Secondary circuit, charging circuit, and charging device

Abstract

The embodiment of the utility model discloses a secondary circuit, a charging circuit and a charging device, the secondary circuit comprises a plurality of output circuits and a control circuit, the input end of each output circuit is used for being connected with a direct current bus, the output end of each output circuit is connected with an output port, and the output port is used for being connected with external equipment; the control circuit is connected with each output port and the DC bus, and is used for adjusting the bus voltage of the DC bus, so that the bus voltage corresponds to the required voltage of the external equipment, and therefore, power supply for the plurality of output ports can be realized only by arranging one rectification module without a DC-DC converter, and the power supply efficiency is improved. Therefore, the use of components in the secondary circuit can be reduced, the space occupation of the secondary circuit in the shell is reduced, the size of the shell is reduced, and the size of the charging device is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of charging, and in particular, to a secondary circuit, a charging circuit, and a charging device. Background Art

[0002] Nowadays, there is an increasing number of smart devices that need to be charged in daily life. Smart devices such as smartphones, laptops, and tablets, as well as power tools, cordless vacuum cleaners, and car vacuum cleaners that support mainstream fast charging protocols all require fast charging. Therefore, multi-port charging devices have been derived from the technology of traditional single-port charging devices. Since the required voltages of the electrical devices connected to each charging port are different, it is necessary to set up a DC-DC converter on the line corresponding to each charging port so that the output voltage of each charging port can be changed according to the required voltage of the electrical device. However, setting up more DC-DC converters will make the volume of the charging device larger, which does not conform to the development trend of miniaturization of the charging device. Summary of the Utility Model

[0003] Embodiments of the present application provide a secondary circuit, a charging circuit, and a charging device, aiming to be able to supply power to multiple output ports by only setting up one rectification module and without a DC-DC converter, thereby supplying power to multiple external devices, reducing the use of components in the secondary circuit, reducing the space occupied by the secondary circuit inside the housing, reducing the volume of the housing, and reducing the volume of the charging device.

[0004] Embodiments of the present application provide a secondary circuit, including a plurality of output circuits and a control circuit. The input end of each output circuit is used to connect to a DC bus, and the input end of each output circuit is used to connect to the DC bus. The output end of each output circuit is connected with an output port, and the output port is used to connect to an external device. When the output circuit is turned on, the DC bus is used to charge the output circuit and charge the external device. When the output circuit is turned off, the electric energy stored in the output circuit is used to charge the external device. The control circuit is connected to the output port and the output circuit, and the control circuit is used to connect to the DC bus and adjust the bus voltage of the DC bus so that the bus voltage corresponds to the required voltage of the external device connected to the output port. When a plurality of output ports are connected to external devices, the control circuit adjusts the bus voltage of the DC bus, and a plurality of output circuits are sequentially turned on one by one to charge a plurality of external devices.

[0005] An embodiment of the present application further provides a charging circuit, including a secondary circuit, a transformer, and a rectification module. The transformer has a primary winding and a secondary winding, and the primary winding and the secondary winding are coupled. The primary winding is used to connect to the mains power supply. The rectification module includes a third switching element, a fourth capacitor, and a third controller. The input end of the third switching element is connected to the positive terminal of the secondary winding, and the output end of the third switching element is connected to the DC bus. The first plate of the fourth capacitor is connected to the output end of the third switching element, and the second plate of the fourth capacitor is connected to the negative terminal of the secondary winding and grounded. The third controller is connected to the controlled end of the third switching element.

[0006] An embodiment of the present application further provides a charging device, including a housing, a circuit board, and a charging circuit. The circuit board is disposed inside the housing; the charging circuit is disposed on the circuit board.

[0007] Based on the secondary circuit of the present application, the output end of the rectification module is connected to the output circuit through the DC bus, so that after the bus voltage of the DC bus is adjusted by the controlled circuit, it can directly charge the external device connected to the output port. Compared with the technical solution provided with multiple rectification modules corresponding to the output ports and multiple DC-DC converters, the present application can set only one rectification module and does not require a DC-DC converter, and can realize the power supply to multiple output ports, thereby reducing the complexity of the secondary circuit and improving the power conversion efficiency of the charging circuit.

