Power management circuit and oral irrigator

Abstract

The utility model discloses a power management circuit and a water pick, and relates to the technical field of power management. The oral irrigator comprises a voltage input end, a battery and a motor, wherein the voltage input end is used for accessing external voltage; the detection circuit is electrically connected with the main control circuit and is used for detecting the working state of the motor and outputting a detection signal to the main control circuit; the controlled end of the switching circuit is electrically connected with the main control circuit, the first end of the switching circuit is electrically connected with the negative electrode of the motor, the second end of the switching circuit is electrically connected with the grounding end, and the switching circuit is used for connecting or disconnecting a path between the negative electrode of the motor and the grounding end according to the switching control signal output by the main control circuit; the charging management circuit is used for performing voltage conversion on the external voltage and then outputting charging voltage to the battery so as to charge the battery; the main control circuit is used for outputting a switch control signal according to the detection signal. The utility model aims to improve the working stability of the oral irrigator.

Description

Technical Field

[0001] The utility model relates to the technical field of the power supply of a dental irrigator, in particular to a power management circuit and a dental irrigator. Background Art

[0002] With the development of social intelligence, more and more electrical appliances have entered the public life, such as electric dental irrigators and electric humidifiers. These electrical appliances use motors as the driving force, which greatly facilitates life. However, due to improper maintenance after frequent use, the situation of motor blockage is likely to occur. If not discovered and protected in time, on the one hand, the motor will be damaged, and on the other hand, there will be potential safety hazards due to power supply. Summary of the Utility Model

[0003] The main purpose of the utility model is to provide a power management circuit, aiming to improve the working stability of the dental irrigator.

[0004] To achieve the above purpose, the power management circuit proposed by the utility model is applied to a dental irrigator. The dental irrigator includes a voltage input terminal for accessing an external voltage, a battery, and a motor. The power management circuit includes:

[0005] A main control circuit;

[0006] A detection circuit, which is electrically connected to the main control circuit. The detection circuit is used to detect the working state of the motor and output a detection signal to the main control circuit;

[0007] A switch circuit, the controlled end of which is electrically connected to the main control circuit. The first end of the switch circuit is electrically connected to the negative electrode of the motor, and the second end of the switch circuit is electrically connected to the ground terminal. The switch circuit is used to conduct or disconnect the path between the negative electrode of the motor and the ground terminal according to the switch control signal output by the main control circuit;

[0008] A charging management circuit, which is used to convert the external voltage and then output a charging voltage to the battery to charge the battery;

[0009] Wherein, the main control circuit is used to output a switch control signal according to the detection signal.

[0010] In an embodiment, the detection circuit includes a first resistor. The first end of the first resistor is electrically connected to the main control circuit, and the second end of the first resistor is electrically connected to the switch circuit. The main control circuit is used to judge the working state of the motor according to the current change of the first resistor.

[0011] In an embodiment, the switch circuit includes:

[0012] A first switch circuit, a first end of the first switch circuit is electrically connected to a negative electrode of the motor, and a controlled end of the first switch circuit is electrically connected to the main control circuit;

[0013] A second switch circuit, a first end of the second switch circuit is electrically connected to a second end of the first switch circuit, a second end of the second switch circuit is electrically connected to a ground terminal, and a controlled end of the second switch circuit is electrically connected to the controlled end of the first switch circuit;

[0014] Wherein, both the first switch circuit and the second switch circuit are used to conduct or disconnect a path between the negative electrode of the motor and the ground terminal.

[0015] In an embodiment, the first switch circuit includes a first switch tube and a second resistor; the second switch circuit includes a second switch tube, a third resistor, and a fourth resistor;

[0016] Wherein, a first end of the second resistor is electrically connected to the main control circuit, a second end of the second resistor is electrically connected to a controlled end of the first switch tube, a controlled end of the second switch tube, and a first end of the third resistor; a second end of the third resistor is electrically connected to the ground terminal; a first end of the first switch tube is electrically connected to a first end of the second switch tube and the negative electrode of the motor, a second end of the first switch tube is electrically connected to a second end of the second switch tube and a first end of the fourth resistor; a second end of the fourth resistor is grounded.

