A radio frequency circuit for a beauty device

Abstract

This utility model discloses a radio frequency (RF) circuit for a beauty device, comprising: an MCU control module for receiving voltage level commands input by the user and outputting a voltage level signal, complementary RF+ / RF- drive signals, and a cooling enable signal according to the voltage level commands; a DC-DC boost module for boosting the received lithium battery input voltage from a first voltage range to a second voltage range according to the voltage level signal, and supplying voltage VOUT to the RF drive module within the second voltage range; and an RF drive module for receiving the voltage VOUT and complementary RF+ / RF- drive signals from the DC-DC boost module, and driving the boost transformer T1 in the RF drive module to output RF energy through alternating conduction of dual MOSFETs. The RF circuit of this application improves RF energy conversion efficiency, reduces circuit heat generation and cost, extends the cooling time, and enhances system safety.

Description

Technical Field

[0001] This utility model relates to the field of beauty instrument circuit technology, and in particular to a beauty instrument radio frequency circuit. Background Technology

[0002] Existing radio frequency beauty devices have three major drawbacks: low efficiency, with a single MOS transistor driving energy conversion efficiency of <65%, resulting in insufficient output power; and poor heat dissipation, with the circuit generating a lot of heat and the cooling chip operating continuously for ≤3 minutes.

[0003] The high cost, relying on current detection chips (such as INA199), increases the BOM cost. Utility Model Content

[0004] To address the technical problems existing in the background art, this utility model proposes a radio frequency circuit for a beauty device.

[0005] The present invention proposes a radio frequency circuit for a beauty device, comprising:

[0006] The MCU control module is used to receive voltage level commands input by the user and output voltage level signals, complementary RF+ / RF- drive signals and cooling enable signals according to the voltage level commands.

[0007] The DC-DC boost module is used to boost the received lithium battery input voltage from a first voltage range to a second voltage range according to the voltage range signal, and to supply voltage VOUT to the RF drive module within the second voltage range;

[0008] The RF drive module is used to receive the voltage VOUT and complementary RF+ / RF- drive signals from the DC-DC boost module, and drive the boost transformer T1 in the RF drive module to output RF energy through the alternating conduction of dual MOS transistors.

[0009] A chipless current detection module is used to sample the voltage signal corresponding to the radio frequency drive module and feed the voltage signal back to the MCU control module.

[0010] The cooling coordination module is used to receive the cooling enable signal and initiate a heat dissipation operation for a preset time period after the radio frequency drive module has finished working, based on the cooling enable signal.

[0011] Preferably, the RF driving module specifically includes: a gate driving chip U3, a MOSFET Q1, and a MOSFET Q9. The HO terminal of the gate driving chip U3 is connected to the gate of the MOSFET Q1 via a series resistor R66. The LO terminal of the gate driving chip U3 is connected to the gate of the MOSFET Q9 via a series resistor R67. The input terminals INA and INB of the gate driving chip U3 are respectively connected to the RF+ and RF- driving signals. The RF+ and RF- driving signals control the MOSFETs Q1 and Q9 to alternately conduct with a 50% duty cycle. The source of the MOSFET Q1 is electrically connected to the source of the MOSFET Q9. The drain of the MOSFET Q9 is electrically connected to the input terminal A of the boost transformer T1. The drain of the MOSFET Q1 is electrically connected to the input terminal B of the boost transformer T1. The output terminal of the boost transformer T1 is connected in parallel with resonant capacitors C6 and C2 and then connected to the load.