[0008] And because the present application does not need to set multiple rectification modules and multiple DC-DC converters, it can reduce the cost of the secondary circuit, thereby reducing the cost of the charging circuit and the charging device; it can also reduce the use of large electronic components in the charging circuit, reduce the space occupied by the electronic components in the housing, and thus can reduce the volume of the housing, so as to reduce the volume of the charging device, and further facilitate the user to use and carry the charging device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0010] Figure 1 It is a schematic structural diagram of a charging device in an embodiment of the present application;

[0011] Figure 2 It is a schematic frame structure diagram of a charging circuit in an embodiment of the present application;

[0012] Figure 3Schematic diagram of the timing of the bus voltage change of the DC bus in an embodiment of the present application;

[0013] Figure 4 Circuit diagram of the charging circuit in an embodiment of the present application;

[0014] Figure 5 Circuit diagram of the control circuit in an embodiment of the present application;

[0015] Figure 6 Circuit diagram of the control circuit in another embodiment of the present application.

[0016] Description of reference numerals: 1. Charging device; 11. Housing; 12. Circuit board; 2. Charging circuit; 21. Rectification module; 211. Transformer; 212. Third controller; 3. Secondary circuit; 31. Output circuit; 311. First controller; 32. Output port; 33. Control circuit; 331. Second controller; 332. Voltage regulation circuit; 333. Resistance circuit; 4. DC bus; Q1. First switching element; Q2. Second switching element;

[0017] Q3. Third switching element; R1. First resistor; R2. Second resistor; R3. Third resistor; R4. Fourth resistor; R5. Fifth resistor; C1. First capacitor; C2. Second capacitor; C3. Third capacitor; C4. Fourth capacitor; L1. Primary winding; L2. Secondary winding; A1. DC current source. Detailed implementation manners

[0018] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying 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.

[0019] Please refer to Figure 1 , an embodiment of the present application provides a charging device 1, including a housing 11, a circuit board 12 and a charging circuit 2.

[0020] The housing 11 can support and protect the electronic components arranged in the housing 11. The material of the housing 11 can be plastic or metal. Specifically, the material of the housing 11 can be plastic, so that the housing 11 is insulated, thereby reducing the risk of electric shock to users. And because the plastic material has a relatively light mass, the mass of the housing 11 is relatively light, so that the overall mass of the charging device 1 is relatively light, making it convenient to carry the charging device 1. Specifically, the housing 11 can be integrally injection-molded, so that the housing 11 has high structural strength, making the housing 11 not easily damaged, capable of protecting other components in the housing 11, reducing the probability of damage to other components, and thus enabling the charging device 1 to have a long service life.

[0021] The charging circuit 2 can be formed on the circuit board 12 through an etching process, thereby improving the manufacturing efficiency of the charging circuit 2 and further reducing the manufacturing cost of the charging circuit 2.

[0022] Please refer to Figure 1 and Figure 2 , in one embodiment, the charging circuit 2 includes a rectification module 21, a secondary circuit 3, and a DC bus 4.

[0023] The input end of the rectification module 21 can be connected to the mains power to access alternating current, and the output end of the rectification module 21 can output direct current to supply power to the DC bus 4.

