Power supply circuit and device and electric equipment

Abstract

The utility model discloses a power supply circuit and device and electric equipment, the power supply circuit comprises a plurality of power supply modules, each power supply module comprises a power supply unit, a current sampling unit, a current sharing unit and a feedback unit, and the output end of the power supply unit is used for being connected with a load; the input end of the current sampling unit is connected with the load; the current sharing unit is used for outputting reference voltage according to the average current of the plurality of power supply modules; the feedback unit is used for outputting a first feedback signal to the power supply unit according to the reference voltage and the first sampling voltage output by the current sampling unit, so that the power supply unit adjusts the output power supply voltage according to the first feedback signal; the power supply circuit can meet the power utilization requirement of the load for high power.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to a power supply circuit, device and electrical equipment. Background Art

[0002] As television screens get larger and larger, the power consumption also increases accordingly. Therefore, a single power supply in a television set cannot meet the high power demand. Utility Model Content

[0003] The present application provides a power supply circuit, device and electrical equipment, which can alleviate the problem that the power supply in the current television cannot meet the high-power power demand.

[0004] The present application provides a power supply circuit, which includes multiple power modules, each of which includes:

[0005] A power supply unit, wherein the output end of the power supply unit is used to connect with a load;

[0006] A current sampling unit, wherein an input end of the current sampling unit is connected to a load;

[0007] A current balancing unit, wherein the input end of the current balancing unit is connected to the output end of the current sampling unit, and the output end of the current balancing unit is connected to the output end of the current balancing unit in each other power supply module; the current balancing unit is used to output a reference voltage according to the average current of multiple power supply modules;

[0008] A feedback unit, wherein the first input end of the feedback unit is connected to the output end of the current sampling unit, the output end of the feedback unit is connected to the feedback end of the power supply unit, and the second input end of the feedback unit is connected to the output end of the current balancing unit; the feedback unit is used to output a first feedback signal to the power supply unit based on the reference voltage and the first sampling voltage output by the current sampling unit, so that the power supply unit adjusts the output supply voltage according to the first feedback signal.

[0009] In the power supply circuit of some embodiments, the output currents of the multiple power modules are equal.

[0010] In the power supply circuit of some embodiments, the current sampling unit includes a sampling subunit and an amplifying subunit, the input end of the sampling subunit is connected to the load, and the input end of the amplifying subunit is connected to the input end of the sampling subunit;

[0011] The sampling subunit is used to output a first sampling voltage according to the current flowing through the load of the power module in which it is located; the amplifying subunit is used to amplify the first sampling voltage.

[0012] In some embodiments of the power supply circuit, the sampling subunit includes a first resistor, one end of the first resistor is connected to the load, and the other end of the first resistor is grounded.

[0013] In the power supply circuit of some embodiments, the amplifying subunit includes a first amplifier, the non-inverting input terminal of the first amplifier is connected to the input terminal of the sampling subunit, the inverting input terminal of the first amplifier is grounded, and the output terminal of the first amplifier is connected to the feedback unit and the current equalizing unit.

[0014] In some embodiments of the power supply circuit, the feedback unit includes a second amplifier, the non-inverting input terminal of the second amplifier is connected to the amplifying sub-unit, the inverting input terminal of the second amplifier is connected to the output terminal of the current equalizing unit, and the output terminal of the second amplifier is connected to the power supply unit.

[0015] In some embodiments of the power supply circuit, the first amplifier and the second amplifier are integrated.

[0016] In the power supply circuit of some embodiments, the current balancing unit includes a second resistor, one end of the second resistor is connected to the output end of the current sampling unit, and the other end of the second resistor is connected to the output end of the current balancing unit in other power supply modules.

[0017] In some embodiments of the power supply circuit, the power module further includes a current limiting unit connected to the second input terminal of the feedback unit; the current limiting unit is used to limit the output current of the power supply unit.

[0018] In some embodiments of the power supply circuit, the current limiting unit includes a voltage regulator diode, the anode of the voltage regulator diode is grounded, and the cathode of the voltage regulator diode is connected to the second input terminal of the feedback unit.

