CN215378542U

CN215378542U - Charging device

Info

Publication number: CN215378542U
Application number: CN202120198409.4U
Authority: CN
Inventors: 朱锰炬
Original assignee: Shenzhen Simsukian Electronics Technology Co ltd
Current assignee: Shenzhen Simsukian Electronics Technology Co ltd
Priority date: 2021-01-25
Filing date: 2021-01-25
Publication date: 2021-12-31
Anticipated expiration: 2031-01-25

Abstract

The utility model discloses a charger, which comprises a bottom shell and a face shell which are matched with each other, wherein a first circuit board and a second circuit board are arranged in a cavity formed by the bottom shell and the face shell; the first circuit board is provided with a first circuit, and the first circuit at least comprises an input rectifying circuit and a PWM control circuit; the second circuit board is provided with a second circuit, and the second circuit at least comprises an output rectifying circuit and an output function control circuit; the bottom shell is provided with a spring sheet electrically connected with the pin, the first circuit board is in contact with and electrically connected with the spring sheet, and the second circuit board is electrically connected with the first circuit board through a transformer and is connected with a control signal welding spot. The charger of the utility model divides the charging circuit into two parts which are respectively arranged on the two circuit boards and connected by the transformer and the signal bonding pad, thus not only making the two loops mutually independent and having less electromagnetic interference, but also utilizing the advantages of the patch element, reducing the volume of the product and being less than 30 percent compared with the conventional design.

Description

Charging device

Technical Field

The utility model belongs to the technical field of electronic circuits, and particularly relates to a PD charger.

Background

In the current mobile intelligent era, and with the popularization of portable electronic products, power adapters and chargers with small volume and high power density are the future trend. In addition to electronic technology, a new layout in structure is required to achieve small volume and high power density, for example, the advantages of patch elements are utilized to reduce the volume and improve the utilization rate of space and volume.

Conventional power adapter and charger design for the technology is convenient, adopts single-sided board and plug-in components element mostly, leads to taking up most space, in order to compromise work efficiency and heat dissipation requirement simultaneously, and final space utilization is not high and final product size is very big. There are also designs using more than three types of circuit boards, which can reduce the volume of the product, but the production process becomes complicated, thereby increasing the production cost and making the space utilization still less desirable. In order to further reduce the size and improve the utilization rate of the product space, the structures of the existing charger and power adapter need to be improved.

SUMMERY OF THE UTILITY MODEL

The following presents a simplified summary of embodiments of the utility model in order to provide a basic understanding of some aspects of the utility model. It should be understood that the following summary is not an exhaustive overview of the utility model. It is not intended to determine the key or critical elements of the present invention, nor is it intended to limit the scope of the present invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

According to one aspect of the application, a charger is provided, which comprises a bottom shell with pins and a face shell matched with the bottom shell, wherein a first circuit board and a second circuit board are arranged in an accommodating cavity formed by the bottom shell and the face shell; the first circuit board is provided with a first circuit, the first circuit at least comprises an input rectifying circuit and a PWM control circuit (which can be realized by adopting a PWM IC), the input rectifying circuit is used for rectifying input alternating-current voltage, and the PWM control circuit is used for PWM control of DC-DC; the second circuit board is provided with a second circuit, the second circuit at least comprises an output rectifying circuit and an output function control circuit, and the output rectifying circuit is used for realizing the control of output voltage and current; the bottom shell is provided with an elastic sheet electrically connected with the pin, the first circuit board is in contact with and electrically connected with the elastic sheet, and the second circuit board is electrically connected with the first circuit board through a transformer and is connected with a control signal welding spot; the transformer is electrically connected with the input rectification circuit and the output rectification circuit, and the transformer is used for converting the output voltage of the input rectification circuit to the output rectification circuit under the control of the PWM control circuit.

Further, the second circuit further comprises a protocol identification circuit; the protocol identification circuit is a control circuit of output voltage and is used for performing handshake communication with load equipment connected to an output end, determining the charging requirement of the load equipment and feeding the charging requirement back to the PWM control circuit and the first circuit board.

