Charging protection circuit and oral irrigator

Abstract

The utility model discloses a charging protection circuit and a water pick, and relates to the technical field of water pick charging protection. The oral irrigator comprises a voltage input end for accessing an external voltage and a battery, and the charging protection circuit comprises a one-way conduction circuit of which the input end is electrically connected with the voltage input end; the first end of the voltage clamping circuit is electrically connected with the one-way conduction circuit; the first end of the filter circuit is electrically connected with the first end of the clamping circuit; the charging management circuit is electrically connected with the filter circuit and is used for performing voltage conversion on the external voltage and then outputting charging voltage to the battery so as to charge the battery; and the battery protection circuit is electrically connected with the charging management circuit and is used for disconnecting the access between the charging management circuit and the battery when the current output by the charging management circuit is in an over-current state. The utility model aims to prolong the charging service life of the oral irrigator.

Description

Technical Field

[0001] The utility model relates to the technical field of charging protection of a water flosser, in particular to a charging protection circuit and a water flosser. Background Art

[0002] A water flosser is a household oral care product that uses high-pressure pulsed water flow to remove food residues trapped in tooth gaps that cannot be reached by teeth and dental floss, thereby effectively cleaning dental plaque, improving gingivitis, reducing gum bleeding, and freshening breath. With the increasing attention of people to personal oral health, water flossers are becoming more and more popular. It mainly includes components such as a water flosser movement, a water tank, and a nozzle. The movement is provided with a control component, a driving component, a liquid pump component, etc., and the water in the water tank is transmitted to the nozzle in the form of pulsed water flow for oral cleaning. The power of the water flosser comes from an internal rechargeable battery. However, after multiple charge and discharge operations, the rechargeable battery in the existing water flosser will cause the service life of the rechargeable battery to be rapidly reduced. Therefore, how to effectively improve the service life of the rechargeable battery in the water flosser has become a technical problem that needs to be solved urgently for the device. Summary of the Utility Model

[0003] The main purpose of the utility model is to provide a charging protection circuit, aiming to improve the service life of the water flosser during charging.

[0004] To achieve the above purpose, the charging protection circuit proposed by the utility model is applied to a water flosser. The water flosser includes a voltage input terminal for accessing an external voltage and a battery. The charging protection circuit includes:

[0005] A one-way conduction circuit, the input terminal of the one-way conduction circuit is electrically connected to the voltage input terminal;

[0006] A voltage clamping circuit, the first end of the voltage clamping circuit is electrically connected to the one-way conduction circuit; the voltage clamping circuit is used to clamp the external voltage within a preset voltage range;

[0007] A filtering circuit, the first end of the filtering circuit is electrically connected to the first end of the clamping circuit, and the filtering circuit is used to filter the accessed external voltage and then output it;

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

[0009] A battery protection circuit, the battery protection circuit is electrically connected to the charging management circuit, and the battery protection circuit is used to disconnect the path between the charging management circuit and the battery when the current output by the charging management circuit is in overcurrent.

[0010] In one embodiment, the unidirectional conduction circuit includes a first diode, and the first diode is used to limit the current flow direction.

[0011] In one embodiment, the voltage clamping circuit includes a TVS tube, and the TVS tube is used to limit the externally applied voltage within a preset voltage.

[0012] In one embodiment, the filtering circuit includes a first capacitor, and the first capacitor is used to filter the externally applied voltage and then output it.

[0013] In one embodiment, the charging management circuit includes a charging management chip.

[0014] In one embodiment, the charging management circuit further includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a second diode, a second capacitor, and a third capacitor;

[0015] Wherein, the first end of the first resistor is electrically connected to the CE pin of the charging management chip, and the second end of the first resistor is electrically connected to the first end of the first capacitor; the first end of the second resistor is electrically connected to the VCC pin of the charging management chip, and the second end of the second resistor is electrically connected to the anode of the second diode; the first end of the third resistor is electrically connected to the ground terminal, and the second end of the third resistor is electrically connected to the PROG pin of the charging management chip; the first end of the fourth resistor is electrically connected to the CE pin of the charging management chip, and the second end of the fourth resistor is electrically connected to the second end of the third capacitor; the first end of the fifth resistor is electrically connected to the STBDY pin of the charging management chip, and the second end of the fifth resistor is electrically connected to the first end of the third capacitor; the cathode of the second diode is electrically connected to the BAT pin of the charging management chip; the first end of the second capacitor is electrically connected to the ground terminal, and the second end of the second capacitor is electrically connected to the VCC pin of the charging management chip; the first end of the third capacitor is electrically connected to the power output terminal; the TEMP pin, GND pin, and CHRG pin of the charging management chip are electrically connected to the ground terminal.

