Power Circuit and Charging Device

Abstract

The present application discloses a power supply circuit and a charging device. The power supply module generates a DC power supply voltage according to the AC input voltage, and the driving module boosts the power supply voltage to a rated voltage value to generate a driving voltage, so that the voltage difference between the driving voltage and the power supply voltage remains unchanged. The driving voltage acting on the switching module changes with the change of the power supply voltage. Therefore, the change of the power supply voltage does not affect the conduction of the switching module. Therefore, there is no need to perform a floating ground connection on the switching module, nor is it necessary to make the driving voltage and the power supply voltage non-common ground. The driving voltage and the power supply voltage do not need to be isolated from each other, effectively reducing the number of power supply modules required for the power supply circuit, thus reducing the volume of the power supply circuit and lowering the cost of the power supply circuit at the same time.

Description

Technical Field

[0001] This application belongs to the technical field of electronic circuits, and particularly relates to a power supply circuit and a charging device. Background Art

[0002] In a traditional power supply circuit, when the switching unit of the power supply circuit is connected in series to the positive terminal of the electrical load, the source electrode of the switching unit will change with the change of the power supply voltage. The traditional solution conducts the switching unit through a rated driving voltage. Therefore, this driving voltage needs to be non - common - ground with the power supply voltage, that is, the source electrode of the switching unit is floating - grounded. The driving power supply that is non - common - ground with the power supply voltage will increase the number of transformer components required for the power supply circuit, resulting in an increase in the volume and cost of the power supply circuit. Summary of the Invention

[0003] The purpose of this application is to provide a power supply circuit, aiming to solve the problems of large volume and high cost in traditional power supply circuits due to the need for two different power supply grounds.

[0004] The first aspect of the embodiment of this application provides a power supply circuit, including:

[0005] A power supply module configured to generate a DC power supply voltage according to an AC input voltage;

[0006] A driving module connected to the power supply module, configured to boost the power supply voltage and generate a driving voltage; wherein, the voltage difference between the driving voltage and the power supply voltage remains unchanged; and

[0007] A switching module respectively connected to the power supply module and the driving module, configured to transfer the power supply voltage to an electrical load when the driving voltage is greater than the starting voltage.

[0008] In one embodiment, the driving module includes a voltage - stabilizing component, an oscillation component, and a clamping and boosting component;

[0009] The voltage - stabilizing component is configured to step down the power supply voltage to generate a regulated voltage;

[0010] The oscillation component is connected to the voltage - stabilizing component and is configured to generate a second AC voltage according to the regulated voltage;

[0011] The clamping and boosting component is connected to the oscillation component and is configured to superimpose the second AC voltage and the power supply voltage to generate the driving voltage.

[0012] In one embodiment, the switching module includes a switching component and a control component;

[0013] The control component is configured to receive a control signal and output a cut-off signal according to the control signal;

[0014] The switch component is connected to the control component and is configured to transfer the power supply voltage to the electrical load when the cut-off signal stops being input and the drive voltage is greater than the start voltage.

[0015] In one embodiment, the power supply module includes a transformer, a first diode, and a first capacitor;

[0016] The first end of the primary winding of the transformer is connected to the first input terminal of the AC input voltage of the power supply module, the second end of the primary winding of the transformer is connected to the second input terminal of the AC input voltage of the power supply module, the first end of the secondary winding of the transformer is connected to the positive electrode of the first diode, the negative electrode of the first diode is connected to the first end of the first capacitor and is connected to the power supply voltage output terminal of the power supply module, and the second end of the secondary winding of the transformer and the second end of the first capacitor are both connected to the power ground.

[0017] In one embodiment, the voltage stabilizing component includes a first field effect transistor, a first resistor, a first voltage stabilizing diode, a second voltage stabilizing diode, and a second capacitor;

[0018] The negative electrode of the first voltage stabilizing diode, the collector of the first field effect transistor, and the first end of the first resistor are commonly connected and connected to the power supply voltage input terminal of the voltage stabilizing component, the positive electrode of the first voltage stabilizing diode, the emitter of the first field effect transistor, and the first end of the second capacitor are commonly connected and connected to the voltage stabilizing voltage output terminal of the voltage stabilizing component, the second end of the first resistor, the base of the first field effect transistor, and the negative electrode of the second voltage stabilizing diode are commonly connected, and the positive electrode of the second voltage stabilizing diode and the second end of the second capacitor are both connected to the power ground.

