Power supply circuit, power supply equipment and electrical equipment
By combining a signal preprocessing module, a voltage conversion module, a sampling module, and a power factor correction chip, the problems of low conversion efficiency and high cost of traditional power supply equipment are solved, achieving efficient and low-cost power conversion.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-04
- Publication Date
- 2026-03-10
AI Technical Summary
Traditional power supply equipment is difficult to meet the high requirements for conversion efficiency and energy conservation and environmental protection in recent years, and its cost is relatively high.
By combining a signal preprocessing module, a voltage conversion module, a sampling module, and a power factor correction chip, high-efficiency conversion and cost reduction are achieved through filtering, rectification, voltage conversion, and power factor correction functions.
It improves conversion efficiency, reduces costs, and meets AC input standards and energy-saving and environmental protection requirements.
Smart Images
Figure CN223987042U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electronic circuit technology, and in particular to a power supply circuit, power supply device, and electrical device. Background Technology
[0002] A power converter is like the heart of the human body, providing power to all electrical devices. However, unlike the heart, a power supply is not singular in form. Parameters that characterize a power supply include power, voltage, frequency, noise, and parameter changes under load, among others. General electricity (such as AC mains power) needs to be converted to meet usage requirements. Especially in recent years, with the increasing frequency of AC switching between various domestic and international power equipment, higher demands have been placed on conversion efficiency to meet the AC input standards of different countries and the requirements of energy conservation and environmental protection. Traditional power supplies can no longer meet these requirements. Utility Model Content
[0003] This application provides a power supply circuit, power supply device, and electrical device that can improve conversion efficiency and reduce costs.
[0004] In a first aspect, embodiments of this application provide a power supply circuit, comprising: a signal preprocessing module connected to an AC power supply and configured to filter and rectify the AC power supply to output a first DC voltage; a voltage conversion module connected to the signal preprocessing module, including a switching device and configured to convert the first DC voltage into a second DC voltage in response to the switching device alternately turning on and off; a sampling module connected to the AC power supply, including a sampling resistor and configured to generate a first sampling voltage based on the voltage across the AC power supply and a second sampling voltage based on the voltage across the sampling resistor, wherein the sampling resistor is connected between the first DC voltage and ground; and a power factor correction chip connected to the sampling module and the voltage conversion module respectively, including a first operational amplifier and a second operational amplifier, configured to output a pulse width modulation signal to the switching device based on the output voltage of the first operational amplifier, the output voltage of the second operational amplifier, and the second DC voltage, to control the switching device to alternately turn on and off, wherein the first operational amplifier inputs the first sampling voltage and the second operational amplifier inputs the second sampling voltage.
[0005] In one or more embodiments, the signal preprocessing module includes: a filtering unit connected to the AC power supply and configured to filter the AC power supply; and a rectification unit connected to the filtering unit and configured to rectify the filtered AC power supply and output the first DC voltage.
[0006] In one or more embodiments, the voltage conversion module further includes a first inductor, a first diode, and a first capacitor; the first inductor is connected between the first DC voltage and the anode of the first diode, the third terminal of the switching device is connected to the anode of the first diode, the first terminal of the switching device receives the pulse width modulation signal, the cathode of the first diode is connected to the first terminal of the first capacitor, and the second terminal of the first capacitor and the second terminal of the switching device are grounded.
[0007] In one or more embodiments, the voltage conversion module further includes a second capacitor, a first resistor, and a second resistor; a first terminal of the second capacitor is connected between the positive and negative terminals of the first DC voltage, the first resistor is connected in parallel with the second capacitor, and the second resistor is connected between the first terminal of the switching device and ground.
[0008] In one or more embodiments, the sampling module includes: a voltage sampling unit connected between the AC power supply and the first operational amplifier, configured to divide and filter the voltage across the AC power supply to generate the first sampling voltage; and a current sampling unit connected between the AC power supply and the second operational amplifier, including the sampling resistor, configured to differentially divide the voltage across the sampling resistor to generate the second sampling voltage.
