Drive circuit for electric toothbrushes and electric toothbrushes

Abstract

This utility model discloses a drive circuit for an electric toothbrush and an electric toothbrush. The drive circuit includes a cleaning drive circuit, which is connected to a first wiring port and a second wiring port of a driver, respectively. The drive circuit also includes an audio drive circuit, which includes a voice chip with a first audio output terminal and a second audio output terminal, respectively connected to the first wiring port and the second wiring port. The cleaning drive circuit further includes a switching resistor module, which includes a resistor and a switch connected in parallel with the resistor. When the switch is controlled to be on, the resistor is not connected to the cleaning drive circuit; when the switch is controlled to be off, the resistor is connected to the cleaning drive circuit. This drive circuit can flexibly connect the audio drive current and control the proportion of the audio drive current in the motor drive current, meeting the needs of different usage scenarios and various audio content outputs.

Description

Technical Field

[0001] This utility model relates to a drive circuit for an electric toothbrush, and more specifically, to a drive circuit with audio drive. Background Technology

[0002] Driven by the modern concept of convenient living, electric toothbrushes have become widely used in daily life due to their efficient cleaning and ease of use, making them the preferred tool for oral care for many consumers.

[0003] Current electric toothbrushes generally employ a technology that transmits sound via a drive shaft. This technology brings numerous significant and undeniable benefits to the functionality of electric toothbrushes. From the perspective of improving user experience, using a drive shaft to transmit sound makes the operation of the device more direct and clear, simplifying the interaction between the user and the device. Simultaneously, this method also demonstrates excellent effectiveness in information delivery; information is not only more direct but also highly efficient. For example, through voice prompts or broadcasts, users can obtain real-time and accurate information about the electric toothbrush's working status, mode switching, and battery level, making the entire usage process more intelligent and user-friendly, significantly enhancing the overall user experience when using an electric toothbrush.

[0004] However, with the continuous advancement and development of technology, people's functional needs for electric toothbrushes are becoming increasingly diversified, and audio transmission scenarios are becoming more complex and varied. At the same time, the market offers a wide variety of electric toothbrushes, with significant differences in their driver designs. To meet these growing and diverse demands, existing circuit designs need continuous adjustment and optimization to adapt to different types of electric toothbrushes and various complex audio transmission scenarios. This situation has led to increasingly complex existing circuit designs, not only increasing the difficulty and cost of manufacturing but also potentially impacting the stability and reliability of the product.

[0005] Therefore, a more versatile circuit solution is needed. This circuit should be highly adaptable and flexible, capable of meeting the personalized needs of different types of electric toothbrushes while seamlessly integrating with various diverse audio transmission scenarios. Utility Model Content

[0006] To overcome the shortcomings of the prior art, this utility model provides a driving circuit for an electric toothbrush. The driving circuit includes a cleaning driving circuit, which is connected to the first and second terminals of the driver. When the cleaning driving circuit is turned on, the cleaning driving current... The flow passes through the driver; the driver circuit also includes an audio driver circuit, which includes a voice chip. The voice chip has a first audio output terminal and a second audio output terminal, which are respectively connected to a first wiring port and a second wiring port. The cleaning driver circuit also includes a switching resistor module, which includes a resistor and a switching switch connected in parallel with the resistor. When the switching switch is controlled to be turned on, since the on-resistance of the switching switch is very small, the resistor is equivalent to being short-circuited by the on-resistance of the switching switch, and the resistor is equivalent to not being connected to the cleaning driver circuit. When the switching switch is controlled to be turned off, the resistor is connected to the cleaning driver circuit.

[0007] According to one aspect of this utility model, when the audio driving circuit provides audio driving current to the driver... The cleaning drive circuit provides a cleaning drive current to the driver. Audio drive current and clean drive current The clean drive current flows separately or simultaneously through the driver's coils. When the switching switch of the switching resistor module is turned off, the clean drive current... Less than the audio drive current .

[0008] According to another aspect of this utility model, the resistance value of the resistor is ten times or more the on-resistance value of the switching resistor module when the switching switch is turned on.

[0009] According to another aspect of the present invention, a switching resistor module includes: a first switching resistor module, the first switching resistor module including a first resistor and a switching switch connected in parallel with the resistor, and connected to a first wiring port of a driver; and a second switching resistor module, the second switching resistor module including a second resistor and a switching switch connected in parallel with the resistor, and connected to a second port of the driver.

