CN212163195U

CN212163195U - Control circuit for adjusting vibration of sound wave motor

Info

Publication number: CN212163195U
Application number: CN202021228101.1U
Authority: CN
Inventors: 路少伟; 王肖友
Original assignee: Wuxi Qinghe Xiaobei Technology Co ltd
Current assignee: Wuxi Qinghe Xiao Bei Technology Co ltd; Beijing Xiaomi Mobile Software Co Ltd
Priority date: 2019-10-12
Filing date: 2020-06-29
Publication date: 2020-12-15
Anticipated expiration: 2030-06-29
Also published as: CN110601634A; CN112217442B; CN112217442A

Abstract

The utility model discloses a control circuit for adjusting the vibration of a sound wave motor, which belongs to the technical field of electric toothbrushes and adopts a micro-control unit; the H bridge unit is connected with the micro control unit, the positive power supply terminal of the H bridge unit is connected with the positive power supply terminal VCC, and the negative power supply terminal of the H bridge unit is grounded; the sound wave motor, the sound wave motor with the H bridge unit is connected, through the H bridge unit does the sound wave motor provides interchange square wave drive signal to solved the mode of the interchange drive signal of every fender position of electric toothbrush among the prior art and can not adjusted at will, caused the user can only switch between the mode that electric toothbrush predetermines, can not adjust the technical problem of electric toothbrush's frequency and/or dynamics at will, reached intelligent degree height, the vibration frequency and the vibration dynamics of sound wave motor can infinitely variable control, the user can select the technical effect of any one frequency point/dynamics point that wants.

Description

Control circuit for adjusting vibration of sound wave motor

Technical Field

The utility model relates to an electric toothbrush technical field, in particular to a control circuit for adjusting sound wave motor vibration.

Background

The electric toothbrush using the sound wave motor has the advantages that the swinging times of the brush head per minute are determined by the vibration frequency of the sound wave motor, and the swinging force of the brush head is determined by the vibration intensity of the sound wave motor. At present, electric toothbrushes using a sound wave motor are all provided with a plurality of different gears when leaving a factory, and are solidified in a main control chip of the electric toothbrush. When the user uses the electric toothbrush, the user switches between the preset gears by pressing a button on the electric toothbrush. The frequency and voltage effective value of the alternating current signal for supplying power to the sound wave motor are different among different preset gears, and the alternating current signal with periodically changed frequency or voltage effective value is sometimes used for driving the sound wave motor.

However, the applicant of the present invention finds that at least the following technical problems exist in the prior art in implementing the embodiments of the present application:

although an electric toothbrush can have a plurality of different gears, the mode of the alternating current driving signal of each gear is solidified when the electric toothbrush leaves a factory and cannot be adjusted freely. That is, the user can only switch between the preset modes of the electric toothbrush, and cannot operate the electric toothbrush at any frequency and/or force desired by the user.

SUMMERY OF THE UTILITY MODEL

The utility model provides a control circuit for adjusting sound wave motor vibration for solve the electric toothbrush among the prior art every mode that keeps off the position alternating current drive signal can not adjust at will, cause the user can only switch between the mode that electric toothbrush predetermines, the technical problem of unable arbitrary frequency and/or dynamics of adjusting electric toothbrush, it is high to have reached intelligent degree, the vibration frequency and the vibration dynamics of sound wave motor can infinitely variable control, the user can select the technological effect of the frequency point/dynamics point that an arbitrary one wanted.

The utility model provides a control circuit for adjusting sound wave motor vibration, control circuit includes: a micro control unit; the H bridge unit is connected with the micro control unit, the positive power supply terminal of the H bridge unit is connected with the positive power supply terminal VCC, and the negative power supply terminal of the H bridge unit is grounded; the sound wave motor is connected with the H-bridge unit and provides an alternating-current square wave driving signal for the sound wave motor through the H-bridge unit.

Preferably, the H-bridge unit includes: the first MOS tube is connected with a first pin of the micro control unit; the second MOS tube is connected with a second pin of the micro control unit; the third MOS tube is connected with a third pin of the micro control unit; and the fourth MOS tube is connected with a fourth pin of the micro control unit.

