical fields is equally within the scope of the patent protection of the present invention.

[0067] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0068] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, replacements, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention, and all are within the protection scope of the present invention.

Claims

1. A protection board current measurement circuit, characterized in that: include: A charge and discharge protection circuit, which is used to perform charge and discharge protection control on the battery; A current acquisition circuit, the current acquisition circuit comprising a current sampling resistor R39 and a current signal processing circuit, the current sampling resistor R39 is arranged on the loop of the battery to sample the current, the signal input end of the current signal processing circuit is connected to the current sampling resistor R39, and the sampled current is processed and then output; A controller circuit, wherein the current detection input end of the controller circuit is connected to the signal output end of the current acquisition circuit, and the controller circuit is also connected to the charge and discharge protection circuit to perform overcurrent protection control through the charge and discharge protection circuit according to the sampled current and / or output the current in flow statistics.

2. The protection board current measurement circuit according to claim 1, characterized in that: The current acquisition circuit comprises: Amplifier A1, the non-inverting input terminal of the amplifier A1 is connected to one end of the current sampling resistor R39 through a resistor R35, the inverting input terminal of the amplifier A1 is connected to the other end of the current sampling resistor R39 through a resistor R37, the inverting input terminal of the amplifier A1 is also connected to one end of a resistor R41, the other end of the resistor R41 is connected to the output terminal of the amplifier A1, and the output terminal of the amplifier A1 is connected to the current detection input terminal of the controller circuit through a resistor R36.

3. The protection board current measurement circuit according to claim 2, characterized in that: The current collection circuit also includes: Capacitor C21, one end of the capacitor C21 is connected to the inverting input end of the amplifier A1, and the other end of the capacitor C21 is connected to the output end of the amplifier A1.

4. The protection board current measurement circuit according to claim 3, characterized in that: The current collection circuit also includes: A transient diode T1, one end of the transient diode T1 is connected to one end of the current sampling resistor R39, and the other end of the transient diode T1 is connected to a reference ground; A transient diode T2, one end of which is connected to the other end of the current sampling resistor R39, and the other end of which is connected to a reference ground; A transient diode T3, one end of which is connected to the non-inverting input end of the amplifier A1, and the other end of which is connected to the inverting input end of the amplifier A1.

5. The protection board current measurement circuit according to any one of claims 1 to 4, characterized in that: The charge and discharge protection circuit comprises: A protection controller U1, wherein a voltage detection terminal of the protection controller U1 is connected to each battery cell to detect the charge and discharge voltage of each battery cell; A charge and discharge switch, wherein the charge and discharge switch is arranged on a charge and discharge circuit of the battery; A charging drive circuit, wherein the protection controller U1 is connected to the charging control terminal of the charging and discharging switch through the charging drive circuit, so as to drive the charging switch under the control of the protection controller U1; Discharge drive circuit: the protection controller U1 is connected to the discharge control terminal of the charge and discharge switch through the discharge drive circuit, so as to drive the discharge switch under the control of the protection controller U1.

6. The protection board current measurement circuit according to claim 5, characterized in that: The charging drive circuit comprises: A transistor Q4, wherein the emitter of the transistor Q4 is connected to the charging signal output terminal of the protection controller U1 through a resistor R15, and the base of the transistor Q4 is connected to the reference ground through a resistor R17; The diode D4 has an anode connected to the collector of the transistor Q4, and a cathode connected to the charging control terminal of the charging and discharging switch through a resistor R48.

7. The protection board current measurement circuit according to claim 5, characterized in that: The discharge driving circuit comprises: A diode D2, wherein the anode of the diode D2 is connected to the discharge signal output terminal of the protection controller U1 through a resistor R16, and the cathode of the diode D2 is connected to the discharge control terminal of the charge and discharge switch through a resistor R47; Transistor Q5, the base of the transistor Q5 is connected to the anode of the diode D2, the base of the transistor Q5 is also connected to the reference ground through a resistor R21, the collector of the transistor Q5 is also connected to the reference ground through a resistor R22, and the emitter of the transistor Q5 is connected to the cathode of the diode D2.

8. The protection board current measurement circuit according to claim 7, characterized in that: The charge and discharge protection circuit also includes: A current sampling resistor R30, wherein the current sampling resistor R30 is connected in series to the charge and discharge circuit of the battery to detect the current of the charge and discharge circuit, and a current detection output end of the current sampling resistor R30 is connected to a current detection end of the protection controller U1; Capacitor C6, one end of the capacitor C6 is connected to the current detection end of the protection controller U1, and the other end of the capacitor C6 is connected to the reference ground.

9. The protection board current measurement circuit according to claim 5, characterized in that: The charge and discharge protection circuit also includes a battery terminal protection circuit, and the battery terminal protection circuit includes: A transistor Q6, wherein the collector of the transistor Q6 is connected to the negative terminal of the first battery through a resistor R26, the emitter of the transistor Q6 is connected to the positive terminal of the first battery, the base of the transistor Q6 is connected to the first detection terminal of the protection controller U1 through a resistor R24, and the emitter of the transistor Q6 is also connected to the first detection terminal of the protection controller U1 through a resistor R20; A transistor Q3, wherein the collector of the transistor Q3 is connected to the negative end of the second battery through a resistor R19, the emitter of the transistor Q3 is connected to the positive end of the second battery, the base of the transistor Q3 is connected to the second detection end of the protection controller U1 through a resistor R18, and the emitter of the transistor Q3 is also connected to the second detection end of the protection controller U1 through a resistor R14; Transistor Q2, the collector of the transistor Q2 is connected to the negative end of the third battery through a resistor R13, the emitter of the transistor Q2 is connected to the positive end of the third battery, the base of the transistor Q2 is connected to the third detection end of the protection controller U1 through a resistor R10, and the emitter of the transistor Q2 is also connected to the third detection end of the protection controller U1 through a resistor R7; Transistor Q1, the collector of the transistor Q1 is connected to the negative end of the fourth battery through a resistor R6, the emitter of the transistor Q1 is connected to the positive end of the fourth battery, the base of the transistor Q1 is connected to the fourth detection end of the protection controller U1 through a resistor R3, and the emitter of the transistor Q1 is also connected to the fourth detection end of the protection controller U1 through a resistor R2.

10. The protection board current measurement circuit according to claim 5, characterized in that: The charge and discharge protection circuit further includes an interface end protection circuit, and the interface end protection circuit includes: A voltage stabilizing diode D3, wherein the cathode of the voltage stabilizing diode D3 is connected to the positive end of the charge and discharge interface, and the anode of the voltage stabilizing diode D3 is connected to the negative end of the charge and discharge interface; Capacitor C8, one end of the capacitor C8 is connected to the positive end of the charge and discharge interface; Capacitor C10, one end of the capacitor C10 is connected to the other end of the capacitor C8, and the other end of the capacitor C10 is connected to the negative end of the charge and discharge interface.

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