Furthermore, the second circuit further comprises a PWM signal feedback optical coupler, the PWM signal feedback optical coupler feeds back the signal output of the protocol control chip, the PWM signal feedback optical coupler is electrically connected with the first circuit board, plays a role in insulating and isolating the electric signals of the primary end and the secondary end, and controls the PWM control circuit on the first circuit board.

Further, the output function control circuit comprises a protocol control chip and an electronic switch circuit, the electronic switch circuit is electrically connected with the protocol control chip and an output signal thereof and the PWM signal feedback optocoupler, and the protocol control chip is controlled by an output voltage switch and an output current value based on the charging requirement of the load equipment; the output rectifying circuit comprises a synchronous rectifying circuit and is used for realizing the high-efficiency conversion from AC to DC to direct-current voltage under the control. The secondary end of the transformer is electrically connected to the synchronous rectification circuit of the output rectification circuit, so that AC-DC conversion for completing PWM control is formed, and the output voltage switch and the output current value based on the charging requirement of the PWM control circuit are matched.

Furthermore, an insulating sleeve with an insulating and isolating function is arranged between the first circuit board and the second circuit board, so that the insulating distance function required by safety standards between the input end and the output end of the charger is ensured.

Furthermore, the first circuit board is sleeved with a first insulating sleeve, the second circuit board is sleeved with a second insulating sleeve, the structural shapes of the first insulating sleeve and the second insulating sleeve are designed according to the shapes of the corresponding first circuit board and the corresponding second circuit board, namely the shape and the size of the first insulating sleeve are uniquely designed based on the shape and the size of the components of the product shell and the first circuit board, and the shape and the size of the second insulating sleeve are uniquely designed based on the shape and the size of the components of the product shell and the second circuit board, so that the insulating and isolating effects completely meet the requirements of safety standards.

Furthermore, the extending direction of the plane of the first circuit board is perpendicular to the extending direction of the plane of the second circuit board.

Wherein the second circuit board is provided with a USB-A socket, a Type-C socket and other sockets.

Furthermore, the plug-in surface of the second circuit board faces the direction of the transformer on the plug-in surface of the first circuit board; the USB-A socket of the second circuit board is arranged on the plug-in surface of the second circuit board; the Type-C socket of the second circuit board is arranged on the soldering tin surface of the second circuit board.

Further, the output rectifying circuit comprises an output filter capacitor, and the output filter capacitor is arranged on the USB-A socket of the second circuit board and is installed in a horizontal mode.

The charger of the utility model divides the charging circuit into two parts which are respectively arranged on the two circuit boards and connected by the transformer and the signal bonding pad, thus not only making the two loops independent from each other and having less electromagnetic interference, but also utilizing the advantages of the patch element, reducing the volume of the product by more than 30 percent compared with the conventional design, increasing the power density to 27.0W/cubic foot and being more than twice of the charger and the adapter with the common structure. Therefore, the portable charger provides a quick charging function in advance, and improves the experience of a user.

Drawings

The utility model may be better understood by referring to the following description in conjunction with the accompanying drawings, in which like reference numerals are used throughout the figures to indicate like or similar parts. The accompanying drawings, which are incorporated in and form a part of this specification, illustrate preferred embodiments of the present invention and, together with the detailed description, serve to further explain the principles and advantages of the utility model. In the drawings:

FIG. 1 is a schematic block circuit diagram of a charger of an embodiment of the present invention;

fig. 2 is an exploded view of a charger of embodiment 1 of the present invention;

fig. 3 is an exploded view of a charger of embodiment 2 of the present invention;

FIG. 4 is a schematic diagram of a first circuit board card surface of the charger according to the embodiment of the utility model;

FIG. 5 is a schematic diagram of a first circuit board soldering surface of a charger according to an embodiment of the utility model;

FIG. 6 is a schematic diagram of a second circuit board card surface of the charger according to the embodiment of the utility model;

fig. 7 is a schematic diagram of a second circuit board soldering surface of the charger according to the embodiment of the utility model.

