Control circuit and oral irrigator

Abstract

The utility model discloses a control circuit and oral irrigator, oral irrigator includes: knob assembly, knob assembly includes first signal transmission end, second signal transmission end and first ground end, and first ground end ground connection, knob assembly still includes third signal transmission end and second ground end, and third signal transmission end is used for accessing power end, first switch circuit, and the input of first switch circuit accesses power end, and first switch circuit has first output and second output, and first output is connected with first signal transmission end, and second output is connected with second signal transmission end, main control circuit, and main control circuit is connected with first signal transmission end, second signal transmission end, third signal transmission end, the controlled end of first switch circuit and motor drive circuit respectively, the utility model aims at improving the operation reliability of oral irrigator.

Description

Technical Field

[0001] This utility model relates to the field of oral irrigator technology, and in particular to a control circuit and an oral irrigator. Background Technology

[0002] With increasing emphasis on oral health, water flossers, as a highly efficient oral cleaning tool, have become widely used in daily life. Water flossers use high-pressure pulsed water to rinse hard-to-reach areas such as between teeth and along the gum line, effectively removing food debris and plaque. They offer advantages such as thorough cleaning and ease of use.

[0003] Current oral irrigators typically have multiple independent buttons, such as a "power on / off button," a "water pressure increase button," and a "water pressure decrease button," used to start / stop the device and adjust the water pressure. Users need to press different buttons during use to activate the oral irrigator and set its parameters.

[0004] However, because the surface area of ​​the water flosser housing is small, the layout of multiple buttons is usually quite compact during the design process. This compact layout can easily lead to accidental touches or repeated presses, resulting in incorrect gear switching or unexpected shutdown. Utility Model Content

[0005] The main purpose of this invention is to propose a control circuit and a water flosser, which aims to improve the operational reliability of the water flosser.

[0006] To achieve the above objectives, this utility model proposes a control circuit for use in a water flosser. The water flosser includes a motor drive circuit and a motor, wherein the motor drive circuit is electrically connected to the motor, and the control circuit includes:

[0007] A knob assembly includes a first signal transmission terminal, a second signal transmission terminal, and a first ground terminal, wherein the first ground terminal is grounded; the knob assembly is used to connect / disconnect the path between the first signal transmission terminal and / or the second signal transmission terminal and the first ground terminal when rotated.

[0008] The knob assembly is used to control the first signal transmission terminal to turn on / off the path with the first ground terminal before the second signal transmission terminal when rotated in the first direction; the knob assembly is also used to control the second signal transmission terminal to turn on / off the path with the first ground terminal before the first signal transmission terminal when rotated in the second direction.

[0009] The knob assembly further includes a third signal transmission terminal and a second ground terminal. The third signal transmission terminal is used to connect to a power supply terminal, and the knob assembly is used to connect / disconnect the path between the third signal transmission terminal and the second ground terminal when pressed.

[0010] A first switching circuit, wherein the input terminal of the first switching circuit is connected to the power supply terminal, the first switching circuit has a first output terminal and a second output terminal, the first output terminal is connected to the first signal transmission terminal, and the second output terminal is connected to the second signal transmission terminal;

[0011] The main control circuit is electrically connected to the first signal transmission terminal, the second signal transmission terminal, the third signal transmission terminal, the controlled terminal of the first switch circuit, and the motor drive circuit, respectively.

[0012] Wherein, the first direction is one of clockwise and counterclockwise, and the second direction is the other of clockwise and counterclockwise.

[0013] In one embodiment, the first switching circuit includes:

[0014] A first switching transistor, a first resistor, and a second resistor are provided. The input terminal of the first switching transistor and the first terminal of the first resistor are both connected to a power supply terminal. The second terminals of the first resistor and the second resistor are both connected to the controlled terminal of the first switching transistor. The first terminal of the second resistor is electrically connected to the main control circuit.