[0010] According to another aspect of the present invention, a first switching resistor module is connected in series between the positive terminal of the power supply and the first terminal, while a second switching resistor module is connected in series between the negative terminal of the power supply and the second terminal.

[0011] According to another aspect of the present invention, the cleaning drive circuit includes an H-bridge circuit, which includes a first bridge arm and a second bridge arm connected between the positive terminal of the power supply and the driver, and a third bridge arm and a fourth bridge arm connected between the negative terminal of the power supply and the driver. The first and third bridge arms are connected to a second terminal, and the second and fourth bridge arms are connected to a first terminal. A first switching resistor module and a second switching resistor module are connected in one of the following ways: the first and second bridge arms are connected to the positive terminal of the power supply via the first switching resistor module, and the third and fourth bridge arms are connected to the negative terminal of the power supply via the second switching resistor module; the first switching resistor module is connected in series in the first bridge arm, and the second switching resistor module is connected in series in the fourth bridge arm; or the first switching resistor module is connected in series in the second bridge arm, and the second switching resistor module is connected in series in the third bridge arm.

[0012] According to another aspect of the present invention, the first resistor and the second resistor are of equal magnitude.

[0013] According to another aspect of this utility model, it also includes a microcontroller unit (MCU), which is connected to the voice chip and to a switch in the switching resistor module to control the switching switch to be turned on or off. When a preset condition is met, the microcontroller unit activates the voice chip and outputs an audio drive current. .

[0014] In addition, the present invention also provides an electric toothbrush, characterized in that it comprises: a driver connected to a drive shaft for connecting a toothbrush head; and a drive circuit as claimed in any of the preceding claims, the drive circuit being used to drive the driver.

[0015] Preferably, the driver includes a motor or a transducer with a flexible component, and the circuit is connected to the drive coil of the motor or the transducer.

[0016] This invention provides a drive circuit that can flexibly connect to and control the proportion of audio drive current in the motor drive current. This circuit can meet the needs of different usage scenarios and various audio content outputs, significantly improving the user experience. For electric toothbrushes with audio playback functions, this circuit design has significant advantages such as simple structure, flexible settings, and high versatility. Regardless of the drive structure used in the electric toothbrush, the sound playback function can be flexibly configured through this novel drive circuit. Attached Figure Description

[0017] For a more complete understanding of this invention, reference can be made to the following description of exemplary embodiments taken in conjunction with the accompanying drawings, in which: Figure 1 A schematic diagram of a drive circuit for an electric toothbrush according to a first embodiment of the present invention is shown.

[0018] Figure 2 A schematic diagram of a drive circuit for an electric toothbrush according to a second embodiment of the present invention is shown.

[0019] Figure 3 A schematic diagram of a drive circuit for an electric toothbrush according to a third embodiment of the present invention is shown.

[0020] Figure 4 A schematic diagram of an electric toothbrush with a drive circuit according to the present invention is shown.

[0021] List of reference numerals

[0022] 1 Electric toothbrush

[0023] 10 handles

[0024] 20 toothbrush heads

[0025] Q1, Q6 toggle switch

[0026] Q2, Q3, Q4, Q5 switching elements

[0027] M motor

[0028] L1 First terminal

[0029] L2 Second terminal

[0030] U1 voice chip Detailed Implementation

[0031] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0032] Figure 4 An electric toothbrush 1 with a motor control circuit according to the present invention is shown. The electric toothbrush 1 includes a toothbrush handle 10 and a detachable toothbrush head 20. The electric toothbrush 1 also includes a driver with a coil mounted within the handle 10 and a drive shaft connected to the driver and extending out of the handle 10. Figure 4 In the electric toothbrush 1 shown, the driver drives the brush head 20 to reciprocate around an axis along the direction of bristle extension. In other electric toothbrushes, the driver drives the brush head 20 to reciprocate around a longitudinal axis.

[0033] Figure 1A drive circuit for driving an electric toothbrush is shown. The driver includes a drive coil through which drive current flows. Here, the driver can be a common motor, and the drive circuit is connected to two terminals L1 and L2 of the motor coil. The current output from the drive circuit enters the motor coil through these two terminals, causing the motor to generate electromagnetic force that rotates the drive shaft.

