Power supply circuit

Abstract

The utility model discloses a power supply circuit, comprising a voltage stabilization source, the output end of which is connected with the feedback end of a first voltage conversion circuit; the input end of the first voltage conversion circuit is connected with the output end of the external power supply, and the output end is connected with first equipment; the input end of the second voltage conversion circuit is connected with the output end of the external power supply, and the output end is connected with second equipment; the input end of the third voltage conversion circuit is connected with the output end of the external power supply, and the output end is connected with third equipment. The working requirements of different devices can be met through a simple circuit structure, and the design cost of the power supply circuit is reduced; meanwhile, a voltage stabilizing signal is provided for the first voltage conversion circuit through the voltage stabilizing source, and it is guaranteed that the first voltage conversion circuit provides stable second voltage for the first device; and meanwhile, the second voltage conversion circuit outputs fourth voltage to the second equipment, and the third voltage conversion circuit outputs fifth voltage to the third equipment, so that the second equipment and the third equipment can maintain normal working states.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply, in particular to a power supply circuit. Background Art

[0002] A power supply circuit is a circuit used to provide different power supply voltages for devices. In the prior art, when there are too many devices in a facial care instrument and the power supply voltages required for each device are different, the prior art often sets an independent power supply circuit for each device to meet the normal power supply needs of each device, resulting in a complex structure of the power supply circuit and numerous circuit elements, which increases the design cost of the power supply circuit. At the same time, the voltage output by the power supply circuit in the prior art to the device is unstable, making it impossible for the device to maintain a normal working state. Utility Model Content

[0003] Based on this, it is necessary to propose a power supply circuit to address the above problems.

[0004] A power supply circuit, comprising:

[0005] A voltage stabilizing source, whose output end is connected to the feedback end of the first voltage conversion circuit, and is used to provide a voltage stabilizing signal to the first voltage conversion circuit;

[0006] The first voltage conversion circuit has an input end connected to the output end of the external power supply, and an output end connected to the first device, and is used to receive the first voltage and the voltage stabilization signal provided by the external power supply, and convert the first voltage into a second voltage and output it to the first device;

[0007] a second voltage conversion circuit, the input end of which is connected to the output end of the external power supply, the output end of which is connected to the second device, and is used to receive a third voltage provided by the external power supply, and convert the third voltage into a fourth voltage and output it to the second device;

[0008] The third voltage conversion circuit has an input end connected to the output end of the external power supply and an output end connected to the third device, and is used to receive the first voltage provided by the external power supply, and convert the first voltage into a fifth voltage and output it to the third device.

[0009] In one embodiment, the first voltage conversion circuit includes:

[0010] a first filtering circuit, whose input end is connected to the output end of the external power supply and whose output end is connected to the input end of the step-down circuit, and is used for receiving the first voltage and outputting the first voltage to the step-down circuit after filtering;

[0011] The step-down circuit has an enable terminal connected to the output terminal of the voltage stabilization source, and an output terminal connected to the input terminal of the second filtering circuit, and is used to receive the filtered first voltage and the voltage stabilization signal, and convert the first voltage into a second voltage and output it to the second filtering circuit;

[0012] The second filtering circuit has an output end connected to the first device, and is used for receiving the second voltage and filtering the second voltage before outputting it to the first device.

[0013] In one embodiment, the voltage stabilizing source includes: a first voltage stabilizing chip, a first operational amplifier, a second operational amplifier, a first capacitor and a first resistor;

[0014] The common terminal and the anode of the first voltage stabilizing chip are both connected to the external power supply;

[0015] The non-inverting input terminal of the first operational amplifier is connected to the anode of the first voltage stabilizing chip, and the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier;

[0016] The non-inverting input terminal of the second operational amplifier is connected to the output terminal of the first operational amplifier, the inverting input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier, the output terminal of the second operational amplifier is connected to one end of the first resistor, and the other end of the first resistor is connected to the feedback terminal of the first voltage conversion circuit;

[0017] One end of the first capacitor is connected to the output end of the first operational amplifier, and the other end is grounded.