[0019] In one embodiment, the oscillation component includes a second resistor, a third resistor, a fourth resistor, a fifth resistor, a second field effect transistor, a third field effect transistor, a third capacitor, and a fourth capacitor;

[0020] The first ends of the second resistor, the third resistor, the fourth resistor, and the fifth resistor are commonly connected and connected to the regulated voltage input terminal of the oscillation component. The second end of the second resistor, the first end of the third capacitor, and the collector of the second field effect transistor are commonly connected. The second end of the third resistor, the base of the second field effect transistor, and the first end of the fourth capacitor are commonly connected. The second end of the fourth resistor, the second end of the third capacitor, and the base of the third field effect transistor are commonly connected. The second end of the fifth resistor, the second end of the fourth capacitor, and the collector of the third field effect transistor are commonly connected and connected to the second AC voltage output terminal of the oscillation component. The emitters of the second field effect transistor and the third field effect transistor are both connected to the power ground.

[0021] In one embodiment, the clamping boost component includes a second diode, a third diode, a fifth capacitor, and a sixth capacitor;

[0022] The first end of the fifth capacitor is connected to the second AC voltage input terminal of the clamping boost component. The second end of the fifth capacitor, the cathode of the second diode, and the anode of the third diode are commonly connected. The cathode of the third diode is connected to the first end of the sixth capacitor and connected to the drive voltage output terminal of the clamping boost component. The anode of the second diode is connected to the second end of the sixth capacitor and connected to the power voltage input terminal of the clamping boost component.

[0023] In one embodiment, the switching component includes a sixth resistor, a seventh resistor, an eighth resistor, a fourth field effect transistor, a fifth field effect transistor, and a third zener diode;

[0024] The first end of the sixth resistor is connected to the drive voltage input terminal of the switching component. The drain of the fourth field effect transistor is connected to the power voltage input terminal of the switching component. The source of the fourth field effect transistor, the first end of the seventh resistor, the first end of the eighth resistor, the anode of the third zener diode, and the source of the fifth field effect transistor are commonly connected. The second end of the sixth resistor, the gate of the fourth field effect transistor, the second end of the seventh resistor, the cathode of the third zener diode, and the gate of the fifth field effect transistor are commonly connected and connected to the cut-off signal input terminal of the switching component. The second end of the eighth resistor is connected to the power ground. The drain of the fifth field effect transistor is connected to the power voltage output terminal of the switching component.

[0025] In one embodiment, the control component includes a ninth resistor, a tenth resistor, and a sixth field effect transistor;

[0026] The first end of the ninth resistor is connected to the cut-off signal output end of the control component, the second end of the ninth resistor is connected to the collector of the sixth field effect transistor, the base of the sixth field effect transistor is connected to the first end of the tenth resistor, the second end of the tenth resistor is connected to the control signal input end of the control component, and the emitter of the sixth field effect transistor is connected to the power ground.

[0027] In the second aspect of the embodiments of the present application, a charging device is further provided, including the power supply circuit according to any one of the first aspect.

[0028] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows: The drive module boosts the power supply voltage to a rated voltage value to generate a drive voltage. Therefore, the voltage difference between the drive voltage and the power supply voltage remains unchanged. The drive voltage acting on the switch module changes with the change of the power supply voltage. Therefore, the change of the power supply voltage will not affect the conduction of the switch module. Therefore, there is no need to perform a floating ground connection on the switch module, and there is no need to make the drive voltage and the power supply voltage non-common ground. Therefore, the drive voltage and the power supply voltage do not need to be isolated from each other, reducing the number of power supply modules required for the power supply circuit. Therefore, the volume of the power supply circuit is reduced and the cost of the power supply circuit is lowered. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a first example principle block diagram of the power supply circuit provided by the embodiments of the present application;

[0030] Figure 2 It is a second example principle block diagram of the power supply circuit provided by the embodiments of the present application;

[0031] Figure 3 It is an example circuit schematic diagram of the power supply circuit provided by the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0033] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0034] Please refer to Figure 1, an embodiment of the present application provides a power supply circuit, which includes a power supply module 100, a driving module 200, and a switching module 300.