[0015] In one embodiment, the control circuit further includes:

[0016] The system comprises a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor. The first end of the third resistor is connected to the first output terminal, and the second end of the third resistor is electrically connected to the first end of the seventh resistor and the main control circuit, respectively. The second end of the seventh resistor is also connected to the first signal transmission terminal. The first end of the fourth resistor is connected to the second output terminal, and the second end of the fourth resistor is electrically connected to the first end of the sixth resistor and the main control circuit, respectively. The second end of the sixth resistor is also connected to the second signal transmission terminal. The first end of the fifth resistor is used to connect to the power supply terminal, and the second end of the fifth resistor is connected to both the main control circuit and the third signal transmission terminal.

[0017] In one embodiment, the control circuit further includes:

[0018] A first capacitor, a second capacitor, and a third capacitor are provided. The first terminal of the first capacitor is connected to the first output terminal and the first signal transmission terminal, respectively, and the second terminal of the first capacitor is grounded. The first terminal of the second capacitor is connected to the second output terminal and the second signal transmission terminal, respectively, and the second terminal of the second capacitor is grounded. The first terminal of the third capacitor is connected to the third signal transmission terminal, and the second terminal of the third capacitor is grounded.

[0019] This utility model also proposes a dental flosser, including a motor drive circuit, a motor, and a control circuit as described in any of the above; the motor drive circuit is electrically connected to the control circuit and the motor respectively.

[0020] In one embodiment, the motor includes a first power supply terminal and a second power supply terminal, the first power supply terminal being used to connect to the power supply terminal, and the motor drive circuit including:

[0021] The second switching circuit has its input terminal connected to the second power supply terminal, its output terminal grounded, and its controlled terminal electrically connected to the main control circuit.

[0022] In one embodiment, the second switching circuit includes:

[0023] The first switch branch and the second switch branch are connected to the second power supply terminal of the motor. The output terminals of the first switch branch and the second switch branch are grounded. The controlled terminals of the first switch circuit and the second switch circuit are electrically connected to the main control circuit.

[0024] In one embodiment, the first switching branch is a second switching transistor, the second switching branch is a third switching transistor, the second switching circuit further includes an eighth resistor and a ninth resistor, the input terminals of the second switching transistor and the third switching transistor are both connected to the second power supply terminal, the controlled terminals of the second switching transistor and the third switching transistor are respectively connected to the first terminal of the eighth resistor and the first terminal of the ninth resistor, the second terminal of the eighth resistor is electrically connected to the main control circuit, and the output terminals of the second switching transistor, the third switching transistor, and the second terminal of the ninth resistor are all grounded.

[0025] In one embodiment, the oral irrigator further includes:

[0026] A current sampling circuit is provided, wherein the sampling terminal of the current sampling circuit is connected to the output terminal of the second switching circuit, and the current sampling circuit is electrically connected to the main control circuit. The current sampling circuit is used to sample the output current of the second switching circuit and output a corresponding current sampling signal. The main control circuit is used to control the second switching circuit to disconnect when it detects that the output current of the second switching circuit is greater than a preset current based on the current sampling signal.

[0027] In one embodiment, the current sampling circuit includes:

[0028] The circuit comprises a tenth resistor, an eleventh resistor, and a fourth capacitor. The first ends of the tenth resistor and the eleventh resistor are both connected to the output terminal of the second switching circuit. The second end of the eleventh resistor is grounded. The second end of the tenth resistor is electrically connected to the first end of the fourth capacitor and the main control circuit, respectively. The second end of the fourth capacitor is grounded.

[0029] The knob assembly of this invention, when pressed, connects the path between the third signal transmission terminal and the second ground terminal, allowing the main control circuit to receive a low-level signal. This control enables the motor drive circuit to operate the motor, putting the water flosser into working condition. It also controls the first switch circuit to connect the power supply terminal to the first and second signal transmission terminals. When rotated in the first direction, the knob assembly controls the first signal transmission terminal to connect / disconnect from the first ground terminal before the second signal transmission terminal, causing the first pulse signal output by the first signal transmission terminal to lead the second pulse signal output by the second signal transmission terminal. When the main control circuit detects that the first pulse signal leads the second pulse signal, it controls the motor drive circuit to increase the water pressure of the water flosser. The knob assembly is used to control the second signal transmission terminal to turn on / off the path between the second signal transmission terminal and the first ground terminal before the first signal transmission terminal when rotated in the second direction, so that the second pulse signal output by the second signal transmission terminal leads the first pulse signal output by the first signal transmission terminal. When the main control circuit identifies that the second pulse signal leads the first pulse signal according to the received signal, it controls the motor drive circuit to drive the motor to control the water pressure of the water flosser to decrease.