[0017] In an embodiment, the power management circuit further includes:

[0018] A current limiting circuit, the current limiting circuit is connected in series between the voltage input terminal and the charging management circuit, and the current limiting circuit is used to limit the input current within a preset current and output it;

[0019] A voltage clamping circuit, an input end of the voltage clamping circuit is electrically connected to an output end of the current limiting circuit, an output end of the current limiting circuit is electrically connected to the charging management circuit, and the voltage clamping circuit is used to limit the externally connected voltage within a preset voltage and output it.

[0020] In an embodiment, the current limiting circuit includes a fuse; the voltage clamping circuit includes a TVS tube;

[0021] Wherein, a second end of the fuse is electrically connected to the DC voltage input terminal, a first end of the fuse is electrically connected to a first end of the TVS tube and the charging management circuit; a second end of the TVS tube is electrically connected to the ground terminal.

[0022] In an embodiment, the charging management circuit includes a charging management chip.

[0023] In one embodiment, the charging management circuit further includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first capacitor, a second capacitor, and a third capacitor;

[0024] Among them, the first end of the first capacitor is electrically connected to the first end of the TVS tube and the VCC pin of the charging management chip, and the second end of the first capacitor is electrically connected to the ground terminal; the second end of the fifth resistor is electrically connected to the second end of the first capacitor, and the first end of the fifth resistor is electrically connected to the ground terminal; the first end of the sixth resistor is electrically connected to the VCC pin of the charging management chip and the second end of the second capacitor, and the second end of the sixth resistor is electrically connected to the first end of the eighth resistor and the CE pin of the charging management chip; the first end of the second capacitor is electrically connected to the first end of the seventh resistor, the GND pin, the TEMP pin of the charging management chip, and the ground terminal; the second end of the seventh resistor is electrically connected to the PROG pin of the charging management chip; the second end of the eighth resistor is electrically connected to the ground terminal; the BAT pin of the charging management chip is electrically connected to the first end of the third capacitor, the second end of the ninth resistor, and the power output terminal; the STANDBY pin of the charging management chip is electrically connected to the first end of the ninth resistor and the main control circuit; the CHRG pin of the charging management chip is electrically connected to the ground terminal.

[0025] The present utility model also proposes a dental irrigator, which includes a voltage input terminal for accessing an external voltage, a battery, a motor, and the power management circuit as described in any one of the above.

[0026] The technical solution of the present utility model detects the working state of the motor through a detection circuit and feeds back a detection signal to the main control circuit, so that the main control circuit determines whether to output a switch control signal to the switch circuit according to the detection signal, and further enables the switch circuit to conduct or disconnect the path between the negative electrode of the motor and the ground terminal. Among them, when the battery power is insufficient to meet the power supply requirements of the motor, the charging management circuit will perform voltage conversion and charging protection on the charging voltage to output a safe and appropriate voltage to the motor to ensure the normal operation of the motor. By adopting the power management circuit, the working stability of the dental irrigator is effectively improved. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0028] Figure 1It is a schematic diagram of the module of the power management circuit of the present utility model;

[0029] Figure 2 It is a schematic diagram of the module of an embodiment of the power management circuit of the present utility model;

[0030] Figure 3 It is a schematic circuit diagram of an embodiment of the power management circuit of the present utility model;

[0031] Figure 4 It is another schematic circuit diagram of the power management circuit of the present utility model.

[0032] Explanation of the reference numerals in the drawings:

[0033] 10. Main control circuit; 20. Detection circuit; 30. Switching circuit; 31. First switching circuit; 32. Second switching circuit; 40. Charge management circuit; 50. Current limiting circuit; 60. Voltage clamping circuit; R1 - R9. First resistor - Ninth resistor; Q1 - Q2. First switching transistor - Second switching transistor; C1 - C3. First capacitor - Third capacitor.

[0034] The realization, functional features and advantages of the object of the present utility model will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0035] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0036] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0037] In addition, the descriptions involving "first", "second", etc. in the present utility model are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0038] With the development of social intelligence, more and more electrical appliances have entered the lives of the general public, such as electric dental irrigators and electric humidifiers. These electrical appliances use motors as drives to generate power, greatly facilitating life. However, with improper maintenance after frequent use, the situation of motor blockage is likely to occur. If not discovered and protected in time, on the one hand, the motor will be damaged, and on the other hand, there will be safety hazards due to power supply.

