Cosmetic instrument and micro-current output circuit thereof

Abstract

The utility model relates to the field of beauty instruments, and provides a beauty instrument and a micro-current output circuit thereof. The micro-current output circuit of the beauty instrument is used for outputting micro-current to a contact electrode of the beauty instrument, and the micro-current output circuit comprises a control unit, a bias voltage output unit and an operational amplifier unit. Wherein the operational amplifier unit is configured with a positive input end and a negative input end, the positive input end is connected with the bias voltage output unit, the negative input end is connected with the control unit, and the bias voltage output unit is connected with the control unit. The control unit can output PWM signals with different duty ratios and output a control signal to control the bias voltage output unit to output different direct current bias voltages to the operational amplifier unit, so that the operational amplifier unit can increase the voltage amplitude range of the PWM signals with different duty ratios to different degrees under the action of different direct current bias voltages, and the voltage amplitude range of the PWM signals with different duty ratios is increased to different degrees. Therefore, the micro-current with different voltage amplitudes is output, and the adjustment ways of the micro-current are enriched.

Description

Technical Field

[0001] The present application belongs to the field of beauty instruments, and in particular, relates to a beauty instrument and a micro-current output circuit of the beauty instrument. Background Art

[0002] At present, most of the beauty devices on the market are equipped with contact electrodes that contact the skin and are used to output microcurrent to act on the skin. Figure 1 As shown, in a conventional beauty instrument, the contact electrode 1 of the beauty instrument is connected to a constant voltage source 2, and the constant voltage source 2 includes a loop switch 3. By inputting a PWM signal to the loop switch 3, the on and off frequency of the constant voltage source 2 is controlled, thereby realizing the control of the periodic output of microcurrent by the constant voltage source 2.

[0003] However, the microcurrent output circuit in the traditional beauty instrument can only adjust the frequency of the microcurrent output by the constant voltage source 2 by adjusting the duty cycle of the PWM signal, and the microcurrent adjustment method is too single. Utility Model Content

[0004] The purpose of the present application is to provide a micro-current output circuit of a beauty instrument and a beauty instrument, aiming to solve the problem that the above beauty instruments have too single micro-current regulation path.

[0005] A first aspect of an embodiment of the present application provides a micro-current output circuit of a beauty instrument, which is used to output micro-current to a contact electrode of the beauty instrument. The micro-current output circuit includes:

[0006] A control unit, used for outputting a pulse modulation PWM signal and a control signal;

[0007] A bias voltage output unit connected to the control unit, the bias voltage output unit is used to output a corresponding DC bias voltage according to a control signal;

[0008] The operational amplifier unit is configured with a positive input terminal and a negative input terminal, the positive input terminal is connected to the bias voltage output unit, and the negative input terminal is connected to the control unit. The operational amplifier unit is used to output a micro current according to the PWM signal and the DC bias voltage.

[0009] A second aspect of an embodiment of the present application provides a beauty instrument, comprising contact electrodes and a microcurrent output circuit provided by the first aspect.

[0010] Compared with the prior art, the beneficial effects of the embodiment of the utility model are as follows: the micro-current output circuit of the above-mentioned beauty instrument is used to output micro-current to the contact electrode of the beauty instrument, and the micro-current output circuit includes a control unit, a bias voltage output unit and an operational amplifier unit. Among them, the operational amplifier unit is configured with a positive input terminal and a negative input terminal, the positive input terminal is connected to the bias voltage output unit, the negative input terminal is connected to the control unit, and the bias voltage output unit is connected to the control unit. When the control unit is used to output the PWM signal and the control signal, since the negative input terminal of the operational amplifier unit receives the PWM signal output by the control unit, the bias voltage output unit can output the corresponding DC bias voltage to the positive input terminal of the operational amplifier unit according to the control signal, so the operational amplifier unit can raise the voltage amplitude range of the PWM signal under the action of the DC bias voltage, that is, it can output micro-current according to the PWM signal and the DC bias voltage. The above scheme utilizes the control unit to output PWM signals with different duty cycles, and the output control signal controls the bias voltage output unit to output different DC bias voltages to the operational amplifier unit, so that the operational amplifier unit can raise the voltage amplitude range of PWM signals with different duty cycles to different degrees under the action of different DC bias voltages, and then output microcurrents with different voltage amplitudes, enriching the microcurrent regulation path. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of a micro-current output circuit of a beauty instrument in a related solution;

[0012] Figure 2 A schematic diagram of the structure of a micro-current output circuit of a beauty instrument provided in an embodiment of the present application;

