Low-power-consumption battery pack power supply control circuit

Abstract

The utility model discloses a low-power-consumption battery pack power supply control circuit which comprises a load power supply control circuit, a controller and a battery voltage detection circuit and is arranged on a power supply loop of a battery pack through the load power supply control circuit. One control end of the controller is connected with the load power supply control circuit; the battery voltage detection circuit is connected with the voltage detection end of the controller so as to detect the output voltage of the battery pack under the control of the controller, and when it is detected that the voltage of the battery pack is smaller than a set voltage value, the load power supply control circuit conducts disconnection control over a power supply loop of the battery pack. Therefore, discharge control of the lithium battery pack can be realized, and the problem of over-discharge of the lithium battery pack is avoided. And the battery voltage detection circuit detects the voltage of the lithium battery pack at the controller of the controller without real-time detection, so that the power consumption of the circuit can be greatly reduced, and low power consumption is realized.

Description

Technical Field

[0001] This utility model relates to the field of battery circuit technology, and in particular to a low-power battery pack power supply control circuit. Background Technology

[0002] Due to the rechargeable and dischargeable properties of lithium batteries, lithium battery packs are widely used in the power supply of electronic devices. However, during the power supply process, lithium battery packs are prone to over-discharge, which can damage their lifespan.

[0003] In addition, to manage over-discharge of lithium battery packs, the battery pack voltage can be monitored in real time for control. This monitoring can be achieved using a time-sharing method with a resistor voltage divider; however, this method typically suffers from significant energy loss due to the long-term operation of the voltage divider resistors. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art. Therefore, one objective of the present invention is to provide a low-power battery pack power supply control circuit.

[0005] To achieve the above objectives, a low-power battery pack power supply control circuit according to an embodiment of the present invention includes:

[0006] A load power supply control circuit is provided on the power supply circuit of the battery pack;

[0007] The controller, one of its control terminals is connected to the load power supply control circuit;

[0008] A battery voltage detection circuit is connected to the voltage detection terminal of the controller to detect the output voltage of the battery pack under the control of the controller. When the voltage of the battery pack is detected to be less than a set voltage value, the power supply circuit of the battery pack is disconnected through the load power supply control circuit.

[0009] Furthermore, according to one embodiment of the present invention, the battery voltage detection circuit includes:

[0010] The first transistor Q3 has its collector connected to one end of the first resistor R6, the other end of the first resistor R6 connected to the positive power output terminal of the battery pack through the second resistor R2, the emitter of the first transistor Q3 connected to the negative source output terminal of the battery pack, and the base of the first transistor Q3 connected to a control terminal of the controller through the third resistor R11.

[0011] The first MOSFET Q2 has its gate connected to the common terminal of the second resistor R2 and the first resistor R6. The source of the first MOSFET Q2 is connected to the positive power output terminal of the battery pack. The drain of the first MOSFET Q2 is connected to one end of the third resistor R5. The other end of the third resistor R5 is connected to the negative power output terminal of the battery pack through the fourth resistor R12. The common terminal of the third resistor R5 and the fourth resistor R12 is connected to the voltage detection terminal of the controller through the fifth resistor R9.

[0012] Furthermore, according to one embodiment of the present invention, the load power supply control circuit includes:

[0013] The second MOSFET Q1 has its source connected to the positive power output terminal of the battery pack, its drain connected to the load, and its source connected to the gate through a sixth resistor R1.

[0014] The collector of the second transistor Q4 is connected to the gate of the second MOSFET Q1 through the seventh resistor R7, the emitter of the second transistor Q4 is connected to the negative source output terminal of the battery pack, and the base of the second transistor Q4 is connected to a control terminal of the controller through the sixth resistor R10.

[0015] Furthermore, according to one embodiment of the present invention, the low-power battery pack power supply control circuit further includes a protection circuit, the protection circuit comprising:

[0016] Fuse F1 is installed in the power supply circuit of the battery pack to provide overcurrent protection for the power supply circuit.

[0017] A transient diode TVS1 is provided, with its cathode connected to the positive power output terminal of the battery pack and its cathode connected to the negative terminal of the battery pack, to provide transient high voltage protection for the battery pack output terminal.

[0018] Furthermore, according to one embodiment of the present invention, the low-power battery pack power supply control circuit further includes:

[0019] The protection circuit is connected to the battery pack through the battery pack interface to draw out the power supply of the battery pack.