Preferably, the first MOS transistor and the third MOS transistor are P-channel field effect transistors.

Preferably, the second MOS tube and the fourth MOS tube are N-channel field effect transistors.

Preferably, the micro control unit further includes a fifth pin, wherein the fifth pin is an input pin of an external control signal.

Preferably, when the first pin and the third pin output low levels, the first MOS transistor and the third MOS transistor are turned on; when the second pin and the fourth pin output high levels, the second MOS tube and the fourth MOS tube are conducted; according to a preset logic truth rule, when the first pin and the second pin are 0 and the third pin and the fourth pin are 1, the first MOS transistor is turned on, the second MOS transistor is turned off, the third MOS transistor is turned off and the fourth MOS transistor is turned on, and a power supply supplies power to the sound wave motor through the first MOS transistor and the fourth MOS transistor, so that the sound wave motor is biased in the forward direction.

Preferably, when the first pin, the second pin, the third pin and the fourth pin are all 1, the first MOS transistor and the third MOS transistor are turned off, the second MOS transistor and the fourth MOS transistor are turned on, the current of the acoustic wave motor flows through the second MOS transistor and the fourth MOS transistor and gradually decreases, and the acoustic wave motor returns to a zero offset position.

Preferably, the fifth pin is connected to a push button switch of the electric toothbrush.

The embodiment of the utility model provides an in above-mentioned one or more technical scheme, have following one or more technological effect at least:

the embodiment of the utility model provides a control circuit for adjusting sound wave motor vibration, control circuit includes: little the control unit, H bridge unit and acoustic wave motor, wherein, H bridge unit and little the control unit connection, and, the power positive terminal and the anodal VCC of power of H bridge unit are connected, and the power negative terminal ground connection of H bridge unit, and then with acoustic wave motor and H bridge unit connection, provide interchange square wave drive signal for the acoustic wave motor through H bridge unit. When the output states of the four pins of the MCU are periodically switched between state 1 and state 2, the frequency of switching the MCU between state 1 and state 2 is f. If f is fixed, the vibration frequency of the acoustic wave motor is also fixed frequency; if f is linearly changed, the vibration frequency of the acoustic wave motor is also linearly changed. When f is gradually increased and then gradually decreased along with time, voltage waveforms at two ends of the sound wave motor can be obtained. When the CTRL pin of the micro-control unit receives an input control signal, the micro-control unit makes f start to change linearly, and when the input control signal of the CTRL is received again, the micro-control unit makes f stop at the frequency when the CTRL signal is received. The CTRL signal can be received on the button switch of brush, like this the user alright with carry out stepless frequency modulation through pressing the switch, make the vibration frequency of sound wave motor stop on the frequency that oneself wanted, thereby solved the mode of the alternating current drive signal of every fender position of electric toothbrush among the prior art and can not adjusted at will, cause the user to switch between the mode that electric toothbrush predetermines, can not adjust the technical problem of frequency and/or dynamics of electric toothbrush at will, reached intelligent degree height, the vibration frequency and the vibration dynamics of sound wave motor can stepless regulation, the user can select the technical effect of any one frequency point/dynamics point that wants.

The above description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented according to the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the present invention is given.

Drawings

Fig. 1 is a schematic diagram of a control circuit for regulating vibration of a sonic motor according to an embodiment of the present invention;

fig. 2 is a schematic diagram of another control circuit for regulating vibration of a sonic motor in an embodiment of the present invention;

fig. 3 is a schematic flow chart of a control method for adjusting vibration of a sonic motor according to an embodiment of the present invention;

fig. 4 is a schematic diagram of ac square wave signals at two ends of the acoustic wave motor in a control method for adjusting vibration of the acoustic wave motor according to an embodiment of the present invention;

fig. 5 is a basic waveform diagram of stepless frequency adjustment of the sound wave motor in the embodiment of the present invention;

fig. 6 is another schematic diagram of an ac square wave signal at two ends of the acoustic wave motor in a control method for adjusting vibration of the acoustic wave motor according to an embodiment of the present invention;

fig. 7 is the basic waveform diagram of the stepless speed regulation of the sound wave motor in the embodiment of the present invention.

