Power supply circuit and electronic equipment

Abstract

The utility model provides a power supply circuit and electronic equipment. The power supply circuit comprises a power factor correction circuit, a power conversion circuit and a detection circuit, and the power conversion circuit is connected with the power factor correction circuit and used for performing power conversion and generating a first control signal; the detection circuit is connected with the power factor correction circuit and the power conversion circuit and used for controlling the power factor correction circuit to work based on the first control signal when the output power of the power conversion circuit is larger than a threshold value. According to the power supply circuit, the size of the power supply circuit can be reduced.

Description

Technical Field

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

[0002] The existing power supply circuit is provided with a power factor correction (PFC) circuit. The PFC circuit is a circuit used to improve the power factor of power electronic equipment. Its main function is to reduce the reactive power in the power grid and improve the utilization rate of electric energy in the power supply circuit.

[0003] At present, when the load of the power supply circuit fluctuates in a large range, such as no-load and full-load switching tests, dynamic tests, etc., the PFC circuit needs a capacitor with a large capacitance to maintain a relatively stable output voltage, so as to prevent the voltage from dropping too much and causing the back-end circuit to malfunction. Therefore, the capacitance of the capacitor in the PFC circuit is relatively high, resulting in a large proportion of the power supply circuit, which poses a challenge to the development of small-volume products. Utility Model Content

[0004] The present application provides a power supply circuit and an electronic device, which can reduce the volume of the power supply circuit.

[0005] The present application provides a power supply circuit, which includes a power factor correction circuit, a power conversion circuit and a detection circuit. The power conversion circuit is connected to the power factor correction circuit for performing power conversion and generating a first control signal; the detection circuit is respectively connected to the power factor correction circuit and the power conversion circuit for controlling the operation of the power factor correction circuit based on the first control signal when the rate of change of the output power of the power conversion circuit is greater than a threshold.

[0006] Among them, the power conversion circuit includes a power conversion output circuit and a second control circuit. The power conversion output circuit is connected to the power factor correction circuit for power conversion; the second control circuit is respectively connected to the detection circuit and the power conversion output circuit for generating a first control signal.

[0007] Among them, the power supply circuit also includes a first acquisition circuit and a second acquisition circuit. The first acquisition circuit is respectively connected to the power conversion output circuit and the second control circuit, and is used to collect the output current of the power conversion output circuit; the second acquisition circuit is respectively connected to the power conversion output circuit and the second control circuit, and is used to collect the output voltage of the power conversion output circuit.

[0008] The power conversion output circuit includes any one of a flyback power conversion output circuit, a forward power conversion output circuit, an asymmetric half-bridge or an LLC half-bridge resonance.

[0009] Among them, the power supply circuit also includes a first control circuit, which is respectively connected to the power factor correction circuit and the detection circuit, and generates a second control signal based on the output signal of the power factor correction circuit; the detection circuit is also used to control the operation of the power factor correction circuit based on the second control signal when the rate of change of the output power is less than a threshold.

[0010] Among them, the detection circuit includes a judgment circuit and a switching circuit. The judgment circuit is connected to the power conversion circuit and is used to determine the relationship between the rate of change of the output power and the threshold based on the first control signal; the switching circuit is respectively connected to the judgment circuit, the power conversion circuit, the first control circuit and the power factor correction circuit. The switching circuit is used to connect the power conversion circuit with the power factor correction circuit, or to connect the first control circuit with the power factor correction circuit.

[0011] The judgment circuit includes a comparison circuit, and the comparison circuit includes a reverse input terminal and a forward input terminal. The reverse input terminal is used to input a first control signal, and the forward input terminal is used to input a reference signal.

[0012] The comparison circuit further includes a plurality of input branches, the plurality of input branches are selectively connected to the positive input terminal, and the plurality of input branches are respectively connected to different reference signals.

[0013] The power supply circuit also includes a rectifier circuit and a filter circuit. The rectifier circuit is used to access external alternating current; the filter circuit is connected to the rectifier circuit and the power factor correction circuit respectively.

[0014] The present application provides an electronic device, which includes the above-mentioned power supply circuit.

[0015] Among them, the electronic device includes a charger.