[0020] Furthermore, according to one embodiment of the present invention, the low-power battery pack power supply control circuit further includes:

[0021] A controller power supply control circuit is connected to the power output terminal of the battery pack to control the power output of the battery pack.

[0022] A DC-DC voltage conversion circuit is connected to the power output terminal of the controller power supply control circuit to convert the output power supply voltage and then power the controller.

[0023] Furthermore, according to one embodiment of the present invention, the controller power supply control circuit includes:

[0024] The third MOSFET Q5 has its source connected to the positive power output terminal of the battery pack, its drain connected to the input terminal of the DC voltage conversion circuit through the eighth resistor R14, its gate connected to the source of the third MOSFET Q5 through the ninth resistor R15, and its gate also connected to the anode of the first diode D1 through the tenth resistor R18.

[0025] Switch SW1, one end of which is connected to the cathode of the first diode D1, and the other end of which is connected to the negative terminal of the battery pack.

[0026] Furthermore, according to one embodiment of the present invention, the controller power supply control circuit further includes:

[0027] The collector of the third transistor Q6 is connected to the gate of the third MOS transistor Q5 through the sixth resistor R17, the emitter of the third transistor Q6 is connected to the reference ground, and the base of the third transistor Q6 is connected to a control terminal of the controller through the eleventh resistor R19.

[0028] Furthermore, according to one embodiment of the present invention, the controller power supply control circuit further includes:

[0029] The second diode D2 has its cathode connected to one end of the switch SW1 and its anode connected to the detection terminal of the controller to detect the state of the switch SW1.

[0030] Furthermore, according to one embodiment of the present invention, the DC voltage conversion circuit includes:

[0031] A linear regulator U1 is connected to the power output terminal of the power supply control circuit of the controller, and the output terminal of the linear regulator U1 is connected to the power supply terminal of the controller.

[0032] The first capacitor C6 has one end connected to the power input terminal of the linear regulator U1, and the other end connected to the negative terminal of the battery pack.

[0033] The second capacitor C8 has one end connected to the power output terminal of the linear regulator U1, and the other end of the first capacitor C6 is connected to the negative terminal of the battery pack.

[0034] Zener diode ZD5, the cathode of which is connected to the power output terminal of the linear regulator U1, and the anode of which is connected to the negative terminal of the battery pack.

[0035] The low-power battery pack power supply control circuit provided in this embodiment of the invention is configured on the power supply circuit of the battery pack via a load power supply control circuit. A control terminal of the controller is connected to the load power supply control circuit. A battery voltage detection circuit is connected to the voltage detection terminal of the controller to detect the output voltage of the battery pack under the control of the controller. When the battery pack voltage is detected to be lower than a set voltage value, the load power supply control circuit disconnects the power supply circuit of the battery pack. This enables discharge control of the lithium battery pack, preventing over-discharge problems. Furthermore, since the battery voltage detection circuit detects the lithium battery pack voltage at the controller's control terminal, it does not require real-time detection, significantly reducing circuit power consumption and achieving low power consumption. Attached Figure Description

[0036] Figure 1 Structural block diagram of the low-power battery pack power supply control circuit provided by this utility model;

[0037] Figure 2 A schematic diagram of the battery interface, protection circuit, battery voltage detection circuit, load power supply control circuit, temperature detection circuit and load circuit provided by this utility model;

[0038] Figure 3 A schematic diagram of the power supply control circuit, DC voltage conversion circuit, and controller circuit structure provided for this utility model.

[0039] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present invention.

[0041] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0042] See Figures 1 to 3 This utility model provides a low-power battery pack power supply control circuit, including: a load power supply control circuit, a controller, and a battery voltage detection circuit. The load power supply control circuit is disposed on the power supply circuit of the battery pack. A control terminal of the controller is connected to the load power supply control circuit. The battery voltage detection circuit is connected to the voltage detection terminal of the controller to detect the output voltage of the battery pack under the control of the controller. When the voltage of the battery pack is detected to be less than a set voltage value, the load power supply control circuit disconnects the power supply circuit of the battery pack.