[0030] With this design, the present invention replaces multiple independent mechanical buttons with a single "rotation + press" integrated knob, realizing multi-functional integrated control of "gear adjustment + switch", eliminating the risk of simultaneous pressing between adjacent buttons and the risk of accidental touch of multiple buttons, thereby improving the operational reliability of the oral irrigator and enhancing the user experience. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of a module according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the circuit structure of an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of a module according to another embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of a module according to another embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of the circuit structure of another embodiment of the present invention;

[0037] Figure 6 This is a schematic diagram of a module according to another embodiment of the present invention;

[0038] Figure 7 This is a schematic diagram of the circuit structure of another embodiment of the present invention.

[0039] Explanation of icon numbers:

[0040] 10. Knob assembly; 20. First switch circuit; 30. Main control circuit; 40. Motor drive circuit; 41. Second switch circuit; 411. First switch branch; 412. Second switch branch; 50. Motor; 60. Current sampling circuit.

[0041] 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

[0042] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0043] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0044] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0045] With increasing emphasis on oral health, water flossers, as a highly efficient oral cleaning tool, have become widely used in daily life. Water flossers use high-pressure pulsed water to rinse hard-to-reach areas such as between teeth and along the gum line, effectively removing food debris and plaque. They offer advantages such as thorough cleaning and ease of use.

[0046] Current oral irrigators typically have multiple independent buttons, such as a "power on / off button," a "water pressure increase button," and a "water pressure decrease button," used to start / stop the device and adjust the water pressure. Users need to press different buttons during use to activate the oral irrigator and set its parameters.

[0047] However, because the surface area of ​​the water flosser housing is small, the layout of multiple buttons is usually quite compact during the design process. This compact layout can easily lead to accidental touches or repeated presses, resulting in incorrect gear switching or unexpected shutdown.

[0048] Therefore, this utility model proposes a control circuit for use in a water flosser. The water flosser includes a motor drive circuit 40 and a motor 50, wherein the motor drive circuit 40 is electrically connected to the motor 50. In one embodiment, refer to... Figure 1 The control circuit includes:

[0049] A knob assembly 10 includes a first signal transmission terminal, a second signal transmission terminal, and a first ground terminal, wherein the first ground terminal is grounded; the knob assembly 10 is used to connect / disconnect the path between the first signal transmission terminal and / or the second signal transmission terminal and the first ground terminal when rotated.

[0050] The knob assembly 10 is used to control the first signal transmission terminal to turn on / off the path with the first ground terminal before the second signal transmission terminal when rotated in the first direction; the knob assembly 10 is also used to control the second signal transmission terminal to turn on / off the path with the first ground terminal before the first signal transmission terminal when rotated in the second direction.

[0051] The knob assembly 10 further includes a third signal transmission terminal and a second ground terminal. The third signal transmission terminal is used to connect to a power supply terminal, and the knob assembly 10 is used to connect / disconnect the path between the third signal transmission terminal and the second ground terminal when pressed.

[0052] A first switching circuit 20 has an input terminal connected to a power supply terminal. The first switching circuit 20 has a first output terminal and a second output terminal. The first output terminal is connected to the first signal transmission terminal, and the second output terminal is connected to the second signal transmission terminal.

[0053] The main control circuit 30 is electrically connected to the first signal transmission terminal, the second signal transmission terminal, the third signal transmission terminal, the controlled terminal of the first switch circuit 20, and the motor drive circuit 40, respectively.

[0054] Wherein, the first direction is one of clockwise and counterclockwise, and the second direction is the other of clockwise and counterclockwise.