Description of reference numerals: the device comprises a first MOS tube 1, a second MOS tube 2, a third MOS tube 3, a fourth MOS tube 4, a sound wave motor 5, a micro control unit 6 and a motor control chip 7.

Detailed Description

The embodiment of the application provides a control circuit and a method for adjusting vibration of a sound wave motor, and solves the technical problems that in the prior art, the mode of an alternating current driving signal of each gear of an electric toothbrush can not be adjusted at will, so that a user can only switch between preset modes of the electric toothbrush, and the frequency and/or the force of the electric toothbrush can not be adjusted at will.

The embodiment of the utility model provides an in technical scheme, the general thinking is as follows:

the embodiment of the utility model provides a control circuit for adjusting sound wave motor vibration, control circuit includes: a micro control unit; the H bridge unit is connected with the micro control unit, the positive power supply terminal of the H bridge unit is connected with the positive power supply terminal VCC, and the negative power supply terminal of the H bridge unit is grounded; the sound wave motor, the sound wave motor with the H bridge unit is connected, through the H bridge unit does the sound wave motor provides interchange square wave drive signal to reached intelligent degree height, the vibration frequency and the vibration dynamics of sound wave motor can infinitely variable control, and the user can select the technological effect of the frequency point/dynamics point that arbitrary one wanted.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Fig. 1 is a schematic diagram of a control circuit for adjusting vibration of a sound wave motor according to an embodiment of the present invention, as shown in fig. 1, the control circuit includes: a micro control unit 6.

Further, the micro control unit 6 further includes a fifth pin, where the fifth pin is an input pin of an external control signal.

Specifically, the micro control Unit 6 is a main control part of the control circuit, the micro control Unit 6 is known as Microcontroller Unit in english, which is abbreviated as MCU, and it properly reduces the frequency and specification of the central processing Unit, and integrates the peripheral interfaces such as memory, counter, USB, a/D conversion, UART, PLC, DMA, etc., even the LCD driving circuit on a single chip to form a chip-level computer, which is used for different applications and different combination control. The micro control unit 6 in this embodiment is provided with a plurality of pins, which are a first pin IO1, a second pin IO2, a third pin IO3, and a fourth pin IO4, respectively, and may be connected to other components through four output pins, and meanwhile, the micro control unit 6 further includes a fifth pin CTRL, where CTRL is an input pin of an external control signal.

The control circuit further includes: the H bridge unit, the H bridge unit with little the control unit 6 is connected, just, the positive terminal of power and the anodal VCC of power of H bridge unit are connected, the power negative pole end ground connection of H bridge unit.

Further, the H-bridge unit includes: the first MOS tube 1, the first MOS tube 1 is connected with a first pin of the micro control unit 6; the second MOS tube 2, the second MOS tube 2 is connected with a second pin of the micro control unit 6; the third MOS tube 3 is connected with a third pin of the micro control unit 6; and the fourth MOS tube 4 is connected with a fourth pin of the micro control unit 6.

Further, the first MOS transistor 1 and the third MOS transistor 3 are P-channel field effect transistors.

Further, the second MOS tube 2 and the fourth MOS tube 4 are N-channel field effect transistors.

In particular, the H-bridge unit is connected to the micro-control unit 6, and the H-bridge unit is an electronic circuit that inverts/inverts the voltage across the connected load or output. Such circuits can be used for forward and reverse control and speed control of dc motors, stepper motor control (bipolar stepper motors must also include two H-bridge motor controllers), most dc-ac converters (such as inverters and frequency converters), partial dc-dc converters (push-pull converters) in power conversion, and other power electronics in robots and other implementations. The H-bridge unit in this embodiment includes a first MOS transistor 1, a third MOS transistor 3, a second MOS transistor 2, and a fourth MOS transistor 4, that is, an H-bridge is formed by the first MOS transistor 1, the third MOS transistor 3, the second MOS transistor 2, and the fourth MOS transistor 4, and an ac square wave drive signal is provided to the acoustic wave motor 5 through the H-bridge unit. The MOS transistor is a metal-oxide-semiconductor (semiconductor) field effect transistor, or is referred to as a metal-insulator-semiconductor (insulator) transistor. Specifically, the method comprises the following steps: the first MOS transistor 1 is connected to a first pin of the micro control unit 6, the second MOS transistor 2 is connected to a second pin of the micro control unit 6, the third MOS transistor 3 is connected to a third pin of the micro control unit 6, and the fourth MOS transistor 4 is connected to a fourth pin of the micro control unit 6, that is, the four MOS transistors are controlled by four output pins (IO1, IO2, IO3, and IO4) of the MCU respectively.