[0043] Specifically, such as Figure 1 As shown, the low-power battery pack power supply control circuit uses a controller to control the output power of the battery pack, thereby controlling the discharge of the battery pack and ensuring its lifespan. Since the battery voltage detection circuit is connected to the power output terminal of the battery pack, it can detect the output voltage of the battery pack and output the detected voltage to the controller. The controller can then obtain the input voltage value of the battery pack and determine whether the voltage value is lower than a preset voltage value. If it is lower than the preset voltage value, the battery pack may have an over-discharge problem. In this case, the controller needs to control the battery pack to stop power output and output a control signal to the load power supply control circuit, which is located on the power supply circuit of the battery pack. This allows the controller to control the conduction or disconnection of the power output circuit of the battery pack. That is, when the battery pack voltage has not dropped to the minimum voltage value, the load power supply control circuit, under the control of the controller, ensures that the battery pack outputs power normally to supply the load; otherwise, it disconnects the power output circuit of the battery pack. This ensures that the battery pack is not over-discharged, thus guaranteeing its lifespan. Furthermore, the battery voltage detection circuit performs voltage detection of the lithium battery pack within the controller, eliminating the need for real-time detection and significantly reducing circuit power consumption, thus achieving low power consumption.

[0044] See Figure 2The battery voltage detection circuit includes: a first transistor Q3 and a first MOSFET Q2. The collector of the transistor is connected to one end of a first resistor R6, and the other end of the first resistor R6 is connected to the positive power output terminal of the battery pack through a second resistor R2. The emitter of the first transistor Q3 is connected to the negative source output terminal of the battery pack, and the base of the first transistor Q3 is connected to a control terminal of the controller through a third resistor R11. The gate of the first MOSFET Q2 is connected to the common terminal of the second resistor R2 and the first resistor R6. The source of the first MOSFET Q2 is connected to the positive power output terminal of the battery pack. The drain of the first MOSFET Q2 is connected to one end of a third resistor R5, and the other end of the third resistor R5 is connected to the negative source output terminal of the battery pack through a fourth resistor R12. The common terminal of the third resistor R5 and the fourth resistor R12 is connected to the voltage detection terminal of the controller through a fifth resistor R9.

[0045] The battery voltage detection circuit operates as follows: When the controller needs to detect the output voltage of the battery pack, it outputs a high-level signal to the base of the first transistor Q3 via the BAT_EN signal terminal. This turns on the first transistor Q3 and pulls down the gate of the first MOSFET Q2 to a low-level signal. This low-level signal turns on the first MOSFET Q2 as well, allowing the third resistor R5 to be connected to the positive output terminal of the battery pack. A voltage divider circuit is formed between the third resistor R5 and the fourth resistor R12, dividing the output power voltage of the battery pack and outputting it to the controller's battery voltage detection terminal via the fifth resistor R9 and the BAT_V Detect signal terminal. In this way, the controller can detect the battery pack voltage value and determine whether to disconnect the battery pack's power supply circuit based on the voltage value. Conversely, when it is not necessary to collect the battery pack voltage value, a low-level signal or a high-impedance signal can be output via the BAT_EN signal terminal. In this case, the first transistor Q3 is turned off, which in turn turns off the first MOSFET Q2, and the third resistor R5 is not connected to the positive output terminal of the battery pack. The voltage divider circuit formed by the third resistor R5 and the fourth resistor R12 consumes some power. To reduce power consumption, the first MOSFET Q2 is used to control whether the battery pack voltage needs to be sampled. For example, when the controller does not need to monitor the battery pack voltage in real time, the voltage divider circuit formed by the third resistor R5 and the fourth resistor R12 can be turned off by the first MOSFET Q2. When the battery pack has sufficient power, its voltage will not drop to the minimum voltage value quickly. Therefore, it is not necessary to monitor the battery pack output voltage in real time. Instead, the battery pack voltage needs to be monitored intermittently. In this way, the first MOSFET Q2 is turned on only when the voltage value is detected, and turned off after the detection is complete. Since the controller's voltage sampling time is very short, the on / off time ratio D of the first MOSFET Q2 is very small. This results in very little power consumption by the voltage divider circuit formed by the third resistor R5 and the fourth resistor R12, greatly reducing power consumption and ensuring the circuit operates in a low-power state.

