Charging circuit and power supply device

Abstract

The application discloses a charging circuit and a power supply device. The charging circuit comprises a first voltage dividing circuit, a second voltage dividing circuit, a driving circuit, an auxiliary power supply circuit and an auxiliary circuit; the first end of the auxiliary power supply circuit is connected with the third end of the driving circuit, and the second end is grounded; the auxiliary power supply circuit is used for external load; the auxiliary circuit is connected with both ends of the auxiliary power supply circuit and the first end of the second voltage dividing circuit; wherein, the driving circuit is turned on when the voltage of the second voltage dividing circuit is greater than the first set value, and charges the auxiliary power supply circuit; the auxiliary circuit controls the driving circuit to be turned off when the voltage of the auxiliary power supply circuit reaches the preset voltage, and stops charging the auxiliary power supply circuit. The above can reduce the energy loss of the charging circuit, improve the efficiency of the charging circuit in the steady state, and improve the portability of the charging circuit.

Description

Technical Field

[0001] This application relates to the field of electronic equipment technology, and in particular to a charging circuit and power supply device. Background Technology

[0002] With the development of technology, the types of electronic devices are increasing, such as power supplies, chargers, power strips, and small household appliances. Among them, charging circuits are widely used in electronic devices. Related technologies propose a charging circuit, but in these technologies, the charging circuit suffers from low efficiency and high energy loss during steady-state operation. Utility Model Content

[0003] The main technical problem addressed by this application is to provide a charging circuit and power supply device that can reduce energy loss in the charging circuit and improve the efficiency of the charging circuit during steady-state operation.

[0004] To address the aforementioned problems, this application provides a charging circuit comprising a first voltage divider circuit, a second voltage divider circuit, a driving circuit, an auxiliary power supply circuit, and an auxiliary power supply circuit. A first terminal of the first voltage divider circuit is connected to a power source. A first terminal of the second voltage divider circuit is connected to a second terminal of the first voltage divider circuit, and the second terminal of the second voltage divider circuit is grounded. A first terminal of the driving circuit is connected to a first terminal of the second voltage divider circuit, and a second terminal is connected to a first terminal of the first voltage divider circuit. A first terminal of the auxiliary power supply circuit is connected to a third terminal of the driving circuit, and a second terminal is grounded. The auxiliary power supply circuit is used to connect an external load. The auxiliary power supply circuit is connected to both terminals of the auxiliary power supply circuit and also to the first terminal of the second voltage divider circuit. The driving circuit conducts when the voltage of the second voltage divider circuit exceeds a first set value, charging the auxiliary power supply circuit. The auxiliary power supply circuit controls the driving circuit to shut down when the voltage of the auxiliary power supply circuit reaches a preset voltage, stopping the charging of the auxiliary power supply circuit.

[0005] In one possible implementation, the auxiliary power supply circuit includes: a third voltage divider circuit, the first terminal of which is connected to the auxiliary power supply circuit; a fourth voltage divider circuit, the first terminal of which is connected to the second terminal of the third voltage divider circuit, and the second terminal of the fourth voltage divider circuit is grounded; and a control transistor, the control terminal of which is connected to the first terminal of the fourth voltage divider circuit, the input terminal of which is connected to the first terminal of the drive circuit, and the output terminal of which is grounded; the control transistor conducts when the voltage of the fourth voltage divider circuit is greater than a second set value, shorting the drive circuit to control the drive circuit to turn off.

[0006] In one possible implementation, the control transistor is an NMOS transistor.

[0007] In one possible implementation, the driving circuit includes: a driving resistor; a driving transistor, wherein a first end of the driving resistor is connected to a first end of the second voltage divider circuit, a control end of the driving transistor is connected to a second end of the driving resistor, an input end of the driving transistor is connected to a first end of the first voltage divider circuit, and an output end of the driving transistor is connected to a first end of the auxiliary power supply circuit.

[0008] In one possible implementation, the driving transistor is an NPN transistor.