[0012] Preferably, the DC-DC boost module specifically includes: a boost chip U7, capacitors C3 and C7, an electrolytic capacitor C8, an inductor L7, Schottky diodes D5 and D15, capacitors C48, C52, C53, and C60, an electrolytic capacitor EC2, resistors R109, R110, R114, R115, R116, R120, and R121; capacitors C7 and C8 are connected in parallel, the positive terminal of electrolytic capacitor C8 is electrically connected to one end of inductor L7, the negative terminal of electrolytic capacitor C8 is grounded, one end of inductor L7 is connected to the lithium battery input voltage VCC, and the other end of inductor L7 is connected to the SW terminal of boost chip U7; Schottky diodes D5 and D15 are connected in parallel in the same direction, the SW terminal of boost chip U7 is electrically connected to the positive terminal of Schottky diode D5, and the negative terminal of Schottky diode D5 is connected to the positive terminal of electrolytic capacitor EC2. The capacitors C52, C53, C60, and electrolytic capacitor EC2 are connected in parallel in pairs. The negative terminal of electrolytic capacitor EC2 is grounded, and the positive terminal of electrolytic capacitor EC2 is connected to the output terminal of voltage VOUT. The other end of resistor R115 is electrically connected to the FB terminal of boost chip U7. The FB terminal of boost chip U7 is electrically connected to one end of resistor R116, and the other end of resistor R116 is grounded. The FB terminal of boost chip U7 is electrically connected to one end of resistor R109. The other end of resistor R109 is connected to ground after being connected in series with capacitor C48. The other end of resistor R109 is electrically connected to one end of resistor R110. The OC terminal of boost chip U7 is electrically connected to one end of resistor R121, and the other end of resistor R121 is grounded. The CE terminal of boost chip U7 is connected in series with resistor R120 to output RF+ / RF- drive signals. The other end of resistor R110 is used to input voltage level signals.

[0013] Preferably, the DC-DC boost module further includes: resistors R3, R13, and R76. The FB terminal of the boost chip U7 is electrically connected to one end of resistor R3, one end of resistor R13, and one end of resistor R76, respectively. The other end of resistor R3, the other end of resistor R13, and the other end of resistor R76 are used as backup input voltage level signals.

[0014] Preferably, the chipless current detection module specifically includes: a current sampling resistor R102 and an RC filter network composed of a resistor R103 and a capacitor C43. The current sampling resistor R102 is connected in series between the source of the MOSFET Q9 and ground, and the resistor R103 is electrically connected to the source of the MOSFET Q9.

[0015] Preferably, the cooling coordination module specifically includes: a cooling chip, a cooling drive circuit, and a temperature sensor. The cooling drive circuit is used to drive the cooling chip, and the temperature sensor is used to detect the operating temperature of the radio frequency drive module. When the radio frequency drive module finishes working, the MCU outputs a cooling enable signal to the cooling chip drive circuit. When the temperature fed back to the MCU module by the temperature sensor reaches a preset temperature threshold, the MCU module controls the cooling chip drive circuit to terminate the cooling.

[0016] Preferably, the MCU module is further configured to compare the voltage signal corresponding to the sampling RF drive module with a preset overcurrent protection threshold. When the voltage signal corresponding to the sampling RF drive module is greater than the preset overcurrent protection threshold, the MCU shuts off the RF+ / RF- drive signal.

[0017] This utility model proposes a beauty device, including the radio frequency circuit of the beauty device described in any one of the above.

[0018] In this invention, the proposed radio frequency (RF) circuit for a beauty device converts the chemical energy within the lithium battery into the required driving voltage VOUT for the RF drive module via a DC-DC boost module. The VOUT voltage is then supplied to the RF drive module. The MCU module controls the operation of MOSFETs Q1 and Q9M in the RF drive module through the gate drive chip U3. Utilizing the electromagnetic induction principle of the boost transformer T1, the changing RF voltage energy is converted to the secondary winding of the transformer. The RF energy converted to the secondary winding is then transferred to the user end as heat. This improves the RF energy conversion efficiency, reduces circuit heat generation and cost, extends the cooling time, and enhances system safety. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall framework of a radio frequency circuit for a beauty device proposed in this utility model.

[0020] Figure 2This is a schematic diagram of one embodiment of a DC-DC boost module for a radio frequency circuit of a beauty device proposed in this utility model.

[0021] Figure 3 This is a schematic diagram of one embodiment of the radio frequency drive module of the radio frequency circuit of a beauty instrument proposed in this utility model. Detailed Implementation

[0022] Reference Figure 1-3 The present invention proposes a radio frequency circuit for a beauty device, comprising:

[0023] The MCU control module is used to receive voltage level commands input by the user and output voltage level signals, complementary RF+ / RF- drive signals, and cooling enable signals according to the voltage level commands.