[0016] In one embodiment, the battery protection circuit includes a battery protection chip.

[0017] In one embodiment, the battery protection circuit further includes a sixth resistor, a seventh resistor, and a fourth capacitor;

[0018] Wherein, the first end of the sixth resistor is electrically connected to the YM1 pin, YM2 pin, YM3 pin, YM4 pin, and ground terminal of the battery protection chip, and the second end of the sixth resistor is electrically connected to the second end of the fourth capacitor and the negative electrode of the battery; the first end of the fourth capacitor is electrically connected to the second end of the seventh resistor and the VDD pin of the battery protection chip, and the second end of the fourth capacitor is electrically connected to the GND pin and EPAD pin of the battery protection chip; the first end of the seventh resistor is electrically connected to the positive electrode of the battery.

[0019] The present utility model further provides an oral irrigator, which includes the charging protection circuit as described in any one of the above.

[0020] The technical solution of the present utility model adopts a charging protection circuit and applies it to an oral irrigator, so as to improve the service life of the oral irrigator. Among them, the oral irrigator includes a voltage input terminal for accessing an external voltage and a battery; the charging protection circuit includes a one-way conduction circuit, a voltage clamping circuit, a filtering circuit, and a charging management circuit. The one-way conduction circuit unidirectionally limits the DC voltage input from the voltage input terminal and inputs it to the voltage clamping circuit, so that the voltage clamping circuit limits the input voltage within a preset voltage range to avoid overvoltage of the input voltage. Further, the input DC voltage is filtered by the filtering circuit to obtain a smooth DC voltage. In addition, the charging protection circuit controls and protects the charging and discharging process of the battery through the charging management circuit and the battery protection circuit to improve the service life of the battery, and further improve the service life of the oral irrigator. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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 drawings in the following description 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.

[0022] Figure 1 It is a schematic diagram of the module of the charging protection circuit of the present utility model;

[0023] Figure 2 It is a circuit diagram of an embodiment of the charging protection circuit of the present utility model;

[0024] Figure 3 It is a circuit diagram of an embodiment of the charging protection circuit of the present utility model.

[0025] Description of the reference numerals in the drawings:

[0026] 10. Unidirectional conduction circuit; 20. Voltage clamping circuit; 30. Filtering circuit; 40. Charging management circuit; 50. Battery protection circuit; R1 - R7, First resistor - Seventh resistor; C1 - C4, First capacitor - Fourth capacitor; D1 - D2, First diode - Second diode.

[0027] The realization, functional features and advantages of the present utility model will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0028] 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. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0029] 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.

[0030] 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 such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions 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.

[0031] The dental irrigator is a household oral care product that uses high-pressure pulsed water flow to remove food residues trapped in tooth gaps that cannot be reached by teeth and dental floss, thereby effectively cleaning dental plaque, improving gingivitis, reducing gingival bleeding, and freshening breath. With the increasing attention of people to personal oral health, the dental irrigator has become more and more popular. It mainly includes components such as the dental irrigator movement, water tank, and nozzle. The movement is equipped with control components, drive components, and liquid pump components, etc. The water in the water tank is transmitted to the nozzle in the form of pulsed water flow for oral cavity cleaning, and the power of the dental irrigator comes from an internal rechargeable battery. However, the rechargeable battery in the existing dental irrigator will cause the life of the rechargeable battery to be rapidly reduced after multiple charge and discharge operations. Therefore, how to effectively improve the service life of the rechargeable battery in the dental irrigator has become a technical problem that the device urgently needs to solve.

