CN219960402U

CN219960402U - Switching circuit

Info

Publication number: CN219960402U
Application number: CN202320879385.8U
Authority: CN
Inventors: 林晓; 蒋海如; 谭嘉良; 杨高强; 周亚
Original assignee: Guangdong Huazhi Beauty Technology Co ltd
Current assignee: Guangdong Huazhi Beauty Technology Co ltd
Priority date: 2023-04-18
Filing date: 2023-04-18
Publication date: 2023-11-03
Anticipated expiration: 2033-04-18

Abstract

The utility model discloses a switching circuit, which comprises a control chip provided with a micro-current control end, an impedance detection driving end, an impedance detection receiving end and a switch switching end; a micro-current circuit connected with the micro-current control end; an impedance detection circuit connected with the impedance detection driving end and the impedance detection receiving end; the switch circuit is provided with a first switch end, a second switch end and a common switch end, wherein the first switch end is connected with the micro-current circuit, the second switch end is connected with the impedance detection circuit, and the common switch end is connected with a first electrode and a second electrode; the switch switching end is connected with the switch circuit and used for controlling the first electrode and the second electrode to be connected with the micro-current circuit when the first end of the switch is connected with the switch public end; when the second end of the control switch is connected with the common end of the switch, the first electrode and the second electrode are connected into the impedance detection circuit. The utility model realizes that a group of electrodes can be used for outputting micro-current and detecting skin impedance, and reduces the arrangement of the electrodes.

Description

Switching circuit

Technical Field

The utility model relates to the technical field of beauty instruments, in particular to a switching circuit.

Background

With the popularization of the household beauty instrument, the functional requirements on the household beauty instrument are higher and higher. In order to improve the intelligence of the beauty instrument, the beauty instrument can automatically adjust the magnitude of the output current according to the skin state so as to achieve the optimal beauty effect, and part of the beauty instrument automatically adjusts the magnitude of the current according to the skin impedance by detecting the skin impedance in real time. However, in order to detect skin impedance in real time, two detection electrodes are required to be added on the electrode head, and the electrode head of the beauty instrument is generally smaller, so that the detection electrodes are additionally arranged, the arrangement space of the output electrodes is occupied to a certain extent, and the action range of current is reduced.

Disclosure of Invention

The utility model aims to overcome the defect that the arrangement of electrodes is affected by adding detection electrodes in a beauty instrument in the prior art, and provides a switching circuit with the same group of electrodes for micro-current output and impedance detection.

The technical scheme of the utility model provides a switching circuit, which comprises

The control chip is provided with a micro-current control end, an impedance detection driving end, an impedance detection receiving end and a switch switching end;

the micro-current circuit is connected with the micro-current control end;

the impedance detection circuit is connected with the impedance detection driving end and the impedance detection receiving end;

the switch circuit is provided with a switch first end, a switch second end and a switch public end, the switch first end is connected with the micro-current circuit, the switch second end is connected with the impedance detection circuit, and the switch public end is connected with a first electrode and a second electrode;

the switch circuit is connected with the switch switching end, when the switch switching end controls the first end of the switch to be connected with the switch public end, the first electrode and the second electrode are connected into the micro-current circuit, and when the switch switching end controls the second end of the switch to be connected with the switch public end, the first electrode and the second electrode are connected into the impedance detection circuit.

Further, the switch switching end comprises a first switching end, a second switching end, a third switching end and a fourth switching end;

the first end of the switch comprises a first connecting end and a second connecting end, and the second end of the switch comprises a third connecting end and a fourth connecting end; the switching circuit comprises a first relay, a second relay, a third relay and a fourth relay;

one end of a coil of the first relay is connected with a positive electrode of a power supply, the other end of the coil of the first relay is connected with the first switching end, one end of a switch of the first relay is connected with the impedance detection circuit, and the other end of the switch of the first relay is connected with the first electrode;

one end of a coil of the second relay is connected with a positive electrode of a power supply, the other end of the coil of the second relay is connected with the second switching end, one end of a switch of the second relay is connected with the impedance detection circuit, and the other end of the switch of the second relay is connected with the second electrode;

one end of a coil of the third relay is connected with a positive electrode of a power supply, the other end of the coil of the third relay is connected with the third switching end, one end of a switch of the third relay is connected with the micro-current circuit, and the other end of the switch of the third relay is connected with the first electrode;

one end of a coil of the fourth relay is connected with the positive electrode of the power supply, the other end of the coil of the fourth relay is connected with the fourth switching end, one end of a switch of the fourth relay is connected with the micro-current circuit, and the other end of the switch of the fourth relay is connected with the second electrode.