Further, the first MOS transistor 1 and the third MOS transistor 3 are P-channel field effect transistors (PMOS), the second MOS transistor 2 and the fourth MOS transistor 4 are N-channel field effect transistors (NMOS), wherein the P-channel field effect transistors include a gate, a source and a drain, and the gate is g (gate); the source is S (source); the drain electrode is D (drain). The power supply of the P-channel field effect transistor is generally connected with S and outputs D. An MOS transistor composed of a p-type substrate and two high-concentration N-diffusion regions is called an N-channel field effect transistor, and when the transistor is turned on, an N-type conduction channel is formed between the two high-concentration N-diffusion regions. One end of the first MOS tube 1 and one end of the third MOS tube 3 form a power supply positive terminal of the H-bridge unit, and the power supply positive terminal is connected to a power supply positive terminal VCC, where VCC is a shorthand of Volt Current connector, which means a power supply voltage of a circuit, that is, a power supply positive terminal of the control circuit in this embodiment; one end of the second MOS transistor 2 and one end of the fourth MOS transistor 4 form a power supply negative terminal of the H-bridge unit, and are connected to a ground terminal GND of the control circuit, where GND is short for a ground terminal of an electric wire, that is, a ground of the control circuit in this embodiment.

The control circuit further includes: and the sound wave motor 5 is connected with the H-bridge unit, and an alternating current square wave driving signal is provided for the sound wave motor 5 through the H-bridge unit.

Specifically, the acoustic wave motor 5 is a driver using mechanical vibration in an ultrasonic frequency domain as a driving source, and the acoustic wave motor 5 in this embodiment is connected to an H-bridge unit, so as to provide an ac square wave driving signal to the acoustic wave motor 5 through the H-bridge unit.

Further, in the control circuit, when the first pin IO1 and the third pin IO3 output a low level, the first MOS transistor and the third MOS transistor are turned on; when the second pin IO2 and the fourth pin IO4 output high levels, the second MOS transistor and the fourth MOS transistor are turned on. According to the control logic truth value in table 1, when IO1 is IO2 is 0, and IO3 is IO4 is 1, the first MOS transistor is turned on, the second MOS transistor is turned off, the third MOS transistor is turned off, and the fourth MOS transistor is turned on, so that the power supply supplies power to the acoustic wave motor 5 through the first MOS transistor and the fourth MOS transistor, and the motor is forward biased.

Table 1: truth value of control logic

	State 1	State 2	State 3	State 4
					IO1	0	1	1	1
IO2	0	1	1	0
					IO3	1	0	1	1
IO4	1	0	1	0
					State of the electric machine	Forward bias	Reverse bias	Stall/slow homing	Stall/fast homing

In the above table, when IO1 is equal to IO2 is equal to IO3 is equal to IO4 is equal to 1, the first MOS transistor and the third MOS transistor are turned off, the second MOS transistor and the fourth MOS transistor are turned on, at this time, the power supply does not supply power to the acoustic wave motor 5, the current of the acoustic wave motor 5 continues to flow through the second MOS transistor and the fourth MOS transistor and gradually decreases, and the acoustic wave motor 5 slowly returns to the zero bias position.