[0016] The beneficial effects of the present application are as follows: the power supply circuit provided by the present application includes a power factor correction circuit, a power conversion circuit and a detection circuit, the power conversion circuit is connected to the power factor correction circuit, and is used to perform power conversion and generate a first control signal; the detection circuit is respectively connected to the power factor correction circuit and the power conversion circuit, and is used to control the power factor correction circuit to work based on the first control signal when the rate of change of the output power of the power conversion circuit is greater than a threshold value. That is, when the rate of change of the output power of the power conversion circuit is large, the detection circuit controls the power factor correction circuit to work based on the first control signal of the power conversion circuit, improves the response speed of the power factor correction circuit, enables the storage capacitor of the power factor correction circuit to replenish energy faster, reduces the value of the voltage drop on the storage capacitor, thereby reducing the capacitance of the storage capacitor, and further reducing the size of the power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0018] Figure 1 It is a structural schematic diagram of an embodiment of a power supply circuit provided by the present application;

[0019] Figure 2 is a circuit diagram of an embodiment of a power conversion circuit provided by the present application;

[0020] Figure 3 is a structural schematic diagram of another embodiment of the power supply circuit provided by the present application;

[0021] Figure 4 is a structural schematic diagram of an embodiment of a detection circuit provided by the present application;

[0022] Figure 5 is a structural diagram of an embodiment of a comparison circuit provided by the present application;

[0023] Figure 6 is a structural schematic diagram of another embodiment of the power supply circuit provided by the present application;

[0024] Figure 7 is a circuit diagram of an embodiment of a power supply circuit provided by the present application;

[0025] Figure 8 It is the waveform of the voltage change of the storage capacitor when the load of the conventional power factor correction circuit changes in different ranges;

[0026] Fig. 9 It is a structural schematic diagram of an embodiment of an electronic device provided by the present application. DETAILED DESCRIPTION

[0027] 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 described embodiments 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 ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0029] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0030] The power supply circuit is connected to an external AC power supply, which can be a mains power supply or other AC power supply. When the load power of the power supply circuit fluctuates in a large range, for example, switching from no-load to full-load, if the loop response speed of the power factor correction circuit is slow, during the response period, the energy output is completely maintained by the storage capacitor in the power factor correction circuit, causing the voltage on the storage capacitor to drop rapidly. In order to prevent the voltage of the storage capacitor from dropping too much and affecting the normal operation of the subsequent circuit of the power factor correction circuit, a larger storage capacitor is set. However, the storage capacitor with a large capacitance value is relatively large, resulting in a larger overall size of the power supply circuit.

[0031] In order to improve the technical problem of a power supply circuit being too large in size, the present application provides a power supply circuit that can improve the response speed of a power factor correction circuit while reducing the size of the power supply circuit.

[0032] See also Figure 1 , Figure 1 is a schematic diagram of the structure of an embodiment of a power supply circuit provided by the present application, such as Figure 1 As shown, the power supply circuit 10 includes a power factor correction circuit 110, a power conversion circuit 120, a first control circuit 140 and a detection circuit 130. The power conversion circuit 120 is connected to the power factor correction circuit 110 for power conversion and generating a first control signal. The first control circuit 140 is connected to the power factor correction circuit 110 and generates a second control signal based on the output signal of the power factor correction circuit 110. The detection circuit 130 is respectively connected to the first control circuit 140, the power factor correction circuit 110 and the power conversion circuit 120, and is used to control the power factor correction circuit 110 to work based on the first control signal when the rate of change of the output power of the power conversion circuit 120 is greater than a threshold value, and to control the power factor correction circuit 110 to work based on the second control signal when the rate of change of the output power is less than or equal to the threshold value.

