CN213249930U - Swing amplitude control device and electric toothbrush - Google Patents
Swing amplitude control device and electric toothbrush Download PDFInfo
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- CN213249930U CN213249930U CN202021397408.4U CN202021397408U CN213249930U CN 213249930 U CN213249930 U CN 213249930U CN 202021397408 U CN202021397408 U CN 202021397408U CN 213249930 U CN213249930 U CN 213249930U
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Abstract
The utility model provides a swing amplitude control device and electric toothbrush, include: the strain gauge is arranged on a motor shaft of the motor and used for detecting deformation information of the motor shaft and sending the deformation information to the control circuit; the control circuit is connected with the strain gauge and used for determining a target PWM signal according to the deformation information and transmitting the target PWM signal to the driving chip; the driving chip is respectively connected with the control circuit and the motor and is used for controlling the motor to work according to the target PWM signal transmitted by the control circuit. The utility model discloses a mode that increases the foil gage realizes the closed-loop control to the motor, the work of control motor that can be accurate to the realization has alleviated the poor technical problem of current electric toothbrush's the swing control mode accuracy nature to the accurate control of electric toothbrush swing.
Description
Technical Field
The utility model belongs to the technical field of controlling means's technique and specifically relates to a swing amplitude controlling means and electric toothbrush are related to.
Background
The existing electric toothbrush mainly generates a group of PWM signals aligned in the middle through the MCU, and the PWM signals are supplied to a driving chip to drive the sound wave motor to work, so that the cleaning effect is achieved. The working process is open-loop control, and based on the basis, closed-loop control can be realized by adding a current detection circuit in a loop of the driving current. The working process for realizing closed-loop control is as follows: and detecting the driving current, outputting the driving current to the MCU through the ADC after the driving current passes through the operational amplifier, and feeding back the MCU to adjust the frequency and the duty ratio of the PWM signal.
In the above scheme of closed-loop control, under different frequency conditions, the relationship between the current I and the frequency f is not linear, the relationship between the current I and the duty ratio D is linear (the higher the duty ratio is, the larger the current is), but the swing force frequency and the current form a linear relationship, and there is a resonant frequency point.
In conclusion, the swing amplitude control method of the existing electric toothbrush has the technical problem of poor accuracy.
SUMMERY OF THE UTILITY MODEL
In view of this, an object of the present invention is to provide an amplitude control device and an electric toothbrush, so as to alleviate the technical problem of poor accuracy of amplitude control of the conventional electric toothbrush.
In a first aspect, an embodiment of the present invention provides a swing amplitude control device, including: the device comprises a strain gauge, a control circuit, a driving chip and a motor;
the strain gauge is arranged on a motor shaft of the motor and used for detecting deformation information of the motor shaft and sending the deformation information to the control circuit;
the control circuit is connected with the strain gauge and used for determining a target PWM signal according to the deformation information and transmitting the target PWM signal to the driving chip;
the driving chip is respectively connected with the control circuit and the motor and is used for controlling the motor to work according to the target PWM signal transmitted by the control circuit.
Further, the control circuit includes: an ADC analog-to-digital conversion chip and a controller;
the ADC analog-to-digital conversion chip is connected with the strain gauge and is used for performing analog-to-digital conversion processing and amplification processing on the deformation information to obtain amplified deformation information and sending the amplified deformation information to the controller;
the controller is connected with the ADC analog-to-digital conversion chip and used for determining the target PWM signal according to the amplified deformation information and transmitting the target PWM signal to the driving chip.
Further, the method also comprises the following steps: a power supply circuit;
the power supply circuit is respectively connected with the control circuit and the driving chip and is used for supplying power to the swing amplitude control device.
Further, the power supply circuit includes: the low dropout regulator comprises a power supply module and a low dropout regulator;
the power supply module is respectively connected with the driving chip and the low dropout regulator;
the low dropout regulator is also connected with the control circuit and used for providing power supply voltage for the control circuit.
Further, the strain gauge includes any one of: single bridge strain gauges, half-bridge strain gauges, and full-bridge strain gauges.
Further, the control circuit further includes: the circuit comprises a first resistor, a second resistor, a third resistor and an RC filter circuit;
the strain gauge is connected with the first resistor, the second resistor and the third resistor to form a full-bridge circuit, and the full-bridge circuit is connected with the input end of the ADC analog-to-digital conversion chip through the RC filter circuit.