[0009] In one or more embodiments, the voltage sampling unit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a second diode, and a third diode; the first end of the third resistor is connected to the first end of the AC power supply; the second end of the third resistor is connected to the first end of the third capacitor, the first end of the fourth capacitor, the anode of the second diode, the anode of the third diode, the first end of the seventh resistor, the first end of the sixth capacitor, and the non-inverting input of the first operational amplifier; the second end of the seventh resistor is connected to the second end of the sixth capacitor; the first end of the fourth resistor is connected to the second end of the AC power supply; the second end of the fourth resistor is connected to the second end of the fourth capacitor, the first end of the fifth capacitor, the cathode of the second diode, the cathode of the third diode, the first end of the fifth resistor, the first end of the sixth resistor, and the inverting input of the first operational amplifier; the second end of the sixth resistor is connected to a third DC voltage; and the second ends of the third capacitor, the fifth capacitor, and the fifth resistor are all grounded.
[0010] In one or more embodiments, the current sampling unit includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a seventh capacitor, and an eighth capacitor; the first end of the eighth resistor is connected to the first end of the sampling resistor, the second end of the eighth resistor is connected to the first end of the seventh capacitor and the first end of the eleventh resistor, the first end of the ninth resistor is connected to the second end of the sampling resistor, the second end of the seventh capacitor is connected to the second end of the ninth resistor and the first end of the tenth resistor, the second end of the tenth resistor is connected to the first end of the twelfth resistor, the first end of the thirteenth resistor, and the non-inverting input terminal of the second operational amplifier, the second end of the twelfth resistor is connected to a third DC voltage, the second end of the thirteenth resistor is grounded, the second end of the eleventh resistor is connected to the first end of the eighth capacitor, the first end of the fourteenth resistor, the first end of the fifteenth resistor, and the inverting input terminal of the second operational amplifier, and the second end of the eighth capacitor is connected to the second end of the fourteenth resistor, the second end of the fifteenth resistor, and the output terminal of the second operational amplifier.
[0011] In one or more embodiments, the power supply circuit further includes a filtering module connected to the voltage conversion module and configured to filter the second DC voltage.
[0012] Secondly, embodiments of this application provide a power supply device, including the power supply circuit described above.
[0013] Thirdly, embodiments of this application provide an electrical device, including a load and a power supply device as described above; the power supply device is connected to the load to supply power to the load.
[0014] The beneficial effects of this application are as follows: The power supply circuit of this application embodiment includes a signal preprocessing module, a voltage conversion module, a sampling module, and a power factor correction chip. The signal preprocessing module is connected to an AC power supply and is configured to filter and rectify the AC power supply to output a first DC voltage. The voltage conversion module is connected to the signal preprocessing module and includes a switching device. The voltage conversion module is configured to convert the first DC voltage into a second DC voltage in response to the switching device alternately turning on and off. The sampling module is connected to the AC power supply and includes a sampling resistor. The sampling module is configured to generate a first sampling voltage based on the voltage across the AC power supply and a second sampling voltage based on the voltage across the sampling resistor, wherein the sampling resistor is connected between the two ends of the AC power supply. The power factor correction chip is connected to both the sampling module and the voltage conversion module. The chip includes a first operational amplifier (op-amp) and a second op-amp. It is configured to output a pulse-width modulation (PWM) signal to a switching device based on the output voltages of the first and second op-amps and a second DC voltage, thereby controlling the switching device to alternately turn on and off. The first op-amp receives a first sampling voltage, and the second op-amp receives a second sampling voltage. This approach improves conversion efficiency by integrating the sampling module and the power factor correction chip, thus eliminating the need for additional op-amps. Furthermore, since the price of a power factor correction chip with integrated op-amps is similar to that without them, this effectively saves the cost of at least two op-amps, achieving cost reduction. Attached Figure Description
[0015] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are not intended to limit the embodiments, and elements having the same reference numerals in the drawings are designated as similar elements.
[0016] Figure 1 This is a schematic diagram of the power supply circuit provided in the embodiments of this application. Figure 1 ;
[0017] Figure 2 This is a schematic diagram of the power supply circuit provided in the embodiments of this application. Figure 2 ;
[0018] Figure 3 This is a schematic diagram of the power supply circuit provided in the embodiments of this application. Figure 3 ;
[0019] Figure 4 This is a schematic diagram of the power supply circuit provided in the embodiments of this application. Figure 4 ;
[0020] Figure 5 This is a schematic diagram of the circuit structure of the voltage conversion module provided in the embodiments of this application;
[0021] Figure 6 This is a schematic diagram of the circuit structure of the voltage sampling unit provided in the embodiments of this application;
[0022] Figure 7 This is a schematic diagram of the circuit structure of the current sampling unit provided in the embodiment of this application. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.