[0019] In the power supply circuit of some embodiments, the power supply unit includes a power subunit and a feedback subunit, and the output end of the power subunit is used to connect to the load and provide a corresponding power supply voltage to the load;

[0020] The input end of the feedback subunit is connected to the output end of the feedback unit and the power subunit, and the output end of the feedback subunit is connected to the feedback end of the power subunit; the feedback subunit is used to sample the supply voltage to obtain a second sampling voltage, and output a second feedback signal to the power subunit based on the first feedback signal and the second sampling voltage, so that the power subunit adjusts the supply voltage according to the second feedback signal.

[0021] In the power supply circuit of some embodiments, the feedback subunit includes a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor and a voltage regulator, one end of the first voltage-dividing resistor is connected to the output end of the power subunit, the other end of the first voltage-dividing resistor is connected to one end of the second voltage-dividing resistor, the other end of the second voltage-dividing resistor is connected to one end of the third voltage-dividing resistor and the first end of the voltage regulator, the other end of the third voltage-dividing resistor is grounded, the first end of the voltage regulator is also connected to the output end of the feedback unit, the second end of the voltage regulator is grounded, and the third end of the voltage regulator is connected to the feedback end of the power subunit.

[0022] An embodiment of the present application further provides a power supply device, which includes the above-mentioned power supply circuit.

[0023] An embodiment of the present application further provides an electrical device, which includes the above-mentioned power supply circuit.

[0024] The present application provides a power supply circuit, device and electrical equipment, wherein a plurality of power modules are arranged in the power supply circuit, each power module is connected in parallel with other power modules through a current balancing unit, and the power supply units in each power module jointly supply power to the load, which is equivalent to connecting multiple power modules in parallel to supply power to the same load. Compared with a single power supply supplying power to the load, the power supply power of the power supply circuit can be improved, thereby meeting the load's demand for high power. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0026] Figure 1 This is a structural block diagram of the first embodiment of the power supply circuit provided in the embodiments of the present application.

[0027] Figure 2 This is a structural block diagram of the second embodiment of the power supply circuit provided in the embodiments of the present application.

[0028] Figure 3 This is a structural block diagram of a current sampling unit in a power supply circuit provided in an embodiment of the present application.

[0029] Figure 4 This is a structural block diagram of the power supply unit in the power supply circuit provided in an embodiment of the present application.

[0030] Figure 5 A circuit diagram of a current sampling unit, a current balancing unit, a feedback unit, and a feedback sub-unit in a power supply circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of technical features indicated. The features specified as "first" and "second" may explicitly or implicitly include one or more features. In the description of this utility model, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0033] See also Figure 1 This embodiment provides a power supply circuit, which includes multiple power modules 10, each of which includes a power supply unit 11, a current sampling unit 12, a current balancing unit 13, and a feedback unit 14; wherein the output end of the power supply unit 11 is used to connect to a load 20 and provide a corresponding power supply voltage, such as Vout, to the load 20; the input end of the current sampling unit 12 is connected to the load 20, the input end of the current balancing unit 13 is connected to the output end of the current sampling unit 12, and the output end of the current balancing unit 13 is connected to the output end of the current balancing unit 13 in each of the other power modules 10; the first input end of the feedback unit 14 is connected to the output end of the current sampling unit 12, the output end of the feedback unit 14 is connected to the feedback end of the power supply unit 11, and the second input end of the feedback unit 14 is connected to the output end of the current balancing unit 13.

[0034] In a specific embodiment, the current sampling unit 12 is used to obtain a first sampling voltage based on the current flowing through the load 20 of the power module in which it is located; the first sampling voltages between multiple power modules 10 are connected in parallel through the current balancing unit 13 to obtain the average current value of the multiple power modules 10, and the corresponding current balancing unit 13 is used to output a reference voltage to the second input end of the feedback unit 14 based on the average current of the multiple power modules 10; the feedback unit 14 is used to compare and amplify the reference voltage, i.e., the average current value input at the corresponding second input end, and the first sampling voltage and then output a first feedback signal to the power unit 11, so that the power unit 11 adjusts the supply voltage of the power module in which it is located according to the first feedback signal, thereby adjusting the output current of the power module in which it is located to achieve the purpose of balancing the output current of each power module 10, thereby realizing the current balancing output between each power module 10, ensuring that the output current and power of each power module 10 are the same.