[0024] In this embodiment, the MCU module is also used to compare the voltage signal corresponding to the sampling RF drive module with a preset overcurrent protection threshold. When the voltage signal corresponding to the sampling RF drive module is greater than the preset overcurrent protection threshold, the MCU turns off the RF+ / RF- drive signal.

[0025] The DC-DC boost module is used to boost the received lithium battery input voltage from a first voltage range to a second voltage range according to the voltage range signal, and to supply voltage VOUT to the RF drive module within the second voltage range.

[0026] In this embodiment, the DC-DC boost module specifically includes: a boost chip U7, capacitors C3 and C7, an electrolytic capacitor C8, an inductor L7, Schottky diodes D5 and D15, capacitors C48, C52, C53, and C60, an electrolytic capacitor EC2, resistors R109, R110, R114, R115, R116, R120, and R121; capacitors C7 and C8 are connected in parallel, the positive terminal of electrolytic capacitor C8 is electrically connected to one end of inductor L7, the negative terminal of electrolytic capacitor C8 is grounded, one end of inductor L7 is connected to the lithium battery input voltage VCC, and the other end of inductor L7 is connected to the SW terminal of boost chip U7; Schottky diodes D5 and D15 are connected in parallel in the same direction, the SW terminal of boost chip U7 is electrically connected to the positive terminal of Schottky diode D5, and the negative terminal of Schottky diode D5 is connected to the positive terminal of electrolytic capacitor EC2. Electrically, capacitors C52, C53, C60, and electrolytic capacitor EC2 are connected in parallel in pairs. The negative terminal of electrolytic capacitor EC2 is grounded, and the positive terminal of electrolytic capacitor EC2 is connected to the output terminal of voltage VOUT. The other end of resistor R115 is electrically connected to the FB terminal of boost chip U7. The FB terminal of boost chip U7 is electrically connected to one end of resistor R116, and the other end of resistor R116 is grounded. The FB terminal of boost chip U7 is electrically connected to one end of resistor R109. The other end of resistor R109 is connected to ground after being connected in series with capacitor C48. The other end of resistor R109 is electrically connected to one end of resistor R110. The OC terminal of boost chip U7 is electrically connected to one end of resistor R121, and the other end of resistor R121 is grounded. The CE terminal of boost chip U7 is connected in series with resistor R120 to output RF+ / RF- drive signals. The other end of resistor R110 is used to input voltage level signals.

[0027] In this embodiment, the DC-DC boost module further includes resistors R3, R13, and R76. The FB terminal of the boost chip U7 is electrically connected to one end of resistor R3, one end of resistor R13, and one end of resistor R76, respectively. The other end of resistor R3, the other end of resistor R13, and the other end of resistor R76 are used as backup input voltage level signals.

[0028] Specifically, C7 is a surface-mount ceramic capacitor, and C8 is a surface-mount aluminum electrolytic capacitor, used for filtering the VCC power supply voltage. The VCC power supply voltage is boosted to VOUT voltage by the U7 chip circuit, and VOUT voltage can then be used to supply power to the VCC power supply. Figure 2 The RF drive circuit uses a parallel connection of dual Schottky diodes D5 and D15 and pin 3 of U7 connected to VOUT to improve the output voltage VOUT's load-driving capability. The FRQ1 signal is provided by the MCU, and three different frequency signals are provided by different button positions to adjust the VOUT voltage. The circuit within the reserved box is functionally equivalent to the circuit connected to R116, R119, R110, and C48.

[0029] In this embodiment, the first voltage range is 3-4.2V, and the second voltage range is 12-24V.

[0030] The RF drive module receives the voltage VOUT from the DC-DC boost module and complementary RF+ / RF- drive signals, and drives the boost transformer T1 in the RF drive module to output RF energy through the alternating conduction of dual MOS transistors.

[0031] In this embodiment, the RF driving module specifically includes: a gate driving chip U3, a MOSFET Q1, and a MOSFET Q9. The HO terminal of the gate driving chip U3 is connected to the gate of the MOSFET Q1 via a series resistor R66. The LO terminal of the gate driving chip U3 is connected to the gate of the MOSFET Q9 via a series resistor R67. The input terminals INA and INB of the gate driving chip U3 are respectively connected to the RF+ and RF- driving signals. The RF+ and RF- driving signals control the MOSFETs Q1 and Q9 to alternately conduct with a 50% duty cycle. The source of the MOSFET Q1 is electrically connected to the source of the MOSFET Q9. The drain of the MOSFET Q9 is electrically connected to the input terminal A of the boost transformer T1. The drain of the MOSFET Q1 is electrically connected to the input terminal B of the boost transformer T1. The output terminal of the boost transformer T1 is connected in parallel with resonant capacitors C6 and C2 and then connected to the load.