[0039] Therefore, referring to Figures 1 to 4 , the present utility model proposes a power management circuit, which is applied to a dental irrigator. The dental irrigator includes a voltage input terminal for accessing an external voltage, a battery, and a motor. The power management circuit includes:

[0040] A main control circuit 10;

[0041] A detection circuit 20, the detection circuit 20 is electrically connected to the main control circuit 10, and the detection circuit 20 is used to detect the working state of the motor and output a detection signal to the main control circuit 10;

[0042] A switch circuit 30, the controlled end of the switch circuit 30 is electrically connected to the main control circuit 10, the first end of the switch circuit 30 is electrically connected to the negative electrode of the motor, the second end of the switch circuit 30 is electrically connected to the ground terminal, and the switch circuit 30 is used to conduct or disconnect the path between the negative electrode of the motor and the ground terminal according to the switch control signal output by the main control circuit 10;

[0043] A charging management circuit 40, the charging management circuit 40 is used to convert the external voltage and then output a charging voltage to the battery to charge the battery;

[0044] Wherein, the main control circuit 10 is used to output a switch control signal according to the detection signal.

[0045] In this embodiment, the main control circuit 10 can be implemented by a main controller, such as an FPGA (Field Programmable Gate Array), an MCU (Microcontroller Unit), a DSP (Digital Signal Process), an SOC (System On Chip), etc. The main control circuit 10 in the power management circuit is mainly responsible for coordinating and controlling data acquisition, processing, decision-making of each circuit and module, as well as the response of the actuator. Using different main controllers will directly affect the system's performance, cost, power consumption, and development flexibility. In practical applications, it can be determined according to the requirements of specific application scenarios, such as factors like processing speed, power consumption limit, cost budget, development cycle, and system scalability. In actual projects, multiple types of processors may be used in combination to achieve the optimal system performance and efficiency.

[0046] In this embodiment, the detection circuit 20 can be implemented by a voltage detection circuit 20, a current detection circuit 20, etc. Among them, the voltage detection circuit 20 can be implemented by a resistor voltage division sampling circuit, a linear operational amplifier voltage sampling circuit, a voltage sampling transformer, etc.; while the current detection circuit 20 can be implemented by sensors such as a resistor shunt, a Hall current sensor, a Rogowski coil current sensor, a fluxgate current sensor, an optical fiber current sensor, etc. Specifically, the detection circuit 20 includes a first resistor R1. The first end of the first resistor R1 is electrically connected to the main control circuit 10, and the second end of the first resistor R1 is electrically connected to the switch circuit 30. The main control circuit 10 is used to judge the working state of the motor according to the current change of the first resistor R1. The main control circuit 10 outputs a corresponding duty cycle signal to control the conduction duration of the switch circuit 30, thereby controlling the current output from the battery or external power supply to the motor. When the motor is blocked, the change in the current value flowing through the first resistor R1 is converted into a voltage change. When the voltage change reaches a preset voltage value, the main control circuit 10 will acquire this change and control the switch circuit 30 to disconnect the path between the negative electrode of the motor and the ground terminal, thereby shutting down the working state of the motor and avoiding damage to the motor.