[0024] Please refer to 2 and Figure 3 , in one embodiment, the rectification module 21 includes a transformer 211, a third switching element Q3, a fourth capacitor C4, and a third controller 212. The transformer 211 has a primary winding L1 and a secondary winding L2, and the primary winding L1 is coupled to the secondary winding L2. The primary winding L1 is connected to the input end of the rectification module 21; the input end of the third switching element Q3 is connected to the positive end of the secondary winding L2, and the output end of the third switching element Q3 is the output end of the rectification module 21; the first plate of the fourth capacitor C4 is connected to the output end of the third switching element Q3, and the second plate of the fourth capacitor C4 is connected to the negative end of the secondary winding L2 and grounded; the third controller 212 is connected to the controlled end of the third switching element Q3. By forming the rectification module 21 with the transformer 211, the third switching element Q3, and the fourth capacitor C4, and controlling the conduction and turn-off of the third switching element Q3 through the third controller 212, the rectification of alternating current can be achieved, so that the output end of the rectification module 21 can output direct current to the DC bus 4.

[0025] Exemplarily, the third switching element Q3 includes at least one of a bipolar junction transistor (BJT), a metal-oxide-semiconductor (MOS) field effect transistor, and an electromagnetic relay. In the embodiments of the present application, the specific form of the third switching element Q3 is not limited.

[0026] In other embodiments, the rectification module 21 can also be in other forms. In the embodiments of the present application, the specific form of the rectification module 21 is not limited.

[0027] The secondary circuit 3 is connected to one end of the DC bus 4, and the output end of the rectification module 21 is connected to the other end of the DC bus 4, so that the output end of the rectification module 21 can charge an external device through the DC bus 4 and the secondary circuit 3.

[0028] Please refer to 2 and Figure 3, in one embodiment, the secondary circuit 3 includes a plurality of output circuits 31 and a control circuit 33.

[0029] The input end of each output circuit 31 is connected to the DC bus 4, and an output port 32 is connected to the output end of each output circuit 31. The output port 32 is used to connect to an external device. Exemplarily, the output port 32 includes at least one of a USB-A interface, a MicroUSB interface, a USB Type-C interface, or a Lightning interface. Exemplarily, the external device includes, but is not limited to, a mobile phone, a tablet computer, and a smart watch. In the embodiment of the present application, neither the type of the output port 32 nor the type of the external device is specifically limited. In the embodiment of the present application, the output port 32 can be connected to the housing 11 and exposed, so as to facilitate the connection between the external device and the output port 32.

[0030] The control circuit 33 is connected to each output port 32 and is also connected to the DC bus 4, and is used to adjust the bus voltage of the DC bus 4 so that the bus voltage corresponds to the required voltage of the external device.

[0031] In the embodiment of the present application, the output end of the rectification module 21 is connected to the output circuit 31 through the DC bus 4, so that after the bus voltage of the DC bus 4 is adjusted by the control circuit 33, it can directly charge the external device connected to the output port 32. Compared with the technical solution in which there are multiple rectification modules 21 corresponding to the output port 32 and multiple DC-DC converters, the present application can achieve power supply to multiple output ports 32 by only setting one rectification module 21 and without a DC-DC converter, thereby reducing the complexity of the charging circuit 2 and improving the power conversion efficiency of the charging circuit 2. And because the present application does not need to set multiple rectification modules 21 and multiple DC-DC converters, the cost of the charging circuit 2 can be reduced, the cost of the charging device 1 can be reduced, and the use of relatively large electronic components in the charging circuit 2 can be reduced, and the space occupied by the electronic components in the housing 11 can be reduced, so that the volume of the housing 11 can be reduced, and the volume of the charging device 1 can be reduced, thereby facilitating the user to use and carry the charging device 1.

[0032] It can be understood that the charging device 1 involved in the present application is mainly suitable for charging mobile phones, earphones, tablet computers, smart watches, and other small external devices. For example, the charging device 1 can be a charger, a mobile power supply, a socket, etc.; and it is not suitable for charging large devices such as electric vehicles and electric scooters. For example, the charging device 1 cannot be a charging pile.

[0033] Please refer to Figure 1 and Figure 2, in one embodiment, when an external device is connected to one of the multiple output ports 32, the output circuit 31 corresponding to the output port 32 to which the external device is connected is turned on, and the control circuit 33 can adjust the bus voltage of the DC bus 4 so that the bus voltage of the DC bus 4 corresponds to the required voltage of the external device, so that the DC bus 4 can charge the external device through the output port 32.