Further, the impedance detection circuit includes a detection voltage output sub-circuit and a differential operation sub-circuit;

the impedance detection driving end is connected with the input end of the detection voltage output sub-circuit, the output end of the detection voltage output sub-circuit is connected with the first electrode through a switch circuit, and the second electrode is connected with the negative electrode of the power supply through the switch circuit;

and two input ends of the differential operation sub-circuit are respectively connected with the first electrode and the second electrode, and an output end of the differential operation sub-circuit is connected with the impedance detection receiving end.

Further, the detection voltage output sub-circuit comprises an amplifying circuit and a first follower circuit;

the impedance detection driving end is connected with the input end of the amplifying circuit, the output end of the amplifying circuit is connected with the input end of the first follower circuit, and the output end of the first follower circuit is connected with the first electrode through the switch circuit.

Further, an interference filtering sub-circuit is connected between the detection voltage output sub-circuit and the differential operation sub-circuit;

the two input ends of the interference filtering sub-circuit are respectively connected with the first electrode and the second electrode and are used for filtering power frequency interference between the first electrode and the second electrode and outputting the power frequency interference from the two output ends of the interference filtering sub-circuit;

and two input ends of the differential operation sub-circuit are respectively connected with two output ends of the interference filtering sub-circuit.

Further, the interference filtering sub-circuit comprises a second follower circuit and a third follower circuit;

the first electrode is connected with the input end of the second follower circuit, and the output end of the second follower circuit is connected with the differential operation sub-circuit;

the second electrode is connected with the input end of the third follower circuit, and the output end of the third follower circuit is connected with the differential operation sub-circuit.

Further, the micro-current control end comprises a power supply control end and an output control end;

the micro-current circuit comprises an electronic circuit and an output sub-circuit, wherein the output end of the electronic circuit is connected with the output sub-circuit and is used for supplying power to the output sub-circuit, and the output end of the output sub-circuit is connected with the first end of the switch;

the power supply control end is connected with the power supply sub-circuit, and the output sub-circuit is connected with the output control end.

Further, the power supply control end comprises a driving end and an adjusting end;

the power supply circuit comprises a switching power supply chip and a voltage regulating circuit module;

the enabling end of the switching power supply chip is connected with the driving end, and the adjusting end, the voltage output end and the feedback end of the switching power supply chip are connected with the voltage regulating circuit module;

and the output end of the voltage regulating circuit module is connected with the output sub-circuit.

Further, the output control end comprises a first signal output end and a second signal output end which are used for respectively outputting two paths of complementary signals;

the output subcircuit comprises a transformer, a first MOS tube and a second MOS tube;

the input side common end of the transformer is connected with the positive electrode output end of the electronic circuit;

the input side first end of the transformer is connected with the drain electrode of the first MOS tube, the source electrode of the first MOS tube is connected with the negative electrode output end of the power supply electronic circuit, and the grid electrode of the first MOS tube is connected with the first signal output end;

the second end of the input side of the transformer is connected with the drain electrode of the second MOS tube, the source electrode of the second MOS tube is connected with the negative electrode output end of the power supply electronic circuit, and the grid electrode of the second MOS tube is connected with the second signal output end;

the first end of the output side and the second end of the output side of the transformer are connected with the first end of the switch.

After the technical scheme is adopted, the method has the following beneficial effects:

according to the utility model, the microcurrent circuit and the impedance detection circuit are both connected with the first electrode and the second electrode through the switch circuit, the control chip controls the switch circuit to act, and the first electrode and the second electrode are selectively connected into the microcurrent circuit or the impedance detection circuit, so that a group of electrodes can be used for outputting microcurrent and detecting skin impedance, and the arrangement of the electrodes is reduced.