Detailed Description

Embodiments of the present invention will be described below with reference to the accompanying drawings. Elements and features depicted in one drawing or one embodiment of the utility model may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that the figures and description omit representation and description of components and processes that are not relevant to the present invention and that are known to those of ordinary skill in the art for the sake of clarity.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Fig. 1 is a schematic circuit block diagram of a charger according to an embodiment of the present invention, which includes an input rectifying circuit and a filter energy storage circuit P1, a transformer P2, an output rectifying circuit and a filter energy storage circuit P3, a PWM control circuit P4, an optical coupling isolation circuit P5, and a protocol identification circuit P6.

Example 1

As a specific example, refer to fig. 2, which includes a face shell 1 and a bottom shell 2 that are matched with each other, and a receiving cavity formed by covering the face shell 1 and the bottom shell 2 with each other; the accommodating cavity is internally provided with a first circuit board 3 and a second circuit board 4.

The first circuit board 3 is used as a main board, on which a first circuit is disposed, and at least includes an input rectification circuit and a PWM control circuit, which are used for rectifying an input alternating voltage and performing DC-DC PWM control, and the PWM circuit is relatively conventional and adopts a high frequency, and the switching frequency is more than 90 KH.

The second circuit board 4 is a small board, on which a second circuit is disposed, and at least includes an output rectifying circuit and an output function control circuit, and is used for controlling output voltage and current.

The bottom shell 2 is provided with a connecting piece electrically connected with the pins, and the first circuit board 3 is contacted and electrically connected with the connecting piece. The first circuit board 3 is electrically connected with the second circuit board 4 through a transformer 31 and is connected with a control signal welding spot; the transformer 31 is electrically connected to the input rectifying circuit and the output rectifying circuit, and is configured to convert the output voltage of the input rectifying circuit to the output rectifying circuit under the control of the PWM control circuit.

The input rectification circuit comprises an input patch rectifier bridge stack arranged on the first circuit board 3, and the input patch rectifier bridge stack is arranged on the soldering tin surface of the first circuit board 3.

In this embodiment, an insulating sheet 33 for insulating and isolating is provided between the first circuit board 3 and the second circuit board 4, so as to ensure the insulating distance required by the safety standard between the input end and the output end of the charger. In this embodiment, referring to fig. 2, the insulating sheet 33 is a special-shaped structure, and is sleeved outside the first circuit board 3 and the second circuit board 4, and the shape of the insulating sheet 33 is set according to the shapes of the two circuit boards, which completely meets the insulation and isolation function required by the safety standard.

Example 2

As another specific embodiment, referring to fig. 3, different from embodiment 1, the bottom case 2 is provided with elastic pieces 21 electrically connected to the pins, and the first circuit board 3 is in contact with and electrically connected to the elastic pieces 21. The first circuit board 3 is electrically connected with the second circuit board 4 through a transformer 31 and is connected with a control signal welding spot; the transformer 31 is electrically connected to the input rectifying circuit and the output rectifying circuit, and is configured to convert the output voltage of the input rectifying circuit to the output rectifying circuit under the control of the PWM control circuit.

In this embodiment, the insulating sleeves for insulating and isolating are also arranged between the first circuit board 3 and the second circuit board 4, which is different from embodiment 1 in that two insulating sleeves are arranged, the first insulating sleeve 5 is arranged outside the first circuit board 3, and the second insulating sleeve 6 is arranged outside the second circuit board 4, wherein the shapes and sizes of the first insulating sleeve 5 and the second insulating sleeve 6 are uniquely designed based on the shapes and sizes of the product housing and the elements on the first circuit board 3 and the second circuit board 4, and the insulating and isolating functions completely meet the requirements of safety standards. Referring to fig. 3, the first insulating sleeve 5 wraps the input rectifying electrolytic capacitor 32 of the first circuit board 3, and the second insulating sleeve 6 is sleeved on the second circuit board 4; the input rectifying electrolytic capacitor 32 of the first circuit board 3 is located between the second circuit board 4 and the transformer on the first circuit board 3.

As a preferred embodiment, the second circuit further comprises a protocol identification circuit, a PWM signal feedback optocoupler and an output rectifying circuit arranged on the second circuit board 4; the protocol identification circuit is a control circuit for outputting voltage, and is used for performing handshake communication with load equipment connected to the output end, determining the charging requirement of the load equipment, and feeding the charging requirement back to the PWM control circuit and the first circuit board 3.