[0034] When external devices are connected to the multiple output ports 32, the output circuits 31 corresponding to the output ports 32 to which the external devices are connected are sequentially turned on one by one, and the control circuit 33 sequentially adjusts the bus voltage according to the conduction sequence of the output circuits 31, so that the bus voltage can correspond to the required voltage of each external device, so that the DC bus 4 can charge multiple external devices through the multiple output ports 32 in sequence, thereby improving the charging efficiency of the charging device 1 for charging external devices.

[0035] Please refer to Figures 1 - 3 , for example, when three output ports 32 are connected to external devices, the three output ports 32 can be respectively the first output port, the second output port and the third output port, and the three output ports 32 are respectively connected with a first output circuit, a second output circuit and a third output circuit;

[0036] In the first preset time period t1, the first output circuit is turned on, and the second output circuit and the third output circuit are turned off. The control circuit 33 adjusts the bus voltage of the DC bus 4 to the first bus voltage VFB1 according to the charging voltage required by the external device connected to the first output port, so that the DC bus 4 can supply power to the first output port through the first output circuit, so that the first output port can charge the external device and charge the first output circuit. Before the end of the first preset time period until the start of the next first preset time period, the energy stored in the first output circuit can charge the external device through the first output port to ensure that the charging circuit 2 can continuously supply power to the first output port, thereby improving the charging efficiency of the charging device 1 for charging external devices.

[0037] In the second preset time period t2, the second output circuit is turned on, and the first output circuit and the third output circuit are turned off. The control circuit 33 adjusts the bus voltage of the DC bus 4 to the second bus voltage VFB2 according to the charging voltage required by the external device connected to the second output port, so that the DC bus 4 can supply power to the second output port through the second output circuit, so that the second output port can charge the external device and charge the second output circuit. Before the end of the second preset time period until the start of the next second preset time period, the energy stored in the second output circuit can charge the external device through the second output port.

[0038] During the third preset time period t3, the third output circuit is turned on, and the first output circuit and the second output circuit are turned off. The control circuit 33 adjusts the bus voltage of the DC bus 4 to the third bus voltage VFB3 according to the charging voltage required by the external device connected to the third output port, so that the DC bus 4 can supply power to the third output port through the third output circuit, so that the third output port can charge the external device and energize the third output circuit. Before the end of the third preset time period to the start of the next third preset time period, the energy stored in the third output circuit can charge the external device through the third output port.

[0039] The first preset time period t1, the second preset time period t2, and the third preset time period t3 are set in sequence, and the above process can be cyclically executed to output different charging powers to different output ports 32 to meet the charging requirements of different external devices.

[0040] It can be understood that the durations of the first preset time period t1, the second preset time period t2, and the third preset time period t3 can be adaptively adjusted according to the charging voltage of the external device, so as to ensure that the charging circuit 2 has a high charging efficiency for the external device. It can also be adaptively adjusted according to the energy storage capacities of the first output circuit, the second output circuit, and the third output circuit, so as to ensure that when the first output circuit, the second output circuit, and the third output circuit are turned off, the energy stored in the first output circuit, the second output circuit, and the third output circuit can respectively charge the corresponding external devices, so as to prevent the charging device 1 from discontinuing charging the external device, thereby also improving the charging efficiency of the charging device 1 for the external device.

[0041] Please refer to 2 and Figure 4 , in an embodiment, each output circuit 31 includes a first switching element Q1, a first controller 311, and a first capacitor C1. The input end of the first switching element Q1 is the input end of the output circuit 31, and the output end of the first switching element Q1 is the output end of the output circuit 31; the first controller 311 is connected to the controlled end of the first switching element Q1; the first plate of the first capacitor C1 is connected to the output end of the first switching element Q1, and the second plate of the first capacitor C1 is grounded.