[0035] A plurality of power modules 10 are provided in the power supply circuit of the present application, and each power module 10 is connected in parallel with other power modules 10 through a current balancing unit 13, and the power supply unit 11 in each power module 10 jointly supplies power to the load 20, which is equivalent to connecting a plurality of power modules 10 in parallel to supply power to the same load 20, thereby increasing the power supply power of the power supply circuit and thus meeting the high power demand of the load 20.

[0036] See also Figure 2In some embodiments, each power module 10 further includes a current limiting unit 15 connected to the output terminal of the current balancing unit 13 (i.e., the second input terminal of the feedback unit 14); the current limiting unit 15 is configured to limit the output current of the power unit 11. Specifically, the current limiting unit 15 in this embodiment is configured to limit the reference voltage. When the first sampled voltage is greater than the set limit voltage, the feedback unit 14 rapidly controls the output voltage of the power module to decrease, thereby limiting the output current of the power module 10 and ensuring the reliability of the power supply circuit.

[0037] See also Figure 3 In some embodiments, the current sampling unit 12 includes a sampling subunit 121 and an amplifying subunit 122. The input end of the sampling subunit 121 is connected to the load 20, and the input end of the amplifying subunit 122 is connected to the input end of the sampling subunit 121. The sampling subunit 121 is used to output a first sampling voltage according to the current flowing through the load 20. The amplifying subunit 122 is used to amplify the first sampling voltage and output it to the feedback unit 14.

[0038] The sampling subunit 121 in this embodiment is connected between the load 20 and the ground of the power module 10 in which it is located (independent of each power module 10), and samples the current flowing through the load 20 of the power module 10 in which it is located, that is, the output current of the power module 10. Based on the current flowing through the load 20, the sampling subunit 121 provides a first sampling voltage to the amplifier subunit 122. After amplification by the amplifier subunit 122, the sampling voltage is output to the feedback unit 14 to facilitate subsequent comparison of the first sampling voltage with a reference voltage (i.e., the average current value of multiple power modules) and output a corresponding first feedback signal, thereby implementing feedback regulation of the output voltage of the power module 10 and ensuring equal current output of each power module 10. It should be noted that the sampling subunit 121 in this embodiment can also be set at the output end of the power module 10 for sampling, and this application is not limited to this.

[0039] See also Figure 4 In some embodiments, the power supply unit 11 includes a power subunit 111 and a feedback subunit 112. The output end of the power subunit 111 is used to connect to the load 20 and provide a corresponding power supply voltage to the load 20. The input end of the feedback subunit 112 is connected to the feedback unit 14 and the output end of the power subunit 111, and the output end of the feedback subunit 112 is connected to the feedback end of the power subunit 111. The feedback subunit 112 is used to sample the power supply voltage to obtain a second sampled voltage, and output a second feedback signal to the power subunit 111 based on the first feedback signal and the second sampled voltage, so that the power subunit 111 adjusts the supply voltage based on the second feedback signal.

[0040] In this embodiment, the feedback subunit 112 samples the output voltage of the power subunit 111, i.e., the supply voltage, to obtain a second sampled voltage. The first feedback signal correspondingly output by the feedback unit 14 is added to the second sampled voltage, amplified, and output as a second feedback signal to the power subunit 111. The power subunit 111 adjusts the output current based on the second feedback signal, thereby regulating the supply voltage. It should be noted that the power subunit 111 in this embodiment has a known circuit structure, such as a switching power supply circuit. Therefore, the specific structure of the power subunit 111 will not be further described in this application.

[0041] Please also refer to Figure 5 As an embodiment, the sampling subunit 121 includes a first resistor R1, one end of which is connected to the load 20, and the other end of the first resistor R1 is grounded. In this embodiment, the first resistor R1 is a current sampling resistor, and a first sampled voltage is obtained based on the resistance value of the first resistor R1 and the current flowing through the first resistor R1. The amplification subunit 122 then amplifies the first sampled voltage and outputs it to the feedback unit 14 to facilitate subsequent comparison of the output current of the corresponding power module 10 with the average current. In this embodiment, sampling of the output current is achieved by providing a resistor, and the circuit structure is simple.

[0042] As an embodiment, the amplifying subunit 122 includes a first amplifier, a non-inverting input terminal of the first amplifier is connected to the input terminal of the sampling subunit 121, an inverting input terminal of the first amplifier is grounded, and an output terminal of the first amplifier is connected to the feedback unit 14 and the current balancing unit 13. The amplifier in this embodiment is used to amplify the first sampled voltage and output it to the feedback unit 14 to facilitate subsequent comparison of the output current of the corresponding power module 10 with the average current.