[0032] Specifically, the switching operation of the dual MOSFETs is controlled by the gate driver chip U3, and the RF+ / RF- drive signals input to the gate driver chip U3 are controlled by the MCU module. Therefore, the input of the RF driver module is controlled by the MCU module. Simultaneously, the symmetrical alternating operation of the high and low sides of the RF driver module's input effectively improves the circuit's energy conversion efficiency, ensuring that the output load receives sufficient RF energy to meet the cosmetic effect requirements. T1 is a step-up RF transformer that uses electromagnetic induction to convert the input energy to the output.

[0033] The chipless current detection module is used to sample the voltage signal corresponding to the RF drive module and feed the voltage signal back to the MCU control module.

[0034] In this embodiment, the chipless current detection module specifically includes: a current sampling resistor R102 and an RC filter network composed of a resistor R103 and a capacitor C43. The current sampling resistor R102 is connected in series between the source of the MOSFET Q9 and ground, and the resistor R103 is electrically connected to the source of the MOSFET Q9.

[0035] Specifically, such as Figure 3As shown, by using R102, R103, and C43 together, the magnitude of the drain-source maximum current power change of MOSFETs Q1 and Q9 can be detected in real time. This eliminates the need for a current detection amplifier chip, simplifying the circuit. The detected signal CURRENT is then judged by the MCU to determine whether there is an abnormality, thus protecting the circuit.

[0036] The cooling coordination module is used to receive the cooling enable signal and initiate a heat dissipation operation for a preset time period after the radio frequency drive module has finished working, based on the cooling enable signal.

[0037] In this embodiment, the cooling coordination module specifically includes: a cooling chip, a cooling drive circuit, and a temperature sensor. The cooling drive circuit is used to drive the cooling chip, and the temperature sensor is used to detect the operating temperature of the radio frequency drive module. When the radio frequency drive module finishes working, the MCU outputs a cooling enable signal to the cooling chip drive circuit. When the temperature fed back to the MCU module by the temperature sensor reaches a preset temperature threshold, the MCU module controls the cooling chip drive circuit to terminate the cooling.

[0038] In this embodiment, the preset time period is typically between 3 and 6 minutes.

[0039] Reference Figure 1-3 The present invention proposes a beauty device, which includes the aforementioned beauty device radio frequency circuit.

[0040] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A radio frequency circuit for a beauty device, characterized in that, include: The MCU control module is used to receive voltage level commands input by the user and output voltage level signals, complementary RF+ / RF- drive signals and cooling enable signals according to the voltage level commands. The DC-DC boost module is used to boost the received lithium battery input voltage from a first voltage range to a second voltage range according to the voltage range signal, and to supply voltage VOUT to the RF drive module within the second voltage range; The RF drive module is used to receive the voltage VOUT and complementary RF+ / RF- drive signals from the DC-DC boost module, and drive the boost transformer T1 in the RF drive module to output RF energy through the alternating conduction of dual MOS transistors. A chipless current detection module is used to sample the voltage signal corresponding to the radio frequency drive module and feed the voltage signal back to the MCU control module. The cooling coordination module is used to receive the cooling enable signal and initiate a heat dissipation operation for a preset time period after the radio frequency drive module has finished working, based on the cooling enable signal.