[0042] When the first controller 311 detects that an external device is connected to the output port 32, the first controller 311 can control the first switching element Q1 to conduct, so that the output circuit 31 corresponding to the output port 32 is turned on, enabling the DC bus 4 to supply power to the output port 32 through the output circuit 31, so that the output port 32 can charge the external device. And when the first switching element Q1 is conducting, the DC bus 4 can also charge the first capacitor C1, so that electrical energy is stored between the first electrode plate and the second electrode plate of the first capacitor C1. Then, when the first switching element Q1 is turned off, the first capacitor C1 discharges, thereby being able to supply power to the output port 32 to charge the external device. And the first capacitor C1 can also stabilize the output voltage of the output port 32, reducing the probability of output voltage fluctuations of the output port 32, thereby reducing the probability of damage to the external device.

[0043] It can be understood that the first switching element Q1 includes at least one of a triode, a field effect transistor, and an electromagnetic relay. In the embodiments of the present application, the specific form of the first switching element Q1 is not limited.

[0044] Please refer to FIGS. 2 and Figure 4 , in one embodiment, the control circuit 33 includes a second controller 331 and a voltage regulating circuit 332. The second controller 331 is connected to each output port 32 and is used to obtain the output voltage of the corresponding output port 32. The voltage regulating circuit 332 is connected to the second controller 331 and the DC bus 4, is controlled by the second controller 331, and is used to adjust the bus voltage so that the output voltage of the output port 32 can match the supply voltage required by the external device, thereby improving the charging efficiency of the charging device 1 for charging the external device.

[0045] It can be understood that a corresponding voltage regulating circuit 332 can be provided for each output port 32. Or all the output ports 32 can share a voltage regulating circuit 332 to achieve the adjustment of the bus voltage. It can be understood that sharing a voltage regulating circuit 332 for all the output ports 32 can reduce the number of electronic components in the charging circuit 2, reducing the complexity of the charging circuit 2, thereby improving the stability of the charging circuit 2. And since the number of electronic components in the charging circuit 2 is small, the space occupied by the charging circuit 2 on the circuit board 12 can be small, making the housing 11 small, and further making the overall volume and mass of the charging device 1 small, facilitating the user to carry and use the charging device 1.

[0046] It can be understood that after the second controller 331 obtains the charging information of the external device, it can perform information interaction with the first controller 311. After the bus voltage of the DC bus 4 increases, the first controller 311 can control the first switching element Q1 to conduct, so as to supply power to the output port 32, so that the output port 32 can charge the external device. And when the first switching element Q1 conducts, the DC bus 4 can also charge the first capacitor C1, so that electrical energy is stored between the first plate and the second plate of the first capacitor C1. Then when the first switching element Q1 is turned off, the first capacitor C1 can supply power to the output port 32 to charge the external device.

[0047] It can be understood that in other embodiments, the first controller 311 and the second controller 331 can be one controller, so as to reduce the use of electronic components in the charging circuit 2, thereby further reducing the volume of the charging device 1.

[0048] Please refer to 2, Figure 4 and Figure 5 , in one embodiment, the voltage regulating circuit 332 includes a first resistor R1, a second resistor R2, and a DC current source A1. The first end of the first resistor R1 is connected to the DC bus 4, and the second end of the first resistor R1 is connected to the voltage reference terminal of the second controller 331; the first end of the second resistor R2 is connected to the second end of the first resistor R1, and the second end of the second resistor R2 is grounded; the input end of the DC current source A1 is connected to the first end of the second resistor R2, the output end of the DC current source A1 is connected to the second end of the second resistor R2, and the controlled end of the DC current source A1 is connected to the second controller 331.