Further, the structure of the full bridge circuit is as follows:
the first end of the first resistor is connected with one end of the strain gauge, and the second end of the first resistor is connected with the first end of the second resistor;
the second end of the second resistor is grounded;
and the first end of the third resistor is connected with the other end of the strain gauge, and the second end of the third resistor is grounded.
Further, a first end of the RC filter circuit is connected to a second end of the first resistor and a first end of the second resistor; and the second end of the RC filter circuit is connected with the first end of the third resistor.
Further, when the strain gauge does not detect the deformation information of the motor shaft, the resistance of the strain gauge is equal to the resistance of the first resistor, the resistance of the second resistor and the resistance of the third resistor.
In a second aspect, embodiments of the present invention further provide an electric toothbrush, including: the swing control device according to any one of the first aspect, further comprising: a brush head and a brush handle;
the swing amplitude control device is arranged in the brush handle and is connected with the brush head through a motor shaft.
In an embodiment of the present invention, the swing amplitude control device includes: the device comprises a strain gauge, a control circuit, a driving chip and a motor; the strain gauge is arranged on a motor shaft of the motor and used for detecting deformation information of the motor shaft and sending the deformation information to the control circuit; the control circuit is connected with the strain gauge and used for determining a target PWM signal according to the deformation information and transmitting the target PWM signal to the driving chip; the driving chip is respectively connected with the control circuit and the motor and is used for controlling the motor to work according to the target PWM signal transmitted by the control circuit. Can know through the above-mentioned description, the utility model discloses a mode that increases the foil gage realizes the closed-loop control to the motor, the work of control motor that can be accurate to the realization has alleviated the poor technical problem of current electric toothbrush's amplitude of oscillation control mode accuracy to the accurate control of electric toothbrush amplitude of oscillation.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an oscillation amplitude control apparatus according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another swing amplitude control device according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of another swing amplitude control device according to an embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a low dropout linear regulator according to an embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a single-bridge strain gauge and an ADC analog-to-digital conversion chip according to an embodiment of the present invention.
Icon: 11-a strain gauge; 12-a control circuit; 13-a driver chip; 14-a motor; 15-a power supply circuit; 121-ADC analog-to-digital conversion chip; 122-a controller; 151-a power supply module; 152-low dropout linear regulator.
Detailed Description
The technical solution of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood 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.
For the convenience of understanding the present embodiment, a swing amplitude control device disclosed in the embodiments of the present invention will be described in detail first.
The first embodiment is as follows:
fig. 1 is a schematic structural diagram of an amplitude control device according to an embodiment of the present invention, as shown in fig. 1, the amplitude control device includes: the device comprises a strain gauge 11, a control circuit 12, a driving chip 13 and a motor 14;
the strain gauge 11 is arranged on a motor shaft of the motor 14 and used for detecting deformation information of the motor shaft and sending the deformation information to the control circuit 12;
the control circuit 12 is connected with the strain gauge 11 and is used for determining a target PWM signal according to the deformation information and transmitting the target PWM signal to the driving chip 13;
the driving chip 13 is connected to the control circuit 12 and the motor 14, respectively, and is configured to control the motor 14 to operate according to the target PWM signal transmitted by the control circuit 12.
In an embodiment of the present invention, the swing amplitude control device includes: the device comprises a strain gauge 11, a control circuit 12, a driving chip 13 and a motor 14; the strain gauge 11 is arranged on a motor shaft of the motor 14 and used for detecting deformation information of the motor shaft and sending the deformation information to the control circuit 12; the control circuit 12 is connected with the strain gauge 11 and is used for determining a target PWM signal according to the deformation information and transmitting the target PWM signal to the driving chip 13; the driving chip 13 is connected to the control circuit 12 and the motor 14, respectively, and is configured to control the motor 14 to operate according to the target PWM signal transmitted by the control circuit 12. According to the above description, the utility model discloses a mode that increases foil gage 11 realizes the closed-loop control to motor 14, the work of control motor 14 that can be accurate to the realization has alleviated the poor technical problem of current electric toothbrush's swing control mode accuracy to the accurate control of electric toothbrush swing.
The above-mentioned structure of the swing control device of the present invention is briefly introduced, and the details related thereto are described in detail below.