[0055] It should be noted that the knob assembly 10 can be implemented using a rotary encoder with encoding function, such as a mechanical incremental encoder. The first signal transmission end and the second signal transmission end correspond to the A-phase output and B-phase output of the encoder, respectively, and the first grounding end corresponds to the common ground of the encoder. Each time the encoder rotates by one step angle, the internal metal spring of the encoder will sequentially connect the path between phase A or phase B and ground, causing the first signal transmission end and the second signal transmission end to generate pulse signals. In a specific embodiment, when the first switching circuit 20 is turned on and the knob assembly 10 rotates clockwise, the first signal transmission end is grounded before the second signal transmission end, and also disconnected from ground before the second signal transmission end. Thus, the first pulse signal output by the first signal transmission end leads the second pulse signal output by the second signal transmission end. When the main control circuit 30 identifies that the first signal transmission end is ahead of the second signal transmission end based on the received signal, it controls the motor drive circuit 40 to drive the motor 50 to increase the spray water pressure of the water flosser. When the knob assembly 10 rotates counterclockwise, the second signal transmission terminal is grounded before the first signal transmission terminal, and also disconnected from ground before the first signal transmission terminal. Thus, the second pulse signal output by the second signal transmission terminal leads the second pulse signal output by the first signal transmission terminal. When the main control circuit 30 detects that the second signal transmission terminal is ahead of the first signal transmission terminal based on the received signal, it controls the motor drive circuit 40 to drive the motor 50 to reduce the water pressure of the water flosser. By detecting the order in which the first and second signal transmission terminals are grounded, the main control circuit 30 can determine the rotation direction of the knob assembly 10, thereby adjusting the water pressure level of the water flosser.

[0056] Understandably, since motor 50 is connected to the water pump of the water flosser, the higher the rotational speed of motor 50, the more water the pump pushes per unit time, and the higher the water pressure setting of the water flosser. The main control circuit 30 can be used to increase the rotational speed of motor 50 via motor drive circuit 40 when it detects that the knob assembly 10 is rotating in the first direction, thereby increasing the water pressure setting of the water flosser. It can also be used to decrease the rotational speed of motor 50 via motor drive circuit 40 when it detects that the knob assembly 10 is rotating in the second direction, thereby decreasing the water pressure setting of the water flosser.

[0057] It is understandable that when the knob assembly 10 rotates clockwise, the pulse signal output by the second signal transmission terminal can lead the first signal transmission terminal, and when it rotates counterclockwise, the pulse signal output by the first signal transmission terminal can lead the second signal transmission terminal, depending on the relative position of the first signal transmission terminal and the second signal transmission terminal.

[0058] Understandably, when the first switching circuit 20 is turned on and the path between the first signal transmission terminal / second signal transmission terminal and the first ground terminal is broken, the voltage of the first signal transmission terminal / second signal transmission terminal is pulled high. Conversely, when the path between the first signal transmission terminal / second signal transmission terminal and the first ground terminal is turned on, the voltage of the first signal transmission terminal / second signal transmission terminal is pulled low. Thus, when the knob assembly 10 is rotated, the first signal transmission terminal / second signal transmission terminal can output a pulse signal to the main control circuit 30.

[0059] It should be noted that the knob assembly 10 has a push switch connected in series between the third signal transmission terminal and the second ground terminal. When the knob assembly 10 is pressed, the push switch opens the path between the third signal transmission terminal and the second ground terminal, so that the third signal transmission terminal outputs a low-level signal to the main control circuit 30. When the main control circuit 30 receives the low-level signal output, it controls the motor drive circuit 40 to drive the motor 50 to work, so that the water flosser enters the working state. It also controls the first switch circuit 20 to open the voltage terminal and the path between the first signal transmission terminal and the second signal transmission terminal, so that when the knob assembly 10 is rotated, the first signal transmission terminal and the second signal transmission terminal can output pulse signals to the main control circuit 30, thereby allowing the user to rotate the knob assembly 10 to adjust the water pressure of the water flosser.