[0049] When the second controller 331 detects that an external device is connected to the output port 32, the second controller 331 can perform information interaction with the external device through the output port 32. The content of the information interaction includes but is not limited to charging information such as the remaining power of the external device and the rated charging power of the external device. In other embodiments, the above process can be referred to as handshake communication between the charging device 1 and the external device. It can be understood that the second controller 331 can be a protocol chip disposed in the charging device 1, and the protocol chip is built-in with at least one charging protocol among the USB PD (Power Delivery) fast charging protocol, QC (Quick Charge) fast charging protocol, FCP (Fast Charge Protocol) protocol, SCP (Super Charge Protocol) protocol, and Mi TurboCharge protocol. In other embodiments, the charging protocols supported by the protocol chip can also include other types, which can be selected according to the applicable range of the product.

[0050] It can be understood that when the required voltage of the external device increases, the second controller 331 controls the current output by the DC current source A1 to increase; when the required voltage of the external device decreases, the second controller 331 controls the current output by the DC current source A1 to decrease.

[0051] Specifically, if the second controller 331 obtains the charging information that the required voltage of the external device increases, the second controller 331 can control the DC current source A1 to work according to the charging information, so that the current flowing through the first resistor R1 increases. Since the voltage reference terminal of the second controller 331 provides a reference voltage to the second end of the first resistor R1, the voltage at the first end of the first resistor R1 increases, and thus the bus voltage of the DC bus 4 increases; if the second controller 331 obtains the charging information that the required voltage of the external device decreases, the second controller 331 can control the DC current source A1 to work according to the charging information, so that the current flowing through the first resistor R1 decreases, thereby reducing the voltage at the first end of the first resistor R1, and thus reducing the bus voltage of the DC bus 4. In both cases, the output voltage of the output port 32 can match the required supply voltage of the external device, so as to improve the charging efficiency of the charging device 1 for the external device.

[0052] Please refer to 2, Figure 4 and Figure 5 furthermore, the voltage regulating circuit 332 further includes a second capacitor C2. The first plate of the second capacitor C2 is connected to the first end of the second resistor R2, and the second plate of the second capacitor C2 is connected to the second end of the second resistor R2, so that the voltage at the first end of the second resistor R2 is stabilized, thereby ensuring that the bus voltage of the DC bus 4 can be adjusted by adjusting the current of the DC current source A1.

[0053] Please refer to 2, Figure 4 and Figure 6 In yet another embodiment, the voltage regulating circuit 332 may include a third resistor R3, a fourth resistor R4, and a plurality of resistor circuits 333. The first end of the third resistor R3 is connected to the DC bus 4, and the second end of the third resistor R3 is connected to the voltage reference terminal of the second controller 331; the first end of the fourth resistor R4 is connected to the second end of the first resistor R1, and the second end of the fourth resistor R4 is grounded. The input end of each resistor circuit 333 is connected to the first end of the fourth resistor R4, the output end of each resistor circuit 333 is connected to the second end of the fourth resistor R4, and the controlled end of each resistor circuit 333 is connected to the second controller 331.

[0054] It can be understood that when the required voltage of the external device increases, the second controller 331 controls the total resistance value of the plurality of resistor circuits 333 to decrease; when the required voltage of the external device decreases, the second controller 331 controls the total resistance value of the resistor circuits 333 to increase.

[0055] Specifically, if the second controller 331 obtains charging information indicating an increase in the required voltage of the external device, the second controller 331 can control the corresponding resistor circuit 333 to conduct according to preset parameters, so that the total resistance of the resistor circuit 333 decreases, so that the corresponding resistor circuit 333 is connected in parallel with the fourth resistor R4, so that the total resistance in the voltage regulating circuit 332 decreases, so that the current flowing through the third resistor R3 increases. Since the voltage reference terminal of the second controller 331 provides a reference voltage to the second end of the third resistor R3, the voltage at the first end of the third resistor R3 can be increased, so that the bus voltage of the DC bus 4 increases; if the second controller 331 obtains charging information indicating a decrease in the required voltage of the external device, the second controller 331 can control the corresponding resistor circuit 333 to turn off according to preset parameters, so that the total resistance of the resistor circuit 333 increases, so that the total resistance in the voltage regulating circuit 332 increases, so that the current flowing through the third resistor R3 decreases, so that the voltage at the first end of the third resistor R3 can be decreased, so that the bus voltage of the DC bus 4 decreases. In both cases, the output voltage of the output port 32 can be matched to the supply voltage required by the external device, so as to improve the charging efficiency of the charging device 1 for the external device.