[0046] See Figure 2 The load power supply control circuit includes: a second MOSFET Q1 and a second transistor Q4. The source of the second MOSFET Q1 is connected to the positive power output terminal of the battery pack, the drain of the second MOSFET Q1 is connected to the load, and the source of the second MOSFET Q1 is also connected to the gate through a sixth resistor R1. The collector of the second transistor Q4 is connected to the gate of the second MOSFET Q1 through a seventh resistor R7, the emitter of the second transistor Q4 is connected to the negative source output terminal of the battery pack, and the base of the second transistor Q4 is connected to a control terminal of the controller through a sixth resistor R10.

[0047] Specifically, such as Figure 2 As shown, since the second MOSFET Q1 is located in the power output circuit of the battery pack, the output power of the battery pack can be controlled by turning the second MOSFET Q1 on or off. The circuit operates as follows: During normal discharge, the controller outputs a high-level signal to the base of the second transistor Q4 via the BAT_OUT signal terminal. This high-level signal turns on the second transistor Q4 and lowers the gate of the second MOSFET Q1 to a low-level signal, which in turn turns on the second MOSFET Q1, thus supplying power to the load. When the controller detects that the battery pack's output voltage is lower than a set value or an abnormal state such as over-temperature, it outputs a low-voltage signal or a high-impedance signal to the base of the second MOSFET Q1. This turns off both the second transistor Q4 and the second MOSFET Q1, disconnecting the power supply circuit of the battery pack, providing over-discharge protection, and ensuring the battery pack's lifespan.

[0048] See Figure 1 and Figure 2 The low-power battery pack power supply control circuit also includes a protection circuit, which comprises a fuse F1 and a transient diode TVS1. The fuse F1 is installed in the power supply circuit of the battery pack to provide overcurrent protection for the power supply circuit. When the current in the power supply circuit exceeds the maximum current through which the fuse F1 passes, the fuse F1 will melt, thereby disconnecting the power supply circuit of the battery pack and achieving overcurrent protection control.

[0049] The cathode of the transient voltage regulator (TVS1) is connected to the positive power output terminal of the battery pack, and the TVS1 is also connected to the negative terminal of the battery pack to provide transient high-voltage protection for the battery pack output terminal. During the connection of the battery pack, high-voltage pulse signals may be generated by static electricity. To prevent damage to the downstream circuitry from these high-voltage pulse signals, the TVS1 absorbs the high-voltage pulse signals, thereby protecting the downstream circuitry.

[0050] See Figure 1 and Figure 2 The low-power battery pack power supply control circuit further includes a battery pack interface. The protection circuit is connected to the battery pack through the battery pack interface to draw out the power supply from the battery pack. The battery pack interface facilitates the connection and removal of the battery pack, making it convenient for users to replace it.

[0051] See Figure 1 and Figure 3The low-power battery pack power supply control circuit further includes: a controller power supply control circuit and a DC-DC voltage conversion circuit. The controller power supply control circuit is connected to the power output terminal of the battery pack to control the power output of the battery pack. The DC-DC voltage conversion circuit is connected to the power output terminal of the controller power supply control circuit to convert the output power to power the controller.

[0052] Since the output power of the battery pack may not meet the power supply requirements of the controller, the DC-DC voltage conversion circuit converts the output power of the battery pack to the voltage required by the controller, thereby powering the controller. To reduce the power consumption of the DC-DC voltage conversion circuit and the controller when not in use, the controller power supply control circuit can control the on / off state of the input power to the DC-DC voltage conversion circuit. When the controller does not need to operate, the power output to the DC-DC voltage conversion circuit can be disconnected, thereby reducing the overall power consumption of the circuit.

[0053] See Figure 3 The controller power supply control circuit includes: a third MOSFET Q5 and a switch SW1. The source of the third MOSFET Q5 is connected to the positive power output terminal of the battery pack. The drain of the third MOSFET Q5 is connected to the input terminal of the DC-DC voltage conversion circuit through an eighth resistor R14. The gate of the third MOSFET Q5 is connected to the source of the third MOSFET Q5 through a ninth resistor R15. The gate of the third MOSFET Q5 is also connected to the anode of the first diode D1 through a tenth resistor R18. One end of the switch SW1 is connected to the cathode of the first diode D1, and the other end of the switch SW1 is connected to the negative terminal of the battery pack.