[0034] According to this invention, the drive circuit includes a cleaning drive circuit and an audio drive circuit. The cleaning drive circuit and the audio drive circuit are independently connected to the motor's wiring ports. The cleaning drive circuit generates a cleaning drive current. Clean drive current The current flowing through the motor drives it to operate and outputs a cleaning force, while the audio drive circuit generates the audio drive current. When audio drive current The flow of current through the motor generates audio vibrations on its drive shaft. This audio is transmitted through the drive shaft, forming a recognizable voice signal. Specifically, the cleaning drive circuit includes a cleaning drive current for controlling the cleaning drive circuit. A switching resistor module of varying sizes. The switching resistor module includes at least one resistor and a switching element connected in parallel with the resistor. When the switching element is controlled to turn off, the resistor is connected to the cleaning drive circuit, reducing the cleaning drive current. . Figure 1A schematic diagram of a drive circuit according to a first embodiment of the present invention is shown. The drive circuit includes an H-bridge circuit serving as a cleaning drive circuit. The H-bridge circuit includes four switching elements Q2, Q3, Q4, and Q5, selected such that current can only flow unidirectionally through the switching elements, such as BJT transistors. The two ends of the motor M are connected between the bridge arm nodes of Q3 and Q4, and between the bridge arm nodes of Q2 and Q5, respectively, forming a current path. Specifically, the H-bridge circuit includes two sets of symmetrical bridge arm structures: the first bridge arm consists of the switching element Q2 and its associated circuit, the second bridge arm consists of the switching element Q3 and its associated circuit, the third bridge arm consists of the switching element Q4 and its associated circuit, and the fourth bridge arm consists of the switching element Q5 and its associated circuit. When the switching elements Q3 and Q4 are controlled to conduct and the switching elements Q2 and Q5 are turned off, current flows sequentially from the positive terminal of the power supply through the second bridge arm, the motor coil, the third bridge arm, and the negative terminal of the power supply. At this time, the motor coil generates a positive electromagnetic field, driving the motor to operate in a first rotation direction. Conversely, when switching elements Q2 and Q5 are turned on while switching elements Q3 and Q4 are turned off, the current path switches to the positive terminal of the power supply, the first bridge arm, the motor coil, the fourth bridge arm, and the negative terminal of the power supply. In this state, the current direction in the motor coil is reversed, and the magnetic field polarity is reversed, causing the motor to rotate in the opposite direction to the previously mentioned direction. By controlling the timing of the on and off of the four sets of switching elements, the H-bridge circuit can periodically change the direction of the current flowing through the motor coil, thereby achieving forward and reverse mechanical output on the drive shaft.

[0035] In particular, Figure 1 In the circuit shown, a first switching resistor module is located between the positive terminal of the power supply and the high-side bridge arm of the H-bridge circuit, including Q2 and Q3. A second switching resistor module is located between the negative terminal of the power supply and the low-side bridge arm of the H-bridge circuit, including Q4 and Q5. The first switching resistor module includes a resistor R2 and a switching switch Q1 connected in parallel with the resistor R2. The second switching resistor module includes a resistor R7 and a switching switch Q6 connected in parallel with the resistor R7. Both switching switches Q1 and Q6 are controlled by a microcontroller unit. When switching switches Q1 and / or Q6 are off, resistors R2 and / or R7 are connected to the H-bridge circuit. When switching switches Q1 and / or Q6 are on, the on-resistance of switching switches Q1 and Q6 is very small, and resistors R2 and / or R7 are bypassed by the on-resistance of the switching elements. In other words, the resistors are equivalent to not being connected to the clean drive circuit. This dynamic reconfiguration mechanism of resistors R2 and / or R7 can directly regulate the clean drive current output by the H-bridge circuit. The amplitude characteristics.

[0036] Figure 1The audio drive circuit shown includes a voice chip U1. Internally, the voice chip U1 includes a voice packet, an internal H-bridge circuit, and a current amplification circuit. The VSS1 pin of the voice chip U1 is grounded. The AUDP pin of the voice chip U1 is the positive audio output terminal, and the AUDN pin is the negative audio output terminal; they are connected to the first terminal L1 and the second terminal L2 of the motor M, respectively. The IOA1 pin of the voice chip U1 is a busy signal output (BUSY), connected to the interrupt pin or status detection pin of the microcontroller unit. The IOA2 pin is used to receive control commands from the microcontroller unit, and the audio drive current of the voice chip U1 is... The timing of the output is controlled by the microcontroller unit.