[0060] In this embodiment, the first switching circuit 20 can be implemented using at least one switching transistor, such as a MOSFET, IGBT, thyristor, transistor, power transistor, etc., and / or using at least one switching device, such as a contactor, circuit breaker, and relay. In a specific embodiment, refer to... Figure 2 The first switching circuit 20 includes:

[0061] A first switch Q1, a first resistor R1, and a second resistor R2 are used. The input terminal of the first switch Q1 and the first terminal of the first resistor R1 are both connected to the power supply. The second terminals of the first resistor R1 and the second terminal of the second resistor R2 are both connected to the controlled terminal of the first switch Q1. The first terminal of the second resistor R2 is electrically connected to the main control circuit 30. The first switch Q1 is a PMOS transistor.

[0062] The main control circuit 30 is used to output a low-level signal to the first switch Q1 when it receives a low-level signal from the third signal transmission terminal, so as to turn on the first switch Q1.

[0063] In this embodiment, the main control circuit 30 can be implemented using a main controller, such as an MCU (Microcontroller Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or a SOC (System On Chip).

[0064] With the above configuration, the knob assembly 10, when pressed, connects the path between the third signal transmission terminal and the second ground terminal, so that the main control circuit 30 receives a low-level signal, controls the motor drive circuit 40 to drive the motor 50 to work, so that the water flosser enters the working state, and controls the first switch circuit 20 to connect the path between the power supply terminal and the first signal transmission terminal and the second signal transmission terminal. When rotated in the first direction, the knob assembly 10 controls the first signal transmission terminal to connect / disconnect the path with the first ground terminal before the second signal transmission terminal, so that the first pulse signal output by the first signal transmission terminal leads the second pulse signal output by the second signal transmission terminal. When the main control circuit 30 identifies that the first pulse signal leads the second pulse signal based on the received signal, it controls the motor drive circuit 40 to drive the motor 50 to increase the water pressure of the water flosser. The knob assembly 10 is used to control the second signal transmission terminal to turn on / off the path between the second signal transmission terminal and the first ground terminal before the first signal transmission terminal when rotated in the second direction, so that the second pulse signal output by the second signal transmission terminal leads the first pulse signal output by the first signal transmission terminal. When the main control circuit 30 identifies that the second pulse signal leads the first pulse signal according to the received signal, it controls the motor drive circuit 40 to drive the motor 50 to control the water jet pressure of the water flosser to decrease.

[0065] With this design, the present invention replaces multiple independent mechanical buttons with a single "rotation + press" integrated knob, realizing multi-functional integrated control of "gear adjustment + switch", eliminating the risk of simultaneous pressing between adjacent buttons and the risk of accidental touch of multiple buttons, thereby improving the operational reliability of the oral irrigator and enhancing the user experience.

[0066] In one embodiment of this utility model, reference is made to Figure 2 The control circuit further includes:

[0067] The system comprises a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. The first end of the third resistor R3 is connected to the first output terminal, and the second end of the third resistor R3 is electrically connected to both the first end of the seventh resistor R7 and the main control circuit 30. The second end of the seventh resistor R7 is also connected to the first signal transmission terminal. The first end of the fourth resistor R4 is connected to the second output terminal, and the second end of the fourth resistor R4 is electrically connected to both the first end of the sixth resistor R6 and the main control circuit 30. The second end of the sixth resistor R6 is also connected to the second signal transmission terminal. The first end of the fifth resistor R5 is connected to the power supply terminal, and the second end of the fifth resistor R5 is connected to both the main control circuit 30 and the third signal transmission terminal.

[0068] In this embodiment, the third resistor R3 and the fourth resistor R4 are both pull-up resistors, used to pull up the voltages of the first signal transmission terminal and the second signal transmission terminal respectively when the first switching circuit 20 is turned on and the first signal transmission terminal and the second signal transmission terminal are not connected to the first ground terminal. The sixth resistor R6 and the seventh resistor R7 are current-limiting resistors, used to limit the current received by the main control circuit 30 through the first signal transmission terminal, serving as a buffer protection function. The fifth resistor R5 is a pull-up resistor, used to pull up the voltage of the third signal transmission terminal when the third signal transmission terminal is not connected to the second ground terminal, so that the main control circuit 30 controls the water flosser to close when it detects that the voltage of the third signal transmission terminal is high.