As shown in the above table, when the sound wave motor 5 is biased in the forward direction in the state 1, and when the sound wave motor 5 is biased in the reverse direction in the state 2, when the output states of the four pins of the MCU are periodically switched between the states 1 and 2, an alternating-current square wave signal with alternating positive and negative voltages can be generated at two ends of the sound wave motor 5, so that the sound wave motor 5 vibrates back and forth. The frequency of the state 1 and the state 2 switching periodically is the frequency of the vibration of the acoustic wave motor 5.

Further, the control circuit can also replace the H-bridge composed of 4 MOS transistors with an integrated motor control chip 7, as shown in fig. 2. The motor control chip 7 integrates an H bridge and control logic inside, and can output square wave signals as same as the control circuit through the pin control of the MCU. The MCU can also adjust the frequency f and duty cycle d% of the square wave signal as well. The same effect as the control circuit is actually achieved.

Fig. 3 is a schematic flow chart of a control method for a control circuit for adjusting vibration of a sound wave motor according to an embodiment of the present invention, as shown in fig. 3, the method is used for controlling the aforementioned control circuit for adjusting vibration of a sound wave motor, and the control method includes:

step 110: a first alternating square wave signal of the sonic motor 5 is obtained.

Step 120: a first vibration frequency of the sonic motor 5 is obtained.

Specifically, as mentioned above, the frequency of the state 1 and the state 2 is periodically switched, that is, the frequency of the vibration of the sonic motor 5, so that an ac square wave signal can be generated at both ends of the sonic motor 5 by switching the output pins of the micro control unit 6. As shown in fig. 4, when the output pin of the MCU is periodically switched between the state 1 and the state 2, stays at 1.923ms in the state 1, and then stays at 1.923ms in the state 2, an ac square wave signal of 260Hz is generated at both ends of the motor. The frequency at which the micro control unit 6 switches between state 1 and state 2 is f. If f is fixed, the vibration frequency of the acoustic wave motor 5 is also fixed; if f is linearly changed, the vibration frequency of the acoustic wave motor 5 is also linearly changed. When f is gradually increased and then gradually decreased with time, the voltage waveform across the two ends of the acoustic wave motor can be obtained as shown in fig. 5.

Step 130: the fifth pin of the micro control unit 6 receives a first control signal input from the outside.

Step 140: and adjusting the first vibration frequency according to the first alternating-current square wave signal and the first control signal so as to enable the first vibration frequency to change linearly.

Specifically, the obtained voltage waveform at the two ends of the sound wave motor is the basis of the stepless frequency modulation of the sound wave motor. Therefore, when the fifth pin of the mcu 6, i.e., the CTRL pin, receives the first control signal, f starts to change linearly.

Step 150: a fifth pin of the micro control unit receives a second control signal input from the outside;

step 160: and stopping the current frequency of the sound wave motor to a second vibration frequency according to the second control signal, wherein the second vibration frequency is the frequency when the micro control unit receives the second control signal.

Specifically, when the fifth pin of the micro control unit 6, i.e., the CTRL pin, again receives the second control signal input to CTRL, the micro control unit 6 causes f to stay at the frequency at which the CTRL signal was received. The CTRL signal can be connected to a push-button switch of the brush, so that the user can perform a stepless frequency modulation by pressing the switch, so that the vibration frequency of the sound wave motor stays at the desired frequency.

Further, the control method further includes: obtaining a second alternating-current square wave signal of the sound wave motor 5; obtaining a first duty ratio of the second alternating-current square wave signal; a fifth pin of the micro control unit 6 receives a third control signal input from the outside; adjusting the first duty ratio according to the second alternating current square wave signal and the third control signal so as to enable the first duty ratio to change linearly; a fifth pin of the micro control unit 6 receives a fourth control signal input from the outside; according to the fourth control signal, stopping the current duty ratio of the second alternating-current square wave signal to a second duty ratio, and obtaining the current vibration strength of the sound wave motor 5 according to the second duty ratio, wherein the second duty ratio is a value when the micro control unit 6 receives the fourth control signal.