[0047] In this embodiment, the switching circuit 30 can be implemented by at least one switching transistor, such as a MOS transistor, an IGBT transistor, a thyristor, a triode, a power transistor, etc., and / or by at least one switching device, such as a contactor, a circuit breaker, and a relay. Specifically, the switching circuit 30 includes: a first switching circuit 31, a first end of the first switching circuit 31 is electrically connected to the negative electrode of the motor, and a controlled end of the first switching circuit 31 is electrically connected to the main control circuit 10; a second switching circuit 32, a first end of the second switching circuit 32 is electrically connected to a second end of the first switching circuit 31, a second end of the second switching circuit 32 is electrically connected to a ground terminal, and a controlled end of the second switching circuit 32 is electrically connected to the controlled end of the first switching circuit 31; wherein, both the first switching circuit 31 and the second switching circuit 32 are used to conduct or disconnect the path between the negative electrode of the motor and the ground terminal. The first switching circuit 31 includes a first switching transistor Q1 and a second resistor R2; the second switching circuit 32 includes a second switching transistor Q2, a third resistor R3, and a fourth resistor R4; wherein, a second end of the second resistor R2 is electrically connected to the controlled end of the first switching transistor Q1, the controlled end of the second switching transistor Q2, and a first end of the third resistor R3; a second end of the third resistor R3 is electrically connected to the ground terminal; a first end of the first switching transistor Q1 is electrically connected to a first end of the second switching transistor Q2 and the negative electrode of the motor, and a second end of the first switching transistor Q1 is electrically connected to a second end of the second switching transistor Q2 and a first end of the fourth resistor R4; a second end of the fourth resistor R4 is grounded. It can be understood that the first ends of the first switching transistor Q1 and the second switching transistor Q2 are electrically connected to the negative electrode of the motor, and the second ends of the first switching transistor Q1 and the second switching transistor Q2 are electrically connected to the ground terminal. Among them, the first switching transistor Q1 and the second switching transistor Q2 are arranged in parallel to achieve the technical effect of shunt conduction. In addition, by setting the first switching transistor Q1 and the second switching transistor Q2, the working stability of the switching transistor is effectively improved, and the possibility of the switching transistor being damaged is greatly reduced. The controlled ends of the first switching transistor Q1 and the second switching transistor Q2 conduct or disconnect the path between the negative electrode of the motor and the ground terminal by receiving the switching control signal output by the main control circuit 10, thereby realizing the control of the motor power supply path. Among them, when the detection circuit 20 detects that the working state of the motor is abnormal, the main control circuit 10 will control the switching circuit 30 to disconnect the path between the negative electrode of the motor and the ground terminal according to the detection signal.

[0048] In this embodiment, the charging management circuit 40 can be implemented by using a charging management chip or a control circuit. Taking the charging management chip as an example, specifically, the charging management circuit 40 further includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a first capacitor C1, a second capacitor C2, and a third capacitor C3. Among them, the first end of the first capacitor C1 is electrically connected to the first end of the TVS tube and the VCC pin of the charging management chip, and the second end of the first capacitor C1 is electrically connected to the ground terminal; the second end of the fifth resistor R5 is electrically connected to the second end of the first capacitor C1, and the first end of the fifth resistor R5 is electrically connected to the ground terminal; the first end of the sixth resistor R6 is electrically connected to the VCC pin of the charging management chip and the second end of the second capacitor C2, and the second end of the sixth resistor R6 is electrically connected to the first end of the eighth resistor R8 and the CE pin of the charging management chip; the first end of the second capacitor C2 is electrically connected to the first end of the seventh resistor R7, the GND pin, the TEMP pin of the charging management chip, and the ground terminal; the second end of the seventh resistor R7 is electrically connected to the PROG pin of the charging management chip; the second end of the eighth resistor R8 is electrically connected to the ground terminal; the BAT pin of the charging management chip is electrically connected to the first end of the third capacitor C3, the second end of the ninth resistor R9, and the power output terminal; the STANDBY pin of the charging management chip is electrically connected to the first end of the ninth resistor R9 and the main control circuit 10; the CHRG pin of the charging management chip is electrically connected to the ground terminal. The charging management circuit 40 achieves the technical effects of voltage stabilization and filtering through external resistors and capacitors to ensure the stable operation of the XC3101 chip when receiving voltage and current signals. Among them, XC3101 is compatible with a maximum charging current of 1000 mA, has built-in OVP, a breakdown voltage of 30 V, and adopts trickle, constant current, and constant voltage control. The ESOP8 package and fewer external component numbers make TP4056SE an ideal choice for portable applications. XC3101 can work with USB power and adapter power. XC3101 adopts an internal PMOSFET architecture and an anti-backcharge circuit, so external sense resistors and isolation diodes are not required. Thermal feedback can automatically adjust the charging current to limit the chip temperature under high-power operation or high ambient temperature conditions. The full charge voltage is 4.2 V, and the charging current can be externally set through a resistor. When the battery reaches the preset voltage, the charging current drops to 1 / 10 of the set value, and the chip will automatically terminate charging. When the input voltage is removed, XC3101 will automatically enter a low-current state, and the leakage current is below 1 μA. Other features of XC3101 include under-voltage lockout, automatic recharge, reverse battery connection protection at the BAT terminal, and two pins for indicating the charging state.