[0009] In one possible implementation, the first voltage divider circuit includes a first resistor, the second voltage divider circuit includes a second resistor, a first end of the first resistor is connected to a power supply, a second end is connected to the first end of the second resistor, a second end of the second resistor is grounded, a first end of the drive circuit is connected to the first end of the second resistor, and a second end is connected to the first end of the first resistor.

[0010] In one possible implementation, the auxiliary power supply circuit includes a power supply capacitor, with a first terminal connected to a third terminal of the drive circuit and a second terminal grounded.

[0011] In one possible implementation, the third voltage divider circuit includes a third resistor, the fourth voltage divider circuit includes a fourth resistor, the first end of the third resistor is connected to the auxiliary power supply circuit, the first end of the fourth resistor is connected to the second end of the third resistor, the second end of the fourth resistor is grounded, and the control terminal of the control transistor is connected to the first end of the fourth resistor.

[0012] In one possible implementation, the charging circuit further includes a rectifier circuit, wherein a first terminal of the first voltage divider circuit is connected to the power source via the rectifier circuit.

[0013] To address the aforementioned problems, this application also provides a power supply device that includes the aforementioned charging circuit.

[0014] The beneficial effects of this application are as follows: The charging circuit includes a driving circuit and an auxiliary power supply circuit. The driving circuit conducts when the voltage of the second voltage divider circuit is greater than a first set value, charging the auxiliary power supply circuit. The auxiliary power supply circuit controls the driving circuit to shut down when the voltage of the auxiliary power supply circuit reaches a preset voltage, stopping the charging of the auxiliary power supply circuit. This reduces the problem of continuous charging of the auxiliary power supply circuit by the driving circuit, thereby reducing the energy loss of the charging circuit and improving the efficiency of the charging circuit in steady-state operation. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a structural block diagram of one embodiment of the charging circuit of this application;

[0017] Figure 2 This is a schematic diagram of the structure of one embodiment of the charging circuit of this application.

[0018] Figure label:

[0019] 100. Charging circuit; 200. Power supply; 300. Load; 10. First voltage divider circuit; 20. Second voltage divider circuit; 30. Auxiliary power supply circuit; 31. Third voltage divider circuit; 32. Fourth voltage divider circuit; 40. Drive circuit; 50. Auxiliary power supply circuit; 11. First resistor; 21. Second resistor; 311. Third resistor; 321. Fourth resistor; 41. Drive resistor; 33. Control transistor; 42. Drive transistor; 51. Power supply capacitor. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0021] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “said,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless otherwise clearly indicated above. “Multiple” generally includes at least two, but does not exclude the inclusion of at least one.

[0022] It should be understood that the term "and / or" used herein is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Furthermore, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0023] It should be understood that the terms "comprising," "including," or any other variations used herein are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in every place in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] Existing charging circuits suffer from low efficiency and high energy loss during steady-state operation.

[0026] To address the technical problem, this application provides a charging circuit and a power supply device. The charging circuit includes a drive circuit and an auxiliary power supply circuit. When the voltage of the auxiliary power supply circuit reaches a preset voltage, the auxiliary power supply circuit can control the drive circuit to shut down, thereby improving the efficiency of the charging circuit during steady-state operation and reducing energy loss.

[0027] For ease of explanation, please refer to the following examples. Figure 1 and Figure 2 , Figure 1 This is a structural block diagram of one embodiment of the charging circuit of this application; Figure 2 This is a schematic diagram of the structure of one embodiment of the charging circuit of this application.

[0028] In one specific embodiment, the charging circuit 100 includes a first voltage divider circuit 10, a second voltage divider circuit 20, a driving circuit 40, an auxiliary power supply circuit 50, and an auxiliary power supply circuit 30. The first terminal of the first voltage divider circuit 10 is connected to a power supply 200. The first terminal of the second voltage divider circuit 20 is connected to the second terminal of the first voltage divider circuit 10, and the second terminal of the second voltage divider circuit 20 is grounded. The first terminal of the driving circuit 40 is connected to the first terminal of the second voltage divider circuit 20, and the second terminal is connected to the first terminal of the first voltage divider circuit 10. The first terminal of the auxiliary power supply circuit 50 is connected to the third terminal of the driving circuit 40, and the second terminal is grounded. The auxiliary power supply circuit 50 is used to connect an external load 300. The auxiliary power supply circuit 30 is connected to both ends of the auxiliary power supply circuit 50 and also to the first terminal of the second voltage divider circuit 20. The driving circuit 40 conducts when the voltage of the second voltage divider circuit 20 is greater than a first set value, charging the auxiliary power supply circuit 50. The auxiliary power supply circuit 30 controls the driving circuit 40 to shut down when the voltage of the auxiliary power supply circuit 50 reaches a preset voltage, stopping the charging of the auxiliary power supply circuit 50.