[0024] It should be noted that when an element is described as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements between them.
[0025] Furthermore, the technical features involved in the various embodiments of this application described below can be combined with each other as long as they do not conflict with each other.
[0026] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the power supply circuit provided in an embodiment of this application. Figure 1 As shown, the power supply circuit 100 includes a signal preprocessing module 10, a voltage conversion module 20, a sampling module 30, and a power factor correction chip 40.
[0027] The signal preprocessing module 10 is connected to the AC power supply 200 and the voltage conversion module 20, respectively. The sampling module 30 is connected to the AC power supply 200, and the power factor correction chip 40 is connected to the sampling module 30 and the voltage conversion module 20, respectively.
[0028] Specifically, the signal preprocessing module 10 is configured to filter and rectify the AC power supply 200 to output a first DC voltage VC1. The voltage conversion module 20 includes a switching device K1 and is configured to convert the first DC voltage VC1 into a second DC voltage VC2 in response to the alternating on and off of the switching device K1. The sampling module 30 includes a sampling resistor RT and is configured to generate a first sampling voltage based on the voltage across the AC power supply 200 and a second sampling voltage based on the voltage across the sampling resistor RT, wherein the sampling resistor RT is connected between the negative terminal of the first DC voltage VC1 and ground GND (not shown here, but shown in subsequent figures). The power factor correction chip 40 includes a first operational amplifier U1 and a second operational amplifier U22. The power factor correction chip 40 is configured to output a pulse width modulation signal PWM1 to a switching device K1 based on the output voltage of the first operational amplifier U1, the output voltage of the second operational amplifier U2, and a second DC voltage VC2, so as to control the switching device K1 to alternately turn on and off. The first operational amplifier U1 is input with a first sampling voltage, and the second operational amplifier U2 is input with a second sampling voltage.
[0029] In summary, on the one hand, by using the power factor correction chip 40 to control the switching device K1 to alternately turn on and off based on the output voltage of the first operational amplifier U1, the output voltage of the second operational amplifier U2, and the second DC voltage VC2, the conversion of the first DC voltage VC1 to the second DC voltage VC2 is achieved, and a negative feedback process is also implemented to ensure that the second DC voltage VC2 is the required and stable voltage. On the other hand, the power factor correction function is realized, which helps to improve the conversion efficiency. In addition, by using the power factor correction chip 40 with its own first operational amplifier U1 and second operational amplifier U2, there is no need to set up other operational amplifiers for voltage and current acquisition. Since the price of the power factor correction chip 40 with its own first operational amplifier U1 and second operational amplifier U2 is similar to that of the power factor correction chip 40 without its own first operational amplifier U1 and second operational amplifier U2, it is equivalent to saving the cost of at least two operational amplifiers, thus achieving the goal of cost reduction.
[0030] In some embodiments, the power factor correction chip 40 is implemented using an SH32F205 MCU (Microcontroller Unit), which integrates multiple operational amplifiers and a PWM (Pulse Width Modulation) module. The specific process of implementing the power factor correction function is common knowledge in the art.
[0031] For example, in one specific implementation, since the desired current waveform and the input voltage are sinusoidal waves with the same phase and frequency, power factor correction can be achieved simply by making the input current change along the desired current waveform. Therefore, the power factor correction chip 40 calculates the current error value by subtracting the actual input current from the desired current, and then calculates a suitable duty cycle through current loop adjustment. Based on this duty cycle, it outputs a pulse width modulation signal PWM1 to the switching device Q1, thereby controlling the switching device Q1 to turn on and off. In this way, current follows voltage, and power factor correction is achieved. Specifically, the output voltage error value is calculated by sampling the second DC voltage VC2 and subtracting it from the output voltage reference value VREF (i.e., the desired output voltage value). Then, through voltage loop adjustment, a coefficient K is output. This K value is only an intermediate calculation quantity and has no practical meaning. Multiplying the K value by the input current, the current reference value is calculated (because the voltage is sinusoidal, the current reference value also changes sinusoidally). This current reference value is the desired current waveform.
[0032] In some embodiments, such as Figure 2 As shown, the signal preprocessing module 10 includes a filtering unit 11 and a rectifier unit 12.