[0056] It can be understood that in other embodiments, the second controller 331 can control the resistor circuit 333 with a relatively large preset resistance value to turn off according to preset parameters, and control the resistor circuit 333 with a relatively small resistance value to conduct, so that the total resistance in the resistor circuit 333 increases; the second controller 331 can also control the resistor circuit 333 with a relatively small resistance value to turn off according to preset parameters, and control the resistor circuit 333 with a relatively large resistance value to conduct, so that the total resistance in the resistor circuit 333 decreases. In the embodiments of the present application, the adjustment method of the total resistance in the resistor circuit 333 is not limited.

[0057] Please refer to 2, Figure 4 and Figure 6, Exemplarily, the resistance circuit 333 may include a fifth resistor R5 and a second switching element Q2. The first end of the fifth resistor R5 is the input end of the resistance circuit 333; the input end of the second switching element Q2 is connected to the output end of the fifth resistor R5, the output end of the second switching element Q2 is the output end of the resistance circuit 333, and the controlled end of the second switching element Q2 is the controlled end of the resistance circuit 333. When it is necessary to boost the DC bus 4, the second controller 331 may send a conduction signal to the controlled end of the second switching element Q2 in the corresponding resistance circuit 333, so that the corresponding second switching element Q2 conducts, so that the corresponding fifth resistor R5 is connected in parallel with the fourth resistor R4, so that the total resistance in the voltage regulating circuit 332 decreases, so that the voltage at the first end of the third resistor R3 increases, so that the bus voltage of the DC bus 4 increases. When it is necessary to step down the DC bus 4, the second controller 331 may send a turn-off signal to the controlled end of the second switching element Q2 in the corresponding resistance circuit 333, so that the corresponding second switching element Q2 turns off, so that the total resistance in the voltage regulating circuit 332 increases, so that the voltage at the first end of the third resistor R3 decreases, so that the bus voltage of the DC bus 4 decreases.

[0058] It can be understood that the second switching element Q2 includes at least one of a triode, a field effect transistor, and an electromagnetic relay. In the embodiments of the present application, the specific form of the second switching element Q2 is not limited.

[0059] Please refer to 2, Figure 4 and Figure 6 , Further, the voltage regulating circuit 332 further includes a third capacitor C3. The first plate of the third capacitor C3 is connected to the first end of the fourth resistor R4, and the second plate of the third capacitor C3 is connected to the second end of the fourth resistor R4, so that the voltage at the first end of the fourth resistor R4 is stabilized, so as to ensure that the bus voltage of the DC bus 4 can be adjusted by adjusting the number of the conducting resistance circuits 333.

[0060] In other embodiments, the voltage regulating circuit 332 may also be in other forms, which will not be elaborated in detail in the embodiments of the present application.

[0061] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, it is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the accompanying drawings are only for illustrative purposes and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0062] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A secondary circuit, characterized in that, Comprising: A plurality of output circuits, the input end of each output circuit is used to connect to a DC bus, the output end of each output circuit is connected with an output port, and the output port is used to connect to an external device; when the output circuit is turned on, the DC bus is used to charge the output circuit and charge the external device; when the output circuit is turned off, the electric energy stored in the output circuit is used to charge the external device; A control circuit, connected to the output port and the output circuit, the control circuit is used to connect to the DC bus and is used to adjust the bus voltage of the DC bus so that the bus voltage corresponds to the required voltage of the external device connected to the output port; Wherein, when a plurality of the output ports are connected to the external devices, the control circuit adjusts the bus voltage of the DC bus, and a plurality of the output circuits are sequentially turned on one by one to charge a plurality of the external devices.