[0037] exist Figure 1 In the driving circuit shown, the cleaning drive circuit frequency is typically between 50Hz and 500Hz, and the alternating cleaning drive current is between 50Hz and 500Hz. The coil flowing through motor M drives the reciprocating rotation of the drive shaft, with a frequency ranging from 50Hz to 500Hz. The frequency of the alternating current output by the voice chip U1 depends on the audio content, with the main audio frequencies ranging from several kilohertz to tens of kilohertz. The audio frequencies of most voice signals are much higher than the frequency of the alternating current in the drive circuit.

[0038] Figure 1 The driving circuit shown is used as follows.

[0039] During normal cleaning operation without voice broadcasting, the audio drive current of the voice chip U1 is... The output is turned off, the cleaning drive circuit is activated, and the driver M operates under the cleaning drive current provided by the cleaning drive circuit. Under the action of the drive shaft, the toothbrush reciprocates and rotates, thus outputting the cleaning force of the toothbrush.

[0040] When pure voice broadcasting is required, the audio drive current of the voice chip U1... Controlled output, the cleaning drive circuit is completely shut off, that is, the H-bridge circuit is in a power-off closed state, and the audio drive current is provided by the voice chip U1. The current flows through the motor coil, causing the drive shaft to vibrate for voice, thus enabling the electric toothbrush to broadcast pure voice messages.

[0041] In scenarios where cleaning drive and voice broadcasting need to operate synchronously, the microcontroller controls the switching switches Q1 and / or Q6 to enter the off state, causing R2 and / or R7 to be connected in series to the H-bridge circuit. This means the cleaning drive current passes through resistors R2 and / or R7. The audio drive current flows through the driver coil, and simultaneously, the audio drive current of the voice chip U1... Controlled output. At this time, the current flowing through the driver coil... ,in It is a vector. After being connected in series with resistors R2 / R7 to the corresponding arms of the H-bridge circuit, the alternating clean drive current... The amplitude decreases, at which point the alternating current flowing through the driver coil... It mainly depends on the audio drive current provided by the voice chip U1. Due to the current in the driver coil Medium alternating frequency drive current The main current component passing through the coil significantly increases the amplitude of the speech vibration generated by the drive shaft, making the speech content clearly distinguishable to the human ear. If the switching switches Q1 and Q6 are turned on again, resistors R2 / R7 are bypassed, thus cleaning the drive current. The alternating audio drive current reaches its maximum value. Alternating current The proportion of [something] decreases. On the one hand, the cleaning torque output by the drive shaft increases; on the other hand, the attenuation of voice vibration intensity leads to a decrease in human ear perception.

[0042] Figure 2 The diagram shows a driving circuit according to a second embodiment of the present invention. The driving circuit includes an H-bridge circuit as a cleaning driving circuit. The H-bridge circuit also includes four switching elements Q2, Q3, Q4, and Q5, which can be selected as MOSFET switching elements.

[0043] In this H-bridge circuit, P-channel MOSFETs, namely Q2 and Q3, can be used as high-side switches. When the microcontroller unit (MCU) outputs a low level to the DRIVE PB IO port or DRIVE PA IO port, switches Q2 or Q3 will conduct; when the MCU outputs a high level, switches Q2 and Q3 will be turned off. N-channel MOSFETs, namely Q4 and Q5, can be used as low-side switches. When the MCU outputs a high level to the DRIVE NA IO port or DRIVE NB IO port, switches Q4 and Q5 will conduct; when the MCU outputs a low level, switches Q4 and Q5 will be turned off.

[0044] In particular, such as Figure 2 As shown, a first switching resistor module is connected in series in the first arm of the H-bridge circuit, and a second switching resistor module is connected in series in the fourth arm of the H-bridge circuit, that is, the upper right arm and the lower left arm are both connected in series with the corresponding switching resistor modules.

[0045] Figure 2 The driving circuit shown also includes an audio driving circuit, which is related to... Figure 1 The circuit connection method of the audio driver circuit is similar, and will not be described again here.

[0046] Figure 2 The driving circuit shown is used as follows.

[0047] During normal cleaning operation without voice broadcasting, the audio drive current of the voice chip U1 is... The output is turned off, the cleaning drive circuit is activated, and the motor M operates under the cleaning drive current provided by the cleaning drive circuit. Under the action of the drive shaft, the toothbrush reciprocates and rotates, thus outputting the cleaning force of the toothbrush.