[0032] For this reason, referring to Figures 1 to 3 , the present utility model proposes a charging protection circuit applied to a dental irrigator. The dental irrigator includes a voltage input terminal for accessing an external voltage and a battery. The charging protection circuit includes:

[0033] A one-way conduction circuit 10, the input end of the one-way conduction circuit 10 is electrically connected to the voltage input terminal;

[0034] A voltage clamping circuit 20, the first end of the voltage clamping circuit 20 is electrically connected to the one-way conduction circuit 10; the voltage clamping circuit 20 is used to clamp the external voltage within a preset voltage range;

[0035] A filtering circuit 30, the first end of the filtering circuit 30 is electrically connected to the first end of the clamping circuit. The filtering circuit 30 is used to filter the accessed external voltage and then output it;

[0036] A charging management circuit 40, the charging management circuit 40 is electrically connected to the filtering circuit 30. 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;

[0037] A battery protection circuit 50, the battery protection circuit 50 is electrically connected to the charging management circuit 40. The battery protection circuit 50 is used to disconnect the path between the charging management circuit 40 and the battery when the current output by the charging management circuit 40 is overcurrent.

[0038] In this embodiment, the unidirectional conduction circuit 10 can be implemented by a circuit composed of components such as diodes and thyristors. Among them, taking the diode as an example. Based on its own PN structure, there is a special boundary layer, namely the space charge region, in the region formed by the contact of two semiconductor materials. In this region, due to the diffusion of electrons and holes, a built-in electric field is formed, and the direction of this electric field is from the N-type semiconductor to the P-type semiconductor, which prevents the further diffusion of majority carriers. When a positive voltage is applied to the P-type end (anode) of the diode and a negative voltage is applied to the N-type end (cathode), the external voltage is opposite to the direction of the built-in electric field, weakening the built-in electric field. If the external voltage exceeds a threshold (usually called the dead zone voltage), the built-in electric field will be completely cancelled, enabling the majority carriers (holes in the P region and electrons in the N region) to move freely under the weakened electric field, forming a large forward current. At this time, the diode conducts, and the diode presents a low-resistance state. When a negative voltage is applied to the P-type end and a positive voltage is applied to the N-type end, the external voltage is in the same direction as the built-in electric field, strengthening the built-in electric field, which effectively prevents the movement of majority carriers. Only a small number of carriers (minority carriers) cross the potential barrier due to thermal excitation, forming a very small reverse saturation current. At this time, the diode is cut off and shows a high resistance. By setting the unidirectional conduction circuit 10, the circuit is protected from damage by reverse voltage or reverse current.

[0039] In this embodiment, the voltage clamping circuit 20 can be implemented by using a TVS tube, a Zener diode, an active clamping circuit, etc. to achieve the technical effect of clamping the external voltage within a preset voltage range. Among them, taking the TVS tube as an example. In the normal working state, the TVS tube presents a high-impedance state, hardly interfering with the normal current flow of the circuit and having little impact on the circuit. When a transient overvoltage occurs in the circuit, such as electrostatic discharge (ESD) or power supply fluctuations, the voltage across the two ends of the TVS tube exceeds the preset voltage. At this time, the PN junction inside the TVS tube quickly enters the avalanche breakdown state, and its impedance drops sharply, becoming a low-impedance path. In the breakdown state, the TVS tube can respond at a nanosecond level, absorb and dissipate the transient energy, clamp the voltage across the two ends at a preset safe level, and protect the sensitive components in the subsequent circuit from overvoltage damage. When the transient voltage event passes, the TVS tube will automatically return from the low impedance to the high impedance state, and the circuit resumes normal operation. This process is usually reversible and will not cause damage to the components. By setting the voltage clamping circuit 20, it effectively ensures that the voltage input at the voltage input end is in a relatively stable state, avoiding the impact of voltage fluctuations on the subsequent circuit.

[0040] In this embodiment, the filtering circuit 30 can be implemented using capacitors, active filtering circuits 30, etc. Among them, a capacitor circuit is taken as an example. When the rectified pulsating DC voltage (including DC component and AC ripple) is higher than the voltage across the capacitor, the capacitor starts to charge, absorbs current and stores electrical energy. Since the capacitor has a lower impedance to high-frequency AC signals, the AC ripple can more easily pass through the capacitor, while the DC component is blocked due to the blocking effect of the capacitor on DC. When the rectified voltage drops below the voltage on the capacitor, the capacitor starts to discharge, provides current to the load, and maintains the stability of the output voltage. This process reduces the voltage fluctuation, making the output voltage smoother. The smoothed voltage reduces the impact of the input voltage on the sensitive components in the circuit and extends the service life of the components.