[0018] In one embodiment, the voltage stabilizing source further includes: a second capacitor and a third capacitor;

[0019] One end of the second capacitor is connected to the non-inverting input terminal of the first operational amplifier, and the other end is grounded;

[0020] One end of the third capacitor is connected to the non-inverting input terminal of the first operational amplifier, and the other end is grounded.

[0021] In one embodiment, the buck circuit includes: a first buck chip, a first inductor, a second resistor and a third resistor;

[0022] The input end of the first buck chip is connected to the external power supply, the switch end SW of the first buck chip is connected to one end of the first inductor, the other end of the first inductor is connected to the first device, and the feedback end of the first buck chip is connected to the output end of the voltage stabilization source;

[0023] One end of the second resistor is connected to the other end of the first inductor, and the other end of the second resistor is connected to the feedback end of the first buck chip and one end of the third resistor;

[0024] The other end of the third resistor is grounded.

[0025] In one embodiment, the first filtering circuit includes: a fourth capacitor, a fifth capacitor and a sixth capacitor;

[0026] The second filtering circuit comprises: a seventh capacitor, an eighth capacitor and a ninth capacitor;

[0027] One end of the fourth capacitor is connected to the external power supply and the input end of the first buck chip, and the other end is grounded;

[0028] The fifth capacitor and the sixth capacitor are both connected in parallel with the fourth capacitor;

[0029] One end of the seventh capacitor is connected to the other end of the first inductor, and the other end is grounded;

[0030] The eighth capacitor and the ninth capacitor are both connected in parallel with the seventh capacitor.

[0031] In one embodiment, the second voltage conversion circuit includes: a second voltage stabilizing chip, a tenth capacitor, an eleventh capacitor, a twelfth capacitor and a thirteenth capacitor;

[0032] The input end of the second voltage stabilizing chip is connected to the external power supply, the output end of the second voltage stabilizing chip is connected to the second device, and the ground end of the second voltage stabilizing chip is grounded;

[0033] One end of the tenth capacitor is connected to the input end of the second voltage stabilizing chip, and the other end is grounded;

[0034] The eleventh capacitor is connected in parallel with the tenth capacitor;

[0035] One end of the twelfth capacitor is connected to the output end of the second voltage stabilizing chip, and the other end is grounded;

[0036] The thirteenth capacitor is connected in parallel with the twelfth capacitor.

[0037] In one embodiment, the second voltage conversion circuit further includes: a fourth resistor and a light emitting diode;

[0038] One end of the fourth resistor is connected to the output end of the second voltage stabilizing chip, and the other end is cascaded with the anode of the light emitting diode, and the cathode of the light emitting diode is grounded.

[0039] In one embodiment, the third voltage conversion circuit includes: a second buck chip, a first diode, a fourteenth capacitor, a fifteenth capacitor, a second inductor, and a second diode;

[0040] The input end of the second buck chip is connected to the anode of the first diode, the cathode of the first diode is connected to the external power supply, the output end of the second buck chip is connected to one end of the second inductor, and the other end of the second inductor is connected to the third device;

[0041] One end of the fourteenth capacitor is connected to the input end of the second buck chip, and the other end is grounded;

[0042] The fifteenth capacitor is connected in parallel with the fourteenth capacitor;

[0043] An anode of the second diode is connected to the output end of the second buck chip, and a cathode of the second diode is grounded.

[0044] In one embodiment, the third voltage conversion circuit further includes: a sixteenth capacitor and a seventeenth capacitor;

[0045] One end of the sixteenth capacitor is connected to the other end of the second inductor, and the other end of the sixteenth capacitor is grounded;

[0046] The seventeenth capacitor is connected in parallel with the sixteenth capacitor.

[0047] Implementing the embodiments of the present utility model will have the following beneficial effects:

[0048] The present application provides a voltage-stabilizing signal to the first voltage conversion circuit through a voltage-stabilizing source; the first voltage conversion circuit receives the first voltage and the voltage-stabilizing signal provided by an external power supply, and converts the first voltage into a second voltage and outputs it to the first device; the second voltage conversion circuit receives the third voltage provided by the external power supply, and converts the third voltage into a fourth voltage and outputs it to the second device; the third voltage conversion circuit receives the first voltage provided by the external power supply, and converts the first voltage into a fifth voltage and outputs it to the third device. The working requirements of different devices can be met through a simple circuit structure, reducing the design cost of the power supply circuit; at the same time, the voltage-stabilizing source provides a voltage-stabilizing signal to the first voltage conversion circuit, ensuring that the first voltage conversion circuit provides a stable second voltage to the first device; at the same time, the second voltage conversion circuit outputs a fourth voltage to the second device, and the third voltage conversion circuit outputs a fifth voltage to the third device, so that the second device and the third device can maintain a normal working state. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] in:

[0051] Figure 1 is a structural block diagram of a power supply circuit in one embodiment;

[0052] Figure 2 A circuit diagram of a voltage stabilizing source, a first filtering circuit, a voltage reducing circuit, and a second filtering circuit in one embodiment;

[0053] Figure 3 is a circuit diagram of a second voltage conversion circuit in one embodiment;

[0054] Figure 4 FIG. 4 is a circuit diagram of a third voltage conversion circuit in an embodiment. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0056] The power supply circuit is a circuit used to provide different power supply voltages for devices. In the prior art, when there are too many devices in a facial care instrument and the power supply voltages required by each device are different, the prior art often sets an independent power supply circuit for each device to meet the normal power supply requirements of each device, resulting in a complex structure of the power supply circuit and numerous circuit elements, which increases the design cost of the power supply circuit. At the same time, the voltage output to the device by the power supply circuit in the prior art is unstable, making it impossible for the device to maintain a normal working state. In order to solve the above technical problems, the present application provides a power supply circuit, such as Figure 1As shown, it includes: a voltage stabilizing source 10, a second voltage conversion circuit 30 and a third voltage conversion circuit 40, wherein the output end of the voltage stabilizing source 10 is connected to the feedback end of the first voltage conversion circuit 20, so as to provide a voltage stabilizing signal to the first voltage conversion circuit 20; the input end of the first voltage conversion circuit 20 is connected to the output end of the external power supply, and the output end is connected to the first device, so as to receive the first voltage and the voltage stabilizing signal provided by the external power supply, and convert the first voltage into a second voltage and output it to the first device; the input end of the second voltage conversion circuit 30 is connected to the output end of the external power supply, and the output end is connected to the second device, so as to receive the third voltage provided by the external power supply, and convert the third voltage into a fourth voltage and output it to the second device; the input end of the third voltage conversion circuit 40 is connected to the output end of the external power supply, and the output end is connected to the third device, so as to receive the first voltage provided by the external power supply, and convert the first voltage into a fifth voltage and output it to the third device. The present application provides a voltage-stabilizing signal to the first voltage conversion circuit through a voltage-stabilizing source; the first voltage conversion circuit receives the first voltage and the voltage-stabilizing signal provided by an external power supply, and converts the first voltage into a second voltage and outputs it to the first device; the second voltage conversion circuit receives the third voltage provided by the external power supply, and converts the third voltage into a fourth voltage and outputs it to the second device; the third voltage conversion circuit receives the first voltage provided by the external power supply, and converts the first voltage into a fifth voltage and outputs it to the third device. The working requirements of different devices can be met through a simple circuit structure, reducing the design cost of the power supply circuit; at the same time, the voltage-stabilizing source provides a voltage-stabilizing signal to the first voltage conversion circuit, ensuring that the first voltage conversion circuit provides a stable second voltage to the first device; at the same time, the second voltage conversion circuit outputs a fourth voltage to the second device, and the third voltage conversion circuit outputs a fifth voltage to the third device, so that the second device and the third device can maintain a normal working state.

[0057] In one embodiment, Figure 2 As shown, the first voltage conversion circuit 20 includes: a first filtering circuit 201, a step-down circuit 202 and a second filtering circuit 203, wherein the input end of the first filtering circuit 201 is connected to the output end of the external power supply, and the output end is connected to the input end of the step-down circuit 202, for receiving the first voltage, and filtering the first voltage and outputting it to the step-down circuit 202; the enable end of the step-down circuit 202 is connected to the output end of the voltage stabilizing source 10, and the output end is connected to the input end of the second filtering circuit 203, for receiving the filtered first voltage and the voltage stabilizing signal, and converting the first voltage into a second voltage and outputting it to the second filtering circuit 203; the output end of the second filtering circuit 203 is connected to the first device, for receiving the second voltage, and filtering the second voltage and outputting it to the first device.