[0013] Figure 3 A schematic diagram of the structure of a micro-current output circuit of a beauty instrument provided in another embodiment of the present application;

[0014] Figure 4 Schematic diagram of the specific structure of the micro-current output circuit of the beauty instrument provided in the embodiment of the present application Figure 1 ;

[0015] Figure 5 Schematic diagram of the specific structure of the micro-current output circuit of the beauty instrument provided in the embodiment of the present application Figure 2 ;

[0016] Figure 6 Schematic diagram of the specific structure of the micro-current output circuit of the beauty instrument provided in the embodiment of the present application Figure 3 ;

[0017] Figure 7 A specific circuit diagram of a micro-current output circuit of a beauty instrument provided in an embodiment of the present application;

[0018] Figure 8 A schematic diagram of the structure of a beauty instrument provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0020] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0021] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and 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 therefore should not be understood as a limitation on the present application.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] Currently, most beauty devices on the market are equipped with contact electrodes that come into contact with the skin and are used to output microcurrents to act on the skin.

[0024] For example, Figure 1 FIG. 1 shows a schematic diagram of a micro-current output circuit of a beauty instrument in a related solution. Figure 1 As shown, in a traditional beauty instrument, the contact electrode 1 of the beauty instrument is connected to a constant voltage source 2, and the constant voltage source 2 includes a loop switch 3. By inputting a PWM signal to the loop switch 3, the on and off frequency of the constant voltage source 2 is controlled to control the periodic output of microcurrent by the constant voltage source 2. However, the microcurrent output circuit in the traditional beauty instrument can only adjust the frequency of the microcurrent output by the constant voltage source 2 by adjusting the duty cycle of the PWM signal, and the microcurrent adjustment method is too single.

[0025] In order to solve the above technical problems, the embodiment of the present application provides a micro-current output circuit of a beauty instrument, which is used to output micro-current to the contact electrode of the beauty instrument, and the micro-current output circuit includes a control unit, a bias voltage output unit and an operational amplifier unit. Among them, the operational amplifier unit is configured with a positive input terminal and a negative input terminal, the positive input terminal is connected to the bias voltage output unit, the negative input terminal is connected to the control unit, and the bias voltage output unit is connected to the control unit. When the control unit is used to output a PWM signal and a control signal, since the negative input terminal of the operational amplifier unit receives the PWM signal output by the control unit, the bias voltage output unit can output a corresponding DC bias voltage to the positive input terminal of the operational amplifier unit according to the control signal, so the operational amplifier unit can raise the voltage amplitude range of the PWM signal under the action of the DC bias voltage, that is, it can output a micro-current according to the PWM signal and the DC bias voltage.

[0026] The above scheme utilizes the control unit to output PWM signals with different duty cycles, and the output control signal controls the bias voltage output unit to output different DC bias voltages to the operational amplifier unit, so that the operational amplifier unit can raise the voltage amplitude range of PWM signals with different duty cycles to different degrees under the action of different DC bias voltages, and then output microcurrents with different voltage amplitudes, enriching the microcurrent regulation path.

[0027] See also Figure 2 , Figure 2 The structure diagram of the micro-current output circuit of the beauty instrument provided in the embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0028] exist Figure 2 In the embodiment, the micro-current output circuit 100 of the beauty instrument is used to output micro-current to the contact electrode 110 of the beauty instrument. The micro-current output circuit 100 of the beauty instrument includes: a control unit 10, a bias voltage output unit 20 and an operational amplifier unit 30. Specifically:

[0029] The control unit 10 is used to output a pulse modulation PWM signal and a control signal. The bias voltage output unit 20 is connected to the control unit 10, and the bias voltage output unit 20 is used to output a corresponding DC bias voltage according to the control signal. The operational amplifier unit 30 is configured with a positive input terminal 31 and a negative input terminal 32, the positive input terminal 31 is connected to the bias voltage output unit 20, and the negative input terminal 32 is connected to the control unit 10, and the operational amplifier unit 30 is used to output a micro current according to the PWM signal and the DC bias voltage.

[0030] In this embodiment, the microcurrent output circuit 100 of the beauty instrument is coupled to the contact electrode 110 of the beauty instrument, and outputs microcurrent to the contact electrode 110 of the beauty instrument. When the user uses the beauty instrument, the microcurrent can act on the skin through the contact electrode 110 contacting the skin.