The output function control circuit comprises a protocol control chip and an electronic switch circuit, the protocol control chip and the PWM signal feedback optocoupler are electrically connected with the electronic switch circuit, and the protocol control chip is controlled by an output voltage switch and an output current value based on the charging requirement; the output rectifying circuit also comprises a synchronous rectifying circuit which is used for realizing the high-efficiency conversion from AC to DC voltage under the control. The synchronous rectification circuit comprises a synchronous IC and a synchronous MOS tube which are arranged on the second circuit board 4, and the synchronous IC and the synchronous MOS tube are arranged on the soldering tin surface of the second circuit board 4.

The PWM signal feedback optocoupler is electrically connected with the first circuit board 3, plays a role in insulating and isolating electric signals of a primary end and a secondary end, and controls and electrically connects a PWM IC on the first circuit board 3; the secondary side of the transformer is electrically connected to a synchronous rectification circuit on the second circuit board 4. Therefore, the AC-DC conversion of PWM control is completed, and the output voltage switch and the output current value based on the charging requirement are matched with the PWM control circuit.

And the second circuit board 4 is provided with a USB-A socket, a Type-C socket and other sockets.

The extension direction of the plane of the first circuit board 3 is perpendicular to the extension direction of the plane of the second circuit board 4. The plug-in surface of the second circuit board 4 faces the direction of the transformer on the plug-in surface of the first circuit board 3; the USB-A socket of the second circuit board 4 is arranged on the plug-in surface of the second circuit board 4; the Type-C socket of the second circuit board 4 is arranged on the soldering tin surface of the second circuit board 4. The USB-a socket of the second circuit board 4 is arranged in a direction facing the transformer on the plug-in side of the first circuit board 3. The output filter capacitor of the second circuit board 4 is arranged on the USB-A socket of the second circuit board 4 in a horizontal mode.

Fig. 4 and 5 are schematic views of a plug-in surface and a soldering surface of a first circuit board in the present embodiment, respectively, and fig. 6 and 7 are schematic views of a plug-in surface and a soldering surface of a second circuit board of a charger according to an embodiment of the present invention, respectively.

Compared with various assembly modes on the market at present, the assembly mode adopting the structure has the advantages that the appearance is attractive, and the reliability is greatly improved; meanwhile, compared with a conventional circuit, the PWM control circuit adopts a high-frequency mode, so that the charger is greatly reduced in size, the power density is increased, and the experience of a user is improved. In addition, the structure assembling mode enables the compatibility control circuit of the charger to be upgraded or replaced conveniently, and the design workload and difficulty of later-stage upgrading of the charger are greatly reduced.

The input rectifying circuit and the filtering energy storage circuit P1 are used for rectifying 90-264V alternating current voltage at an AC input end into direct current voltage through the patch rectifying bridge stack, and storing energy on the filtering electrolytic capacitor. For example, an input voltage, such as 220V ac, is processed by an input rectifying circuit, converted into a pulsed dc, and then filtered by an electrolytic capacitor for energy storage. Illustratively, the input rectification circuit may include a patch bridge stack disposed on the circuit board.

The transformer P2 is used to convert the voltage of the dc power output from the input rectifying circuit to output a required voltage. The transformer 4 comprises a primary coil and a secondary coil mounted on the first circuit board 3.

The output rectifying circuit and the filtering energy storage circuit P3 are used for converting the voltage output by the transformer 4 into the voltage required by the load, and then the voltage is filtered by the electrolytic capacitor to store energy. Illustratively, the output rectifying circuit and the filter tank circuit may include a synchronous MOS transistor and a synchronous IC disposed on the second circuit board 4 and an output filter inductor.

The protocol identification circuit P6 is used for handshaking communication with the load device connected to the output terminal, determining the charging requirement of the load device, and feeding the charging requirement back to the PWM control circuit. Illustratively, the protocol identification circuit can comprise a charging protocol chip arranged on the circuit board and peripheral circuits thereof, and supports PD, QC and PIQ charging protocols.