[0043] As an embodiment, the feedback unit 14 includes a second amplifier, wherein the non-inverting input of the second amplifier is connected to the amplifier sub-unit 122, the inverting input of the second amplifier is connected to the output of the current balancing unit 13, and the output of the second amplifier is connected to the power supply unit 11. In this embodiment, the output of the second amplifier can be added to the reference voltage as a negative feedback signal. The second amplifier is used to receive the reference voltage output by the current balancing unit 13 and the first sampled voltage output by the amplifier sub-unit 122, perform error amplification on the first sampled voltage, and then output a first feedback signal to the power supply unit 11 to facilitate subsequent output voltage regulation, thereby regulating the output current of the power supply module 10 to achieve the purpose of balancing the output currents of each power supply module 10.

[0044] Please continue reading Figure 5As an embodiment, the first amplifier and the second amplifier can be integrated to form a dual operational amplifier U1. For example, the model of the dual operational amplifier can be LM358. Correspondingly, the 2IN+ signal terminal of the dual operational amplifier corresponds to the non-inverting input terminal of the first amplifier, the 2OUT signal terminal of the dual operational amplifier corresponds to the output terminal of the first amplifier, and the 2IN- signal terminal of the dual operational amplifier corresponds to the inverting input terminal of the first amplifier. The 1IN+ signal terminal of the dual operational amplifier corresponds to the non-inverting input terminal of the second amplifier, the 1IN- signal terminal of the dual operational amplifier corresponds to the inverting input terminal of the second amplifier, and the 1OUT of the dual operational amplifier corresponds to the output terminal of the second amplifier.

[0045] As an embodiment, the feedback unit 14 further includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a capacitor C1, and a diode D1; one end of the third resistor R3 is connected to the output end of the current balancing unit 13 and the current limiting unit 15, the other end of the third resistor R3, one end of the capacitor C1, and one end of the fourth resistor R4 are all connected to the inverting input end of the second amplifier, the other end of the capacitor C1 is connected to the output end of the second amplifier via the sixth resistor R6, the other end of the fourth resistor R4, one end of the fifth resistor R5, and the positive electrode of the diode D1 are all connected to the output end of the second amplifier, the other end of the fifth resistor R5 is connected to the feedback sub-unit 112, and the negative electrode of the diode D1 is connected to the feedback sub-unit 112. In this embodiment, the reference voltage output by the current balancing unit 13 and the output signal of the second amplifier are added together through the third resistor R3 and the fourth resistor R4 and output to the second amplifier, forming negative feedback; and the output signal of the second amplifier, i.e., the first feedback signal, is output to the feedback sub-unit 112 via the fifth resistor R5. The amplification factor of the second amplifier may be determined by the third resistor R3 and the fourth resistor R4, that is, the amplification factor of the second amplifier may be (R3+R4) / R3, where R3 and R4 correspond to the resistance values ​​of the third resistor R3 and the fourth resistor R4.

[0046] As an embodiment, the current balancing unit 13 includes a second resistor R2, one end of the second resistor R2 is connected to the output end of the current sampling unit 12, and the other end of the second resistor R2 is connected to the output end of the current balancing unit 13 in the other power module 10. That is, the first sampling voltage output by the amplifier subunit 122 in this embodiment is connected in parallel with the other power modules 10 through the second resistor R2 to obtain the average current of each power module 10, which serves as the reference voltage of the second amplifier to facilitate amplification of the error between the output current of the corresponding power module 10 and the average current. In this embodiment, the connection with the other power modules 10 is achieved by only setting a resistor, and the circuit structure is simple, which is conducive to simplifying the structure of the power supply circuit, reducing the space occupied by the power supply circuit structure, and facilitating miniaturization, meeting the requirements of lightweight and thin design of electrical equipment.