[0031] like Figure 2 As shown, in the micro-current output circuit 100 of the beauty instrument, the control unit 10 is connected to the bias voltage output unit 20, and the control unit 10 is also connected to the negative input terminal 32 of the operational amplifier unit 30. The bias voltage output unit 20 is connected to the positive input terminal 31 of the operational amplifier unit 30, and the output terminal of the operational amplifier unit 30 is used to couple the contact electrode 110. Among them, the control unit 10 can output a PWM signal to the negative input terminal 32 of the operational amplifier unit 30, and at the same time output a control signal to the bias voltage output unit 20, and control the bias voltage output unit 20 to output a corresponding DC bias voltage to the positive input terminal 31 of the operational amplifier unit 30. Since the DC bias voltage is input to the positive input terminal 31 of the operational amplifier unit 30, and the PWM signal is input to the negative input terminal 32, the operational amplifier unit 30 can raise the voltage amplitude range of the PWM signal to a corresponding degree according to the DC bias voltage, and then output the micro-current after the voltage amplitude is raised.

[0032] It is easy to understand that, since the waveform of the PWM signal is related to its duty cycle, the degree to which the operational amplifier unit 30 raises the voltage amplitude range of the PWM signal according to the DC bias voltage is related to the voltage value of the DC bias voltage, so the control unit 10 can be used to output PWM signals with multiple duty cycles. In addition, the control unit 10 is used to output different control signals to control the bias voltage output unit 20 to output DC bias voltages with multiple voltage values, so as to adjust the frequency and / or voltage amplitude of the microcurrent, thereby providing a basis for providing various types of microcurrents to the contact electrode 110.

[0033] It is understandable that the contact electrode 110 can be a metal electrode. When the operational amplifier unit 30 outputs a microcurrent, the microcurrent can be applied to the skin through the contact electrode 110, thereby stimulating the skin with the microcurrent and playing a role in maintaining the skin.

[0034] In a specific implementation, the bias voltage output unit 20 may be a voltage source circuit or a DC voltage conversion circuit, etc. For example, the bias voltage output unit 20 may specifically include a plurality of voltage source circuits, and different voltage source circuits may be selected to work according to a control signal, thereby outputting a corresponding DC bias voltage. For another example, the bias voltage output unit 20 may specifically include a DC voltage conversion circuit, which may perform voltage conversion according to a preset power supply, that is, may perform multiple levels of conversion on the preset power supply according to a control signal, thereby outputting a DC bias voltage of multiple voltage values.

[0035] In some embodiments, the bias voltage output unit 20 may further include at least one voltage source and a plurality of voltage divider circuits. For example, the voltage source provides an initial DC voltage, and the corresponding voltage divider circuit is turned on according to the control signal, and then the initial DC voltage is divided to output a corresponding DC bias voltage.

[0036] It should be noted that the PWM signal output by the control unit 10 to the negative input terminal 32 of the operational amplifier unit 30 can be regarded as a sinusoidal electrical signal, that is, the PWM signal has a high level part and a low level part. When the operational amplifier unit 30 only inputs the PWM signal, it can only output a signal corresponding to the high level part, and does not respond to or output a corresponding signal for the low level part of the PWM signal, resulting in a low utilization rate of the PWM signal.

[0037] In this embodiment, in order to fully utilize the full band of the PWM signal, the bias voltage output unit 20 is used to output a corresponding DC bias voltage to the positive input terminal 31 of the operational amplifier unit 30. Under the action of the DC bias voltage, the operational amplifier unit 30 can raise the voltage amplitude range of the PWM signal to a corresponding degree, that is, raise the voltage values ​​of the high and low levels of the PWM signal. In a specific implementation, the operational amplifier unit 30 can be an operational amplifier circuit built based on an operational amplifier, and the positive input terminal of the operational amplifier circuit is used to access the DC bias voltage, the negative input terminal is used to access the PWM signal, and the output terminal is coupled to the contact electrode 110.

[0038] As an example, assume that the voltage value of the high level part of the PWM signal is 3.3V, and the voltage value of the low level part is 0V. By inputting the PWM signal to the negative input terminal 32 of the operational amplifier unit 30 and inputting a DC bias voltage to the positive input terminal 31 of the operational amplifier unit 30, the voltage amplitude range of the PWM signal can be raised. For example, the high level and low level of the PWM signal are raised by 2V, that is, the amplitude range of the micro-current output by the operational amplifier unit 30 can be 2V to 5.3V. Here, the high level voltage of the micro-current is 5.3V, the low level voltage is 2V, and the voltage difference between the high and low levels of the micro-current is 5.3V-2V=3.3V, and the voltage difference between the high and low levels of the PWM signal is 3.3V-0V=3.3V, and the high and low voltage differences of the two are both 3.3V.