[0041] In this embodiment, the charging management circuit 40 can be implemented using a charging management chip or a control circuit. Among them, taking the charging management chip as an example, specifically, it can be the XC3101 chip. Further, the charging management circuit 40 further includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a second diode D2, a second capacitor C2, and a third capacitor C3;

[0042] Among them, the first end of the first resistor R1 is electrically connected to the CE pin of the charging management chip, and the second end of the first resistor R1 is electrically connected to the first end of the first capacitor C1; the first end of the second resistor R2 is electrically connected to the VCC pin of the charging management chip, and the second end of the second resistor R2 is electrically connected to the anode of the second diode D2; the first end of the third resistor R3 is electrically connected to the ground terminal, and the second end of the third resistor R3 is electrically connected to the PROG pin of the charging management chip; the first end of the fourth resistor R4 is electrically connected to the CE pin of the charging management chip, and the second end of the fourth resistor R4 is electrically connected to the second end of the third capacitor C3; the first end of the fifth resistor R5 is electrically connected to the STBDY pin of the charging management chip, and the second end of the fifth resistor R5 is electrically connected to the first end of the third capacitor C3; the cathode of the second diode D2 is electrically connected to the BAT pin of the charging management chip; the first end of the second capacitor C2 is electrically connected to the ground terminal, and the second end of the second capacitor C2 is electrically connected to the VCC pin of the charging management chip; the first end of the third capacitor C3 is electrically connected to the power output terminal; the TEMP pin, GND pin, and CHRG pin of the charging management chip are electrically connected to the ground terminal. The charging management circuit 40 achieves the technical effects of voltage stabilization and filtering through peripheral 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, 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 no external sense resistor and isolation diode are 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 protection at the BAT terminal, and two pins for indicating the charging state.

[0043] In this embodiment, the battery protection circuit 50 can be implemented using a battery protection chip or a protection circuit. Among them, taking the battery protection chip as an example, it can be specifically the XB8886A chip. Among them, the battery protection circuit 50 further includes a sixth resistor R6, a seventh resistor R7, and a fourth capacitor C4; the first end of the sixth resistor R6 is electrically connected to the YM1 pin, YM2 pin, YM3 pin, YM4 pin, and ground terminal of the battery protection chip, and the second end of the sixth resistor R6 is electrically connected to the second end of the fourth capacitor C4 and the negative electrode of the battery; the first end of the fourth capacitor C4 is electrically connected to the second end of the seventh resistor R7 and the VDD pin of the battery protection chip, and the second end of the fourth capacitor C4 is electrically connected to the GND pin and EPAD pin of the battery protection chip; the first end of the seventh resistor R7 is electrically connected to the positive electrode of the battery. The XB8886A chip is used to protect the battery from damage in abnormal situations such as overcharging, over-discharging, overcurrent, and short circuits. This chip has high-precision voltage and current detection functions, can monitor the state of the battery in real time, and cut off the connection between the battery and the load when necessary to protect the safety and life of the battery. In addition, the XB8886A chip also has low-power consumption characteristics, can reduce power consumption in the standby mode, and extend the usage time of the battery.

[0044] It should be understood that when using a charging management chip and a battery protection chip, some of the pins are not connected to other components in the circuit design for easy design according to actual needs or to be compatible with different usage scenarios. Specifically, in this embodiment, the second capacitor C2, the first resistor R1, the fourth resistor R4, and the sixth resistor R6 may not be provided.

[0045] This application adopts a charging protection circuit and applies it to a dental irrigator, which improves the service life of the dental irrigator. Among them, the dental irrigator includes a voltage input terminal for accessing an external voltage and a battery; the charging protection circuit includes a one-way conduction circuit 10, a voltage clamping circuit 20, a filtering circuit 30, and a charging management circuit 40. The one-way conduction circuit 10 unidirectionally limits the DC voltage input from the voltage input terminal and inputs it to the voltage clamping circuit 20, so that the voltage clamping circuit 20 limits the input voltage within a preset voltage range to avoid overvoltage of the input voltage. Further, the filtering circuit 30 filters the input DC voltage to obtain a smooth DC voltage. In addition, the charging protection circuit controls and protects the charging and discharging process of the battery through the charging management circuit 40 and the battery protection circuit 50 to improve the service life of the battery, and thus improve the service life of the dental irrigator.