[0029] The first terminal of the first voltage divider circuit 10 is used to connect to the power supply 200, which can be a high-voltage mains power supply, a battery device, a generator, etc. In this embodiment, the first voltage divider circuit 10 includes a first resistor 11, and the second voltage divider circuit 20 includes a second resistor 21. On the one hand, the first voltage divider circuit 10 can be used for voltage division, which can play the role of voltage reduction protection and current limiting. On the other hand, when connecting power supplies 200 with different voltage values, the voltage division ratio can be adjusted by selecting different values ​​for the first resistor 11 and the second resistor 21. This ensures that when the charging circuit 100 is connected to different power supplies 200, the voltage on the second voltage divider circuit 20 is exactly greater than the first set value, thereby improving the portability of the charging circuit 100. In some other embodiments, the first voltage divider circuit 10 may also include a Zener diode, a fuse, etc., to further improve the protection function of the first voltage divider circuit 10. The second voltage divider circuit 20 is used to control the conduction of the drive circuit 40. The drive circuit 40 charges the auxiliary power supply circuit 50 when it is on, and also stops charging the auxiliary power supply circuit 50 when it is off. In this embodiment, the drive circuit 40 implements the drive control function by setting a transistor. In some other embodiments, the drive circuit 40 can also implement the drive control function by setting an integrated switching chip. The auxiliary power supply circuit 50 is used to connect an external load 300 to charge the load 300. Related technologies propose a charging circuit where, after the auxiliary power supply circuit reaches a preset voltage and the charging circuit is in steady-state operation, the drive circuit remains on. The long-term on-state of the drive circuit causes the auxiliary power supply circuit to continuously charge, resulting in energy loss and low efficiency. To address this issue, the charging circuit 100 in this embodiment includes an auxiliary power supply circuit 30. The auxiliary power supply circuit 30 controls the drive circuit 40 to shut down when the voltage of the auxiliary power supply circuit 50 reaches a preset voltage. This reduces the problem of the drive circuit 40 remaining in a continuously conducting state and the auxiliary power supply circuit 50 continuously charging. Specifically, the auxiliary power supply circuit 30 can achieve its shut-down function by using transistors, integrated switching chips, or other similar devices.

[0030] Unlike existing technologies, this application provides a charging circuit 100, which includes a driving circuit 40 and an auxiliary power supply circuit 30. The driving circuit 40 conducts when the voltage of the second voltage divider circuit 20 is greater than a first preset value, charging the auxiliary power supply circuit 50. The auxiliary power supply circuit 30 controls the driving circuit 40 to shut down when the voltage of the auxiliary power supply circuit 50 reaches a preset voltage, stopping the charging of the auxiliary power supply circuit 50. This reduces the problem of continuous charging of the auxiliary power supply circuit 50 by the driving circuit 40, thereby reducing the energy loss of the charging circuit 100 and improving the efficiency of the charging circuit 100 in steady-state operation. On the other hand, when connecting power supplies 200 with different voltage values, by adjusting the voltage division ratio of the first voltage divider circuit 10 and the second voltage divider circuit 20, the voltage on the second voltage divider circuit 20 can be made to be exactly greater than the first preset value when the charging circuit 100 is connected to different power supplies 200, thereby improving the portability of the charging circuit 100.