[0049] The technical solution of the present utility model detects the working state of the motor by using the detection circuit 20, and feeds back the detection signal to the main control circuit 10, so that the main control circuit 10 determines whether to output a switch control signal to the switch circuit 30 according to the detection signal, thereby enabling the switch circuit 30 to conduct or disconnect the path between the negative electrode of the motor and the ground terminal. Among them, when the battery power is insufficient to meet the power supply requirements of the motor, the charging management circuit 40 will perform voltage conversion and charging protection on the charging voltage to output a safe and appropriate voltage to the motor to ensure the normal operation of the motor. By adopting the power management circuit, the stability of the operation of the oral irrigator is effectively improved.

[0050] Reference Figure 2 , in an embodiment of the present utility model, the power management circuit further includes:

[0051] A current limiting circuit 50, the current limiting circuit 50 is connected in series between the voltage input terminal and the charging management circuit 40, and the current limiting circuit 50 is used to limit the input current within a preset current and output it;

[0052] A voltage clamping circuit 60, the input end of the voltage clamping circuit 60 is electrically connected to the output end of the current limiting circuit 50, the output end of the current limiting circuit 50 is electrically connected to the charging management circuit 40, and the voltage clamping circuit 60 is used to limit the externally connected voltage within a preset voltage and output it.

[0053] Furthermore, the current limiting circuit 50 includes a fuse; the voltage clamping circuit 60 includes a TVS tube;

[0054] Among them, the second end of the fuse is electrically connected to the DC voltage input terminal, the first end of the fuse is electrically connected to the first end of the TVS tube and the charging management circuit 40; the second end of the TVS tube is electrically connected to the ground terminal.

[0055] In this embodiment, to ensure the safety of the charging management circuit 40 when a DC voltage is connected, a protection circuit can be added to the positive pole of the DC voltage input interface to improve the safety of the circuit. The current limiting circuit 50 can be implemented by means of a current limiting diode, a fuse, etc. Specifically, taking the fuse as an example, when a fault or abnormality occurs in the circuit, as the current continuously increases, the increased current may damage some important components in the circuit, and may also burn out the circuit or even cause a fire. If a fuse is properly installed in the circuit, then the fuse will melt and cut off the current by itself when the current abnormally rises to a certain height and heat, thus playing a role in protecting the safe operation of the circuit. By setting the current limiting circuit 50, the input DC current is limited within a preset current, that is, below the safe current, to improve the safety of the charging management circuit 40. The voltage clamping circuit 60 can be implemented by means of a voltage stabilizing diode circuit, a triode clamping circuit, a TVS tube circuit, etc. Specifically, taking the TVS tube as an example. Among them, the TVS tube is an overvoltage protection device with bidirectional voltage stabilizing characteristics and bidirectional negative resistance characteristics, similar to a varistor. It is applied to various AC and DC power supply circuits to suppress instantaneous overvoltage. When a surge pulse voltage appears instantaneously in the protected circuit, the bidirectional breakdown diode can quickly break down in a Zener manner, changing from a high-resistance state to a low-resistance state, shunting and clamping the surge voltage, so as to protect each component in the circuit from being damaged by the instantaneous surge pulse voltage. By using a set of 24V TVS tubes, the DC voltage input at the DC voltage input interface is limited within a preset voltage threshold to improve the safety of the charging management circuit 40.

[0056] The present utility model also proposes a dental irrigator, and the dental irrigator includes the power management circuit as described in any one of the above. It should be noted that since the dental irrigator of the present utility model is based on the above power management circuit, therefore, the embodiments of the dental irrigator of the present utility model include all the technical solutions of all the embodiments of the above power management circuit, and the achieved technical effects are also exactly the same, and will not be elaborated here.

[0057] The above are only the preferred embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. Any equivalent structural transformation made under the inventive concept of the present utility model by using the content of the specification and drawings of the present utility model, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present utility model.

Claims

1. A power management circuit, applied to a water flosser, the water flosser comprising a voltage input terminal for connecting to an external voltage, a battery, and a motor, characterized in that: The power management circuit comprises: Main control circuit; A detection circuit, the detection circuit is electrically connected to the main control circuit, the detection circuit is used to detect the working state of the motor and output a detection signal to the main control circuit; a switch circuit, wherein a controlled end of the switch circuit is electrically connected to the main control circuit, a first end of the switch circuit is electrically connected to the negative electrode of the motor, a second end of the switch circuit is electrically connected to the ground end, and the switch circuit is used to open or close the path between the negative electrode of the motor and the ground end according to a switch control signal output by the main control circuit; A charging management circuit, the charging management circuit is used to convert the external voltage into a voltage and then output a charging voltage to the battery to charge the battery; Wherein, the main control circuit is used to output a switch control signal according to the detection signal.