[0039] Based on this, by raising the voltage values ​​of the high and low levels of the PWM signal, the waveform of the output microcurrent is similar to the waveform of the PWM signal. By adjusting the waveform of the PWM signal and / or adjusting the DC bias voltage, the microcurrent output by the operational amplifier unit 30 can be adjusted accordingly. For example, by adjusting the duty cycle of the PWM signal, the high and low level distribution or proportion of the microcurrent can be adjusted, and by adjusting the voltage value of the DC bias voltage, the amplitude of the microcurrent can be adjusted. For another example, by adjusting the duty cycle of the PWM signal and adjusting the voltage value of the DC bias voltage at the same time, the high and low level distribution or proportion of the microcurrent can be adjusted, and the voltage value of the high and low level of the microcurrent can also be adjusted. In this way, a variety of adjustment methods can be provided for the output of microcurrent by the operational amplifier unit 30. In addition, it is also possible to output a variety of microcurrents for beauty instruments to provide a basis for realizing a variety of working modes.

[0040] Figure 3 FIG. 2 shows a schematic diagram of a micro-current output circuit of a beauty instrument provided by another embodiment of the present application. Figure 3 As shown, the micro-current output circuit 100 of the beauty instrument also includes a current enhancement unit 40. Specifically:

[0041] The current enhancement unit 40 is connected between the operational amplifier unit 30 and the contact electrode 110 and is used to amplify the current of the microcurrent.

[0042] In a specific implementation, the current enhancement unit 40 can be an emitter follower or an emitter follower circuit constructed using a switch tube. The high potential end of the switch tube is connected to a preset power supply, the controlled end of the switch tube is connected to the output end of the operational amplifier unit 30, and the low potential end of the switch tube is used as a signal output end, so as to achieve the following and amplification of the micro-current output from the output end of the operational amplifier unit 30. Since the current enhancement unit 40 has the characteristics of high input impedance and low output impedance, the current required from the output end of the operational amplifier unit 30 is small, and the load capacity of the micro-current output circuit 100 of the beauty instrument to the contact electrode 110 can be improved.

[0043] Figure 4 The specific structure of the micro-current output circuit of the beauty instrument provided in the embodiment of the present application is shown in FIG. Figure 1 .like Figure 4 As shown, as an embodiment, the bias voltage output unit 20 includes a first voltage dividing branch 21 and a second voltage dividing branch 22 .

[0044] exist Figure 4In the embodiment, the first end of the first voltage dividing branch 21 is connected to the first end of the second voltage dividing branch 22 to form a reference node ref, and the reference node ref is used to connect the positive input terminal 31 of the operational amplifier unit 30, the second end of the first voltage dividing branch 21 is used for grounding, and the second end of the second voltage dividing branch 22 is used for grounding.

[0045] The bias voltage output unit 20 is used to conduct the path between the first voltage dividing branch 21 and the ground, and / or conduct the path between the second voltage dividing branch 22 and the ground according to the control signal, so as to output the corresponding DC bias voltage to the positive input terminal of the operational amplifier unit 30 through the reference node ref.

[0046] In this embodiment, the first end of the first voltage dividing branch 21 is connected to the first end of the second voltage dividing branch 22 to form a reference node ref, and the reference node ref is used to connect the positive input terminal 31 of the operational amplifier unit 30. The reference node ref can be voltage-divided to different degrees by controlling the first voltage dividing branch 21 and / or the second voltage dividing branch 22 to be turned on.

[0047] As an example, in a specific implementation, the positive input terminal 31 of the operational amplifier unit 30 can be connected to a preset voltage. Since the second end of the first voltage-dividing branch 21 is used for grounding and the second end of the second voltage-dividing branch 22 is used for grounding, the first voltage-dividing branch 21 and / or the second voltage-dividing branch 22 can be controlled to be turned on, thereby achieving different degrees of voltage division of the reference node ref, and thus the voltage value of the DC bias voltage output to the positive input terminal of the operational amplifier unit 30 can be adjusted.

[0048] In some embodiments, in a specific implementation, the first voltage-dividing branch 21 and the second voltage-dividing branch 22 are both voltage source branches, wherein the positive electrode of the voltage source can be used as the first end of the voltage-dividing branch (the first voltage-dividing branch 21 and the second voltage-dividing branch 22), and the negative electrode of the voltage source is grounded through a switch. By outputting a control signal to the bias voltage output unit 20, the switch in the first voltage-dividing branch 21 is controlled to be turned on, and / or the switch in the second voltage-dividing branch 22 is controlled to be turned on, thereby adjusting the voltage value of the DC bias voltage output to the positive input terminal of the operational amplifier unit 30.