Drawings

The present disclosure will become more readily understood with reference to the accompanying drawings. It should be understood that: the drawings are for illustrative purposes only and are not intended to limit the scope of the present utility model. In the figure:

FIG. 1 is a schematic diagram of a switching circuit according to an embodiment of the utility model;

FIG. 2 is a circuit diagram of a switching circuit according to an embodiment of the utility model;

FIG. 3 is a second circuit diagram of a switching circuit according to an embodiment of the utility model;

FIG. 4 is a third circuit diagram of a switching circuit according to an embodiment of the utility model;

FIG. 5 is a circuit diagram of a switching circuit according to an embodiment of the present utility model.

Reference numeral control table:

a control chip 01;

microcurrent circuit 02: a power supply sub-circuit 21 and an output sub-circuit 22;

impedance detection circuit 03: a detection voltage output sub-circuit 31, a differential operation sub-circuit 32, an interference filtering sub-circuit 33;

a switch circuit 04, a first electrode 05, a second electrode 06.

Detailed Description

Specific embodiments of the present utility model will be further described below with reference to the accompanying drawings.

It is to be readily understood that, according to the technical solutions of the present utility model, those skilled in the art may replace various structural modes and implementation modes with each other without changing the true spirit of the present utility model. Accordingly, the following detailed description and drawings are merely illustrative of the utility model and are not intended to limit or restrict the utility model in its entirety or to apply for the utility model.

Terms of orientation such as up, down, left, right, front, rear, front, back, top, bottom, etc. mentioned or possible to be mentioned in the present specification are defined with respect to the configurations shown in the drawings, which are relative concepts, and thus may be changed according to different positions and different use states thereof. These and other directional terms should not be construed as limiting terms. 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.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between the two components. The above-described specific meanings belonging to the present utility model are understood as appropriate by those of ordinary skill in the art.

The switching circuit in the embodiment of the utility model, as shown in FIG. 1, comprises

The control chip 01 is provided with a micro-current control end, an impedance detection driving end, an impedance detection receiving end and a switch switching end;

the micro-current circuit 02, the micro-current circuit 02 is connected with the micro-current control end;

the impedance detection circuit 03, the impedance detection circuit 03 is connected with the impedance detection driving end and the impedance detection receiving end;

the switch circuit 04 is provided with a first switch end, a second switch end and a common switch end, wherein the first switch end is connected with the micro-current circuit 02, the second switch end is connected with the impedance detection circuit 03, and the common switch end is connected with the first electrode 05 and the second electrode 06;

the switch circuit 04 is connected with a switch switching end, when the switch switching end controls the first end of the switch to be connected with the switch public end, the first electrode 05 and the second electrode 06 are connected with the micro-current circuit 02, and when the switch switching end controls the second end of the switch to be connected with the switch public end, the first electrode 05 and the second electrode 06 are connected with the impedance detection circuit 03.

Specifically, the control chip 01 may be a single-chip microcomputer, where the micro-current control end, the impedance detection driving end, the impedance detection receiving end and the switch switching end are all monolithic I/O ports, and specifically, see the single-chip microcomputer enabling circuit in fig. 2.

The micro-current circuit 02 is configured to output EMS micro-current to the first electrode 05 and the second electrode 06 through the switch circuit 04, and the control chip 01 controls the output current of the micro-current circuit 02 through the micro-current control terminal. The impedance detection circuit 03 is configured to detect skin impedance between the first electrode 05 and the second electrode 06 through the switch circuit 04 and send an impedance detection value to an impedance detection receiving end of the control chip 01, and the control chip 01 outputs a voltage between the first electrode 05 and the second electrode 06 through the impedance detection receiving end to drive impedance detection.

A preset control program is programmed in the control chip 01, and the control chip controls the switch circuit 04 to control the common end of the switch to be sequentially connected with the first end and the second end of the switch according to a preset time interval.

Exemplarily, the switch public terminal is switched to be communicated with the switch second terminal for one skin impedance detection every time when the switch public terminal is communicated with the switch first terminal for 1s, the control chip 01 receives the impedance detection value and judges whether the impedance detection value is in a preset range, if so, the switch public terminal is controlled to be communicated with the switch first terminal, the micro-current is continuously output, and if not, the micro-current is stopped to be output. In the process, the impedance detection time is extremely short, and is generally a plurality of microseconds, so that a user does not feel the change of the current, and the real-time monitoring of the skin impedance in the micro-current output process is realized.