[0048] When pure voice broadcasting is required, the audio drive current of the voice chip U1... Controlled output, the cleaning drive circuit is completely shut off, that is, the H-bridge circuit is in a power-off closed state, and the audio drive current is provided by the voice chip U1. The current flows through the motor coil, causing the drive shaft to vibrate for voice, thus enabling the electric toothbrush to broadcast pure voice messages.

[0049] In scenarios where cleaning drive and voice broadcasting need to operate synchronously, the microcontroller controls the switching switches Q1 and / or Q6 to enter the off state, causing R2 and / or R7 to be connected in series to the H-bridge circuit. Simultaneously, the audio drive current of the voice chip U1... Controlled output. At this time, the current flowing through the motor coil... ,in It is a vector. When resistors R2 / R7 are connected in series in the H-bridge circuit, the alternating clean drive current... The amplitude decreases, at which point the alternating current flowing through the motor coil... It mainly depends on the audio drive current provided by the voice chip U1. Due to the current in the motor coil Alternating audio drive current This becomes the main current component passing through the motor coil, significantly increasing the amplitude of the voice vibration generated by the drive shaft, making the speech content clearly distinguishable to the human ear. If the switching switches Q1 and Q6 are turned on again, resistors R2 / R7 are bypassed, thus cleaning the drive current. The alternating audio drive current reaches its maximum value. Alternating current flowing in the motor coil The proportion of [something] decreases. On the one hand, the cleaning torque output by the drive shaft increases; on the other hand, the attenuation of voice vibration intensity leads to a decrease in human ear perception.

[0050] Figure 3 A circuit diagram according to a third embodiment of the present invention is shown. In this embodiment, the drive circuit includes a function to provide a clean drive current. The cleaning drive circuit and the audio drive circuit connected to the voice chip U1 are described. The difference from the first and second embodiments is that the cleaning drive circuit does not use an H-bridge drive circuit. The cleaning drive circuit provides unidirectional current so that the drive shaft always rotates in one direction. The cleaning drive circuit includes a first-side circuit connected to the first terminal L1 of the motor and a second-side circuit connected to the second terminal L2 of the motor. A first switching resistor module is connected to the first-side circuit, and a second switching resistor module is connected to the second-side circuit. The first switching resistor module includes a resistor R2 and a switch Q1 connected in parallel with the resistor R2. The second switching resistor module includes a resistor R7 and a switch Q6 connected in parallel with the resistor R7. The two audio output terminals of the audio drive circuit are directly connected to the two terminals of the motor.

[0051] In use, the microcontroller can control one or both of the switching switches Q1 and Q6 to be turned off, thereby reducing the cleaning drive current. The total current flowing through the motor coil The proportion in. Ideally, the degree of reduction can be controlled as needed.

[0052] In a preferred embodiment, in order to achieve a more ideal effect of audio transmission via the drive shaft, the resistance values ​​of resistors R2 and R7 are much greater than the on-resistance value of the switching resistor module when the switching switch Q1 or Q6 is turned on. Preferably, the resistance values ​​of resistors R2 / R7 are more than 10 times the on-resistance value of Q1 or Q6.

[0053] The audio output content of the language module chip is preset and can be called by the microcontroller according to different usage scenarios. For example, the audio output content can include power on / off prompts, duration reminders, pressure alarms, rhythmic sounds, etc. Some audio content needs to appear as accompaniment to cleaning actions, while other audio content needs to appear independently of cleaning actions. The drive circuit according to this invention can selectively control whether the resistor in the switching resistor module is connected according to the specific audio content, thereby realizing the drive shaft transmission of more audio content.

[0054] Whether resistors R2 / R7 in the switching resistor module of this utility model are connected to the cleaning drive circuit can be controlled through the design of the microcontroller unit according to the specific usage scenario. One or both resistors can be selectively connected to the drive circuit, or neither can be connected. For example, when the pressure applied during use exceeds a threshold to trigger the voice chip to output a prompt voice to the driver, resistors R2 and R7 in the switching resistor module are connected through MCU control to reduce the drive current and make the prompt voice clearer. Besides being applicable to electric toothbrushes with a motor M and a drive shaft directly connected to the motor M, the drive circuit of this utility model is also applicable to other types of electric toothbrushes, such as those driven by a transducer (such as the transducer disclosed in Chinese patent application CN115603539A, the disclosure of which is incorporated herein by reference). The transducer typically includes a drive coil and a transducer, which further includes an elastic component, a permanent magnet, and a drive coil. The drive circuit of this utility model (particularly applicable to...) Figure 1 The drive circuit shown connects to the drive coil. Furthermore, the drive circuit of this invention is also applicable to other electric toothbrushes where the motor is connected to the drive shaft via a mechanical transmission device (such as gears or connecting rods).