[0049] Figure 5 The specific structure of the micro-current output circuit of the beauty instrument provided in the embodiment of the present application is shown in FIG. Figure 2 .like Figure 5As shown, as an embodiment, the control unit 10 includes a PWM signal output terminal 101, a first control terminal 11 and a second control terminal 12, the PWM signal output terminal 101 is used to connect the negative input terminal 32 of the operational amplifier unit 30, the first control terminal 11 is used to connect the first voltage-dividing branch 21, and the second control terminal 12 is used to connect the second voltage-dividing branch 22. The control unit 10 is specifically used to output a first control signal to the first voltage-dividing branch 21 through the first control terminal 11, and output a second control signal to the second voltage-dividing branch 22 through the second control terminal 12, so as to conduct the path between the first voltage-dividing branch 21 and the ground and / or conduct the path between the second voltage-dividing branch 22 and the ground.

[0050] In this embodiment, the first control signal is used to control the path between the first voltage-dividing branch 21 and the ground, and the second control signal is used to control the path between the second voltage-dividing branch 22 and the ground. Since different voltage-dividing branches have different degrees of voltage division on the reference node ref, different control strategies can be configured according to actual needs to conduct the paths between different voltage-dividing branches and the ground, thereby providing DC bias voltages of different voltage values ​​to the operational amplifier unit 30.

[0051] Based on the above example, it is assumed that in a specific implementation, the positive input terminal 31 of the operational amplifier unit 30 is connected to a preset voltage. Since the second end of the first voltage-dividing branch 21 is used for grounding and the second end of the second voltage-dividing branch 22 is used for grounding, the control unit 10 can be used to output a first control signal to the first voltage-dividing branch 21 through the first control terminal 11, and / or output a second control signal to the second voltage-dividing branch 22 through the second control terminal 12, thereby achieving different degrees of voltage division of the reference node ref, and thereby adjusting the voltage value of the DC bias voltage output to the positive input terminal of the operational amplifier unit 30.

[0052] Figure 6 The specific structure of the micro-current output circuit of the beauty instrument provided in the embodiment of the present application is shown in FIG. Figure 3 .like Figure 6 As shown, as an embodiment, the bias voltage output unit 20 further includes a power supply branch 23 .

[0053] The first end of the power supply branch 23 is connected to the reference node ref, the second end of the power supply branch is grounded, and the power supply branch 23 is used to provide a preset voltage for the reference node ref. The first voltage dividing branch 21 is used to divide the voltage of the reference node ref when the path between the first control signal and the ground is connected. The second voltage dividing branch 22 is used to divide the voltage of the reference node ref when the path between the second control signal and the ground is connected.

[0054] In this embodiment, the power supply branch 23 can provide a preset voltage to the reference node ref. By turning on different voltage dividing branches, the reference node ref can be divided to different degrees, thereby inputting DC bias voltages of different voltage values ​​to the positive input terminal 31 of the operational amplifier unit 30.

[0055] For example, in a specific implementation, the control unit 10 outputs a control signal to the bias voltage output unit 20. Specifically, the control unit 10 outputs a first control signal to the first voltage divider branch 21 through the first control terminal 11, thereby turning on the path between the first voltage divider branch 21 and the ground, thereby performing a voltage dividing effect on the reference node ref to a smaller extent, thereby realizing inputting a DC bias voltage with a higher voltage value to the positive input terminal 31 of the operational amplifier unit 30.

[0056] For another example, the control unit 10 outputs a second control signal to the second voltage-dividing branch 22 through the second control terminal 12, thereby conducting the path between the second voltage-dividing branch 22 and the ground, thereby achieving a greater degree of voltage-dividing effect on the reference node ref, and inputting a DC bias voltage of a lower voltage value to the positive input terminal 31 of the operational amplifier unit 30.

[0057] For example, the control unit 10 outputs a first control signal to the first voltage-dividing branch 21 through the first control terminal 11, and outputs a second control signal to the second voltage-dividing branch 22 through the second control terminal 12, thereby connecting the path between the first voltage-dividing branch 21 and the ground, and connecting the path between the second voltage-dividing branch 22 and the ground, thereby maximizing the voltage-dividing effect on the reference node ref, and realizing the input of a DC bias voltage with the lowest voltage value to the positive input terminal 31 of the operational amplifier unit 30.