In the embodiment of the utility model, the microcurrent circuit 02 and the impedance detection circuit 03 are connected with the first electrode 05 and the second electrode 06 through the switch circuit 04, the control chip 01 controls the switch circuit 04 to act, and the first electrode 05 and the second electrode 06 are selectively connected into the microcurrent circuit 02 or the impedance detection circuit 03, so that a group of electrodes can be used for outputting microcurrent and detecting skin impedance, and the arrangement of the electrodes is reduced.

In one embodiment, as shown in fig. 2, the switch switching terminals include a first switching terminal io_relay1, a second switching terminal io_relay2, a third switching terminal io_relay3, and a fourth switching terminal io_relay4.

As shown in fig. 3, the switch first terminal includes a first connection terminal OUT1 and a second connection terminal OUT2, and the switch second terminal includes a third connection terminal OUT3 and a fourth connection terminal OUT4; the switching circuit 04 includes a first relay K1, a second relay K2, a third relay K3, and a fourth relay K4.

One end of a coil of the first Relay K1 is connected with a positive electrode of a power supply, the other end of the coil of the first Relay K1 is connected with a first switching end IO_Relay1, one end of a switch of the first Relay K1 is connected with an impedance detection circuit 03, and the other end of the switch of the first Relay K1 is connected with a first electrode 05;

one end of a coil of the second Relay K2 is connected with a positive electrode of a power supply, the other end of the coil of the second Relay K2 is connected with a second switching end IO_Relay2, one end of a switch of the second Relay K2 is connected with the impedance detection circuit 03, and the other end of the switch of the second Relay K2 is connected with the second electrode 06.

The control chip 01 controls the coil of the first Relay K1 and the coil of the second Relay K2 to be simultaneously electrified through the first switching end IO_Relay1 and the second switching end IO_Relay2, and the switch of the first Relay K1 and the switch of the second Relay K2 are simultaneously closed, so that the first electrode 05 and the second electrode 06 are simultaneously connected into the impedance detection circuit 03, and at the moment, the first electrode 05 and the second electrode 06 are used as detection electrodes.

One end of a coil of the third Relay K3 is connected with the positive electrode of the power supply, the other end of the coil of the third Relay K3 is connected with the third switching end IO_Relay3, one end of a switch of the third Relay K3 is connected with the micro-current circuit 02, and the other end of the switch of the third Relay K3 is connected with the first electrode 05;

one end of a coil of the fourth Relay K4 is connected with a positive electrode of a power supply, the other end of the coil of the fourth Relay K4 is connected with a fourth switching end IO_Relay4, one end of a switch of the fourth Relay K4 is connected with the micro-current circuit 02, and the other end of the switch of the fourth Relay K4 is connected with the second electrode 06.

The control chip 01 controls the coil of the third Relay K3 and the coil of the fourth Relay K4 to be simultaneously electrified through the third switching end IO_Relay3 and the fourth switching end IO_Relay4, and the switches of the third Relay K3 and the fourth Relay K4 are simultaneously closed, so that the first electrode 05 and the second electrode 06 are simultaneously connected to the micro-current circuit 02, and at the moment, the first electrode 05 and the second electrode 06 are used as output electrodes.

The embodiment of the utility model realizes the selective control of the circuit through four relays, and the coil and the switch in the relay are isolated, so that the safety of the impedance detection circuit 03 and the micro-current circuit 02 is further ensured.

In one embodiment, as shown in fig. 1 and 4, the impedance detection circuit 03 includes a detection voltage output sub-circuit 31 and a differential operation sub-circuit 32;

the impedance detection driving end PWM is connected with the input end of the detection voltage output sub-circuit 31, the output end of the detection voltage output sub-circuit 31 is connected with the first electrode 05 through the switch circuit 04, and the second electrode 06 is connected with the negative electrode of the power supply through the switch circuit 04;

two input ends of the differential operation sub-circuit 32 are respectively connected with the first electrode 05 and the second electrode 06, and an output end of the differential operation sub-circuit 32 is connected with the impedance detection receiving end IO_U4_OUT_ADC.