In an alternative embodiment of the present invention, referring to fig. 2, the control circuit 12 includes: an ADC analog-to-digital conversion chip 121 and a controller 122;
the ADC analog-to-digital conversion chip 121 is connected to the strain gauge 11, and is configured to perform analog-to-digital conversion and amplification on the deformation information to obtain amplified deformation information, and send the amplified deformation information to the controller 122;
the controller 122 is connected to the ADC analog-to-digital conversion chip 121, and is configured to determine a target PWM signal according to the amplified deformation information, and transmit the target PWM signal to the driving chip 13.
The working process of the swing control device of the present invention is described below with reference to fig. 2:
the strain gauge 11 is arranged on the motor shaft, when the motor 14 does not brush teeth, the motor shaft has no deformation change, and the corresponding strain gauge 11 has no resistance change; when the brush head senses a load, namely when a person brushes teeth, the brush head drives the motor shaft to deform, the strain gauge 11 can sense the micro deformation of the motor shaft, a physical signal of the deformation is converted into an electric signal to obtain deformation information, the deformation information is sent to the ADC analog-to-digital conversion chip 121, the ADC analog-to-digital conversion chip 121 carries out analog-to-digital conversion processing and amplification processing on the deformation information, the amplified deformation information is sent to the controller 122 through the two-line SPI, the controller 122 compares the amplified deformation information with a preset threshold value after receiving the amplified deformation information, if the amplified deformation information does not exceed the preset threshold value, the frequency and the duty ratio of a PWM signal are not changed, and the original PWM signal is continuously used as a target PWM signal; if the frequency and the duty ratio of the original PWM signal are changed (the frequency and the duty ratio of the PWM signal can be adjusted to be a first preset value and the duty ratio of the PWM signal is adjusted to be a second preset value according to internal settings, if the frequency and the duty ratio of the PWM signal exceed the first preset value), a target PWM signal is obtained, the target PWM signal is transmitted to the driving chip 13, and finally the driving chip 13 drives the motor 14 to work according to the target PWM signal, so that closed-loop control is realized, and the toothbrush works in a self-adaptive range which is most suitable for users.
In an optional embodiment of the present invention, referring to fig. 3, the swing control device further includes: a power supply circuit 15;
the power supply circuit 15 is connected to the control circuit 12 and the driving chip 13, respectively, and is configured to supply power to the swing control device.
Specifically, the power supply circuit 15 includes: a power supply module 151 and a low dropout linear regulator 152;
the power module 151 is respectively connected with the driving chip 13 and the low dropout regulator 152; the power module 151 may be a battery.
The low dropout regulator 152 is further connected to the control circuit 12 for providing a supply voltage to the control circuit 12.
In an optional embodiment of the present invention, the strain gauge 11 includes any one of the following: single bridge strain gauges, half-bridge strain gauges, and full-bridge strain gauges.
When the strain gauge 11 is a single-bridge strain gauge, the motor shaft only needs to be transversely cut into a smaller surface; and when foil gage 11 is the full-bridge foil gage, can restrain the temperature drift, the better precision of promotion monitoring, but need increase the crosscut area of motor shaft, realize wheatstone full-bridge's mode and detect.
In an optional embodiment of the present invention, the motor 14 includes: a one-way motor.
In an optional embodiment of the present invention, the controller 122 includes: a micro control unit (i.e. MCU).
In an optional embodiment of the present invention, referring to fig. 5, the control circuit further includes: the circuit comprises a first resistor R5, a second resistor R6, a third resistor R7 and an RC filter circuit;
the strain gauge (not shown in fig. 5, and the position of the strain gauge connected to the two ends of the pad M in fig. 5) is connected to the first resistor R5, the second resistor R6, and the third resistor R7 to form a full bridge circuit, and the full bridge circuit is connected to the input terminal of the ADC analog-to-digital conversion chip CS1237 via the RC filter circuit.
In an alternative embodiment of the present invention, referring to fig. 5, the structure of the full bridge circuit is:
a first end of the first resistor R5 is connected with one end of a strain gauge (not shown in FIG. 5), and a second end of the first resistor R5 is connected with a first end of the second resistor R6;
a second end of the second resistor R6 is grounded;
the first end of the third resistor R7 is connected to the other end of the strain gauge, and the second end of the third resistor R7 is grounded.