[0046] The present utility model also provides a dental irrigator, which includes the charging protection 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 charging protection 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 charging protection circuit, and the achieved technical effects are also exactly the same, which will not be elaborated herein again.

[0047] The above are only the preferred embodiments of the present utility model, and do not limit the patent scope of the present utility model. 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 charging protection circuit, applied to a water flosser, the water flosser comprising a voltage input terminal for connecting to an external voltage and a battery, characterized in that: The charging protection circuit comprises: A unidirectional conducting circuit, wherein an input terminal of the unidirectional conducting circuit is electrically connected to the voltage input terminal; A voltage clamping circuit, wherein a first end of the voltage clamping circuit is electrically connected to the unidirectional conducting circuit; the voltage clamping circuit is used to clamp the external voltage within a preset voltage range; A filter circuit, wherein a first end of the filter circuit is electrically connected to a first end of the clamp circuit, and the filter circuit is used to filter an external voltage connected thereto and then output it; a charging management circuit, the charging management circuit being electrically connected to the filter circuit, and configured to convert the external voltage into a voltage and then output a charging voltage to the battery to charge the battery; A battery protection circuit is electrically connected to the charging management circuit, and is used to disconnect the path between the charging management circuit and the battery when the current output by the charging management circuit is in overcurrent.

2. The charging protection circuit according to claim 1, characterized in that: The unidirectional conducting circuit includes a first diode, and the first diode is used to limit the current flow direction.

3. The charging protection circuit according to claim 1, characterized in that: The voltage clamping circuit includes a TVS tube, and the TVS tube is used to limit the connected external voltage to a preset voltage.

4. The charging protection circuit according to claim 1, characterized in that: The filtering circuit includes a first capacitor, and the first capacitor is used to filter the connected external voltage and then output it.

5. The charging protection circuit according to claim 4, characterized in that: The charging management circuit includes a charging management chip.

6. The charging protection circuit according to claim 5, characterized in that: The charging management circuit further includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a second diode, a second capacitor, and a third capacitor; Among them, the first end of the first resistor is electrically connected to the CE pin of the charging management chip, and the second end of the first resistor is electrically connected to the first end of the first capacitor; the first end of the second resistor is electrically connected to the VCC pin of the charging management chip, and the second end of the second resistor is electrically connected to the anode of the second diode; the first end of the third resistor is electrically connected to the ground terminal, and the second end of the third resistor is electrically connected to the PROG pin of the charging management chip; the first end of the fourth resistor is electrically connected to the CE pin of the charging management chip, and the second end of the fourth resistor is electrically connected to the second end of the third capacitor; the first end of the fifth resistor is electrically connected to the STBDY pin of the charging management chip, and the second end of the fifth resistor is electrically connected to the first end of the third capacitor; the cathode of the second diode is electrically connected to the BAT pin of the charging management chip; the first end of the second capacitor is electrically connected to the ground terminal, and the second end of the second capacitor is electrically connected to the VCC pin of the charging management chip; the first end of the third capacitor is electrically connected to the power output terminal; the TEMP pin, GND pin, and CHRG pin of the charging management chip are electrically connected to the ground terminal.

7. The charging protection circuit according to claim 1, characterized in that: The battery protection circuit includes a battery protection chip.

8. The charging protection circuit according to claim 7, characterized in that: The battery protection circuit also includes a sixth resistor, a seventh resistor, and a fourth capacitor; Among them, the first end of the sixth resistor is electrically connected to the YM1 pin, YM2 pin, YM3 pin, YM4 pin and the ground terminal of the battery protection chip, and the second end of the sixth resistor is electrically connected to the second end of the fourth capacitor and the negative electrode of the battery; the first end of the fourth capacitor is electrically connected to the second end of the seventh resistor and the VDD pin of the battery protection chip, and the second end of the fourth capacitor is electrically connected to the GND pin and EPAD pin of the battery protection chip; the first end of the seventh resistor is electrically connected to the positive electrode of the battery.

9. A dental flosser, characterized in that: The water flosser comprises a charging protection circuit as described in any one of claims 1-8.

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