The detection voltage output sub-circuit 31 is configured to convert the PWM signal output by the impedance detection driving end PWM into a sine wave and output the sine wave to the first electrode 05, and since the second electrode 06 is connected to the negative electrode of the power supply, a voltage difference can be generated between the first electrode 05 and the second electrode 06. If the skin impedance is ignored, the voltage difference between the first electrode 05 and the second electrode 06 should be the voltage output by the detection voltage output sub-circuit 31 to the first electrode 05, and the voltage difference between the first electrode 05 and the second electrode 06 should be smaller than the voltage output by the detection voltage output sub-circuit 31 to the first electrode 05 due to the presence of the skin impedance, so that the skin impedance value can be calculated by acquiring the voltage difference between the first electrode 05 and the second electrode 06.

The differential operation sub-circuit 32 is configured to detect a voltage difference between the first electrode 05 and the second electrode 06 and output the voltage difference to the impedance detection receiving terminal io_u4_out_adc.

As shown in fig. 4, the detection voltage output sub-circuit 31 includes an amplifying circuit and a first follower circuit;

the impedance detection driving end PWM is connected with the input end of the amplifying circuit, the output end of the amplifying circuit is connected with the input end of the first follower circuit, and the output end of the first follower circuit is connected with the first electrode through the switch circuit.

Specifically, the detection voltage output sub-circuit 31 adopts an operational amplification chip U2, wherein two paths of operational amplifiers are integrated, and the amplification circuit adopts a first path of amplifier, specifically pins 1-3; the first follower circuit adopts a second path amplifier, specifically pins 5-7; the pin 4 is a grounding pin and is connected with the negative electrode of the power supply; the pin 8 is a power pin and is connected with the positive electrode of the power supply, and meanwhile, the pin 8 is connected with the negative electrode of the power supply through a capacitor C11.

The impedance detection driving end PWM is connected with a pin 3 of the operational amplification chip U2 through a resistor R8, the pin 3 of the operational amplification chip U2 is also connected with a power supply cathode through a capacitor C14, and the resistor R8 and the capacitor C14 form a filter circuit to convert PWM square waves output by the impedance detection driving end PWM into sine waves and input the sine waves into the amplifier. The pin 2 of the operational amplification chip U2 is connected with the negative electrode of the power supply through a resistor R5, and is connected with the pin 1 of the operational amplification chip U2 through a resistor R4; the pin 1 of the operational amplifier chip U2 is an output terminal of the first amplifier, and is also connected to an input terminal of the second amplifier, i.e. the pin 5. Both the pin 6 and the pin 7 of the operational amplifier chip U2 are connected to the switch of the first relay K1 of the switch circuit 04. One end of a switch of the second relay K2 is connected with the negative electrode of the power supply through a resistor R9, and two ends of the resistor R9 are connected with a capacitor C15 in parallel.

The detection voltage output sub-circuit 31 firstly converts the PWM square wave output by the impedance detection driving end PWM into a sine wave, inputs the sine wave into the amplifying circuit, amplifies the sine wave signal, inputs the amplified sine wave signal into the first follower circuit, plays an isolating role, and the output waveform of the first follower circuit is the target waveform of impedance detection and directly acts on the skin of a human body.

Further, an interference filtering sub-circuit 33 is further connected between the detection voltage output sub-circuit 31 and the differential operation sub-circuit 32;

the two input ends of the interference filtering sub-circuit 33 are respectively connected with the first electrode 05 and the second electrode 06, and are used for filtering the power frequency interference between the first electrode 05 and the second electrode 06 and outputting from the two output ends of the interference filtering sub-circuit 33;

the two inputs of the differential operation sub-circuit 32 are connected to the two outputs of the interference rejection sub-circuit 33, respectively.

As shown in fig. 4, the interference filtering sub-circuit 33 includes a second follower circuit and a third follower circuit;

the first electrode 05 is connected with the input end of a second follower circuit through a switch circuit 04, and the output end of the second follower circuit is connected with a differential operation sub-circuit 32;

the second electrode 06 is connected to the input of a third follower circuit through a switch circuit 04, and the output of the third follower circuit is connected to the differential operation sub-circuit 32.

Specifically, the interference filtering sub-circuit 33 adopts an operational amplification chip U3, wherein two paths of operational amplifiers are integrated, and the second following circuit adopts a first path of amplifier, specifically pins 1-3; the third follower circuit adopts a second path amplifier, specifically pins 5-7; the pin 4 is a grounding pin and is connected with the negative electrode of the power supply; the pin 8 is a power pin and is connected with the positive electrode of the power supply, and meanwhile, the pin 8 is connected with the negative electrode of the power supply through the capacitor C10.