2. The secondary circuit according to claim 1, characterized in that, When one of the output ports is connected to the external device, the control circuit adjusts the bus voltage of the DC bus, and the corresponding output circuit is turned on to charge the external device.

3. The secondary circuit according to claim 1, wherein, Each of the output circuits includes: A first switching element, the input end of the first switching element is the input end of the output circuit, and the output end of the first switching element is the output end of the output circuit; A first controller, connected to the controlled end of the first switching element; A first capacitor, the first electrode plate of the first capacitor is connected to the output end of the first switching element, and the second electrode plate of the first capacitor is grounded.

4. The secondary circuit according to claim 1, wherein The control circuit includes: A second controller, connected to each output port, for obtaining the output voltage of the corresponding output port; A voltage regulating circuit, connected to the second controller and the DC bus, controlled by the second controller and used to adjust the bus voltage.

5. The secondary circuit according to claim 4, wherein The voltage regulating circuit includes: A first resistor, the first end of the first resistor is connected to the DC bus, and the second end of the first resistor is connected to the voltage reference end of the second controller; A second resistor, the first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is grounded; A DC current source, the input end of the DC current source is connected to the first end of the second resistor, the output end of the DC current source is connected to the second end of the second resistor, and the controlled end of the DC current source is connected to the second controller; A second capacitor, the first electrode plate of the second capacitor is connected to the first end of the second resistor, and the second electrode plate of the second capacitor is connected to the second end of the second resistor; Wherein, when the required voltage of the external device increases, the second controller is used to control the current output by the DC current source to increase; when the required voltage of the external device decreases, the second controller is used to control the current output by the DC current source to decrease.

6. The secondary circuit according to claim 4, wherein The voltage regulating circuit includes: A third resistor, the first end of the third resistor is connected to the DC bus, and the second end of the third resistor is connected to the voltage reference end of the second controller; A fourth resistor, a first end of the fourth resistor is connected to a second end of the third resistor, and a second end of the fourth resistor is grounded; A plurality of resistor circuits, an input end of each resistor circuit is connected to the first end of the fourth resistor, an output end of each resistor circuit is connected to the second end of the fourth resistor, and a controlled end of each resistor circuit is connected to the second controller; Wherein, when the required voltage of the external device increases, the second controller controls the total resistance value of the plurality of resistor circuits to decrease; when the required voltage of the external device decreases, the second controller controls the total resistance value of the plurality of resistor circuits to increase.

7. The secondary circuit according to claim 6, wherein Each of the resistor circuits includes: A fifth resistor, a first end of the fifth resistor is the input end of the resistor circuit; A second switching element, an input end of the second switching element is connected to an output end of the fifth resistor, an output end of the second switching element is the output end of the resistor circuit, and a controlled end of the second switching element is the controlled end of the resistor circuit.

8. The secondary circuit according to claim 6, wherein The voltage regulating circuit further includes: A third capacitor, a first plate of the third capacitor is connected to the first end of the fourth resistor, and a second plate of the third capacitor is connected to the second end of the fourth resistor.

9. A charging circuit, characterized in that, Comprising: The secondary circuit according to any one of claims 1 to 8; A DC bus, one end of the DC bus is connected to the secondary circuit; A rectification module, an input end of the rectification module is used to access the commercial power, an output end of the rectification module is connected to the other end of the DC bus, and the rectification module includes: A transformer having a primary winding and a secondary winding, the primary winding is coupled to the secondary winding, and the primary winding is connected to the input end of the rectification module; A third switching element, an input end of the third switching element is connected to the positive end of the secondary winding, and an output end of the third switching element is the output end of the rectification module; A fourth capacitor, a first plate of the fourth capacitor is connected to the output end of the third switching element, and a second plate of the fourth capacitor is connected to the negative end of the secondary winding and grounded; A third controller, connected to the controlled end of the third switching element.

10. A charging device, characterized in that, Comprising: A housing; A circuit board disposed inside the housing; The charging circuit according to claim 9, disposed on the circuit board.

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