[0058] It can be understood that the control unit 10 can output PWM signals with different duty cycles through the PWM signal output terminal 101, and can control the conduction of different voltage-dividing branches through the first control terminal 11 and the second control terminal 12, thereby exerting different degrees of voltage-dividing effects on the reference node ref, thereby realizing the input of DC bias voltages of different voltage values ​​to the positive input terminal 31 of the operational amplifier unit 30, and providing a basis for adjusting the microcurrent output by the operational amplifier unit 30 from different dimensions.

[0059] Figure 7 FIG. 2 shows a specific circuit diagram of a micro-current output circuit of a beauty instrument provided in an embodiment of the present application. Figure 7 As shown, as an embodiment, the power supply branch 23 includes a first preset power supply S1 and a first resistor R1. The negative terminal of the first preset power supply S1 is grounded, the positive terminal of the first preset power supply S1 is connected to the first end of the first resistor R1, and the second end of the first resistor R1 serves as the first end of the power supply branch 23.

[0060] In this embodiment, the first preset power supply S1 is used to provide a preset voltage to the reference node ref through the first resistor R1. At the same time, since the reference node ref is formed by connecting the first end of the first voltage-dividing branch 21 and the first end of the second voltage-dividing branch 22, the voltage-dividing operation on the reference node ref can be achieved by opening the path between the first voltage-dividing branch 21 and the ground, and / or opening the path between the second voltage-dividing branch 22 and the ground, that is, the voltage value of the DC bias voltage input to the positive input terminal 31 of the operational amplifier unit 30 can be adjusted.

[0061] As an embodiment, the first voltage-dividing branch 21 includes a first switch tube Q1 and a second resistor R2, the first end of the second resistor R2 serves as the first end of the first voltage-dividing branch 21, the second end of the second resistor R2 is connected to the first potential end of the first switch tube Q1, the second potential end of the first switch tube Q1 is grounded, and the controlled end of the first switch tube Q1 is connected to the first control end 11 of the control unit 10.

[0062] The second voltage-dividing branch 22 includes a second switch tube Q2 and a third resistor R3. The first end of the third resistor R3 serves as the first end of the second voltage-dividing branch 22. The second end of the third resistor R3 is connected to the first potential end of the second switch tube Q2. The second potential end of the second switch tube Q2 is grounded. The controlled end of the second switch tube Q2 is connected to the second control end 12 of the control unit 10.

[0063] In this embodiment, the controlled end of the first switch tube Q1 is connected to the first control end 11 of the control unit 10, so the first switch tube Q1 is controlled by the first control signal. The controlled end of the second switch tube Q2 is connected to the second control end 12 of the control unit 10, so the second switch tube Q2 is controlled by the second control signal.

[0064] It is easy to understand that by using the control unit 10 to output a first control signal to the controlled end of the first switch tube Q1, and / or output a second control signal to the controlled end of the second switch tube Q2, the first switch tube Q1 and / or the second switch tube Q2 can be controlled to be turned on, and then the second resistor R2 and / or the third resistor R3 can be used to perform different degrees of voltage division on the reference node ref.

[0065] like Figure 7 As shown, the control unit 10 may specifically include a first chip U1, wherein the signal output terminal DAC of the first chip U1 serves as the PWM signal output terminal 101 of the control unit 10, the first communication terminal GPIO1 of the first chip U1 serves as the first control terminal 11 of the control unit 10, and the second communication terminal GPIO2 of the first chip U1 serves as the second control terminal 12 of the control unit 10.

[0066] Combination Figure 6 and Figure 7, the first chip U1 can be used to input a first control signal to the controlled end of the first switch tube Q1 through the first communication terminal GPIO1, and the first switch tube Q1 is turned on according to the first control signal, that is, the loop between the second resistor R2 and the ground is turned on, and the reference node ref is divided by the second resistor R2. Alternatively, the first chip U1 can be used to input a second control signal to the controlled end of the second switch tube Q2 through the second communication terminal GPIO2, and the second switch tube Q2 is turned on according to the second control signal, that is, the loop between the third resistor R3 and the ground is turned on, and the reference node ref is divided by the third resistor R3. Of course, the first chip U1 can also be used to input a first control signal to the controlled end of the first switch tube Q1, and at the same time input a second control signal to the controlled end of the second switch tube Q2, so that the first switch tube Q1 and the second switch tube Q2 are turned on at the same time, and the first voltage dividing branch 21 and the second voltage dividing branch 22 divide the reference node ref at the same time.