[0035] The power supply module 100 is configured to generate a DC power supply voltage according to an AC input voltage.

[0036] The driving module 200 is connected to the power supply module 100 and is configured to boost the power supply voltage and generate a driving voltage. Among them, the voltage difference between the driving voltage and the power supply voltage remains unchanged.

[0037] The switching module 300 is respectively connected to the power supply module 100 and the driving module 200, and is configured to transfer the power supply voltage to the electrical load 400 when the driving voltage is greater than the starting voltage.

[0038] In a specific application, the power supply module 100 can generate a power supply voltage after processing such as isolating and stepping down and rectifying the AC input voltage.

[0039] In this embodiment, the power supply module 100 generates a DC power supply voltage according to the AC input voltage of the external power supply and outputs it to the driving module 200. The driving module 200 boosts the power supply voltage to a rated voltage value to generate a driving voltage and outputs it to the switching module 300. When the driving voltage is greater than the starting voltage, the switching module 300 conducts and transfers the power supply voltage to the electrical load 400 to supply power to the electrical load 400.

[0040] The driving module 200 generates a driving voltage by boosting the power supply voltage to a rated voltage value. Therefore, the voltage difference between the driving voltage and the power supply voltage remains unchanged. The driving voltage acting on the switching module 300 changes with the power supply voltage. Therefore, the change of the power supply voltage will not affect the conduction of the switching module 300. Therefore, there is no need to perform a floating ground connection on the switching module 300, and there is no need to perform a non-common ground treatment on the driving voltage and the power supply voltage. The driving voltage and the power supply voltage do not need to be isolated from each other. The driving voltage can be directly provided by the power supply voltage. Therefore, applying the power supply circuit provided by the embodiment of the present application can effectively reduce the number of power supply modules 100 required for the power supply circuit, thus reducing the volume of the power supply circuit while being able to reduce the cost of the power supply circuit. Further, because the driving voltage can be obtained from the power supply voltage, the withstand voltage level of the electronic components used in the driving module 200 is reduced, the stability of the driving module 200 is improved, and the cost of the power supply circuit is further reduced.

[0041] Among them, the magnitude of the starting voltage is designed by those skilled in the art according to actual needs and is not limited herein; the electrical load 400 can be a battery. When the electrical load 400 is a battery, this power supply circuit serves as a charging circuit for the battery.

[0042] Please refer toFigure 2 In one embodiment, the driving module 200 includes a voltage stabilizing component 210, an oscillation component 220, and a clamping boost component 230.

[0043] The voltage stabilizing component 210 is configured to step down the power supply voltage to generate a regulated voltage.

[0044] The oscillation component 220 is connected to the voltage stabilizing component 210 and is configured to generate a second AC voltage according to the regulated voltage.

[0045] The clamping boost component 230 is connected to the oscillation component 220 and is configured to superimpose the second AC voltage and the power supply voltage to generate a driving voltage.

[0046] In this embodiment, the voltage stabilizing component 210 steps down the power supply voltage to generate a regulated voltage and outputs it to the oscillation component 220. The oscillation component 220 inverts the regulated voltage to generate a second AC voltage and outputs it to the clamping boost component 230. The clamping boost component 230 superimposes the second AC voltage and the power supply voltage to generate a driving voltage. Therefore, the difference between the driving voltage and the power supply current is equal to the voltage value of the second AC voltage and remains unchanged. At the same time, the voltage stabilizing component 210 steps down the power supply voltage output by the power supply module 100 to generate a regulated voltage. The second AC voltage is generated from the regulated voltage. The driving voltage is formed by superimposing the power supply voltage and the second AC voltage. Therefore, the voltage stabilizing component 210, the oscillation component 220, and the clamping boost component 230 are all isolated from the AC input voltage.

[0047] Among them, the second AC voltage is a square wave voltage.

[0048] Please refer to Figure 2 In one embodiment, the switch module 300 includes a switch component 310 and a control component 320.

[0049] The control component 320 is configured to receive a control signal and output a cut-off signal according to the control signal.