[0058] In one embodiment, Figure 2 As shown, the voltage stabilizing source 10 includes: a first voltage stabilizing chip U3, a first operational amplifier U2B, a second operational amplifier U2A, a first capacitor C13 and a first resistor R22; wherein the common end and the anode of the first voltage stabilizing chip U3 are both connected to the external power supply; the in-phase input end of the first operational amplifier U2B is connected to the anode of the first voltage stabilizing chip U3, and the inverting input end of the first operational amplifier U2B is connected to the output end of the first operational amplifier U2B; the in-phase input end of the second operational amplifier U2A is connected to the output end of the first operational amplifier U2B, the inverting input end of the second operational amplifier U2A is linked to the output end of the second operational amplifier U2A, the output end of the second operational amplifier U2A is connected to one end of the first resistor R22, and the other end of the first resistor R22 is connected to the feedback end of the first voltage conversion circuit 20; one end of the first capacitor C13 is connected to the output end of the first operational amplifier U2B, and the other end is grounded.

[0059] In one embodiment, Figure 2 As shown, the voltage stabilizing source 10 also includes: a second capacitor C11 and a third capacitor C12; wherein, one end of the second capacitor C11 is connected to the in-phase input terminal of the first operational amplifier U2B, and the other end is grounded; one end of the third capacitor C12 is connected to the in-phase input terminal of the first operational amplifier U2B, and the other end is grounded.

[0060] In one embodiment, Figure 2 As shown, the buck circuit 201 includes: a first buck chip U1, a first inductor L1, a second resistor R17 and a third resistor R18; wherein, the input terminal VIN of the first buck chip U1 is connected to the external power supply, the switch terminal SW of the first buck chip U1 is connected to one end of the first inductor L1, the other end of the first inductor L1 is connected to the first device, and the feedback terminal FB of the first buck chip U1 is connected to the output end of the voltage regulator 10; one end of the second resistor R17 is connected to the other end of the first inductor L1, and the other end of the second resistor R17 is connected to the feedback terminal FB of the first buck chip U1 and one end of the third resistor R18; the other end of the third resistor R18 is grounded.

[0061] In one embodiment, Figure 2As shown, the first filter circuit 202 includes: a fourth capacitor C4, a fifth capacitor C7 and a sixth capacitor C8; wherein the second filter circuit 203 includes: a seventh capacitor C9, an eighth capacitor C5 and a ninth capacitor C6; one end of the fourth capacitor C4 is connected to the external power supply and the input terminal VIN of the first buck chip U1, and the other end is grounded; the fifth capacitor C7 and the sixth capacitor C8 are both connected in parallel with the fourth capacitor C4; one end of the seventh capacitor C9 is connected to the other end of the first inductor L1, and the other end is grounded; the eighth capacitor C5 and the ninth capacitor C6 are both connected in parallel with the seventh capacitor C9.

[0062] In one embodiment, Figure 3 As shown, the second voltage conversion circuit 30 includes: a second voltage stabilizing chip U5, a tenth capacitor C19, an eleventh capacitor C20, a twelfth capacitor C2 and a thirteenth capacitor C22; wherein, the input terminal Vin of the second voltage stabilizing chip U5 is connected to the external power supply, the output terminal Vout of the second voltage stabilizing chip U5 is connected to the second device, and the ground terminal of the second voltage stabilizing chip U5 is grounded; one end of the tenth capacitor C19 is connected to the input terminal VIN of the second voltage stabilizing chip U5, and the other end is grounded; the eleventh capacitor C20 is connected in parallel with the tenth capacitor C19; one end of the twelfth capacitor C2 is connected to the output terminal Vout of the second voltage stabilizing chip U5, and the other end is grounded; the thirteenth capacitor C22 is connected in parallel with the twelfth capacitor C2.

[0063] In one embodiment, Figure 3 As shown, the second voltage conversion circuit 30 also includes: a fourth resistor R26 and a light emitting diode N1; wherein one end of the fourth resistor R26 is connected to the output end Vout of the second voltage stabilizing chip U5, and the other end is cascaded with the anode of the light emitting diode N1, and the cathode of the light emitting diode N1 is grounded.