Specifically, the vibration strength of the acoustic wave motor 5 is positively correlated with the effective voltage value of the alternating current signal that drives it. When the output pin state of the mcu 6 is toggled between state 1 and state 2, the duty cycle of the control signal is 100% (i.e. the power supply is always supplying power); when a state 3 is added between the state 1 and the state 2, the duty ratio of the control signal is less than 100% (the power supply does not supply power in the state 3). For example, when the output pin of the mcu 6 is periodically switched between the state 1, the state 3, the state 2 and the state 3, stays at 0.962ms in the state 1, stays at 0.962ms in the state 3, stays at 0.962ms in the state 2, stays at 0.962ms in the state 3, and stays at 0.962ms in the state 3, an ac square wave signal with 260 Hz/50% duty ratio is generated across the motor, as shown in fig. 6, it can be seen that the power source does not supply power to the motor in the state 3, so the effective value of the voltage of the above 50% duty ratio waveform is only half of the 100% duty ratio waveform. When the waveform is used for driving the sound wave motor, the vibration strength of the sound wave motor is obviously reduced. Duty cycle is the percentage of the time that a signal is high during a cycle that occupies the entire signal cycle.

In order to ensure that the sound wave motor vibrates uniformly, the driving signals must be strictly positive and negative symmetrical, so that the duration of the state 1 and the state 2 in one period is strictly consistent, and the duration of the state 3 added on both sides is also strictly consistent. The frequency at which the micro control unit 6 switches between state 1 and state 2 is f. If f is fixed and unchanged, the ratio of the state 1 to the state 2 in the same period is reduced, and the ratio of the state 3 is increased, the duty ratio of the alternating-current square wave signal is reduced, and the vibration power of the motor is synchronously weakened. Let the ratio of the sum of the durations of the state 1 and the state 2 to the period in one period be d%, and then d% is the duty cycle of the square wave signal. When f is not changed, d% is gradually reduced and then gradually increased along with time, the obtained waveform is shown in fig. 7, and the waveform is the basis of the stepless regulation force of the sound wave motor.

Therefore, when the CTRL pin of the mcu 6 receives the input third control signal, d% starts to change linearly, and when the CTRL pin receives the input fourth control signal again, the mcu 6 keeps d% at the value at which the CTRL signal was received. The CTRL signal can be connected to a button switch of the electric brush, so that a user can perform stepless force adjustment by pressing the switch, and the vibration force of the sound wave motor is stopped at a desired value.

Therefore, in the present embodiment, the control method for steplessly adjusting the vibration frequency and the vibration strength of the acoustic wave motor is implemented by continuously and linearly increasing/decreasing the frequency/voltage effective value of the driving signal of the acoustic wave motor, and this method is a control circuit logic algorithm. By the control method, when the electric toothbrush works, a user can stop the sound wave motor of the electric brush at any frequency point/force point which the user wants. Further, the technical basis of this algorithm is: due to the characteristics of the acoustic wave motor, when a forward voltage drop is applied to two ends of the acoustic wave motor, the acoustic wave motor can deflect in the forward direction; when a negative voltage drop is applied across it, the motor will deflect in the negative direction. A regular alternating current signal (usually a square wave) with an average voltage of 0V can make the sonic motor vibrate back and forth. The vibration frequency of the sound wave motor is the frequency of the alternating current signal, and the vibration strength of the sound wave motor is positively correlated with the effective voltage value of the alternating current signal. Therefore, the frequency of the alternating current signal is increased, and the vibration frequency of the acoustic wave motor is synchronously increased; when the effective value of the voltage of the alternating current signal is increased, the vibration power of the acoustic wave motor is synchronously increased.