[0031] In some embodiments, the auxiliary power supply circuit 30 includes a third voltage divider circuit 31, a fourth voltage divider circuit 32, and a control transistor 33. The first terminal of the third voltage divider circuit 31 is connected to the auxiliary power supply circuit 50. The first terminal of the fourth voltage divider circuit 32 is connected to the second terminal of the third voltage divider circuit 31, and the second terminal of the fourth voltage divider circuit 32 is grounded. The control terminal of the control transistor 33 is connected to the first terminal of the fourth voltage divider circuit 32, the input terminal is connected to the first terminal of the drive circuit 40, and the output terminal is grounded. The control transistor 33 conducts when the voltage of the fourth voltage divider circuit 32 is greater than a second set value, shorting the drive circuit 40 to control the drive circuit 40 to turn off.

[0032] The control transistor 33 is a switching device that changes its on and off states by the voltage change at the control terminal. When the voltage at the control terminal of the control transistor 33 reaches the second set value, the control transistor 33 is turned on. In this embodiment, the fourth voltage divider circuit 32 is connected to the control terminal of the control transistor 33. The control transistor 33 can be turned on by the voltage difference on the fourth voltage divider circuit 32. The fourth voltage divider circuit 32 and the auxiliary power supply circuit 50 are connected in parallel. The voltage across the fourth voltage divider circuit 32 is positively correlated with the voltage on the auxiliary power supply circuit 50. When the auxiliary power supply circuit 50 has not been charged to the preset voltage, the voltage on the fourth voltage divider circuit 32 is less than the second set value, so the control transistor 33 is turned off, and the current flows through the drive circuit 40 to charge the auxiliary power supply circuit 50. When the auxiliary power supply circuit 50 is charged to the preset voltage, the voltage on the fourth voltage divider circuit 32 increases to the second set value, causing the control transistor 33 to turn on. After the control transistor 33 turns on, the second voltage divider circuit 20 is short-circuited, and the voltage on the second voltage divider circuit 20 is less than the first set value, thereby turning off the drive circuit 40 and stopping the drive circuit 40 from charging the auxiliary power supply circuit 50. The above describes how the control drive circuit 40 is shut down after the voltage on the auxiliary power supply circuit 50 reaches the preset voltage and the charging circuit 100 is in steady-state operation. This reduces the energy loss of the charging circuit 100 and improves its efficiency during steady-state operation. In this embodiment, the third voltage divider circuit 31 may include a third resistor 311, and the fourth voltage divider circuit 32 may include a fourth resistor 321. The voltage division ratio can be adjusted by using different values ​​for the third resistor 311 and the fourth resistor 321, so that when the auxiliary power supply circuit 50 reaches the preset voltage, the voltage on the fourth voltage divider circuit 32 exactly reaches the second set value. Furthermore, in this embodiment, the control transistor 33 is specifically an NMOS transistor. In some other embodiments, the control transistor 33 may also be an NPN transistor, a PNP transistor, etc.

[0033] In some embodiments, the driving circuit 40 includes a driving resistor 41 and a driving transistor 42. The first end of the driving resistor 41 is connected to the first end of the second voltage divider circuit 20, the control end of the driving transistor 42 is connected to the second end of the driving resistor 41, the input end of the driving transistor 42 is connected to the first end of the first voltage divider circuit 10, and the output end of the driving transistor 42 is connected to the first end of the auxiliary power supply circuit 50.

[0034] A driving resistor 41 is connected to the control terminal of the driving transistor 42. The driving resistor 41 functions as a current limiter; by selecting different values ​​for the driving resistor 41, the current at the control terminal of the driving transistor 42 can be limited to control the charging speed of the auxiliary power supply circuit 50. The driving transistor 42 is a switching device whose on / off state is changed by voltage changes at its control terminal. When the voltage at the control terminal of the driving transistor 42 reaches a first set value, the driving transistor 42 is turned on, charging the auxiliary power supply circuit 50. Furthermore, in this embodiment, the driving transistor 42 can specifically be an NPN transistor; in some other embodiments, the driving transistor 42 can also be a PNP transistor, an NMOS transistor, etc.