The switch of the first relay K1 of the switch circuit 04 is connected with the pin 3 of the operational amplification chip U3 through a capacitor C12, the pin 3 of the operational amplification chip U3 is also connected with the negative electrode of the power supply through a resistor R6, and the pin 1 and the pin 2 of the operational amplification chip U3 are the output ends U3_OUT+ of the second follower circuit and are connected with the differential operator circuit 32.

The switch of the second relay K2 of the switch circuit 04 is connected with the pin 5 of the operational amplification chip U3 through a capacitor C13, the pin 5 of the operational amplification chip U3 is also connected with the negative electrode of the power supply through a resistor R7, and the pin 6 and the pin 7 of the operational amplification chip U3 are the output end U3-OUT-of the third follower circuit and are connected with the differential operator circuit 32.

The first follower circuit is used for following the voltage of the first electrode 05, the second follower circuit is used for following the voltage of the second electrode 06, and the first follower circuit plays an isolating role to filter the power frequency interference of the human body, so that the waveform input into the differential operation sub-circuit 32 is filtered.

As shown in fig. 4, the differential operation sub-circuit 32 adopts a differential operational amplifier chip U4, an output end u3_out-of the second follower circuit is connected with a pin 2 of the differential operational amplifier chip U4 through a capacitor C16, the pin 2 of the differential operational amplifier chip U4 is also connected with a power supply negative electrode through a resistor R12 and a resistor R14, and the capacitor C16, the resistor R12 and the resistor R14 play a role in secondary filtering on an output waveform of the second follower circuit; the output end U3-OUT+ of the third follower circuit is connected with the pin 3 of the differential operational amplifier chip U4 through a capacitor C17, the pin 3 of the differential operational amplifier chip U4 is also connected with the negative electrode of the power supply through a resistor R13 and a resistor R14, and the capacitor C17, the resistor R13 and the resistor R14 play a secondary filtering role on the output waveform of the third follower circuit; the pin 6 of the differential operational amplifier chip U4 is connected with an impedance detection receiving end IO_U4_OUT_ADC through a resistor R11, and the impedance detection receiving end IO_U4_OUT_ADC is also connected with a power supply cathode through a capacitor C18. A resistor R10 is connected between a pin 1 and a pin 8 of the differential operational amplifier chip U4, the pin 4 and the pin 5 are both connected with a power supply cathode, the pin 7 is connected with a power supply anode, and meanwhile, the differential operational amplifier chip U is also connected with the power supply cathode through a capacitor C19.

The differential operation sub-circuit 32 inputs the output waveform of the second follower circuit and the output waveform of the third follower circuit into the differential operation unit, calculates the voltage difference between the two, and inputs the filtered voltage difference to the impedance detection receiving terminal io_u4_out_adc for calculating the skin impedance value.

In one embodiment, as shown in fig. 2 and 5, the micro-current control terminal includes a power supply control terminal and an output control terminal;

the micro-current circuit 02 comprises a power supply sub-circuit 21 and an output sub-circuit 22, wherein the output end of the power supply sub-circuit 21 is connected with the output sub-circuit 22 and is used for supplying power to the output sub-circuit 22, and the output end of the output sub-circuit 22 is connected with the first end of the switch;

the power supply circuit 21 is connected to the power supply control terminal, and the output sub-circuit 22 is connected to the output control terminal.

Specifically, the power supply sub-circuit 21 outputs a voltage to the output sub-circuit 22, and the control chip 01 adjusts the output voltage of the power supply circuit 21 through the power supply control terminal, and the larger the output voltage of the power supply circuit is, the larger the output voltage of the output sub-circuit is. The control chip 01 outputs a driving signal through the output control end to drive the output sub-circuit 22, the output sub-circuit 22 converts the driving signal into a voltage waveform to be output from the first electrode 05 and the second electrode 06, so that EMS micro-current is formed on the skin, the control chip 01 outputs the driving signal through the output control end to adjust the current frequency output by the first electrode 05 and the second electrode 06, and the driving signal can be a PWM signal or a pulse signal and the like.