In an optional embodiment of the present invention, a first terminal of the RC filter circuit is connected to a second terminal of the first resistor R5 and a first terminal of the second resistor R6; the second terminal of the RC filter circuit is connected to the first terminal of the third resistor R7.
When the strain gauge does not detect the deformation information of the motor shaft, the resistance of the strain gauge is equal to the resistance of the first resistor, the resistance of the second resistor and the resistance of the third resistor.
In the embodiment of the utility model provides an in, the work of foil gageThe principle is as follows: the phenomenon that the resistance value of the strain resistor adsorbed on the substrate material changes along with the mechanical deformation is commonly called as resistance strain effect. Here, the wire strain gauge is taken as an example, and the resistance value of the metal conductor, R ═ ρ L/S, where: ρ represents the resistivity (Ω · cm) of the metal conductor, and S represents the cross-sectional area (cm) of the metal conductor2) And L represents the length (cm) of the metal conductor. Taking the wire strain gauge as an example, when the wire is subjected to an external force, the length and the sectional area of the wire will change, and the resistance value will change as can be easily seen from the above formula. If the wire is stretched by an external force, the length is increased and the cross-sectional area is decreased, so that the resistance is increased. When the wire is compressed by an external force, the length is reduced and the cross section is increased, and the resistance value is reduced. The strain of the wire strain gauge can be obtained by detecting the change in resistance across the wire strain gauge (usually by measuring the voltage across the wire strain gauge).
The foil gage is applied to among the utility model discloses a back among the amplitude of oscillation controlling means, when the foil gage detects motor shaft deformation, the foil gage resistance changes, and its both ends produce voltage difference, and then the controller is exported for through two line SPI after voltage passes through ADC analog-to-digital conversion, and the controller is controlled driver chip driving motor again and is shaken.
The embodiment of the utility model provides a swing control device's partial circuit structure is given, fig. 4 shows the circuit structure of low dropout linear regulator 152, wherein, low dropout linear regulator chip XC6206_ 3.3's input VIN is connected with the first end of power and first electric capacity C12 respectively, first electric capacity C12's second end ground connection, low dropout linear regulator chip XC6206_ 3.3's output VOUT respectively with second electric capacity C11's first end, third electric capacity C13's first end is connected, the second end C11 of second power and the second end C13 ground connection of third electric capacity, low dropout linear regulator chip XC 6_ 3.3's earthing terminal GND ground connection, first electric capacity C12, second electric capacity C11 and third electric capacity C13 are used for filtering the voltage, realize the purpose of steady voltage.
Fig. 5 shows a circuit structure of the single bridge strain gauge and the ADC analog-to-digital conversion chip CS 1237. In operation of the swing control device, the ADC analog-to-digital conversion chip CS1237 therein needs a suitable reference voltage, which can be provided by the LDO chip (i.e., the low dropout linear regulator 152).
As can be seen from fig. 5, the two pads M are externally connected to the single-bridge strain gauge at the upper end of the PCB, the resistance value is 120 Ω, the circuit and the three other resistors form a full bridge (since the variation value of the resistance of the strain gauge 11 is fine, the precision of the three other resistors needs to be high, here, the precision of ± 0.1% is selected, and the differential line and impedance matching need to be noticed for the PCB Layout), and the power supply is provided by the output reference source of the ADC analog-to-digital conversion chip CS1237, so that when the motor is in the non-operating sleep state, the full bridge is not powered, and the extra power consumption can be avoided.
A group of analog differential signals output by the full bridge are input to an ADC (analog-to-digital converter) chip CS1237 after being filtered by an RC (resistor-capacitor) and are transmitted to an MCU (not shown in figure 5) through two-line SPI (serial peripheral interface) after being subjected to analog-to-digital conversion and amplification processing, the pressure sensing detection is realized by the MCU, when a person brushes teeth, the detected deformation value exceeds a set threshold value, the PWM (pulse-width modulation) frequency and the duty ratio are changed, and the self-adaption of high-precision detection in the true sense is realized.
It should be noted that the model of the chip in fig. 4 and 5 may be determined according to actual parameter requirements, and the embodiment of the present invention does not specifically limit the model therein.
The swing control device of the utility model can be converted into electric signals through external pressure induction, thereby realizing the closed loop feedback of the whole system, detecting the load stress change during tooth brushing, and simultaneously, the MCU makes adjustment to provide better tooth brushing experience for users; structurally, only one plane needs to be transversely cut by the motor shaft, and compared with current detection, the self-adaptive calibration can be more accurate.