[0050] / The switch component 310 is connected to the control component 320 and is configured to transfer the power supply voltage to the electrical load 400 when the cut-off signal stops being input and the driving voltage is greater than the starting voltage.

[0051] In this embodiment, when the control component 320 does not receive the control signal output by the external control signal output module 500, the control component 320 does not output a cut-off signal to the switch component 310. On the premise that no cut-off signal is input and the input drive voltage is greater than the start-up voltage, the switch component 310 conducts and transfers the power supply voltage to the electrical load 400. When it is necessary to stop supplying power to the electrical load 400, a control signal is input to the control component 320 so that the control component 320 outputs a cut-off signal to the switch component 310. When the cut-off signal is input, the switch component 310 changes from the conducting state to the cut-off state and stops transferring the power supply voltage to the electrical load 400.

[0052] Please refer to Figure 3 , in one embodiment, the power supply module 100 includes a transformer T1, a first diode D1, and a first capacitor C1.

[0053] The first end of the primary winding of the transformer T1 is connected to the first input terminal of the AC input voltage of the power supply module 100, the second end of the primary winding of the transformer T1 is connected to the second input terminal of the AC input voltage of the power supply module 100, the first end of the secondary winding of the transformer T1 is connected to the positive electrode of the first diode D1, the negative electrode of the first diode D1 is connected to the first end of the first capacitor C1 and is connected to the power supply voltage output terminal of the power supply module 100, and the second end of the secondary winding of the transformer T1 and the second end of the first capacitor C1 are both connected to the power ground.

[0054] Please refer to Figure 3 , in one embodiment, the voltage stabilizing component 210 includes a first field effect transistor Q1, a first resistor R1, a first zener diode ZD1, a second zener diode ZD2, and a second capacitor C2.

[0055] The negative electrode of the first zener diode ZD1, the collector of the first field effect transistor Q1, and the first end of the first resistor R1 are commonly connected and connected to the power supply voltage input terminal of the voltage stabilizing component 210. The positive electrode of the first zener diode ZD1, the emitter of the first field effect transistor Q1, and the first end of the second capacitor C2 are commonly connected and connected to the regulated voltage output terminal of the voltage stabilizing component 210. The second end of the first resistor R1, the base of the first field effect transistor Q1, and the negative electrode of the second zener diode ZD2 are commonly connected, and the positive electrode of the second zener diode ZD2 and the second end of the second capacitor C2 are both connected to the power ground.

[0056] Please refer to Figure 3 , in one embodiment, the oscillation component 220 includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a second field effect transistor Q2, a third field effect transistor Q3, a third capacitor C3, and a fourth capacitor C4.

[0057] The first ends of the second resistor R2, the third resistor R3, the fourth resistor R4, and the fifth resistor R5 are commonly connected and connected to the regulated voltage input terminal of the oscillation component 220. The second end of the second resistor R2, the first end of the third capacitor C3, and the collector of the second field effect transistor Q2 are commonly connected. The second end of the third resistor R3, the base of the second field effect transistor Q2, and the first end of the fourth capacitor C4 are commonly connected. The second end of the fourth resistor R4, the second end of the third capacitor C3, and the base of the third field effect transistor Q3 are commonly connected. The second end of the fifth resistor R5, the second end of the fourth capacitor C4, and the collector of the third field effect transistor Q3 are commonly connected and connected to the second AC voltage output terminal of the oscillation component 220. The emitters of the second field effect transistor Q2 and the third field effect transistor Q3 are both connected to the power supply ground.

[0058] Please refer to Figure 3 , in one embodiment, the clamping boost component 230 includes a second diode D2, a third diode D3, a fifth capacitor C5, and a sixth capacitor C6.

[0059] The first end of the fifth capacitor C5 is connected to the second AC voltage input terminal of the clamping boost component 230. The second end of the fifth capacitor C5, the negative electrode of the second diode D2, and the positive electrode of the third diode D3 are commonly connected. The negative electrode of the third diode D3 is connected to the first end of the sixth capacitor C6 and connected to the drive voltage output terminal of the clamping boost component 230. The positive electrode of the second diode D2 is connected to the second end of the sixth capacitor C6 and connected to the power supply voltage input terminal of the clamping boost component 230.