[0054] like Figure 3 As shown, the switch SW1 controls the conduction or cutoff of the third MOSFET Q5. When switch SW1 is in the on state, the gate of the third MOSFET Q5 is pulled down to a low level by the first diode D1 and the tenth resistor R18, thereby turning on the third MOSFET Q5. This allows the battery pack's output power (BAT+20V) to be output to the DC-DC voltage conversion circuit for voltage conversion, ultimately powering the controller. Conversely, when switch SW1 is in the off state, the third MOSFET Q5 is also off, and no power is output to the DC-DC voltage conversion circuit.

[0055] See Figure 3In one embodiment of this utility model, the controller power supply control circuit further includes a third transistor Q6. The collector of the third transistor Q6 is connected to the gate of the third MOSFET Q5 through a sixth resistor R17. The emitter of the third transistor Q6 is connected to a reference ground, and the base of the third transistor Q6 is connected to a control terminal of the controller through an eleventh resistor R19. When the switch SW1 is a flexible switch, in order to control the conduction of the third MOSFET Q5, after the controller is started, the controller can output a high level to the base of the third transistor Q6 through the Power_ON signal terminal, thereby turning on the third transistor Q6 and keeping the gate of the third MOSFET Q5 at a low level, thus keeping the third MOSFET Q5 in a conducting state. When the controller does not need to work, it can output a low level signal or a high impedance signal through the Power_ON signal terminal, thereby turning off both the third transistor Q6 and the third MOSFET Q5. At this time, the DC voltage conversion circuit and the controller are in a zero-power state because there is no power supply, greatly reducing the standby power consumption of the circuit. When restarting is required, the controller can be powered by pressing switch SW1.

[0056] See Figure 3 In one embodiment of this utility model, the controller power supply control circuit further includes a second diode D2. The cathode of the second diode D2 is connected to one end of the switch SW1, and the anode of the second diode D2 is connected to the detection terminal of the controller to detect the state of the switch SW1. The second diode D2 can be connected to a detection terminal of the controller via the SW_Detect signal terminal, so that the controller can detect the state of the switch SW1; wherein, the switch SW1 can be a spring switch. When pressed by external force, the two ends of the switch SW1 can be connected, so that the SW_Detect signal terminal can output a low-level signal to the controller. When the external force is removed, the two ends of the switch SW1 are disconnected, and the SW_Detect signal terminal can output a high-level signal to the controller. This allows the controller to determine whether the switch SW1 is pressed based on the high or low level state of the SW_Detect signal terminal, and to determine whether the controller needs to maintain its own power supply through the Power_ON signal terminal. That is, the operation or standby mode of the controller can be controlled through the switch SW1.

[0057] See Figure 3The DC-DC voltage conversion circuit includes: a linear regulator U1, a first capacitor C6, a second capacitor C8, and a Zener diode ZD5. The linear regulator U1 is connected to the power output terminal of the controller power supply control circuit, and the output terminal of the linear regulator U1 is connected to the power supply terminal of the controller. One end of the first capacitor C6 is connected to the power input terminal of the linear regulator U1, and the other end of the first capacitor C6 is connected to the negative terminal of the battery pack. One end of the second capacitor C8 is connected to the power output terminal of the linear regulator U1, and the other end of the first capacitor C6 is connected to the negative terminal of the battery pack. The cathode of the Zener diode ZD5 is connected to the power output terminal of the linear regulator U1, and the anode of the Zener diode ZD5 is connected to the negative terminal of the battery pack.

[0058] Specifically, the linear regulator U1 can step down the power output from the battery pack. For example, it can step down the voltage to 3.3V or 5V to power the controller. The first capacitor C6 and the second capacitor C8 can filter out the pulse signal from the linear regulator U1 to avoid large voltage fluctuations. The Zener diode ZD5 can further stabilize the voltage and prevent high-voltage pulse signals from damaging the controller.

[0059] The above are merely embodiments of this utility model, but do not limit the patent scope of this utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this utility model specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this utility model.