[0035] In some embodiments, the first voltage divider circuit 10 includes a first resistor 11, the second voltage divider circuit 20 includes a second resistor 21, the first end of the first resistor 11 is connected to the power supply 200, the second end is connected to the first end of the second resistor 21, the second end of the second resistor 21 is grounded, the first end of the drive circuit 40 is connected to the first end of the second resistor 21, and the second end is connected to the first end of the first resistor 11.

[0036] In this embodiment, a first resistor 11 and a second resistor 21 are used to achieve a voltage divider function. By selecting different resistance values ​​for the first resistor 11 and the second resistor 21, the voltage division ratio can be adjusted, ensuring that the voltage on the second voltage divider circuit 20 is greater than a first set value when connected to different power supplies 200. In other embodiments, to further simplify the circuit, a sliding rheostat can be used to achieve the voltage division function of the first voltage divider circuit 10 and the second voltage divider circuit 20. For example, the sliding rheostat has a first fixed terminal and a second fixed terminal, and also has a sliding terminal. The first fixed terminal of the sliding rheostat is connected to the power supply 200, and the sliding terminal is connected to the first terminal of the drive circuit 40. The second terminal of the sliding rheostat is grounded, and the voltage division ratio can be adjusted by sliding the sliding terminal.

[0037] In some embodiments, the auxiliary power supply circuit 50 includes a power supply capacitor 51, with the first end of the power supply capacitor 51 connected to the third end of the drive circuit 40 and the second end grounded.

[0038] In this embodiment, a power supply capacitor 51 is provided to charge the load 300. The power supply capacitor 51 also acts as a filter, removing high-frequency signals and protecting the load 300. The auxiliary power supply circuit 50 can also be an RC circuit (resistor and capacitor circuit), an LCπ-type filter circuit (inductor and capacitor π-type filter circuit), etc. In some embodiments, the LCπ-type filter circuit can be composed of a capacitor and an inductor. Alternatively, the function of the power supply capacitor 51 can be achieved by using electronic components such as a ceramic filter. In other embodiments, a multilayer ceramic capacitor combined with a common-mode choke can be used to form the power supply 200 output connected to the load 300.

[0039] In some embodiments, the third voltage divider circuit 31 includes a third resistor 311, the fourth voltage divider circuit 32 includes a fourth resistor 321, the first end of the third resistor 311 is connected to the auxiliary power supply circuit 50, the first end of the fourth resistor 321 is connected to the second end of the third resistor 311, the second end of the fourth resistor 321 is grounded, and the control terminal of the control transistor 33 is connected to the first end of the fourth resistor 321.

[0040] In this embodiment, the third resistor 311 and the fourth resistor 321 achieve a voltage divider function. By selecting different resistance values ​​for the third resistor 311 and the fourth resistor 321, the voltage division ratio can be adjusted so that when the auxiliary power supply circuit 50 reaches a preset voltage, the voltage on the fourth voltage divider circuit 32 exactly reaches a second set value. In other embodiments, to further simplify the circuit, a sliding rheostat can be used to achieve the voltage division function of the third voltage divider circuit 31 and the fourth voltage divider circuit 32.

[0041] In some embodiments, the charging circuit 100 further includes a rectifier circuit (not shown), and the first terminal of the first voltage divider circuit 10 is connected to the power supply 200 through the rectifier circuit.

[0042] A rectifier circuit is used to convert alternating current (AC) to direct current (DC). The rectification function can be achieved using a diode bridge circuit or a single diode combined with a capacitor for filtering. For example, a rectifier circuit can use four diodes forming a bridge for rectification. In some embodiments, the rectifier circuit can also be a half-wave rectifier circuit or a full-wave rectifier circuit.