The optical coupling isolation circuit P5 is used for signal connection of the primary side and the secondary side, and plays a role in electrical isolation to ensure safe insulation. Specifically, the electrical signals processed by the output rectifying circuit and the filtering energy storage circuit P3 and the protocol identification circuit P6 according to the charging requirement of the load device are converted by the optical-electrical signal of the optical coupling isolation circuit P5 and then transmitted to the PWM control circuit P4. Illustratively, the optical coupler isolation circuit may include an optical coupler disposed on a circuit board and peripheral circuitry thereof.

The PWM control circuit P4 controls the power signal flowing through the primary side of the transformer according to the electrical signal of the optocoupler isolation circuit P5 reflecting the charging requirement of the load device, so as to control the transformer to output the power required by the load device, and then the output rectifying circuit and the filtering energy storage circuit P3 rectify the signal and output it to the load device. In this embodiment, the PWM control circuit P4 includes a PWM IC disposed on the circuit board and a chip high voltage MOS transistor of the power switch, the chip high voltage MOS transistor is electrically connected to the primary terminal of the transformer, and the PWM IC controls the chip high voltage MOS transistor of the power switch to generate the PWM signal based on the charging requirement of the load device. The other primary winding of the transformer is electrically connected to the PWM IC for feeding back the output signal to the PWM IC.

In the present embodiment, in order to reduce the volume of the charger, the circuit of the charger is divided into two parts, the primary circuit is provided on the first circuit board 3, and the secondary circuit is provided on the second circuit board 4. The second circuit board 4 is directly inserted into the first circuit board 3 and is electrically connected through welding points; in addition, the secondary of the transformer is electrically connected to the second circuit board 4 by flying lead-out. The term "electrically connected" as used herein refers to a plug provided on one circuit board and directly inserted into a slot provided on another circuit board, so as to finally electrically connect the two circuit boards.

In order to reduce the size of the charger, the switching frequency of the PWM IC is further increased to be above 90KHz so as to reduce the size specification of the transformer, the output rectifying circuit and the filter energy storage circuit P3 elements.

In addition, the output filter capacitor is horizontally inserted above the USB-A socket so as to fully utilize the space.

The printed circuit boards of the first circuit board 3 and the second circuit board 4 adopt the process of more than double-layer boards, so that the electric connection is convenient.

In the embodiment of the present invention, the first Circuit Board 3 and the second Circuit Board 4 may be selected from a PCB (Printed Circuit Board) substrate, a ceramic substrate, a Pre-injection (Pre-mold) substrate, and the like.

In a specific embodiment, the first Circuit Board 3 and the second Circuit Board 4 are PCB (Printed Circuit Board) substrates, wherein the PCB is manufactured by processing different components and complex technologies, and the PCB has a single-layer, double-layer, and multi-layer structure, and different hierarchical structures are manufactured in different manners. Optionally, the printed circuit board is mainly composed of pads, vias, mounting holes, wire copper foils, electrical boundaries, and the like.

In order to reduce the volume of the charger, the first circuit board 3 and the second circuit board 4 are mounted with components on the plug-in surface and the soldering surface by the surface packaging technology, and the space is fully utilized. The specific mounting method may be a method commonly used in the art, for example, a SMT method such as solder paste may be used for mounting on the substrate.

Finally, in order to ensure the requirement of the safety distance, the first circuit board 3 and the second circuit board 4 are sufficiently insulated and isolated by the first insulating sleeve 5 and the second insulating sleeve 6, and the space is not wasted by a close fit mode.

In order to further reduce the volume of the charger, the first circuit board 3 and the second circuit board 4 are subjected to three-dimensional layout optimization, and the internal space of the charger can be fully utilized. In the layout, the copper foil of the PCB is utilized to help the heat dissipation of the heating element, the heat dissipation speed of the element is increased, and the solution of EMI (electromagnetic interference) and the solution of the safety distance between the original pair are facilitated.