Example two:
the embodiment of the utility model provides an electric toothbrush is still provided, and this electric toothbrush includes the swing amplitude controlling means in the above-mentioned embodiment one, still includes: a brush head and a brush handle;
the swing amplitude control device is arranged in the brush handle and is connected with the brush head through a motor shaft.
In an optional embodiment of the present invention, the electric toothbrush further comprises: an indicator light;
and the indicator light is used for indicating the working state of the electric toothbrush.
In an optional embodiment of the present invention, the electric toothbrush further comprises: a switch button;
the switch button is arranged on the brush handle and is used for controlling the working state of the electric toothbrush.
In addition, in the description of the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (10)
1. A swing control apparatus comprising: control circuit, driver chip and motor, its characterized in that still includes: a strain gauge;
the strain gauge is arranged on a motor shaft of the motor and used for detecting deformation information of the motor shaft and sending the deformation information to the control circuit;
the control circuit is connected with the strain gauge and used for determining a target PWM signal according to the deformation information and transmitting the target PWM signal to the driving chip;
the driving chip is respectively connected with the control circuit and the motor and is used for controlling the motor to work according to the target PWM signal transmitted by the control circuit.
2. The swing control device according to claim 1, wherein the control circuit comprises: an ADC analog-to-digital conversion chip and a controller;
the ADC analog-to-digital conversion chip is connected with the strain gauge and is used for performing analog-to-digital conversion processing and amplification processing on the deformation information to obtain amplified deformation information and sending the amplified deformation information to the controller;
the controller is connected with the ADC analog-to-digital conversion chip and used for determining the target PWM signal according to the amplified deformation information and transmitting the target PWM signal to the driving chip.
3. The swing control apparatus according to claim 1, further comprising: a power supply circuit;
the power supply circuit is respectively connected with the control circuit and the driving chip and is used for supplying power to the swing amplitude control device.
4. The swing control device according to claim 3, wherein the power supply circuit comprises: the low dropout regulator comprises a power supply module and a low dropout regulator;
the power supply module is respectively connected with the driving chip and the low dropout regulator;
the low dropout regulator is also connected with the control circuit and used for providing power supply voltage for the control circuit.
5. The swing control device according to claim 1, wherein the strain gauge comprises any one of: single bridge strain gauges, half-bridge strain gauges, and full-bridge strain gauges.
6. The swing control device according to claim 2, wherein the control circuit further comprises: the circuit comprises a first resistor, a second resistor, a third resistor and an RC filter circuit;
the strain gauge is connected with the first resistor, the second resistor and the third resistor to form a full-bridge circuit, and the full-bridge circuit is connected with the input end of the ADC analog-to-digital conversion chip through the RC filter circuit.
7. The swing control device according to claim 6, wherein the full bridge circuit is configured as follows:
the first end of the first resistor is connected with one end of the strain gauge, and the second end of the first resistor is connected with the first end of the second resistor;
the second end of the second resistor is grounded;
and the first end of the third resistor is connected with the other end of the strain gauge, and the second end of the third resistor is grounded.
8. The swing control device according to claim 6, wherein a first terminal of the RC filter circuit is connected to a second terminal of the first resistor and a first terminal of the second resistor; and the second end of the RC filter circuit is connected with the first end of the third resistor.
9. The swing control device according to claim 6, wherein when the strain gauge does not detect the deformation information of the motor shaft, the resistance of the strain gauge is equal to the resistances of the first resistor, the second resistor and the third resistor.
10. An electric toothbrush, comprising: the swing control apparatus according to any one of claims 1 to 9, further comprising: a brush head and a brush handle;
the swing amplitude control device is arranged in the brush handle and is connected with the brush head through a motor shaft.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021397408.4U CN213249930U (en) | 2020-07-15 | 2020-07-15 | Swing amplitude control device and electric toothbrush |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021397408.4U CN213249930U (en) | 2020-07-15 | 2020-07-15 | Swing amplitude control device and electric toothbrush |
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| Publication Number | Publication Date |
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| CN213249930U true CN213249930U (en) | 2021-05-25 |
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| CN202021397408.4U Active CN213249930U (en) | 2020-07-15 | 2020-07-15 | Swing amplitude control device and electric toothbrush |
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| CN (1) | CN213249930U (en) |
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