[0043] As described above, this application provides a charging circuit 100, which includes a driving circuit 40 and an auxiliary power supply circuit 30. The driving circuit 40 conducts when the voltage of the second voltage divider circuit 20 is greater than a first preset value, charging the auxiliary power supply circuit 50. The auxiliary power supply circuit 30 controls the driving circuit 40 to shut down when the voltage of the auxiliary power supply circuit 50 reaches a preset voltage, stopping the charging of the auxiliary power supply circuit 50. This reduces the problem of continuous charging of the auxiliary power supply circuit 50 by the driving circuit 40, thereby reducing the energy loss of the charging circuit 100 and improving the efficiency of the charging circuit 100 in steady-state operation. On the other hand, when connecting power supplies 200 with different voltage values, by adjusting the voltage division ratio of the first voltage divider circuit 10 and the second voltage divider circuit 20, it can be ensured that the voltage on the second voltage divider circuit 20 is exactly greater than the first preset value when the charging circuit 100 is connected to different power supplies 200, thereby improving the portability of the charging circuit 100.

[0044] Correspondingly, this application also proposes a power supply device 200, which includes the charging circuit 100 of any of the above embodiments.

[0045] Finally, in a specific application scenario, the existing charging circuit 100 has technical problems such as low efficiency and high energy loss during steady-state operation. The charging circuit 100 of this application includes a first voltage divider circuit 10, a second voltage divider circuit 20, a drive circuit 40, an auxiliary power supply circuit 50, and an auxiliary power supply circuit 30. The first terminal of the first voltage divider circuit 10 is connected to a power supply 200. The first terminal of the second voltage divider circuit 20 is connected to the second terminal of the first voltage divider circuit 10, and the second terminal of the second voltage divider circuit 20 is grounded. The first terminal of the drive circuit 40 is connected to the first terminal of the second voltage divider circuit 20, and the second terminal is connected to the first terminal of the first voltage divider circuit 10. The first terminal of the auxiliary power supply circuit 50 is connected to the third terminal of the drive circuit 40, and the second terminal is grounded. The auxiliary power supply circuit 50 is used to connect an external load 300. The auxiliary power supply circuit 30 is connected to both ends of the auxiliary power supply circuit 50 and also to the first terminal of the second voltage divider circuit 20. The drive circuit 40 conducts when the voltage of the second voltage divider circuit 20 is greater than a first set value, charging the auxiliary power supply circuit 50. The auxiliary power supply circuit 30 controls the drive circuit 40 to shut down when the voltage of the auxiliary power supply circuit 50 reaches a preset voltage, stopping the charging of the auxiliary power supply circuit 50. The auxiliary power supply circuit 30 includes: a third voltage divider circuit 31, the first terminal of which is connected to the auxiliary power supply circuit 50; a fourth voltage divider circuit 32, the first terminal of which is connected to the second terminal of the third voltage divider circuit 31, and the second terminal of the fourth voltage divider circuit 32 is grounded; and a control transistor 33, the control terminal of which is connected to the first terminal of the fourth voltage divider circuit 32, the input terminal of which is connected to the first terminal of the drive circuit 40, and the output terminal of which is grounded. The control transistor 33 conducts when the voltage of the fourth voltage divider circuit 32 is greater than a second set value, shorting the drive circuit 40 to control the drive circuit 40 to turn off. The control transistor 33 is an NMOS transistor. The drive circuit 40 includes: a drive resistor 41; and a drive transistor 42, the first terminal of which is connected to the first terminal of the second voltage divider circuit 20, the control terminal of which is connected to the second terminal of the drive resistor 41, the input terminal of which is connected to the first terminal of the first voltage divider circuit 10, and the output terminal of which is connected to the first terminal of the auxiliary power supply circuit 50. The drive transistor 42 is an NPN transistor. The first voltage divider circuit 10 includes a first resistor 11, and the second voltage divider circuit 20 includes a second resistor 21. The first end of the first resistor 11 is connected to the power supply 200, and the second end is connected to the first end of the second resistor 21. The second end of the second resistor 21 is grounded. The first end of the drive circuit 40 is connected to the first end of the second resistor 21, and the second end is connected to the first end of the first resistor 11. The auxiliary power supply circuit 50 includes a power supply capacitor 51. The first end of the power supply capacitor 51 is connected to the third end of the drive circuit 40, and the second end is grounded.The third voltage divider circuit 31 includes a third resistor 311, and the fourth voltage divider circuit 32 includes a fourth resistor 321. The first end of the third resistor 311 is connected to the auxiliary power supply circuit 50, and the first end of the fourth resistor 321 is connected to the second end of the third resistor 311. The second end of the fourth resistor 321 is grounded, and the control terminal of the control transistor 33 is connected to the first end of the fourth resistor 321. The charging circuit 100 also includes a rectifier circuit, and the first end of the first voltage divider circuit 10 is connected to the power supply 200 through the rectifier circuit.