[0033] The filter unit 11 is connected to the AC power supply 200 and is configured to filter the AC power supply 200. The rectifier unit 12 is connected to the filter unit 11 and is configured to rectify the filtered AC power supply 200 and output a first DC voltage VC1.
[0034] Specifically, the filter unit 11 eliminates high-frequency noise and pulsation in the AC power supply 200 input, prevents transient interference in the AC power supply 200, improves the frequency response and stability of the AC power supply 200, thereby improving energy utilization efficiency and making the voltage more stable. The rectifier unit 12 can convert the input AC voltage into DC voltage.
[0035] In some embodiments, such as Figure 3 As shown, the sampling module 30 includes a voltage sampling unit 31 and a current sampling unit 32.
[0036] The voltage sampling unit 31 is connected between the AC power supply 200 and the first operational amplifier U1. The voltage sampling unit 31 is configured to divide and filter the voltage across the AC power supply 200 to generate a first sampling voltage. The current sampling unit 32 is connected between the AC power supply 200 and the second operational amplifier U2. The current sampling unit 32 includes a sampling resistor RT. The current sampling unit 32 is configured to differentially divide the voltage across the sampling resistor RT to generate a second sampling voltage.
[0037] It should be noted that, as Figures 1-3The hardware structure of the power supply circuit 100 shown is only an example, and the power supply circuit 100 may have more or fewer components than those shown in the figure, may combine two or more components, or may have different component configurations. The various components shown in the figure may be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and / or application-specific integrated circuits.
[0038] For example, such as Figure 4 As shown, the power supply circuit 100 also includes a filter module 50, which is connected to the voltage conversion module 20. The filter module 50 is configured to filter the second DC voltage VC2, thereby enabling a smooth output of the second DC voltage VC2.
[0039] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the circuit structure of the voltage conversion module provided in an embodiment of this application. Figure 5 As shown, the voltage conversion module 20 also includes a first inductor L1, a first diode D1, and a first capacitor C1.
[0040] In this configuration, the first inductor L1 is connected between the first DC voltage VC1 and the anode of the first diode D1, the third terminal of the switching device K1 is connected to the anode of the first diode D1, the first terminal of the switching device K1 receives the pulse width modulation signal PWM1, the cathode of the first diode D1 is connected to the first terminal of the first capacitor C1, and the second terminal of the first capacitor C1 and the second terminal of the switching device K1 are grounded to GND.
[0041] In this embodiment, the switching device K1 is a PMOS transistor. The gate of the PMOS transistor is the first terminal of the switching device K1, the source of the PMOS transistor is the second terminal of the switching device K1, and the drain of the PMOS transistor is the third terminal of the switching device K1.
[0042] In addition, the switching device K1 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field-effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.
[0043] In some embodiments, the voltage conversion module 20 further includes a second capacitor C2, a first resistor R1, and a second resistor R2.
[0044] In this configuration, the first terminal of the second capacitor C2 is connected between the positive and negative terminals of the first DC voltage VC1. The first resistor R1 is connected in parallel with the second capacitor C2. The second resistor R2 is connected between the first terminal of the switching device K1 and ground GND. The sampling resistor RT is connected between the negative terminal of the first DC voltage VC1 and ground GND.
[0045] Specifically, the switching device K1 is alternately turned on and off by a pulse width modulation signal PWM1. When the switching device K1 is on, the first DC voltage VC1 charges the first inductor L1; when the switching device K1 is off, the sum of the first DC voltage VC1 and the voltage across the first inductor L1 charges the first capacitor C1. By continuously repeating the on and off process of the switching device K1, the voltage of the first capacitor C1 can be stabilized at the second DC voltage VC2.
[0046] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the circuit structure of the voltage sampling unit provided in an embodiment of this application. Figure 6 As shown, the voltage sampling unit 31 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a second diode D2, and a third diode D3.