[0060] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A low-power battery pack power supply control circuit, characterized in that, include: A load power supply control circuit is provided on the power supply circuit of the battery pack; The controller, one of its control terminals is connected to the load power supply control circuit; A battery voltage detection circuit is connected to the voltage detection terminal of the controller to detect the output voltage of the battery pack under the control of the controller. When the voltage of the battery pack is detected to be less than a set voltage value, the power supply circuit of the battery pack is disconnected through the load power supply control circuit. The battery voltage detection circuit includes: The first transistor (Q3) has its collector connected to one end of a first resistor (R6), the other end of the first resistor (R6) connected to the positive power output terminal of the battery pack through a second resistor (R2), its emitter connected to the negative power output terminal of the battery pack, and its base connected to a control terminal of the controller through a third resistor (R11). The first MOSFET (Q2) has its gate connected to the common terminal of the second resistor (R2) and the first resistor (R6). The source of the first MOSFET (Q2) is connected to the positive power output terminal of the battery pack. The drain of the first MOSFET (Q2) is connected to one end of the third resistor (R5). The other end of the third resistor (R5) is connected to the negative power output terminal of the battery pack through the fourth resistor (R12). The common terminal of the third resistor (R5) and the fourth resistor (R12) is connected to the voltage detection terminal of the controller through the fifth resistor (R9).

2. The low-power battery pack power supply control circuit according to claim 1, characterized in that, The load power supply control circuit includes: The second MOSFET (Q1) has its source connected to the positive power output terminal of the battery pack, its drain connected to the load, and its source connected to the gate via a sixth resistor (R1). The collector of the second transistor (Q4) is connected to the gate of the second MOSFET (Q1) through the seventh resistor (R7), the emitter of the second transistor (Q4) is connected to the negative source output terminal of the battery pack, and the base of the second transistor (Q4) is connected to a control terminal of the controller through the sixth resistor (R1).

3. The low-power battery pack power supply control circuit according to claim 1, characterized in that, It also includes a protection circuit, which includes: A fuse (F1) is provided in the power supply circuit of the battery pack to provide overcurrent protection for the power supply circuit. A transient voltage regulator (TVS1) is provided, with its cathode connected to the positive power output terminal of the battery pack and its negative terminal connected to the battery pack, to provide transient high voltage protection for the battery pack output terminal.

4. The low-power battery pack power supply control circuit according to claim 3, characterized in that, Also includes: The protection circuit is connected to the battery pack through the battery pack interface to draw out the power supply of the battery pack.

5. The low-power battery pack power supply control circuit according to any one of claims 1 to 4, characterized in that, Also includes: A controller power supply control circuit is connected to the power output terminal of the battery pack to control the power output of the battery pack. A DC-DC voltage conversion circuit is connected to the power output terminal of the controller power supply control circuit to convert the output power supply voltage and then power the controller.

6. The low-power battery pack power supply control circuit according to claim 5, characterized in that, The controller power supply control circuit includes: The third MOSFET (Q5) has its source connected to the positive power output terminal of the battery pack, its drain connected to the input terminal of the DC-DC voltage conversion circuit via the eighth resistor (R14), its gate connected to the source of the third MOSFET (Q5) via the ninth resistor (R15), and its gate also connected to the anode of the first diode (D1) via the tenth resistor (R18). A switch (SW1) is provided, one end of which is connected to the cathode of the first diode (D1), and the other end of which is connected to the negative terminal of the battery pack.

7. The low-power battery pack power supply control circuit according to claim 6, characterized in that, The controller power supply control circuit also includes: The collector of the third transistor (Q6) is connected to the gate of the third MOS transistor (Q5) through the sixth resistor (R1)7, the emitter of the third transistor (Q6) is connected to the reference ground, and the base of the third transistor (Q6) is connected to a control terminal of the controller through the eleventh resistor (R19).

8. The low-power battery pack power supply control circuit according to claim 7, characterized in that, The controller power supply control circuit also includes: A second diode (D2) is used, with its cathode connected to one end of the switch (SW1) and its anode connected to the detection terminal of the controller to detect the state of the switch (SW1).

9. The low-power battery pack power supply control circuit according to any one of claims 6 to 8, characterized in that, The DC-DC voltage conversion circuit includes: A linear regulator (U1) is connected to the power output terminal of the power supply control circuit of the controller, and the output terminal of the linear regulator (U1) is connected to the power supply terminal of the controller. The first capacitor (C6) has one end connected to the power input terminal of the linear regulator (U1), and the other end connected to the negative terminal of the battery pack. The second capacitor (C8) has one end connected to the power output terminal of the linear regulator (U1), and the other end of the first capacitor (C6) is connected to the negative terminal of the battery pack. A Zener diode (ZD5) is used, the cathode of which is connected to the power output terminal of the linear regulator (U1), and the anode of which is connected to the negative terminal of the battery pack.

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