[0046] The above are merely embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A charging circuit, characterized in that, The charging circuit includes: A first voltage divider circuit, wherein the first terminal of the first voltage divider circuit is used to connect to a power supply; A second voltage divider circuit, wherein the first terminal of the second voltage divider circuit is connected to the second terminal of the first voltage divider circuit, and the second terminal of the second voltage divider circuit is grounded; A driving circuit, wherein the first end of the driving circuit is connected to the first end of the second voltage divider circuit, and the second end is connected to the first end of the first voltage divider circuit. An auxiliary power supply circuit, wherein the first terminal of the auxiliary power supply circuit is connected to the third terminal of the drive circuit, and the second terminal is grounded; the auxiliary power supply circuit is used to connect an external load. The auxiliary power supply circuit is connected to both ends of the auxiliary power supply circuit and also to the first end of the second voltage divider circuit; The driving circuit is turned on when the voltage of the second voltage divider circuit is greater than a first set value to charge the auxiliary power supply circuit; the auxiliary power supply circuit controls the driving circuit to turn off when the voltage of the auxiliary power supply circuit reaches a preset voltage to stop charging the auxiliary power supply circuit.

2. The charging circuit according to claim 1, characterized in that, The auxiliary power circuit includes: The third voltage divider circuit, the first terminal of which is connected to the auxiliary power supply circuit; The fourth voltage divider circuit has its first terminal connected to the second terminal of the third voltage divider circuit, and its second terminal grounded. A control transistor, wherein the control terminal of the control transistor is connected to the first terminal of the fourth voltage divider circuit, the input terminal is connected to the first terminal of the drive circuit, and the output terminal is grounded; The control transistor turns on when the voltage of the fourth voltage divider circuit is greater than the second set value, shorting the drive circuit to control the drive circuit to turn off.

3. The charging circuit according to claim 2, characterized in that, The control transistor is an NMOS transistor.

4. The charging circuit according to claim 1 or 2, characterized in that, The driving circuit includes: Drive resistor; A driving transistor is provided, with the first end of the driving resistor connected to the first end of the second voltage divider circuit, the control end of the driving transistor connected to the second end of the driving resistor, the input end of the driving transistor connected to the first end of the first voltage divider circuit, and the output end of the driving transistor connected to the first end of the auxiliary power supply circuit.

5. The charging circuit according to claim 4, characterized in that, The driving transistor is an NPN type transistor.

6. The charging circuit according to claim 4, characterized in that, The first voltage divider circuit includes a first resistor, and the second voltage divider circuit includes a second resistor. The first end of the first resistor is connected to a power supply, and the second end is connected to the first end of the second resistor. The second end of the second resistor is grounded. The first end of the driving circuit is connected to the first end of the second resistor, and the second end is connected to the first end of the first resistor.

7. The charging circuit according to claim 4, characterized in that, The auxiliary power supply circuit includes a power supply capacitor, the first end of which is connected to the third end of the drive circuit, and the second end is grounded.

8. The charging circuit according to claim 2, characterized in that, The third voltage divider circuit includes a third resistor, the fourth voltage divider circuit includes a fourth resistor, the first end of the third resistor is connected to the auxiliary power supply circuit, the first end of the fourth resistor is connected to the second end of the third resistor, the second end of the fourth resistor is grounded, and the control terminal of the control transistor is connected to the first end of the fourth resistor.

9. The charging circuit according to claim 1, characterized in that, The charging circuit also includes: A rectifier circuit, wherein the first terminal of the first voltage divider circuit is connected to the power supply through the rectifier circuit.

10. A power supply device, characterized in that, The power supply device includes the charging circuit as described in any one of claims 1-9.

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