2. The radio frequency circuit of the beauty device according to claim 1, characterized in that, The RF driving module specifically includes: a gate driver chip U3, a MOSFET Q1, and a MOSFET Q9. The HO terminal of the gate driver chip U3 is connected to the gate of the MOSFET Q1 via a series resistor R66. The LO terminal of the gate driver chip U3 is connected to the gate of the MOSFET Q9 via a series resistor R67. The input terminals INA and INB of the gate driver chip U3 are connected to the RF+ and RF- driving signals, respectively. The RF+ and RF- driving signals control the MOSFETs Q1 and Q9 to conduct alternately with a 50% duty cycle. The source of the MOSFET Q1 is electrically connected to the source of the MOSFET Q9. The drain of the MOSFET Q9 is electrically connected to the input terminal A of the boost transformer T1. The drain of the MOSFET Q1 is electrically connected to the input terminal B of the boost transformer T1. The output terminal of the boost transformer T1 is connected to the load via resonant capacitors C6 and C2 in parallel.

3. The radio frequency circuit of the beauty device according to claim 1, characterized in that, The DC-DC boost module specifically includes: a boost chip U7, capacitors C3 and C7, an electrolytic capacitor C8, an inductor L7, Schottky diodes D5 and D15, capacitors C48, C52, C53, and C60, an electrolytic capacitor EC2, resistors R109, R110, R114, R115, R116, R120, and R121; capacitors C7 and C8 are connected in parallel, the positive terminal of electrolytic capacitor C8 is electrically connected to one end of inductor L7, the negative terminal of electrolytic capacitor C8 is grounded, one end of inductor L7 is connected to the lithium battery input voltage VCC, and the other end of inductor L7 is connected to the SW terminal of boost chip U7; Schottky diodes D5 and D15 are connected in parallel in the same direction, the SW terminal of boost chip U7 is electrically connected to the positive terminal of Schottky diode D5, and the negative terminal of Schottky diode D5 is electrically connected to the positive terminal of electrolytic capacitor EC2. Connect capacitors C52, C53, C60, and electrolytic capacitor EC2 in parallel. The negative terminal of electrolytic capacitor EC2 is grounded, and the positive terminal of electrolytic capacitor EC2 is connected to the output terminal of voltage VOUT. The other end of resistor R115 is electrically connected to the FB terminal of boost chip U7. The FB terminal of boost chip U7 is electrically connected to one end of resistor R116, and the other end of resistor R116 is grounded. The FB terminal of boost chip U7 is electrically connected to one end of resistor R109. The other end of resistor R109 is connected to ground after being connected in series with capacitor C48. The other end of resistor R109 is electrically connected to one end of resistor R110. The OC terminal of boost chip U7 is electrically connected to one end of resistor R121, and the other end of resistor R121 is grounded. The CE terminal of boost chip U7 is connected in series with resistor R120 to output RF+ / RF- drive signals. The other end of resistor R110 is used to input voltage level signals.

4. The radio frequency circuit of the beauty device according to claim 3, characterized in that, The DC-DC boost module also includes resistors R3, R13, and R76. The FB terminal of the boost chip U7 is electrically connected to one end of resistor R3, one end of resistor R13, and one end of resistor R76, respectively. The other ends of resistors R3, R13, and R76 are used as backup input voltage level signals.

5. The radio frequency circuit of the beauty device according to claim 2, characterized in that, The chipless current detection module specifically includes: a current sampling resistor R102 and an RC filter network composed of a resistor R103 and a capacitor C43. The current sampling resistor R102 is connected in series between the source of the MOSFET Q9 and ground, and the resistor R103 is electrically connected to the source of the MOSFET Q9.

6. The radio frequency circuit of the beauty device according to claim 1, characterized in that, The cooling coordination module specifically includes: a cooling chip, a cooling drive circuit, and a temperature sensor. The cooling drive circuit is used to drive the cooling chip, and the temperature sensor is used to detect the operating temperature of the radio frequency drive module. When the radio frequency drive module finishes working, the MCU outputs a cooling enable signal to the cooling chip drive circuit. When the temperature fed back to the MCU module by the temperature sensor reaches a preset temperature threshold, the MCU module controls the cooling chip drive circuit to terminate the cooling.

7. The radio frequency circuit of the beauty device according to claim 1, characterized in that, The MCU module is also used to compare the voltage signal corresponding to the sampling RF drive module with the preset overcurrent protection threshold. When the voltage signal corresponding to the sampling RF drive module is greater than the preset overcurrent protection threshold, the MCU shuts off the RF+ / RF- drive signal.

8. A beauty device, characterized in that, Includes the radio frequency circuit of the beauty device as described in any one of claims 1-7.

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