[0069] In one embodiment of this utility model, reference is made to Figure 2 The control circuit further includes:

[0070] The capacitor consists of a first capacitor C1, a second capacitor C2, and a third capacitor C3. The first terminal of the first capacitor C1 is connected to the first output terminal and the first signal transmission terminal, respectively, and the second terminal of the first capacitor C1 is grounded. The first terminal of the second capacitor C2 is connected to the second output terminal and the second signal transmission terminal, respectively, and the second terminal of the second capacitor C2 is grounded. The first terminal of the third capacitor C3 is connected to the power supply terminal and the third signal transmission terminal, respectively, and the second terminal of the third capacitor C3 is grounded.

[0071] In this embodiment, the first capacitor C1, the second capacitor C2, and the third capacitor C3 are all filter capacitors. The first capacitor C1 and the second capacitor C2 are used to provide hardware-level debouncing and high-frequency filtering at the first signal transmission end and the second signal transmission end, respectively, so that the pulse signal received by the main control circuit 30 is smooth and jitter-free, ensuring that the rotation direction and number of steps of the knob assembly 10 are accurately identified by the main control circuit 30. The third capacitor C3 eliminates the jitter when the knob assembly 10 is pressed, preventing the main control circuit 30 from misinterpreting it as multiple presses.

[0072] This utility model also proposes a dental flosser, including a motor drive circuit 40, a motor 50, and the control circuit described above; the motor drive circuit 40 is electrically connected to the control circuit and the motor 50 respectively.

[0073] It is worth noting that since the oral irrigator of this utility model is based on the above-mentioned control circuit, the embodiments of the oral irrigator of this utility model include all the technical solutions of all the embodiments of the above-mentioned control circuit, and the technical effects achieved are exactly the same, so they will not be repeated here.

[0074] In one embodiment of this utility model, reference is made to Figure 3 The motor 50 includes a first power supply terminal and a second power supply terminal, the first power supply terminal being used to connect to the power supply terminal, and the motor drive circuit 40 including:

[0075] The second switching circuit 41 has its input terminal connected to the second power supply terminal, its output terminal grounded, and its controlled terminal electrically connected to the main control circuit 30.

[0076] In this embodiment, the main control circuit 30 is used to output a corresponding control signal to control the conduction duration / conduction frequency of the second switch circuit 41 when the rotation of the knob assembly 10 is detected, so as to increase / decrease the current received by the motor 50, thereby adjusting the speed of the motor 50 and ultimately adjusting the spray pressure of the water flosser.

[0077] In this embodiment, the second switching circuit 41 can be implemented using at least one switching transistor, such as a MOSFET, IGBT, thyristor, transistor, or power transistor. In a specific embodiment, refer to... Figure 4 The second switching circuit 41 includes:

[0078] The first switch branch 411 and the second switch branch 412 are connected to the second power supply terminal of the motor 50. The output terminals of the first switch branch 411 and the second switch branch 412 are grounded. The controlled terminals of the first switch circuit 20 and the second switch circuit 41 are electrically connected to the main control circuit 30.

[0079] In this embodiment, the first switch branch 411 and the second switch branch 412 are used to shunt the current output from the second power supply terminal of the motor 50, preventing excessive current output from the second power supply terminal from damaging a single switch branch. Furthermore, even if one switch branch experiences poor contact or aging, the other can still maintain basic functionality, improving the reliability of the water flosser.

[0080] In this embodiment, the first switch branch 411 and the second switch branch 412 can be implemented using at least one switching transistor, such as a MOSFET, IGBT, thyristor, transistor, power transistor, etc.