[0055] According to this invention, a drive circuit is provided that can flexibly connect to and control the proportion of audio drive current in the motor drive current. The cleaning drive current and audio drive current can flow through the driver independently or simultaneously. This circuit can meet the needs of different usage scenarios and various audio content outputs, significantly improving the user experience. For electric toothbrushes with audio playback functions, this circuit design has significant advantages such as simple structure, flexible settings, and high versatility. Regardless of the drive structure used in the electric toothbrush, the sound playback function can be flexibly configured using this novel drive circuit.

[0056] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the scope of the present invention. Any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention are permitted. Therefore, any modifications, equivalent variations, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention's technical solution shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A drive circuit for an electric toothbrush, the drive circuit comprising: A cleaning drive circuit is connected to the first and second terminals of the driver, respectively. The driving circuit is characterized in that it further includes an audio driving circuit, which includes a voice chip. The voice chip has a first audio output terminal and a second audio output terminal, which are respectively connected to the first wiring port and the second wiring port. The cleaning driving circuit further comprises a switching resistance module, the switching resistance module comprises a resistance and a switching switch connected in parallel with the resistance, when the switching switch is controlled to be turned on, the resistance is short-circuited by the switching switch, the resistance is equivalent to not being connected to the cleaning driving circuit, when the switching switch is controlled to be turned off, the resistance is connected to the cleaning driving circuit, and the cleaning driving current is reduced .

2. The drive circuit of claim 1, wherein when the audio drive circuit provides an audio drive current to the driver , the cleaning drive circuit provides a cleaning drive current to the driver , the audio drive current and the cleaning drive current flow through the coil of the driver, respectively or simultaneously, when the switching switch of the switching resistance module is off, the cleaning drive current less than the audio drive current .

3. The drive circuit according to claim 1 or 2, wherein The resistance value of the resistor is ten times or more the on-resistance value of the switching resistor module when the switching switch is turned on.

4. The drive circuit of claim 1, wherein, The switching resistor module includes: A first switching resistor module, comprising a first resistor and a switching switch connected in parallel with the resistor, and connected to a first terminal of the driver; and The second switching resistor module includes a second resistor and a switching switch connected in parallel with the resistor, and is connected to the second port of the driver.

5. The drive circuit of claim 4, wherein, The first switching resistor module is connected in series between the positive terminal of the power supply and the first terminal, while the second switching resistor module is connected in series between the negative terminal of the power supply and the second terminal.

6. The drive circuit of claim 4, wherein, The cleaning drive circuit includes an H-bridge circuit, which includes a first bridge arm and a second bridge arm connected between the positive terminal of the power supply and the driver, and a third bridge arm and a fourth bridge arm connected between the negative terminal of the power supply and the driver. The first and third bridge arms are connected to a second terminal, and the second and fourth bridge arms are connected to a first terminal. The first switching resistor module and the second switching resistor module are connected in one of the following ways: The first bridge arm and the second bridge arm are connected to the positive terminal of the power supply via the first switching resistor module, and the third bridge arm and the fourth bridge arm are connected to the negative terminal of the power supply via the second switching resistor module; The first switching resistor module is connected in series in the first bridge arm and the second switching resistor module is connected in series in the fourth bridge arm; or The first switching resistor module is connected in series in the second bridge arm, and the second switching resistor module is connected in series in the third bridge arm.

7. The drive circuit of claim 4, wherein, The first resistor and the second resistor are of equal value.

8. The drive circuit of claim 1, wherein, It also includes a microcontroller unit, which is connected to the voice chip and to the switching switch in the switching resistor module to control the switching switch to be turned on or off. When the preset condition is met, the micro control unit activates the voice chip to output an audio driving current .

9. An electric toothbrush characterized by comprising: include: A driver, the driver being connected to a drive shaft for connecting a toothbrush head; and The driving circuit as described in any one of the preceding claims is used to drive the driver.

10. The electric toothbrush of claim 9, wherein the head is pivotally connected to the handle. The driver includes a motor or a transducer with a resilient component, and the circuit is connected to the drive coil of the motor or the transducer.

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