In summary, the charger of the utility model divides the charging circuit into a primary side and a secondary side, and the two circuit boards are respectively arranged on the two circuit boards, and the two circuit boards are electrically connected with the PCB direct-insert bonding pad only through the flying wire of the transformer, so that the circuit boards of the two circuit loops are mutually independent, the electromagnetic interference between the circuit boards is greatly reduced, the advantages of the patch are fully utilized to further reduce the volume of the product, and simultaneously, the optimization of the structure is utilized, the connection distance of components is reduced, and the problems of too long interference and EMC of the feedback loop are solved. The volume of the product is greatly reduced to more than 30%, and the power density of the product can be more than 25W/cubic inch, which is close to 5 times of that of a common flyback switching power supply. Like this volume size's charger, very convenient carry has promoted user's use and has experienced the sense.

It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, elements, steps or components, but does not preclude the presence or addition of one or more other features, elements, steps or components.

While the present invention has been disclosed above by the description of specific embodiments thereof, it should be understood that all of the embodiments and examples described above are illustrative and not restrictive. Various modifications, improvements and equivalents of the utility model may be devised by those skilled in the art within the spirit and scope of the appended claims. Such modifications, improvements and equivalents are also intended to be included within the scope of the present invention.

Claims

1. A charger, characterized by: the circuit board comprises a bottom shell with pins and a face shell matched with the bottom shell, wherein a first circuit board and a second circuit board are arranged in an accommodating cavity formed by the bottom shell and the face shell;

the first circuit board is provided with a first circuit, the first circuit at least comprises an input rectifying circuit and a PWM control circuit, the input rectifying circuit is used for rectifying input alternating-current voltage, and the PWM control circuit is used for PWM control of DC-DC;

the second circuit board is provided with a second circuit, the second circuit at least comprises an output rectifying circuit and an output function control circuit, and the output rectifying circuit is used for realizing the control of output voltage and current;

the bottom shell is provided with an elastic sheet electrically connected with the pin, the first circuit board is in contact with and electrically connected with the elastic sheet, and the second circuit board is electrically connected with the first circuit board through a transformer and is connected with a control signal welding spot;

the transformer is electrically connected with the input rectification circuit and the output rectification circuit, and the transformer is used for converting the output voltage of the input rectification circuit to the output rectification circuit under the control of the PWM control circuit.

2. The charger of claim 1, wherein: the second circuit further comprises a protocol identification circuit; the protocol identification circuit is a control circuit of output voltage and is used for performing handshake communication with load equipment connected to an output end to obtain the charging requirement of the load equipment and feeding the charging requirement back to the PWM control circuit and the first circuit board.

3. The charger of claim 2, wherein: the second circuit further comprises a PWM signal feedback optical coupler, the PWM signal feedback optical coupler is electrically connected with the first circuit board, and the PWM signal feedback optical coupler is used for insulating and isolating primary end and secondary end electric signals and controlling the PWM control circuit on the first circuit board.

4. The charger of claim 3, wherein: the output function control circuit comprises a protocol control chip and an electronic switch circuit, the electronic switch circuit is electrically connected with the protocol control chip and the PWM signal feedback optocoupler, and the protocol control chip is used for controlling output voltage switching and output current value according to the charging requirement of load equipment; the output rectifying circuit comprises a synchronous rectifying circuit and is used for realizing the high-efficiency conversion from AC to DC to direct-current voltage under the control.

5. The charger according to any one of claims 1 to 4, wherein: an insulating sleeve with insulating and isolating functions is arranged between the first circuit board and the second circuit board.

6. The charger of claim 5, wherein: the first circuit board is sleeved with a first insulating sleeve, the second circuit board is sleeved with a second insulating sleeve, and the structural shapes of the first insulating sleeve and the second insulating sleeve are designed and realized according to the shapes of the corresponding first circuit board and the second circuit board.

7. The charger according to any one of claims 1 to 4, wherein: the extension direction of the plane of the first circuit board is perpendicular to the extension direction of the plane of the second circuit board.

8. The charger according to any one of claims 1 to 4, wherein: the plug-in surface of the second circuit board faces the direction of the transformer on the plug-in surface of the first circuit board; the USB-A socket of the second circuit board is arranged on the plug-in surface of the second circuit board; the Type-C socket of the second circuit board is arranged on the soldering tin surface of the second circuit board.

9. The charger of claim 1, wherein: the output rectifying circuit comprises an output filter capacitor, and the output filter capacitor is arranged on the USB-A socket of the second circuit board and is installed in a horizontal mode.