In the embodiment of the utility model, the micro-current circuit 02 is composed of a power supply sub-circuit 21 and an output sub-circuit 22, the power supply sub-circuit 21 supplies power to the output sub-circuit 22, and the control chip 01 controls the voltage and the frequency of the output EMS micro-current through a power supply control end and an output control end respectively, so that the voltage and the frequency can be reasonably adjusted according to actual requirements.

In one embodiment, as shown in fig. 2 and 5, the power supply control terminal includes a driving terminal io_vcc_ems_en and a regulating terminal io_ems_dc_pwm;

the electronic circuit comprises a switching power supply chip U5 and a voltage regulating module;

the enable end EN of the switching power supply chip U5 is connected with the driving end IO_VCC_EMS_EN, the regulating end IO_EMS_DC_PWM and the voltage output end LX and the feedback end FB of the switching power supply chip U5 are connected with the voltage regulating circuit module;

the output of the voltage regulation circuit module is connected to an output sub-circuit 22.

The switching power supply chip U5 adopts a DCDC conversion chip, and is configured to adjust the voltage level output to the output sub-circuit 22 according to the PWM signal output by the regulating terminal io_ems_dc_pwm of the control chip 01.

Specifically, the switching power supply chip U5 is provided with six pins, which are a positive terminal VIN, a negative terminal GND, an enable terminal EN, a voltage output terminal LX, a feedback terminal FB, and a bootstrap terminal BOOT.

The positive pole VIN is connected with the positive pole of the power supply, and the embodiment of the utility model is connected with the positive pole of the power supply by connecting a VBAT pin of the singlechip. Meanwhile, the positive terminal VIN is also connected with the negative electrode of the power supply through a capacitor C21, so that the power supply is filtered. The negative terminal GND is connected with the negative electrode of the power supply.

The enable end EN is connected to the driving end io_vcc_ems_en of the control chip 01, and drives the first switching power supply chip U5 to start when the driving end io_vcc_ems_en outputs a high level.

The voltage regulating circuit module comprises an inductor L3, a resistor R15, a resistor R16, a resistor R17 and a capacitor C22. One end of the inductor L3 is connected with the voltage output end LX, and one ends of the resistor R15, the resistor R16 and the resistor R17 are connected with the feedback end FB; the other end of the resistor R16 is connected with the other end of the inductor L3; the other end of the resistor R15 is connected with the negative electrode of the power supply; the other end of the resistor R17 is connected with the regulating end IO_EMS_DC_PWM; one end of the capacitor C22 is connected to one end of the inductor L3 connected with the resistor R16, the other end of the capacitor C22 is connected with the negative electrode of the power supply, the two ends of the capacitor C22 form the output end of the voltage regulating circuit module, namely the output end of the power supply circuit 21, one end of the capacitor C22 connected with the negative electrode of the power supply is a negative electrode output end, and the other end of the capacitor C22 is a positive electrode output end.

And, a capacitor C20 is further connected between the voltage output end LX and the bootstrap end BOOT of the switching power supply chip U5 for stabilizing the output voltage signal.

In one embodiment, as shown in fig. 2, the output control terminal includes a first signal output terminal io_ems_pwma and a second signal output terminal io_ems_pwmb for outputting two complementary signals, respectively.

As shown in fig. 5, the output sub-circuit 22 includes a transformer T1, a first MOS transistor Q1, and a second MOS transistor Q2, where the first MOS transistor Q1 and the second MOS transistor Q2 may be integrated on a chip.

The input side common terminal (pin 3) of the transformer T1 is connected to the positive electrode output terminal of the power supply electronic circuit 21. Meanwhile, the common end of the input side of the transformer T1 is also connected with the negative electrode of the power supply through a unidirectional diode D1; the input end of the unidirectional diode D1 is connected with the negative electrode of the power supply, and the output end of the unidirectional diode D1 is connected with the common end of the input side of the transformer T1; when the current output from the positive output terminal of the power supply electronic circuit 21 is too large, the unidirectional diode D1 breaks down, and directs the current to the negative electrode of the power supply, thereby realizing the effect of absorbing the peak current.