[0067] As an embodiment, the operational amplifier unit 30 includes: an amplifier U2 and a fourth resistor R4. The positive input terminal +in of the amplifier U2 serves as the positive input terminal 31 of the operational amplifier unit 30, the inverting input terminal -in of the amplifier U2 serves as the negative input terminal 32 of the operational amplifier unit 30, the first end of the fourth resistor R4 is connected to the inverting input terminal -in of the amplifier U2, and the second end of the fourth resistor R4 is used to couple with the contact electrode 110.

[0068] In this embodiment, the first end of the fourth resistor R4 is connected to the inverting input terminal -in of the amplifier U2, and the second end of the fourth resistor R4 is used to couple with the contact electrode 110, so the fourth resistor R4 serves as negative feedback of the operational amplifier unit 30. The output terminal out of the amplifier U2 is used to output a micro current.

[0069] Combination Figure 6 and Figure 7 , the first chip U1 can be used to input a PWM signal to the positive input terminal +in of the amplifier U2 through the signal output terminal DAC. Since the negative input terminal -in of the amplifier U2 can input a DC bias voltage of different voltage values, the voltage range of the PWM signal can be raised to different degrees. In specific implementation, the voltage value of the micro-current output by the output terminal out of the amplifier U2 can be adjusted based on the negative feedback characteristics of the amplifier U2.

[0070] Here, the negative feedback characteristics of amplifier U2 can be specifically characterized by the negative feedback formula of the operational amplifier. The negative feedback formula is specifically: Wherein, Vdac is the high level voltage value of the PWM signal, Vref is the voltage value of the DC bias voltage, R represents the line resistance value of the inverting input terminal -in of the amplifier U2, and R4 is the resistance value of the fourth resistor R4. Wherein, R represents the line resistance value of the inverting input terminal -in of the amplifier U2. In practical applications, the inverting input terminal -in of the amplifier U2 can also be coupled with the signal output terminal DAC of the first chip U1 through a series resistor. That is, R can also be used to represent the resistance value of the series resistor between the inverting input terminal -in of the amplifier U2 and the signal output terminal DAC of the first chip U1. When R = R4, according to the above feedback formula, it can be obtained that: Vout = 2Vref-Vdac. Based on this, the voltage value of the micro-current output to the output terminal out of the amplifier U2 can be achieved by adjusting the voltage value of the DC bias voltage and / or the high level voltage value of the PWM signal.

[0071] As an embodiment, the current enhancement unit 40 includes: a second preset power source S2, a third switch tube Q3, and a fifth resistor R5. The negative terminal of the second preset power source S2 is grounded, the positive terminal of the second preset power source S2 is connected to the high potential terminal of the third switch tube Q3, the controlled terminal of the third switch tube Q3 is connected to the output terminal of the amplifier U2, the low potential terminal of the third switch tube Q3 is used to couple with the contact electrode 110, and the fifth resistor R5 is connected between the low potential terminal of the third switch tube Q3 and the ground.

[0072] In a specific implementation, the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 can all be triodes, MOS tubes or IGBT tubes, etc., which are not limited here.

[0073] In this embodiment, the third switch tube Q3 can be specifically a triode Q3, the base of the triode Q3 serves as the controlled end of the third switch tube Q3, the collector of the triode Q3 serves as the high potential end of the third switch tube Q3, and the emitter of the triode Q3 serves as the low potential end of the third switch tube Q3. Based on this, the second preset power supply S2 and the third switch tube Q3 form an emitter follower circuit, so the low potential end of the third switch tube Q3 can follow the micro-current outputted from the output end out of the amplifier U2, that is, the low potential end of the third switch tube Q3 can output a waveform signal corresponding to the micro-current, and can also amplify the micro-current, and can transmit the amplified micro-current to the contact electrode 110 by coupling with the contact electrode 110, which can improve the carrying capacity of the micro-current output circuit 100 of the beauty instrument to the contact electrode 110.

[0074] Figure 8 The structure diagram of the beauty instrument provided in the embodiment of the present application is shown. Figure 8As shown, the beauty instrument 200 includes the micro-current output circuit 100 of the beauty instrument provided in any embodiment of the present application.

[0075] It is understandable that in Figure 8 In the embodiment shown, due to the improvements and specific implementations related to the present application, Figures 2 to 7 The corresponding embodiments are described in detail, so they will not be described again here.

[0076] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units.