[0081] In one specific embodiment, reference is made to Figure 5 The first switch branch 411 is the second switch transistor Q2, the second switch branch 412 is the third switch transistor Q3, and the second switch circuit 41 also includes an eighth resistor R8 and a ninth resistor R9. The input terminals of the second switch transistor Q2 and the third switch transistor Q3 are both connected to the second power supply terminal. The controlled terminals of the second switch transistor Q2 and the third switch transistor Q3 are respectively connected to the first terminals of the eighth resistor R8 and the ninth resistor R9. The second terminal of the eighth resistor R8 is electrically connected to the main control circuit 30. The output terminals of the second switch transistor Q2, the third switch transistor Q3, and the second terminal of the ninth resistor R9 are all grounded. Both the second switch transistor Q2 and the third switch transistor Q3 are NMOS transistors. The main control circuit 30 controls the conduction duration / frequency of the second switch transistor Q2 and the third switch transistor Q3 by outputting control signals with the same duty cycle, thereby controlling the current flowing into the motor 50.

[0082] In one embodiment of this utility model, reference is made to Figure 6 The oral irrigator also includes:

[0083] A current sampling circuit 60 is provided, the sampling terminal of which is connected to the output terminal of the second switching circuit 41. The current sampling circuit 60 is electrically connected to the main control circuit 30. The current sampling circuit 60 is used to sample the output current of the second switching circuit 41 and output a corresponding current sampling signal. The main control circuit 30 is used to control the second switching circuit 41 to disconnect when it detects that the output current of the second switching circuit 41 is greater than a preset current based on the current sampling signal.

[0084] In this embodiment, the main control circuit 30 is used to control the second switch circuit 41 to disconnect when the current flowing into the motor 50 is determined to be too large (greater than the preset current) based on the current sampling signal, so as to stop the motor 50 from working and avoid the excessive current from affecting the motor 50.

[0085] In this embodiment, optionally, the current sampling circuit 60 can be implemented using a sampling resistor. (See reference...) Figure 7 The current sampling circuit 60 includes:

[0086] The system comprises a tenth resistor R10, an eleventh resistor R11, and a fourth capacitor C4. The first terminals of both the tenth and eleventh resistors R10 and R11 are connected to the output terminal of the second switching circuit 41. The second terminal of the eleventh resistor R11 is grounded. The second terminal of the tenth resistor R10 is electrically connected to both the first terminal of the fourth capacitor C4 and the main control circuit 30. The second terminal of the fourth capacitor C4 is also grounded. The main control circuit 30 determines the current flowing into the motor 50 based on the detected voltage of the eleventh resistor R11.

[0087] Optionally, the current sampling circuit 60 can also be implemented using a current sensor, such as a Hall effect current sensor or a current transformer.

[0088] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A control circuit applied to a water flosser, the water flosser comprising a motor drive circuit and a motor, the motor drive circuit being electrically connected to the motor, characterized in that, The control circuit includes: A knob assembly includes a first signal transmission terminal, a second signal transmission terminal, and a first ground terminal, wherein the first ground terminal is grounded; the knob assembly is used to connect / disconnect the path between the first signal transmission terminal and / or the second signal transmission terminal and the first ground terminal when rotated. The knob assembly is used to control the first signal transmission terminal to turn on / off the path with the first ground terminal before the second signal transmission terminal when rotated in the first direction; the knob assembly is also used to control the second signal transmission terminal to turn on / off the path with the first ground terminal before the first signal transmission terminal when rotated in the second direction. The knob assembly further includes a third signal transmission terminal and a second ground terminal. The third signal transmission terminal is used to connect to a power supply terminal, and the knob assembly is used to connect / disconnect the path between the third signal transmission terminal and the second ground terminal when pressed. A first switching circuit, wherein the input terminal of the first switching circuit is connected to the power supply terminal, the first switching circuit has a first output terminal and a second output terminal, the first output terminal is connected to the first signal transmission terminal, and the second output terminal is connected to the second signal transmission terminal; The main control circuit is electrically connected to the first signal transmission terminal, the second signal transmission terminal, the third signal transmission terminal, the controlled terminal of the first switch circuit, and the motor drive circuit, respectively. Wherein, the first direction is one of clockwise and counterclockwise, and the second direction is the other of clockwise and counterclockwise.