[0033] It can be known that the power supply circuit 10 also includes other circuits for maintaining the normal operation of the power supply circuit 10. When the power supply circuit 10 is connected to the mains, when the output signal of the power factor correction circuit 110 is used as the feedback signal for adjusting the operation of the power factor correction circuit 110, the loop response of the power factor correction circuit 110 is related to the power frequency signal of the mains; when the output signal of the power conversion circuit 120 is used as the feedback signal for adjusting the operation of the power factor correction circuit 110, the loop response of the power factor correction circuit 110 is related to the operating frequency of the power conversion circuit 120. Among them, the power frequency signal is 47-63Hz, which is a low frequency; the operating frequency of the power conversion circuit 120 is at the level of 100KHz, which is a high frequency. Based on this, the detection circuit 130 of this embodiment is used to control the operation of the power factor correction circuit 110 based on the first control signal when the rate of change of the output power of the power conversion circuit 120 is greater than the threshold, and to control the operation of the power factor correction circuit 110 based on the second control signal when the rate of change of the output power is less than the threshold. That is, when the rate of change of the output power of the power conversion circuit 120 is large, the detection circuit 130 controls the power factor correction circuit 110 to work based on the first control signal of the power conversion circuit 120, thereby improving the response speed of the power factor correction circuit 110, so that the storage capacitor of the power factor correction circuit 110 can replenish energy faster, reduce the value of the voltage drop on the storage capacitor, thereby reducing the capacitance of the storage capacitor, and further reducing the size of the power supply circuit 10. When the rate of change of the output power of the power conversion circuit 120 is small, the detection circuit 130 controls the power factor correction circuit 110 to work based on the first control signal of the power conversion circuit 120. At this time, even if the voltage of the storage capacitor drops, it will not affect the normal operation of the power factor correction circuit 110.

[0034] The rate of change of the output power is the rate of change obtained by comparing two adjacent output powers. The second control signal generated by the first control circuit 140 based on the output signal of the power factor correction circuit 110 is a conventional control signal for controlling the operation of the power factor correction circuit 110 when the load power is relatively stable. The first control signal may be associated with the rate of change of the output power, or the first control signal includes the rate of change of the output power and an adjustment signal for controlling the operation of the power factor correction circuit 110. The detection circuit 130 may obtain information on the rate of change of the output power from the first control signal, so that the detection circuit 130 controls the operation of the power factor correction circuit 110 based on the first control signal when the rate of change of the output power of the power conversion circuit 120 is greater than a threshold value, and controls the operation of the power factor correction circuit 110 based on the second control signal when the rate of change of the output power is less than a threshold value. In other embodiments, the detection circuit 130 may also obtain the rate of change of the output power and the first control signal for controlling the operation of the power factor correction circuit 110 from the power conversion circuit 120.

[0035] Among them, controlling the operation of the power factor correction circuit 110 is to control the on and off of the switch tube of the power factor correction circuit 110. Specifically, the peak value of the output signal of the power factor correction circuit 110 is changed by changing the on and off time of the switch tube. For example, the state in which the rate of change of the output power is less than or equal to the threshold is a stable state, and the state in which the rate of change of the output power is greater than the threshold is a switching state. In the stable state, the rear-stage power of the power factor correction circuit 110 is basically unchanged, and the detection circuit 130 can use the second control signal to control the operation of the power factor correction circuit 110; in the switching state, the rear-stage power of the power factor correction circuit 110 has a large range of changes, and the detection circuit 130 can use the first control signal to control the operation of the power factor correction circuit 110, so as to achieve a rapid response of the power factor correction circuit 110 and reduce the voltage drop of the storage capacitor.

[0036] Optionally, see Figure 2 , Figure 2 is a circuit diagram of an embodiment of a power conversion circuit provided by the present application, such as Figure 2 As shown, the power conversion circuit 120 includes a power conversion output circuit 121 and a second control circuit 122. Among them, the power conversion output circuit 121 is connected to the power factor correction circuit 110 for power conversion. The second control circuit 122 is respectively connected to the detection circuit 130 and the power conversion output circuit 121 for generating a first control signal. The second control circuit 122 can obtain the output power of the power conversion output circuit 121 in real time to obtain the rate of change of the output power. For example, the second control circuit 122 associates the rate of change of the output power with the adjustment signal used to control the operation of the power factor correction circuit to generate a first control signal. When the rate of change of the output power is less than or equal to the threshold, the first control signal is generated based on the invalid adjustment signal; when the rate of change of the output power is greater than the threshold, the first control signal is generated based on the valid adjustment signal. The power conversion circuit 120 of this embodiment includes a power conversion output circuit 121 and a second control circuit 122. The second control circuit 122 is used to generate the first control signal, and the change of the output power can be fed back to the detection circuit 130 in time, which can improve the response speed of the power factor correction circuit 110.

[0037] Optionally, the second control circuit 122 may also be used to control the output power of the power conversion output circuit 121 .