[0047] Specifically, the first end of the third resistor R3 is connected to the first end of the AC power supply 200. The second end of the third resistor R3 is connected to the first end of the third capacitor C3, the first end of the fourth capacitor C4, the anode of the second diode D2, the anode of the third diode D3, the first end of the seventh resistor R7, the first end of the sixth capacitor C6, and the non-inverting input of the first operational amplifier U1. The second end of the seventh resistor R7 is connected to the second end of the sixth capacitor C6. The first end of the fourth resistor R4 is connected to the second end of the AC power supply 200. The second end of the fourth resistor R4 is connected to the second end of the fourth capacitor C4, the first end of the fifth capacitor C5, the cathode of the second diode D2, the cathode of the third diode D3, the first end of the fifth resistor R5, the first end of the sixth resistor R6, and the inverting input of the first operational amplifier U1. The second end of the sixth resistor R6 is connected to the third DC voltage VC3. The second ends of the third capacitor C3, the fifth capacitor C5, and the fifth resistor R5 are all grounded to GND.
[0048] Specifically, capacitors C3, C4, C5, and C6 are used for filtering. Resistors R3 and R4 are used for current limiting. Resistors R3 and R7 are used for voltage division. Resistors R5 and R6 are used for voltage division to input a constant voltage to the inverting input terminal of the first operational amplifier U1. The voltage input to the non-inverting and inverting input terminals of the first operational amplifier U1 is the first sampling voltage. The first sampling voltage is amplified by the first operational amplifier U1 and then output. Based on the voltage output by the first operational amplifier U1, the first sampling voltage can be determined, and thus the voltage of the AC power supply 200 can be determined.
[0049] Please refer to Figure 7 , Figure 7 This is a schematic diagram of the circuit structure of the current sampling unit provided in an embodiment of this application. Figure 7 As shown, the current sampling unit 32 includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a seventh capacitor C7, and an eighth capacitor C8.
[0050] Specifically, the first end of the eighth resistor R8 is connected to the first end of the sampling resistor RT; the second end of the eighth resistor R8 is connected to the first end of the seventh capacitor C7 and the first end of the eleventh resistor R11; the first end of the ninth resistor R9 is connected to the second end of the sampling resistor RT; the second end of the seventh capacitor C7 is connected to the second end of the ninth resistor R9 and the first end of the tenth resistor R10; the second end of the tenth resistor R10 is connected to the first end of the twelfth resistor R12, the first end of the thirteenth resistor R13, and the non-inverting input of the second operational amplifier U2; the second end of the twelfth resistor R12 is connected to the third DC voltage VC3; the second end of the thirteenth resistor R13 is grounded (GND); the second end of the eleventh resistor R11 is connected to the first end of the eighth capacitor C8, the first end of the fourteenth resistor R14, the first end of the fifteenth resistor R15, and the inverting input of the second operational amplifier U2; and the second end of the eighth capacitor C8 is connected to the second end of the fourteenth resistor R14, the second end of the fifteenth resistor R15, and the output of the second operational amplifier U2.
[0051] The circuit consists of resistors R8 (eighth), R9 (ninth), R10 (tenth), R11 (eleventh), R12 (twelfth), R13 (thirteenth), R14 (fourteenth), R15 (fifteenth), capacitor C7 (seventh), capacitor C8 (eighth), and the second operational amplifier U2. This circuit differentially amplifies and outputs the voltage across the sampling resistor RT. The second sampling voltage can then be determined based on the voltage output by the second operational amplifier U2. This allows the voltage across the sampling resistor RT to be derived. Finally, the current flowing through the sampling resistor RT can be determined based on the ratio of the voltage across the sampling resistor RT to the resistance value of the sampling resistor RT.
[0052] This application also provides a power supply device, which includes the power supply circuit 100 in any embodiment of this application.
[0053] This application also provides an electrical device, which includes a load and a power supply device as described in any embodiment of this application. The power supply device is connected to the load to supply power to the load.
[0054] In some implementations, the electrical device is a heat pump dryer.
[0055] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
[0056] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A power supply circuit, characterized by comprising: The signal preprocessing module is connected with the alternating power supply and is configured to filter and rectify the alternating power supply and output a first direct current voltage. The voltage conversion module is connected with the signal preprocessing module and includes a switching device, and is configured to convert the first direct current voltage into a second direct current voltage by alternately turning on and off the switching device. The sampling module is connected with the alternating power supply and includes a sampling resistor, and is configured to generate a first sampling voltage based on a voltage across the alternating power supply and generate a second sampling voltage based on a voltage across the sampling resistor, wherein the sampling resistor is connected between the first direct current voltage and the ground. The power factor correction chip is connected with the sampling module and the voltage conversion module, respectively, and includes first and second operational amplifiers, and is configured to output a pulse width modulation signal to the switching device based on an output voltage of the first operational amplifier, an output voltage of the second operational amplifier and the second direct current voltage, so as to control the switching device to alternately turn on and off, wherein the first operational amplifier inputs the first sampling voltage and the second operational amplifier inputs the second sampling voltage. The signal preprocessing module includes:
2. The power supply circuit according to claim 1, characterized in that, The filtering unit is connected with the alternating power supply and is configured to filter the alternating power supply. The rectifying unit is connected with the filtering unit and is configured to rectify the filtered alternating power supply and output the first direct current voltage. The voltage conversion module further includes a first inductor, a first diode and a first capacitor.