[0060] Please refer to Figure 3 , in one embodiment, the switch component 310 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a fourth field effect transistor Q4, a fifth field effect transistor Q5, and a third zener diode ZD3.

[0061] The first end of the sixth resistor R6 is connected to the drive voltage input terminal of the switch component 310. The drain of the fourth field effect transistor Q4 is connected to the power supply voltage input terminal of the switch component 310. The source of the fourth field effect transistor Q4, the first end of the seventh resistor R7, the first end of the eighth resistor R8, the positive electrode of the third zener diode ZD3, and the source of the fifth field effect transistor Q5 are commonly connected. The second end of the sixth resistor R6, the gate of the fourth field effect transistor Q4, the second end of the seventh resistor R7, the negative electrode of the third zener diode ZD3, and the gate of the fifth field effect transistor Q5 are commonly connected and connected to the cut-off signal input terminal of the switch component 310. The second end of the eighth resistor R8 is connected to the power supply ground. The drain of the fifth field effect transistor Q5 is connected to the power supply voltage output terminal of the switch component 310.

[0062] Please refer to Figure 3, in one embodiment, the control component 320 includes a ninth resistor R9, a tenth resistor R10, and a sixth field effect transistor Q6.

[0063] The first end of the ninth resistor R9 is connected to the cut-off signal output end of the control component 320. The second end of the ninth resistor R9 is connected to the collector of the sixth field effect transistor Q6. The base of the sixth field effect transistor Q6 is connected to the first end of the tenth resistor R10. The second end of the tenth resistor R10 is connected to the control signal input end of the control component 320. The emitter of the sixth field effect transistor Q6 is connected to the power ground.

[0064] The following describes the Figure 3 power supply circuit shown in conjunction with the working principle:

[0065] The primary winding of transformer T1 is used to connect to an external power supply, and transformer T1 steps down the AC input voltage to generate a third AC voltage. The first diode D1 rectifies the third AC voltage to generate a DC power supply voltage. The first zener diode ZD1, the second zener diode ZD2, and the first resistor R1 jointly limit the regulated voltage at the emitter of the first field-effect transistor Q1, such that the regulated voltage at the emitter of the first field-effect transistor Q1 is equal to the breakdown voltage of the second zener diode ZD2, and the regulated voltage at the emitter of the first field-effect transistor Q1 is equal to the power supply voltage minus the breakdown voltage of the first zener diode ZD1, thereby making the regulated voltage at the emitter of the first field-effect transistor Q1 at a stable value. For example, when the power supply voltage is 48V, the breakdown voltage of the first zener diode ZD1 is 18V, and the breakdown voltage of the second zener diode ZD2 is 30V, at this time the regulated voltage at the emitter of the first field-effect transistor Q1 is 18V. The regulated voltage becomes a square-wave voltage (second AC voltage) after passing through the oscillation component 220 composed of the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the second field-effect transistor Q2, the third field-effect transistor Q3, the third capacitor C3, and the fourth capacitor C4. When the voltage value of the square-wave voltage is at the trough, the third field-effect transistor Q3 conducts, and the power supply voltage charges the fifth capacitor C5, making the voltage at the second terminal of the fifth capacitor C5 become the power supply voltage. When the voltage value of the square-wave voltage is at the peak, the third field-effect transistor Q3 turns off, and the square-wave voltage acts on the first terminal of the fifth capacitor C5. Because the voltage of the capacitor cannot change suddenly, at this time the voltage at the second terminal of the fifth capacitor C5 is equal to the square-wave voltage plus the power supply voltage, and the voltage at the first terminal of the sixth capacitor C6 (drive voltage) is also equal to the square-wave voltage plus the power supply voltage. At this time, the voltage at the first terminal of the sixth capacitor C6 acts on the sixth resistor R6, the seventh resistor R7, and the eighth resistor R8, and the voltage division of the seventh resistor R7 is greater than the conduction voltages of the fourth field-effect transistor Q4 and the fifth field-effect transistor Q5 respectively. Therefore, the fourth field-effect transistor Q4 and the fifth field-effect transistor Q5 conduct. The voltage division of the seventh resistor R7 is positively correlated with the drive voltage. Therefore, the voltage division of the seventh resistor R7 changes with the change of the power supply voltage. After the voltage division of the seventh resistor R7 is greater than the conduction voltages of the fourth field-effect transistor Q4 and the fifth field-effect transistor Q5, as the power supply voltage increases, the voltage division of the seventh resistor R7 also increases. Therefore, the fourth field-effect transistor Q4 and the fifth field-effect transistor both remain conducting. The third zener diode ZD3 ensures that the voltage division of the seventh resistor R7 will not exceed the breakdown voltage of the third zener diode ZD3. Therefore, it can protect the gate-source voltages of the fourth field-effect transistor Q4 and the fifth field-effect transistor Q5 from exceeding the breakdown voltage of the third zener diode ZD3, playing a protective role for the fourth field-effect transistor Q4 and the fifth field-effect transistor Q5. At this time, the power supply voltage OUT output by the first diode D1 is output to the electrical load through the fourth field-effect transistor Q4 and the fifth field-effect transistor Q5.The negative electrode of the electrical load is connected to the power supply ground.