[0038] In other embodiments, the rate of change of the output power may also be the rate of change of the output current of the power conversion output circuit 121 , or the rate of change of the output voltage, etc.

[0039] Optionally, the power conversion output circuit 121 can be any one of LLC half-bridge resonant (LLC-HB resonant, LLC), flyback power conversion output circuit, forward power conversion output circuit, and asymmetrical half-bridge (Asymmetrical half-bridge, AHB). Among them, the flyback power conversion output circuit refers to an output circuit that uses a flyback high-frequency transformer to isolate the input and output loops. The forward power conversion output circuit refers to an output circuit that uses a forward high-frequency transformer to isolate the coupled energy. The specific type of the power conversion output circuit 121 is not limited here.

[0040] Optionally, see Figure 3 , Figure 3 is a schematic diagram of the structure of another embodiment of the power supply circuit provided by the present application, such as Figure 3 As shown, the power supply circuit 10 also includes a first acquisition circuit 150 and a second acquisition circuit 160. The first acquisition circuit 150 is connected to the power conversion output circuit 121 and the second control circuit 122 respectively, and is used to collect the output current of the power conversion output circuit 121. The second acquisition circuit 160 is connected to the power conversion output circuit 121 and the second control circuit 122 respectively, and is used to collect the output voltage of the power conversion output circuit 121. The second control circuit 122 calculates the output power according to the output voltage and the output current, and the output power change rate can be obtained based on the output power of adjacent time. Among them, the first acquisition circuit 150 and the second acquisition circuit 160 are both existing conventional circuits for collecting voltage and current. The power supply circuit 10 of this embodiment also includes the first acquisition circuit 150 and the second acquisition circuit 160, so as to collect the output voltage and output current of the power conversion output circuit 121 through different acquisition circuits, so as to achieve the purpose of the second control circuit 122 obtaining the output power of the power conversion output circuit 121.

[0041] Optionally, see Figure 4 , Figure 4 is a schematic diagram of the structure of an embodiment of a detection circuit provided by the present application, such as Figure 4As shown, the detection circuit 130 includes a judgment circuit 131 and a switch circuit 132. The judgment circuit 131 is connected to the power conversion circuit 120 and the switch circuit 132 respectively. The switch circuit 132 is also connected to the power conversion circuit 120, the first control circuit 140 and the power factor correction circuit 110 respectively. The judgment circuit 131 is used to determine the magnitude relationship between the change rate of the output power of the power conversion circuit 120 and the threshold value based on the first control signal, and control the switch circuit 132 to connect the power conversion circuit 120 with the power factor correction circuit 110 when it is determined that the change rate of the output power is greater than the threshold value, so that the first control signal of the power conversion circuit 120 controls the power factor correction circuit 110 to work. And when the judgment circuit 131 determines that the change rate of the output power is less than or equal to the threshold value, it controls the switch circuit 132 to connect the first control circuit 140 with the power factor correction circuit 110, so that the second control signal controls the power factor correction circuit 110 to work. The judgment circuit 131 may include a conventional circuit for realizing the magnitude relationship judgment of two electrical signals. For example, the judgment circuit 131 may include an optocoupler, a comparison circuit composed of an operational amplifier circuit, etc. The switch circuit 132 may be a conventional circuit composed of different switch tubes, diodes, electric control switches, etc., for accessing or conducting different branches.

[0042] The detection circuit 130 of this embodiment uses the judgment circuit 131 and the switch circuit 132 to enable the branch of the power conversion circuit 120 and the power factor correction circuit 110 to be turned on when the rate of change of the output power is greater than the threshold value, so that the first control signal of the power conversion circuit 120 controls the operation of the power factor correction circuit 110, improves the response rate of the power factor correction circuit 110, reduces the capacity of the storage capacitor of the power factor correction circuit 110, and reduces the size of the power supply circuit 10; and when the rate of change of the output power is less than or equal to the threshold value, the first control circuit 140 and the branch of the power factor correction circuit 110 are turned on, so that the second control signal controls the operation of the power factor correction circuit 110.