3. The power supply circuit of claim 1, wherein, The first inductor is connected between the first direct current voltage and an anode of the first diode, a third terminal of the switching device is connected with the anode of the first diode, a first terminal of the switching device inputs the pulse width modulation signal, a cathode of the first diode is connected with a first terminal of the first capacitor, and a second terminal of the first capacitor and a second terminal of the switching device are grounded. The voltage conversion module further includes a second capacitor, a first resistor and a second resistor.
4. The power supply circuit of claim 3, wherein, A first terminal of the second capacitor is connected between a positive electrode and a negative electrode of the first direct current voltage, the first resistor and the second capacitor are connected in parallel, and the second resistor is connected between the first terminal of the switching device and the ground. The sampling module includes:
5. The power supply circuit of claim 1, wherein, The voltage sampling unit is connected between the alternating power supply and the first operational amplifier, and is configured to divide and filter a voltage across the alternating power supply to generate the first sampling voltage. The current sampling unit is connected between the alternating power supply and the second operational amplifier and includes the sampling resistor, and is configured to difference a voltage across the sampling resistor to generate the second sampling voltage. The voltage sampling unit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a second diode and a third diode.
6. The power supply circuit of claim 5, wherein, The first end of the third resistor is connected with the first end of the alternating current power supply, the second end of the third resistor is connected with the first end of the third capacitor, the first end of the fourth capacitor, the anode of the second diode, the anode of the third diode, the first end of the seventh resistor, the first end of the sixth capacitor and the non-inverting input end of the first operational amplifier respectively, the second end of the seventh resistor is connected with the second end of the sixth capacitor, the first end of the fourth resistor is connected with the second end of the alternating current power supply, the second end of the fourth resistor is connected with the second end of the fourth capacitor, the first end of the fifth capacitor, the cathode of the second diode, the cathode of the third diode, the first end of the fifth resistor, the first end of the sixth resistor and the inverting input end of the first operational amplifier respectively, the second end of the sixth resistor is connected with the third direct current voltage, the second end of the third capacitor, the second end of the fifth capacitor and the second end of the fifth resistor are grounded.
7. The power supply circuit of claim 5, wherein, The current sampling unit comprises an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a seventh capacitor and an eighth capacitor; The first end of the eighth resistor is connected with the first end of the sampling resistor, the second end of the eighth resistor is connected with the first end of the seventh capacitor and the first end of the eleventh resistor respectively, the first end of the ninth resistor is connected with the second end of the sampling resistor, the second end of the seventh capacitor is connected with the second end of the ninth resistor and the first end of the tenth resistor respectively, the second end of the tenth resistor is connected with the first end of the twelfth resistor, the first end of the thirteenth resistor and the non-inverting input end of the second operational amplifier respectively, the second end of the twelfth resistor is connected with the third direct current voltage, the second end of the thirteenth resistor is grounded, the second end of the eleventh resistor is connected with the first end of the eighth capacitor, the first end of the fourteenth resistor, the first end of the fifteenth resistor and the inverting input end of the second operational amplifier respectively, the second end of the eighth capacitor is connected with the second end of the fourteenth resistor, the second end of the fifteenth resistor and the output end of the second operational amplifier respectively.
8. The power supply circuit of claim 1, wherein, The power supply circuit further comprises: A filtering module connected with the voltage conversion module and configured to filter the second direct current voltage.
9. A power supply device characterized by comprising: The power supply circuit comprises the power supply circuit according to any one of claims 1-8.
10. An electrical appliance characterized by The power supply device comprises the power supply device according to claim 9. The power supply device is connected with the load to supply power for the load.