[0064] In one embodiment, Figure 4As shown, the third voltage conversion circuit 40 includes: a second buck chip U4, a first diode D4, a fourteenth capacitor C15, a fifteenth capacitor C16, a second inductor L2, and a second diode D5; wherein, the input terminal Vin of the second buck chip U4 is connected to the anode of the first diode D4, the cathode of the first diode D4 is connected to the external power supply, the output terminal Vsw of the second buck chip U4 is connected to one end of the second inductor L2, and the other end of the second inductor L2 is connected to the third device; one end of the fourteenth capacitor C15 is connected to the input terminal Vin of the second buck chip U4, and the other end is grounded; the fifteenth capacitor C16 is connected in parallel with the fourteenth capacitor C15; the anode of the second diode D5 is connected to the output terminal Vsw of the second buck chip U4, and the cathode of the second diode D5 is grounded.

[0065] In one embodiment, Figure 4 As shown, the third voltage conversion circuit 40 also includes: a sixteenth capacitor C17 and a seventeenth capacitor C18; wherein, one end of the sixteenth capacitor C17 is connected to the other end of the second inductor L2, and the other end of the sixteenth capacitor C17 is grounded; the seventeenth capacitor C18 is connected in parallel with the sixteenth capacitor C17.

[0066] The present application provides a voltage-stabilizing signal to the first voltage conversion circuit through a voltage-stabilizing source; the first voltage conversion circuit receives the first voltage and the voltage-stabilizing signal provided by an external power supply, and converts the first voltage into a second voltage and outputs it to the first device; the second voltage conversion circuit receives the third voltage provided by the external power supply, and converts the third voltage into a fourth voltage and outputs it to the second device; the third voltage conversion circuit receives the first voltage provided by the external power supply, and converts the first voltage into a fifth voltage and outputs it to the third device. The working requirements of different devices can be met through a simple circuit structure, reducing the design cost of the power supply circuit; at the same time, the voltage-stabilizing source provides a voltage-stabilizing signal to the first voltage conversion circuit, ensuring that the first voltage conversion circuit provides a stable second voltage to the first device; at the same time, the second voltage conversion circuit outputs a fourth voltage to the second device, and the third voltage conversion circuit outputs a fifth voltage to the third device, so that the second device and the third device can maintain a normal working state.

[0067] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope covered by the present invention.

Claims

1. A power supply circuit, characterized in that: include: A voltage stabilizing source, whose output end is connected to the feedback end of the first voltage conversion circuit, and is used to provide a voltage stabilizing signal to the first voltage conversion circuit; The first voltage conversion circuit has an input end connected to the output end of the external power supply, and an output end connected to the first device, and is used to receive the first voltage and the voltage stabilization signal provided by the external power supply, and convert the first voltage into a second voltage and output it to the first device; a second voltage conversion circuit, the input end of which is connected to the output end of the external power supply, the output end of which is connected to the second device, and is used to receive a third voltage provided by the external power supply, and convert the third voltage into a fourth voltage and output it to the second device; The third voltage conversion circuit has an input end connected to the output end of the external power supply and an output end connected to the third device, and is used to receive the first voltage provided by the external power supply, and convert the first voltage into a fifth voltage and output it to the third device.

2. The power supply circuit according to claim 1, characterized in that: The first voltage conversion circuit comprises: a first filtering circuit, whose input end is connected to the output end of the external power supply and whose output end is connected to the input end of the step-down circuit, and is used for receiving the first voltage and outputting the first voltage to the step-down circuit after filtering; The step-down circuit has an enable terminal connected to the output terminal of the voltage stabilization source, and an output terminal connected to the input terminal of the second filtering circuit, and is used to receive the filtered first voltage and the voltage stabilization signal, and convert the first voltage into a second voltage and output it to the second filtering circuit; The second filtering circuit has an output end connected to the first device, and is used for receiving the second voltage and filtering the second voltage before outputting it to the first device.