[0043] Optionally, the judgment circuit 131 includes a comparison circuit, the comparison circuit includes a reverse input terminal and a forward input terminal, the reverse input terminal is used to input a first control signal, and the forward input terminal is used to input a reference signal. Wherein, the reference signal can be a signal corresponding to a threshold value, the comparison circuit compares the first control signal and the reference signal, and the comparison result of the comparison circuit can be used to confirm the relationship between the rate of change of the output power and the magnitude of the threshold value. Wherein, the comparison circuit can be a conventional comparison circuit, for example, a comparison circuit formed using an operational amplifier circuit. It can be known that the judgment circuit 131 also includes other peripheral circuits for its normal operation. The judgment circuit 131 of this embodiment includes a comparison circuit, and the relationship between the rate of change of the output power and the magnitude of the threshold value is confirmed by the comparison circuit, wherein the structure of the comparison circuit is simple, which can reduce the design difficulty of the judgment circuit 131.

[0044] Optionally, see Figure 5 , Figure 5 is a schematic diagram of the structure of an embodiment of a comparison circuit provided by the present application, such as Figure 5 As shown, the comparison circuit 131a further includes a plurality of input branches, the plurality of input branches are selectively connected to the positive input terminal, and the plurality of input branches are respectively connected to different reference signals 1, reference signals 2, and reference signals 3. Different reference signals correspond to different thresholds, and the present embodiment sets a plurality of different thresholds to perform a graded design on the rate of change of the output power, so that when the rate of change of the output power is at different gears, the power factor correction circuit 110 is controlled to work by different first control signals, thereby improving the control accuracy of the power factor correction circuit 110.

[0045] Optionally, see Figure 6 to Figure 7 , Figure 6 is a structural schematic diagram of another embodiment of the power supply circuit provided by the present application, Figure 7 1 is a circuit diagram of an embodiment of a power supply circuit provided by the present application. Figure 6As shown, the power supply circuit 10 includes a rectifier circuit 170, a filter circuit 180, a power factor correction circuit 110, a power conversion circuit 120, a first acquisition circuit 150, a second acquisition circuit 160, a first control circuit 140 and a detection circuit 130. Among them, the rectifier circuit 170 is connected to the external alternating current to convert the alternating voltage into pulsating direct current. The filter circuit 180 is connected to the rectifier circuit 170 and the power factor correction circuit 110 respectively to filter out the pulsating part of the pulsating direct current. The power factor correction circuit 110, the power conversion circuit 120, the first acquisition circuit 150, the second acquisition circuit 160, the first control circuit 140 and the detection circuit 130 of this embodiment have the same working principle as the power factor correction circuit 110, the power conversion circuit 120, the first acquisition circuit 150, the second acquisition circuit 160, the first control circuit 140 and the detection circuit 130 of the above-mentioned embodiment, which will not be repeated here.

[0046] See also Figure 8 , Figure 8 It is the waveform of the voltage change of the storage capacitor C3 when the load of the conventional power factor correction circuit is in different change ranges. Among them, signal 1 is the AC input waveform; signal 2 is the working current of the power factor correction circuit 110; signal 3 is the voltage of the storage capacitor C3 of the power factor correction circuit 110; the block diagram shows that when the subsequent load of the power factor correction circuit 110 switches from no-load to full-load, the voltage of the storage capacitor C3 is decreasing (point A in the figure), and the working current of the power factor correction circuit 110 is not replenished in time during this period of time in the block diagram, resulting in a decrease in the voltage of the storage capacitor C3. After the power factor correction circuit 110 responds (point B in the figure), the power factor correction circuit 110 starts to work, the voltage of the power factor correction circuit 110 starts to replenish energy, and the voltage of the storage capacitor C3 starts to rise. Therefore, the period tA-B is the response lag time. The voltage on the storage capacitor C3 of the power factor correction circuit 110:

[0047] Vt=Vo-Io*△t / C (1)

[0048] Io is the output load of the power factor correction circuit 110, Vo is the initial steady-state voltage of the storage capacitor C3, △t is the load change maintenance time, and C is the capacitance of the storage capacitor C3. It can be seen from formula (1) that if the switched load is larger, that is, the larger Io is, the longer the switching delay time is, the smaller the capacitance of the storage capacitor C3 is, then the voltage Vt on the storage capacitor C3 at time t is lower. When Io and C are determined, △t is an adjustable variable. If the parameter △t is reduced, the capacitance of C can be reduced synchronously.