In this embodiment, the frequency and duty ratio of the ac square wave signal that drives the sound wave motor are linearly adjusted to implement the stepless adjustment method for the vibration frequency and the vibration force of the sound wave motor, and at the same time, the control of the user can be responded to, so that the vibration frequency and the vibration force of the sound wave motor stay at the frequency point/force point desired by the user, thereby achieving the technical effect that the vibration frequency and the vibration force of the sound wave motor can be steplessly adjusted, and the user can select any desired frequency point/force point and is not limited to the preset frequency point/force point.

the embodiment of the utility model provides a control circuit and method for adjusting sound wave motor vibration, control circuit includes: little the control unit, H bridge unit and acoustic wave motor, wherein, H bridge unit and little the control unit connection, and, the power positive terminal and the anodal VCC of power of H bridge unit are connected, and the power negative terminal ground connection of H bridge unit, and then with acoustic wave motor and H bridge unit connection, provide interchange square wave drive signal for the acoustic wave motor through H bridge unit. When the output states of the four pins of the MCU are periodically switched between state 1 and state 2, the frequency of switching the MCU between state 1 and state 2 is f. If f is fixed, the vibration frequency of the acoustic wave motor is also fixed frequency; if f is linearly changed, the vibration frequency of the acoustic wave motor is also linearly changed. When f is gradually increased and then gradually decreased along with time, voltage waveforms at two ends of the sound wave motor can be obtained. When the CTRL pin of the micro-control unit receives an input control signal, the micro-control unit makes f start to change linearly, and when the input control signal of the CTRL is received again, the micro-control unit makes f stop at the frequency when the CTRL signal is received. The CTRL signal can be received on the button switch of brush, like this the user alright with carry out stepless frequency modulation through pressing the switch, make the vibration frequency of sound wave motor stop on the frequency that oneself wanted, thereby solved the mode of the alternating current drive signal of every fender position of electric toothbrush among the prior art and can not adjusted at will, cause the user to switch between the mode that electric toothbrush predetermines, can not adjust the technical problem of frequency and/or dynamics of electric toothbrush at will, reached intelligent degree height, the vibration frequency and the vibration dynamics of sound wave motor can stepless regulation, the user can select the technical effect of any one frequency point/dynamics point that wants.

While the preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the appended claims be interpreted as including the preferred embodiment and all such alterations and modifications as fall within the scope of the invention.

It is apparent that those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if such modifications and variations of the embodiments of the present invention fall within the scope of the claims and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A control circuit for regulating vibration in a sonic motor, said control circuit comprising:

a micro control unit;

the H bridge unit is connected with the micro control unit, the positive power supply terminal of the H bridge unit is connected with the positive power supply terminal VCC, and the negative power supply terminal of the H bridge unit is grounded;

the sound wave motor is connected with the H-bridge unit and provides an alternating-current square wave driving signal for the sound wave motor through the H-bridge unit.

2. The control circuit of claim 1, wherein the H-bridge unit comprises:

the first MOS tube is connected with a first pin of the micro control unit;

the second MOS tube is connected with a second pin of the micro control unit;

the third MOS tube is connected with a third pin of the micro control unit;

and the fourth MOS tube is connected with a fourth pin of the micro control unit.

3. The control circuit of claim 2, wherein the first and third MOS transistors are P-channel field effect transistors.

4. The control circuit of claim 2, wherein the second and fourth MOS transistors are N-channel field effect transistors.

5. The control circuit of claim 1, wherein the micro control unit further comprises a fifth pin, wherein the fifth pin is an input pin for an external control signal.

6. The control circuit of claim 2, wherein when the first pin and the third pin output a low level, the first MOS transistor and the third MOS transistor are turned on; when the second pin and the fourth pin output high levels, the second MOS tube and the fourth MOS tube are conducted; according to a preset logic truth rule, when the first pin and the second pin are 0 and the third pin and the fourth pin are 1, the first MOS transistor is turned on, the second MOS transistor is turned off, the third MOS transistor is turned off and the fourth MOS transistor is turned on, and a power supply supplies power to the sound wave motor through the first MOS transistor and the fourth MOS transistor, so that the sound wave motor is biased in the forward direction.

7. The control circuit according to claim 6, wherein when all of the first pin, the second pin, the third pin, and the fourth pin are 1, the first MOS transistor and the third MOS transistor are turned off, the second MOS transistor and the fourth MOS transistor are turned on, the current of the sonic motor freewheels through the second MOS transistor and the fourth MOS transistor and gradually decreases, and the sonic motor returns to a zero bias position.

8. The control circuit of claim 5, wherein the fifth pin is connected to a push button switch of the electric toothbrush.