2. The power management circuit according to claim 1, characterized in that: The detection circuit includes a first resistor, a first end of the first resistor is electrically connected to the main control circuit, a second end of the first resistor is electrically connected to the switch circuit, and the main control circuit is used to determine the working state of the motor according to the current change of the first resistor.

3. The power management circuit according to claim 2, characterized in that: The switch circuit comprises: a first switch circuit, wherein a first end of the first switch circuit is electrically connected to a negative electrode of the motor, and a controlled end of the first switch circuit is electrically connected to the main control circuit; a second switch circuit, wherein a first end of the second switch circuit is electrically connected to a second end of the first switch circuit, a second end of the second switch circuit is electrically connected to a ground end, and a controlled end of the second switch circuit is electrically connected to a controlled end of the first switch circuit; The first switch circuit and the second switch circuit are both used to open or close the path between the negative pole of the motor and the ground terminal.

4. The power management circuit according to claim 3, characterized in that: The first switch circuit includes a first switch tube and a second resistor; the second switch circuit includes a second switch tube, a third resistor and a fourth resistor; Among them, the first end of the second resistor is electrically connected to the main control circuit, the second end of the second resistor is electrically connected to the controlled end of the first switch tube, the controlled end of the second switch tube, and the first end of the third resistor; the second end of the third resistor is electrically connected to the ground end; the first end of the first switch tube is electrically connected to the first end of the second switch tube and the negative pole of the motor, the second end of the first switch tube is electrically connected to the second end of the second switch tube and the first end of the fourth resistor; the second end of the fourth resistor is grounded.

5. The power management circuit according to claim 1, wherein: The power management circuit further includes: A current limiting circuit, the current limiting circuit is connected in series between the voltage input terminal and the charging management circuit, and the current limiting circuit is used to limit the input current to a preset current and output it; A voltage clamping circuit, wherein the input end of the voltage clamping circuit is electrically connected to the output end of the current limiting circuit, the output end of the current limiting circuit is electrically connected to the charging management circuit, and the voltage clamping circuit is used to limit the connected external voltage to a preset voltage and output it.

6. The power management circuit according to claim 5, characterized in that: The current limiting circuit includes a fuse; the voltage clamping circuit includes a TVS tube; Among them, the second end of the fuse is electrically connected to the voltage input end, the first end of the fuse is electrically connected to the first end of the TVS tube and the charging management circuit; the second end of the TVS tube is electrically connected to the ground end.

7. The power management circuit according to claim 6, characterized in that: The charging management circuit includes a charging management chip.

8. The power management circuit according to claim 7, characterized in that: The charging management circuit further includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first capacitor, a second capacitor, and a third capacitor; Among them, the first end of the first capacitor is electrically connected to the first end of the TVS tube and the VCC pin of the charging management chip, and the second end of the first capacitor is electrically connected to the ground terminal; the second end of the fifth resistor is electrically connected to the second end of the first capacitor, and the first end of the fifth resistor is electrically connected to the ground terminal; the first end of the sixth resistor is electrically connected to the VCC pin of the charging management chip and the second end of the second capacitor, and the second end of the sixth resistor is electrically connected to the first end of the eighth resistor and the CE pin of the charging management chip; the first end of the second capacitor is electrically connected to the first end of the seventh resistor, the GND pin, the TEMP pin, and the ground terminal of the charging management chip; the second end of the seventh resistor is electrically connected to the PROG pin of the charging management chip; the second end of the eighth resistor is electrically connected to the ground terminal; the BAT pin of the charging management chip is electrically connected to the first end of the third capacitor, the second end of the ninth resistor, and the power output terminal; the STDBY pin of the charging management chip is electrically connected to the first end of the ninth resistor and the main control circuit; the CHRG pin of the charging management chip is electrically connected to the ground terminal.

9. A dental flosser, characterized in that: The water flosser comprises a voltage input terminal for connecting to an external voltage, a battery, a motor and a power management circuit as described in any one of claims 1 to 8.

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