[0049] In the power supply circuit 10 of this embodiment, when the rate of change of the output power is less than or equal to the threshold value, that is, the power of the subsequent stage is basically unchanged, the detection circuit 130 controls the power factor correction circuit 110 to work based on the second control signal. When the rate of change of the output power is greater than the threshold value, that is, when the change of the power of the subsequent stage exceeds a certain threshold value, the detection circuit 130 controls the power factor correction circuit 110 to work based on the first control signal, that is, the power factor correction circuit 110 of this embodiment responds quickly from point A, and immediately replenishes energy to the storage capacitor C3, and the voltage on the storage capacitor C3 basically does not drop, so the capacitance of the storage capacitor C3 can be effectively reduced, thereby reducing the volume of the storage capacitor C3, and further reducing the volume of the power supply circuit 10.

[0050] The present application provides an electronic device, referring to Fig. 9 , Fig. 9 is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. Fig. 9 As shown, the electronic device 20 includes a power supply circuit 21, wherein the power supply circuit 21 includes the power supply circuit of any embodiment of the above-mentioned power supply circuit.

[0051] Optionally, the electronic device may be a charger, for example, a charger that meets the fast protocol, and the charger can output a voltage signal of 3.3V to 48V. In other embodiments, the electronic device may be a docking station, etc. The specific type of the electronic device is not limited here.

[0052] The above are only implementation methods of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A power supply circuit, characterized in that: include: Power factor correction circuit; A power conversion circuit, connected to the power factor correction circuit, for performing power conversion and generating a first control signal; The detection circuit is connected to the power factor correction circuit and the power conversion circuit respectively, and is used to control the operation of the power factor correction circuit based on the first control signal when the rate of change of the output power of the power conversion circuit is greater than a threshold.

2. The power supply circuit according to claim 1, characterized in that: The power conversion circuit comprises: A power conversion output circuit, connected to the power factor correction circuit, for performing power conversion; The second control circuit is connected to the detection circuit and the power conversion output circuit respectively, and is used to generate the first control signal.

3. The power supply circuit according to claim 2, characterized in that: The power supply circuit also includes: A first acquisition circuit is connected to the power conversion output circuit and the second control circuit respectively, and is used to acquire the output current of the power conversion output circuit; The second acquisition circuit is connected to the power conversion output circuit and the second control circuit respectively, and is used to acquire the output voltage of the power conversion output circuit.

4. The power supply circuit according to claim 2, characterized in that: The power conversion output circuit includes any one of a flyback power conversion output circuit, a forward power conversion output circuit, an asymmetric half-bridge or an LLC half-bridge resonance.

5. The power supply circuit according to claim 1, characterized in that: The power supply circuit also includes: A first control circuit is connected to the power factor correction circuit and the detection circuit respectively, and generates a second control signal based on an output signal of the power factor correction circuit; The detection circuit is further configured to control the operation of the power factor correction circuit based on the second control signal when the rate of change of the output power is less than the threshold.

6. The power supply circuit according to claim 5, characterized in that: The detection circuit comprises: a judgment circuit, connected to the power conversion circuit, and configured to determine a magnitude relationship between the rate of change of the output power and the threshold value based on the first control signal; The switch circuit is respectively connected to the judgment circuit, the power conversion circuit, the first control circuit and the power factor correction circuit, and the switch circuit is used to connect the power conversion circuit with the power factor correction circuit, or to connect the first control circuit with the power factor correction circuit.

7. The power supply circuit according to claim 6, characterized in that: The judgment circuit comprises: The comparison circuit comprises an inverting input terminal and a forward input terminal, wherein the inverting input terminal is used to input the first control signal, and the forward input terminal is used to input a reference signal.

8. The power supply circuit according to claim 7, characterized in that: The comparison circuit also includes a plurality of input branches, which are selectively connected to the positive input terminal and are respectively connected to different reference signals.

9. The power supply circuit according to claim 1, characterized in that: The power supply circuit also includes: A rectifier circuit for connecting to an external voltage; The filter circuit is connected to the rectifier circuit and the power factor correction circuit respectively.

10. An electronic device, characterized in that: include: The power supply circuit according to any one of claims 1 to 9.

11. The electronic device according to claim 10, characterized in that: The electronic device includes a charger.

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