[0066] When it is necessary to stop outputting the power supply voltage OUT to the electrical load, a high-level signal is input to the base of the sixth field-effect transistor Q6 to turn on the sixth field-effect transistor Q6. At this time, the gates of the fourth field-effect transistor Q4 and the fifth field-effect transistor Q5 are both connected to the power supply ground through the fourth field-effect transistor Q4, and the fourth field-effect transistor and the fifth field-effect transistor Q5 are both turned off to stop outputting the power supply voltage to the electrical load.

[0067] The driving voltage of the power supply circuit in this embodiment shares the power supply ground with the power supply voltage, and there is no need to isolate the driving voltage from the power supply voltage. Therefore, a transformer T1 can be shared to obtain electrical energy from the AC input voltage. Compared with the power supply circuit that needs to isolate the driving voltage and the power supply voltage, the volume is reduced, the cost is lowered, and the power consumption is reduced. At the same time, the power supply circuit in this embodiment does not use optocouplers. The fourth field-effect transistor Q4 and the fifth field-effect transistor Q5 are used for control, further reducing the cost.

[0068] The embodiment of the present application also provides a charging device, including the power supply circuit of any of the above embodiments. Since the charging device of this embodiment includes the power supply circuit of any of the above embodiments, the charging device of this embodiment at least includes the beneficial effects corresponding to the power supply circuit of any of the above embodiments.

[0069] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the above-mentioned division of each functional unit and module is used as an example. In actual applications, the above-mentioned functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction and do not limit the protection scope of the present application. The specific working processes of the units and modules in the above system can refer to the corresponding processes in the foregoing method embodiments and will not be repeated here.

[0070] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0071] Those of ordinary skill in the art will appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of this application.

[0072] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included in the protection scope of this application.

Claims

1. A power supply circuit, characterized in that, Comprising: A power supply module configured to generate a DC power supply voltage based on an AC input voltage; A driving module connected to the power supply module and configured to boost the power supply voltage to a rated voltage value and generate a driving voltage; wherein, the voltage difference between the driving voltage and the power supply voltage remains unchanged; and A switching module respectively connected to the power supply module and the driving module and configured to transfer the power supply voltage to an electrical load when the driving voltage is greater than a starting voltage; The driving module includes a voltage stabilizing component, an oscillating component, and a clamping and boosting component; The voltage stabilizing component is configured to step down the power supply voltage to generate a stabilized voltage; The oscillating component is connected to the voltage stabilizing component and configured to generate a second AC voltage based on the stabilized voltage; The clamping and boosting component is connected to the oscillating component and configured to superimpose the second AC voltage and the power supply voltage to generate the driving voltage.

2. The power supply circuit according to claim 1, wherein, The switching module includes a switching component and a control component; The control component is configured to receive a control signal and output a cut-off signal according to the control signal; The switching component is connected to the control component and configured to transfer the power supply voltage to the electrical load when the cut-off signal is not input and the driving voltage is greater than the starting voltage.