2. The control circuit as described in claim 1, characterized in that, The first switching circuit includes: a first switching transistor, a first resistor, and a second resistor. The input terminal of the first switching transistor and the first terminal of the first resistor are both used to connect to the power supply terminal. The second terminals of the first resistor and the second resistor are both connected to the controlled terminal of the first switching transistor. The first terminal of the second resistor is electrically connected to the main control circuit.

3. The control circuit as described in claim 1, characterized in that, The control circuit also includes: The system comprises a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor. The first end of the third resistor is connected to the first output terminal, and the second end of the third resistor is electrically connected to the first end of the seventh resistor and the main control circuit, respectively. The second end of the seventh resistor is also connected to the first signal transmission terminal. The first end of the fourth resistor is connected to the second output terminal, and the second end of the fourth resistor is electrically connected to the first end of the sixth resistor and the main control circuit, respectively. The second end of the sixth resistor is also connected to the second signal transmission terminal. The first end of the fifth resistor is used to connect to the power supply terminal, and the second end of the fifth resistor is connected to both the main control circuit and the third signal transmission terminal.

4. The control circuit as described in claim 1, characterized in that, The control circuit also includes: A first capacitor, a second capacitor, and a third capacitor are provided. The first terminal of the first capacitor is connected to the first output terminal and the first signal transmission terminal, respectively, and the second terminal of the first capacitor is grounded. The first terminal of the second capacitor is connected to the second output terminal and the second signal transmission terminal, respectively, and the second terminal of the second capacitor is grounded. The first terminal of the third capacitor is connected to the third signal transmission terminal, and the second terminal of the third capacitor is grounded.

5. A dental flosser, characterized in that, It includes a motor drive circuit, a motor, and a control circuit as described in any one of claims 1 to 4; the motor drive circuit is electrically connected to the control circuit and the motor, respectively.

6. The oral irrigator as described in claim 5, characterized in that, The motor includes a first power supply terminal and a second power supply terminal, the first power supply terminal being used to connect to the power supply terminal, and the motor drive circuit including: The second switching circuit has its input terminal connected to the second power supply terminal, its output terminal grounded, and its controlled terminal electrically connected to the main control circuit.

7. The oral irrigator as described in claim 6, characterized in that, The second switching circuit includes: The first switch branch and the second switch branch are connected to the second power supply terminal of the motor. The output terminals of the first switch branch and the second switch branch are grounded. The controlled terminals of the first switch circuit and the second switch circuit are electrically connected to the main control circuit.

8. The oral irrigator as described in claim 7, characterized in that, The first switch branch is a second switch transistor, the second switch branch is a third switch transistor, and the second switch circuit also includes an eighth resistor and a ninth resistor. The input terminals of the second switch transistor and the third switch transistor are both connected to the second power supply terminal. The controlled terminals of the second switch transistor and the third switch transistor are respectively connected to the first terminal of the eighth resistor and the first terminal of the ninth resistor. The second terminal of the eighth resistor is electrically connected to the main control circuit. The output terminals of the second switch transistor, the third switch transistor, and the ninth resistor are all grounded.

9. The oral irrigator as described in claim 6, characterized in that, The oral irrigator also includes: A current sampling circuit is provided, wherein the sampling terminal of the current sampling circuit is connected to the output terminal of the second switching circuit, and the current sampling circuit is electrically connected to the main control circuit. The current sampling circuit is used to sample the output current of the second switching circuit and output a corresponding current sampling signal. The main control circuit is used to control the second switching circuit to disconnect when it detects that the output current of the second switching circuit is greater than a preset current based on the current sampling signal.

10. The oral irrigator as described in claim 9, characterized in that, The current sampling circuit includes: The circuit comprises a tenth resistor, an eleventh resistor, and a fourth capacitor. The first ends of the tenth resistor and the eleventh resistor are both connected to the output terminal of the second switching circuit. The second end of the eleventh resistor is grounded. The second end of the tenth resistor is electrically connected to the first end of the fourth capacitor and the main control circuit, respectively. The second end of the fourth capacitor is grounded.

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