3. The power supply circuit according to claim 1, characterized in that: The voltage stabilizing source includes: a first voltage stabilizing chip, a first operational amplifier, a second operational amplifier, a first capacitor and a first resistor; The common terminal and the anode of the first voltage stabilizing chip are both connected to the external power supply; The non-inverting input terminal of the first operational amplifier is connected to the anode of the first voltage stabilizing chip, and the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier; The non-inverting input terminal of the second operational amplifier is connected to the output terminal of the first operational amplifier, the inverting input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier, the output terminal of the second operational amplifier is connected to one end of the first resistor, and the other end of the first resistor is connected to the feedback terminal of the first voltage conversion circuit; One end of the first capacitor is connected to the output end of the first operational amplifier, and the other end is grounded.

4. The power supply circuit according to claim 3, characterized in that: The voltage stabilizing source further includes: a second capacitor and a third capacitor; One end of the second capacitor is connected to the non-inverting input terminal of the first operational amplifier, and the other end is grounded; One end of the third capacitor is connected to the non-inverting input terminal of the first operational amplifier, and the other end is grounded.

5. The power supply circuit according to claim 2, characterized in that: The step-down circuit comprises: a first step-down chip, a first inductor, a second resistor and a third resistor; The input end of the first buck chip is connected to the external power supply, the switch end SW of the first buck chip is connected to one end of the first inductor, the other end of the first inductor is connected to the first device, and the feedback end of the first buck chip is connected to the output end of the voltage stabilization source; One end of the second resistor is connected to the other end of the first inductor, and the other end of the second resistor is connected to the feedback end of the first buck chip and one end of the third resistor; The other end of the third resistor is grounded.

6. The power supply circuit according to claim 5, characterized in that: The first filtering circuit includes: a fourth capacitor, a fifth capacitor and a sixth capacitor; The second filtering circuit comprises: a seventh capacitor, an eighth capacitor and a ninth capacitor; One end of the fourth capacitor is connected to the external power supply and the input end of the first buck chip, and the other end is grounded; The fifth capacitor and the sixth capacitor are both connected in parallel with the fourth capacitor; One end of the seventh capacitor is connected to the other end of the first inductor, and the other end is grounded; The eighth capacitor and the ninth capacitor are both connected in parallel with the seventh capacitor.

7. The power supply circuit according to claim 1, characterized in that: The second voltage conversion circuit includes: a second voltage stabilizing chip, a tenth capacitor, an eleventh capacitor, a twelfth capacitor and a thirteenth capacitor; The input end of the second voltage stabilizing chip is connected to the external power supply, the output end of the second voltage stabilizing chip is connected to the second device, and the ground end of the second voltage stabilizing chip is grounded; One end of the tenth capacitor is connected to the input end of the second voltage stabilizing chip, and the other end is grounded; The eleventh capacitor is connected in parallel with the tenth capacitor; One end of the twelfth capacitor is connected to the output end of the second voltage stabilizing chip, and the other end is grounded; The thirteenth capacitor is connected in parallel with the twelfth capacitor.

8. The power supply circuit according to claim 7, characterized in that: The second voltage conversion circuit further includes: a fourth resistor and a light emitting diode; One end of the fourth resistor is connected to the output end of the second voltage stabilizing chip, and the other end is cascaded with the anode of the light emitting diode, and the cathode of the light emitting diode is grounded.

9. The power supply circuit according to claim 1, characterized in that: The third voltage conversion circuit includes: a second step-down chip, a first diode, a fourteenth capacitor, a fifteenth capacitor, a second inductor, and a second diode; The input end of the second buck chip is connected to the anode of the first diode, the cathode of the first diode is connected to the external power supply, the output end of the second buck chip is connected to one end of the second inductor, and the other end of the second inductor is connected to the third device; One end of the fourteenth capacitor is connected to the input end of the second buck chip, and the other end is grounded; The fifteenth capacitor is connected in parallel with the fourteenth capacitor; An anode of the second diode is connected to the output end of the second buck chip, and a cathode of the second diode is grounded.

10. The power supply circuit according to claim 9, characterized in that: The third voltage conversion circuit further includes: a sixteenth capacitor and a seventeenth capacitor; One end of the sixteenth capacitor is connected to the other end of the second inductor, and the other end of the sixteenth capacitor is grounded; The seventeenth capacitor is connected in parallel with the sixteenth capacitor.

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