[0047] As an embodiment, the current limiting unit 15 includes a Zener diode ZD1, the positive electrode of the Zener diode ZD1 is grounded, and the negative electrode of the Zener diode ZD1 is connected to the feedback terminal of the feedback unit 14. When the Zener diode ZD1 is not conducting, the amplification factor of the second amplifier is 1; when the output current of the power module 10, that is, the current flowing through the second resistor R2, reaches a set upper limit, causing the Zener diode ZD1 to conduct, the amplification factor of the second amplifier is (R3+R4) / R3. At this time, the voltage corresponding to the output signal of the second amplifier rises rapidly, and the diode D1 is turned on, thereby causing the supply voltage to drop rapidly, limiting the further increase of the output current of the power module 10, thereby achieving the purpose of current limiting.

[0048] As an embodiment, the feedback sub-unit 112 includes a first voltage-dividing resistor R01, a second voltage-dividing resistor R02, a third voltage-dividing resistor R03 and a voltage regulator U2, one end of the first voltage-dividing resistor R01 is connected to the output end of the power sub-unit 111, the other end of the first voltage-dividing resistor R01 is connected to one end of the second voltage-dividing resistor R02, the other end of the second voltage-dividing resistor R02 is connected to one end of the third voltage-dividing resistor R03 and the first end of the voltage regulator U2, the other end of the third voltage-dividing resistor R03 is grounded, the first end of the voltage regulator U2 is also connected to the output end of the feedback unit 14, the second end of the voltage regulator U2 is grounded, and the third end of the voltage regulator U2 is connected to the feedback end of the power sub-unit 111.

[0049] The first, second, and third voltage-dividing resistors R01, R02, and R03 form a voltage sampling section that samples the output voltage of the power module 10, i.e., the supply voltage, to obtain a second sampled voltage. The reference voltage output by the current balancing unit 13 and the output signal of the second amplifier are summed via the third and fourth resistors R3 and R4 before being output to the second amplifier, forming negative feedback. The output signal of the second amplifier, i.e., the first feedback signal, is summed with the second sampled voltage via the fifth resistor R5 before being output to the voltage regulator U2. The voltage regulator U2 amplifies the error between the feedback signal and the internal reference voltage and outputs the second feedback signal to the power subunit 111, thereby regulating the supply voltage.

[0050] In some embodiments, the power module 10 further includes an undervoltage detection unit, which is disposed at the output end of the power supply unit 11. The undervoltage detection unit is configured to provide undervoltage protection for the power supply unit 11. When a load 20 fault triggers current limiting, the output voltage of the power supply unit 11 drops. Upon detecting an undervoltage condition, protection is implemented, thereby improving the reliability of the power supply circuit. It should be noted that since the circuit structure corresponding to the undervoltage detection unit is known, the specific circuit structure of the undervoltage detection unit will not be described in detail.

[0051] The present application also provides a power supply device, which includes the above-mentioned power supply circuit. Multiple power modules are provided in the power supply circuit. Each power module is connected in parallel with other power modules through a current balancing unit. The power supply units in each power module jointly supply power to the load, which is equivalent to connecting multiple power modules in parallel to supply power to the same load. This increases the power supply of the power supply circuit and thus meets the load's demand for high power. Since the power supply circuit has been described in detail above, it will not be repeated here.

[0052] The embodiment of the present application also provides an electrical device, which is integrated with the above-mentioned power supply circuit. A plurality of power modules are provided in the power supply circuit. Each power module is connected in parallel with other power modules through a current balancing unit, and the power supply units in each power module jointly supply power to the load, which is equivalent to connecting multiple power modules in parallel to supply power to the same load, thereby increasing the power supply power of the power supply circuit and meeting the load's demand for high power. Among them, the current balancing unit, feedback unit and current sampling unit in the power supply circuit are realized by simple components such as resistors and amplifiers, so that the structure of the power supply circuit is simple. While meeting the high-power supply requirements, the circuit structure is simplified, the space occupied by the power supply circuit is reduced, and it is conducive to the lightweight design of the electrical device. Since the power supply circuit has been described in detail above, it will not be repeated here.

[0053] In some embodiments, the electrical device in this embodiment includes a display device such as a television. The above-mentioned power supply circuit is set in the television, which can ensure the thin and light design of the television while meeting the high-power power supply requirements of the television.