The input side first end (pin 4) of the transformer T1 is connected to the drain of the first MOS transistor Q1, the source of the first MOS transistor Q1 is connected to the negative output end (i.e., the negative power supply) of the power supply electronic circuit 21, and the gate of the first MOS transistor Q1 is connected to the first signal output end io_ems_pwma. When the first signal output end IO_EMS_PWMA inputs a high level to the grid electrode of the first MOS tube Q1, the drain electrode and the source electrode of the first MOS tube Q1 are conducted; when the first signal output end io_ems_pwma inputs a low level to the gate of the first MOS transistor Q1, the drain and source transistors of the first MOS transistor Q1 are turned off.

The second end (pin 1) of the input side of the transformer T1 is connected to the drain of the second MOS transistor Q2, the source of the second MOS transistor Q2 is connected to the negative output end (i.e., the negative power supply) of the power supply electronic circuit 21, and the gate of the second MOS transistor Q2 is connected to the second signal output end io_ems_pwmb. When the second signal output end IO_EMS_PWMB inputs a high level to the grid electrode of the second MOS tube Q2, the drain electrode and the source electrode of the second MOS tube Q2 are conducted; when the second signal output terminal io_ems_pwmb inputs a low level to the gate of the second MOS transistor Q2, the drain and source transistors of the second MOS transistor Q2 are turned off.

The output side first end (pin 5) and the output side second end (pin 8) of the transformer T1 are both connected to the switch first end, wherein the output side first end is connected to the switch of the fourth relay K4, and the output side second end is connected to the switch of the third relay K3.

Specifically, the control chip 01 controls the first signal output terminal io_ems_pwma and the second signal output terminal io_ems_pwmb to output a set of complementary PWM signals, that is, when the first signal output terminal io_ems_pwma outputs a low level, the second signal output terminal io_ems_pwmb outputs a high level; when the first signal output terminal io_ems_pwma outputs a high level, the second signal output terminal io_ems_pwmb outputs a low level.

Based on this, as the two paths of PWM signals are output, the first MOS transistor Q1 and the second MOS transistor Q2 are alternately turned on, so that an alternating current is output on the output side of the transformer T1: when the first signal output end IO_EMS_PWMA outputs a low level and the second signal output end IO_EMS_PWMB outputs a high level, current flows from the first end of the output side to the second end of the output side; when the first signal output terminal io_ems_pwma outputs a high level and the second signal output terminal io_ems_pwmb outputs a low level, current flows from the second output terminal to the first output terminal, and the conversion frequency of the current flowing is the same as the frequency of the two PWM signals.

Further, a filter circuit is connected between the first end of the output side and the second end of the output side of the transformer T1. For filtering the current output between the first electrode 05 and the second electrode 06, improving the stability and safety of the current. The filter circuit includes a resistor R1 connected between the output side first end and the output side second end of the transformer T1, a capacitor C1 connected between the resistor R1 and the output side first end, and a capacitor C2 connected between the resistor R1 and the output side second end.

The above technical schemes can be combined according to the need to achieve the best technical effect.

What has been described above is merely illustrative of the principles and preferred embodiments of the present utility model. It should be noted that, for a person skilled in the art, an implementation manner in which the technical solutions disclosed in the different embodiments are appropriately combined is also included in the technical scope of the present utility model, and several other modifications are possible on the basis of the principle of the present utility model, which should also be regarded as the protection scope of the present utility model.

Claims

1. A switching circuit, comprising

the micro-current circuit is connected with the micro-current control end;

2. The switching circuit of claim 1, wherein the switch switching terminals comprise a first switching terminal, a second switching terminal, a third switching terminal, and a fourth switching terminal;

3. The switching circuit of claim 1, wherein the impedance detection circuit comprises a detection voltage output sub-circuit and a differential operation sub-circuit;

4. A switching circuit according to claim 3, wherein the detection voltage output sub-circuit comprises an amplifying circuit and a first follower circuit;

5. The switching circuit of claim 3, wherein an interference filtering sub-circuit is further connected between the detection voltage output sub-circuit and the differential operation sub-circuit;

6. The switching circuit of claim 5, wherein the interference rejection subcircuit comprises a second follower circuit and a third follower circuit;

7. The switching circuit of claim 1, wherein the micro-current control terminal comprises a power supply control terminal and an output control terminal;

8. The switching circuit of claim 7, wherein the power control terminal comprises a drive terminal and an adjustment terminal;

9. The switching circuit according to claim 7, wherein the output control terminal includes a first signal output terminal and a second signal output terminal for outputting two complementary signals, respectively;