[0077] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A micro-current output circuit of a beauty instrument, characterized in that: Used to output microcurrent to the contact electrodes of the beauty instrument, the microcurrent output circuit includes: A control unit, used for outputting a pulse modulation PWM signal and a control signal; A bias voltage output unit connected to the control unit, the bias voltage output unit being used to output a corresponding DC bias voltage according to the control signal; The operational amplifier unit is configured with a positive input terminal and a negative input terminal, the positive input terminal is connected to the bias voltage output unit, and the negative input terminal is connected to the control unit. The operational amplifier unit is used to output a micro current according to the PWM signal and the DC bias voltage.

2. The micro-current output circuit according to claim 1, characterized in that: Also includes: The current enhancement unit is connected between the operational amplifier unit and the contact electrode, and is used to amplify the current of the microcurrent.

3. The micro-current output circuit according to claim 1 or 2, characterized in that: The bias voltage output unit includes a first voltage dividing branch and a second voltage dividing branch; The first end of the first voltage dividing branch is connected to the first end of the second voltage dividing branch to form a reference node, the reference node is used to connect the positive input end of the operational amplifier unit, the second end of the first voltage dividing branch is used to be grounded, and the second end of the second voltage dividing branch is used to be grounded; The bias voltage output unit is used to conduct the path between the first voltage dividing branch and the ground and / or conduct the path between the second voltage dividing branch and the ground according to the control signal, so as to output a corresponding DC bias voltage to the positive input terminal of the operational amplifier unit through the reference node.

4. The micro-current output circuit according to claim 3, characterized in that: The control unit includes a PWM signal output terminal, a first control terminal and a second control terminal, the PWM signal output terminal is used to connect the negative input terminal of the operational amplifier unit, the first control terminal is used to connect the first voltage dividing branch, and the second control terminal is used to connect the second voltage dividing branch; The control unit is specifically used to output a first control signal to the first voltage-dividing branch through the first control end, and output a second control signal to the second voltage-dividing branch through the second control end, so as to open a path between the first voltage-dividing branch and the ground, and / or open a path between the second voltage-dividing branch and the ground.

5. The micro-current output circuit according to claim 4, characterized in that: The bias voltage output unit also includes a power supply branch; A first end of the power supply branch is connected to the reference node, a second end of the power supply branch is grounded, and the power supply branch is used to provide a preset voltage for the reference node; The first voltage dividing branch is used to divide the voltage of the reference node when the path between the first control signal and the ground is turned on; The second voltage dividing branch is used to divide the voltage of the reference node when the path between the second control signal and the ground is turned on.

6. The micro-current output circuit according to claim 5, characterized in that: The power supply branch includes a first preset power supply and a first resistor; The negative terminal of the first preset power supply is grounded, the positive terminal of the first preset power supply is connected to the first end of the first resistor, and the second end of the first resistor serves as the first end of the power supply branch.

7. The micro-current output circuit according to claim 5, characterized in that: The first voltage-dividing branch includes a first switch tube and a second resistor, the first end of the second resistor serves as the first end of the first voltage-dividing branch, the second end of the second resistor is connected to the first potential end of the first switch tube, the second potential end of the first switch tube is grounded, and the controlled end of the first switch tube is connected to the first control end of the control unit; The second voltage-dividing branch includes a second switch tube and a third resistor, the first end of the third resistor serves as the first end of the second voltage-dividing branch, the second end of the third resistor is connected to the first potential end of the second switch tube, the second potential end of the second switch tube is grounded, and the controlled end of the second switch tube is connected to the second control end of the control unit.

8. The micro-current output circuit according to claim 2, characterized in that: The operational amplifier unit comprises: an amplifier and a fourth resistor; The positive input terminal of the amplifier serves as the positive input terminal of the operational amplifier unit, the inverting input terminal of the amplifier serves as the negative input terminal of the operational amplifier unit, the first end of the fourth resistor is connected to the inverting input terminal of the amplifier, and the second end of the fourth resistor is used to couple with the contact electrode.

9. The micro-current output circuit according to claim 8, characterized in that: The current enhancement unit includes: a second preset power supply, a third switch tube and a fifth resistor; The negative terminal of the second preset power supply is grounded, the positive terminal of the second preset power supply is connected to the high potential terminal of the third switch tube, the controlled end of the third switch tube is connected to the output end of the amplifier, the low potential terminal of the third switch tube is used to couple with the contact electrode, and the fifth resistor is connected between the low potential terminal of the third switch tube and the ground.

10. A beauty instrument, comprising a contact electrode, characterized in that: The beauty instrument comprises the micro-current output circuit according to any one of claims 1 to 9.

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