3. The power supply circuit according to claim 1, wherein The power supply module includes a transformer, a first diode, and a first capacitor; A first end of a primary winding of the transformer is connected to a first input terminal of the AC input voltage of the power supply module, a second end of the primary winding of the transformer is connected to a second input terminal of the AC input voltage of the power supply module, a first end of a secondary winding of the transformer is connected to a positive electrode of the first diode, a negative electrode of the first diode is connected to a first end of the first capacitor and connected to a power supply voltage output terminal of the power supply module, and a second end of the secondary winding of the transformer and a second end of the first capacitor are both connected to a power supply ground.

4. The power supply circuit according to claim 1, characterized in that, The voltage stabilizing component includes a first field effect transistor, a first resistor, a first zener diode, a second zener diode, and a second capacitor; A negative electrode of the first zener diode, a collector of the first field effect transistor, and a first end of the first resistor are commonly connected and connected to a power supply voltage input terminal of the voltage stabilizing component, a positive electrode of the first zener diode, an emitter of the first field effect transistor, and a first end of the second capacitor are commonly connected and connected to a stabilized voltage output terminal of the voltage stabilizing component, a second end of the first resistor, a base of the first field effect transistor, and a negative electrode of the second zener diode are commonly connected, and a positive electrode of the second zener diode and a second end of the second capacitor are both connected to a power supply ground.

5. The power supply circuit according to claim 1, characterized in that, The oscillating component includes a second resistor, a third resistor, a fourth resistor, a fifth resistor, a second field effect transistor, a third field effect transistor, a third capacitor, and a fourth capacitor; The first ends of the second resistor, the third resistor, the fourth resistor, and the fifth resistor are commonly connected and connected to the regulated voltage input terminal of the oscillation component. The second ends of the second resistor, the first end of the third capacitor, and the collector of the second field effect transistor are commonly connected. The second ends of the third resistor, the base of the second field effect transistor, and the first end of the fourth capacitor are commonly connected. The second ends of the fourth resistor, the second end of the third capacitor, and the base of the third field effect transistor are commonly connected. The second ends of the fifth resistor, the second end of the fourth capacitor, and the collector of the third field effect transistor are commonly connected and connected to the second AC voltage output terminal of the oscillation component. The emitters of the second field effect transistor and the third field effect transistor are both connected to the power ground.

6. The power supply circuit according to claim 1, wherein, The clamping boost component includes a second diode, a third diode, a fifth capacitor, and a sixth capacitor; The first end of the fifth capacitor is connected to the second AC voltage input terminal of the clamping boost component. The second end of the fifth capacitor, the negative electrode of the second diode, and the positive electrode of the third diode are commonly connected. The negative electrode of the third diode is connected to the first end of the sixth capacitor and connected to the drive voltage output terminal of the clamping boost component. The positive electrode of the second diode is connected to the second end of the sixth capacitor and connected to the power voltage input terminal of the clamping boost component.

7. The power supply circuit according to claim 2, characterized in that, The switching component includes a sixth resistor, a seventh resistor, an eighth resistor, a fourth field effect transistor, a fifth field effect transistor, and a third zener diode; The first end of the sixth resistor is connected to the drive voltage input terminal of the switching component. The drain of the fourth field effect transistor is connected to the power voltage input terminal of the switching component. The source of the fourth field effect transistor, the first end of the seventh resistor, the first end of the eighth resistor, the positive electrode of the third zener diode, and the source of the fifth field effect transistor are commonly connected. The second end of the sixth resistor, the gate of the fourth field effect transistor, the second end of the seventh resistor, the negative electrode of the third zener diode, and the gate of the fifth field effect transistor are commonly connected and connected to the cut-off signal input terminal of the switching component. The second end of the eighth resistor is connected to the power ground. The drain of the fifth field effect transistor is connected to the power voltage output terminal of the switching component.

8. The power supply circuit according to claim 2, wherein, The control component includes a ninth resistor, a tenth resistor, and a sixth field effect transistor; The first end of the ninth resistor is connected to the cut-off signal output terminal of the control component. The second end of the ninth resistor is connected to the collector of the sixth field effect transistor. The base of the sixth field effect transistor is connected to the first end of the tenth resistor. The second end of the tenth resistor is connected to the control signal input terminal of the control component. The emitter of the sixth field effect transistor is connected to the power ground.

9. A charging device, characterized in that, It includes the power supply circuit according to any one of claims 1 to 8.

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