[0054] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0055] The power supply circuit provided in the embodiments of the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A power supply circuit, characterized in that: The power supply circuit includes a plurality of power modules, each of which includes: A power supply unit, wherein an output end of the power supply unit is used to be connected to a load; a current sampling unit, wherein an input end of the current sampling unit is connected to the load; a current balancing unit, wherein the input end of the current balancing unit is connected to the output end of the current sampling unit, and the output end of the current balancing unit is connected to the output end of the current balancing unit in each of the other power modules; the current balancing unit is used to output a reference voltage according to the average current of the multiple power modules; A feedback unit, wherein a first input end of the feedback unit is connected to the output end of the current sampling unit, the output end of the feedback unit is connected to the feedback end of the power supply unit, and a second input end of the feedback unit is connected to the output end of the current balancing unit; the feedback unit is used to output a first feedback signal to the power supply unit based on the reference voltage and the first sampled voltage output by the current sampling unit, so that the power supply unit adjusts the output supply voltage according to the first feedback signal.

2. The power supply circuit according to claim 1, wherein: The output currents of the multiple power modules are equal.

3. The power supply circuit according to claim 2, wherein: The current sampling unit includes a sampling subunit and an amplifying subunit, the input end of the sampling subunit is connected to the load, and the input end of the amplifying subunit is connected to the input end of the sampling subunit; The sampling subunit is used to output a first sampling voltage according to the current flowing through the load from the power module in which it is located; and the amplifying subunit is used to amplify the first sampling voltage.

4. The power supply circuit according to claim 3, characterized in that: The sampling subunit includes a first resistor, one end of the first resistor is connected to the load, and the other end of the first resistor is grounded.

5. The power supply circuit according to claim 3, characterized in that: The amplifying subunit includes a first amplifier, a non-inverting input terminal of the first amplifier is connected to the input terminal of the sampling subunit, an inverting input terminal of the first amplifier is grounded, and an output terminal of the first amplifier is connected to the feedback unit and the current balancing unit.

6. The power supply circuit according to claim 5, characterized in that: The feedback unit includes a second amplifier, a non-inverting input terminal of the second amplifier is connected to the amplifying sub-unit, an inverting input terminal of the second amplifier is connected to the output terminal of the current balancing unit, and an output terminal of the second amplifier is connected to the power supply unit.

7. The power supply circuit according to claim 6, characterized in that: The first amplifier and the second amplifier are integrated.

8. The power supply circuit according to any one of claims 1 to 7, characterized in that: The current balancing unit includes a second resistor, one end of the second resistor is connected to the output end of the current sampling unit, and the other end of the second resistor is connected to the output end of the current balancing unit in the other power supply module.

9. The power supply circuit according to any one of claims 1 to 7, characterized in that: The power supply module further includes a current limiting unit connected to the second input terminal of the feedback unit; the current limiting unit is used to limit the output current of the power supply unit.

10. The power supply circuit according to claim 9, characterized in that: The current limiting unit includes a voltage stabilizing diode, an anode of the voltage stabilizing diode is grounded, and a cathode of the voltage stabilizing diode is connected to the second input end of the feedback unit.

11. The power supply circuit according to any one of claims 1 to 7, characterized in that: The power supply unit includes a power subunit and a feedback subunit, wherein the output end of the power subunit is used to connect to the load and provide the corresponding power supply voltage for the load; The input end of the feedback subunit is connected to the output ends of the feedback unit and the power subunit, and the output end of the feedback subunit is connected to the feedback end of the power subunit; the feedback subunit is used to sample the supply voltage to obtain a second sampled voltage, and output a second feedback signal to the power subunit based on the first feedback signal and the second sampled voltage, so that the power subunit adjusts the supply voltage according to the second feedback signal.

12. The power supply circuit according to claim 11, characterized in that: The feedback subunit includes a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor and a voltage regulator, one end of the first voltage-dividing resistor is connected to the output end of the power subunit, the other end of the first voltage-dividing resistor is connected to one end of the second voltage-dividing resistor, the other end of the second voltage-dividing resistor is connected to one end of the third voltage-dividing resistor and the first end of the voltage regulator, the other end of the third voltage-dividing resistor is grounded, the first end of the voltage regulator is also connected to the output end of the feedback unit, the second end of the voltage regulator is grounded, and the third end of the voltage regulator is connected to the feedback end of the power subunit.

13. A power supply device, characterized in that: The power supply device includes the power supply circuit according to any one of claims 1 to 12.

14. An electrical device, characterized in that: The electrical equipment includes the power supply circuit according to any one of claims 1 to 12.

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