WO2017219659A1 - Adapter - Google Patents

Abstract

An adapter, comprising a switching power supply module (200), a communication module (300), and a charging interface (100). The charging interface (100) is configured to connect the adapter with an electrical device; the electrical device is configured to send a power requirement protocol signal to the communication module (300); the communication module (300) is configured to receive the power requirement protocol signal and control, according to the power requirement protocol signal, the switching power supply module (200) to output a corresponding voltage and current. By means of the technical solution, the standards of various adapters on the market are unified, the applicability of the adapter is improved, resources are saved, and rapid charging is achieved.

Description

 Adapter

Technical field

The present invention relates to the field of electronic circuit technologies, and in particular, to an adapter.

Background technique

The traditional adapter can only output a constant voltage, so that the adapter can only be paired with one type of powered device. For example, the output 5V adapter can only supply power to the mobile phone; the output 12V adapter can only supply power to the TV. This has resulted in a large number of adapters for the market for electrical equipment, resulting in waste of social resources and an increase in the cost of additional adapters for electronic products.

Summary of the invention

The main object of the present invention is to provide an adapter that aims to unify the standards of various adapters on the market, improve the applicability of the adapter, and save resources.

To achieve the above object, the present invention provides an adapter including a switching power supply module, a communication module, and a charging interface;

The charging interface connects the adapter with the powered device; the powered device sends a power supply requirement protocol signal to the communication module;

The communication module receives the power supply requirement protocol signal and controls the switching power supply module to output a corresponding voltage value and current value according to the power supply demand protocol signal.

Preferably, the adapter further includes a discharge module; when the charging interface pulls out the power device, the communication module controls the discharge module to be turned on, and discharges the switch power module.

Preferably, the switching power supply module includes a power management circuit, a switch circuit, a transformer, a constant voltage control circuit, a first rectification filter circuit, and a second rectification filter circuit; the transformer includes a primary coil and a secondary coil; a driving end of the circuit is connected to the controlled end of the switching circuit, a feedback end of the power management circuit is connected to an output end of the constant voltage control circuit; an output end of the switching circuit is connected to a primary winding of the transformer The first end is connected, the input end of the switch circuit is grounded; the input end of the first rectifying and filtering circuit is connected to the mains, the output end of the first rectifying and filtering circuit and the second end of the primary coil of the transformer Connecting; the input ends of the second filter rectifier circuit are respectively connected to the first end and the second end of the secondary coil, and the output end of the second rectification filter circuit is connected to the charging interface; the constant voltage control circuit The sampling end is connected to the output end of the second rectifying filter circuit; the regulating end of the constant voltage control circuit is connected to the output end of the communication module.

Preferably, the charging interface is a USB Type-C interface.

Preferably, the second rectifying and filtering circuit includes a first diode, a first inductor, a first capacitor, and a second capacitor; an anode of the first diode is connected to a first end of the secondary coil, a cathode of the first diode is connected to the first end of the inductor; a second end of the first inductor is connected to the charging interface; a first end of the first capacitor and the first inductor The first end of the first capacitor is connected to the ground, the second end of the second capacitor is connected to the second end of the first capacitor, and the second end of the second capacitor is grounded.

Preferably, the constant voltage control circuit includes an optical coupler, a first resistor, a second resistor, a third resistor, a fourth resistor, and a voltage reference chip; an execution input end of the optocoupler and the power management circuit a feedback end connection, the output end of the optical coupler is grounded; a first end of the first resistor is coupled to a cathode of the first diode, and a second end of the first resistor is via the a second resistor is connected to the output end of the voltage reference chip; a first end of the third resistor is connected to the second end of the first inductor, and a second end of the third resistor is grounded via the fourth resistor The input end of the voltage reference chip is grounded, the reference end of the voltage reference chip is connected to the second end of the third resistor; the control input end of the optical coupler and the second end of the first resistor Connected, the control output of the optocoupler is coupled to the second end of the third resistor.

Preferably, the constant voltage control circuit further includes a fifth resistor and a third capacitor; a first end of the fifth resistor is connected to an output end of the voltage reference chip, and a second end of the fifth resistor is a first end of the third capacitor is connected, a second end of the third capacitor is connected to a second end of the third resistor; an output end of the voltage reference chip is further connected to a control output of the optocoupler connection.

Preferably, the communication module includes a communication control chip, a sixth resistor, and a seventh resistor; the communication control chip includes a first signal input end, a second signal input end, a first detection end, a second detection end, and a first An adjustment end and a second adjustment end; the first signal input end and the second signal input end of the communication control chip are both grounded, and the sixth resistor is connected to the first signal input end and the second signal input end The first detecting end and the second signal detecting end of the communication control chip are both connected to the charging interface; the first adjusting end is connected to the control input end of the optical coupler, and the second adjustment The terminal is connected to the control output of the optical coupler via the seventh resistor.

Preferably, the communication module reads the power of the power device, and adjusts the output power of the power module according to the power consumption of the power device.

Preferably, the adapter further includes a protection module, an input end of the protection module is connected to the output end of the second rectifying and filtering circuit, an output end of the protection module is connected to the charging interface, and the protection module is The control terminal is connected to the control end of the communication module.

Preferably, the protection module includes a first MOS transistor and a second MOS transistor, and the communication control chip further includes a second driving end, a third driving end, a power input end, and a detecting control end; a gate is connected to the second driving end, a source of the first MOS transistor is connected to a second end of the first inductor, and a drain of the first MOS transistor and a drain of the second MOS transistor a pole connection; a source of the second MOS transistor is connected to the charging interface, a gate of the second MOS transistor is connected to the third driving end; and the power input end and the first MOS transistor The source is connected, and the detection control terminal is connected to the drain of the second MOS transistor.

Preferably, the discharge module includes an eighth resistor, a ninth resistor, a tenth resistor, and a triode, and the communication control chip further includes a first driving end; a base of the triode is connected to the first driving end, The emitter of the triode is grounded; the first end of the eighth resistor is connected to the second end of the first inductor, and the second end of the eighth resistor is connected to the collector of the triode; The nine resistors and the tenth resistor are both connected in parallel between the first end of the eighth resistor and the second end of the eighth resistor.

Preferably, the switching power supply module further includes an EMI filter circuit and an AC input plug, wherein an input end of the EMI filter circuit is electrically connected to the AC input plug, and an output end of the EMI filter circuit and the first rectification filter Circuit connection.

The technical solution of the present invention forms an adapter by setting a charging interface, a communication module, and a switching power supply module. The charging module reads the charging voltage value and the charging current value of the electric device, and then adjusts the voltage and current corresponding to the output of the control switching power supply module, so that a plurality of different voltage and current values can be output by using only one type of adapter. Therefore, it can meet the needs of a variety of different working voltage requirements, improve the applicability of the adapter, and save social resources.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and those skilled in the art can obtain other drawings according to the structures shown in the drawings without any creative work.

1 is a functional block intent of an embodiment of an adapter of the present invention;

2 is a schematic diagram of a charging step of the adapter of the present invention;

Figure 3 is a functional block diagram of a further embodiment of the adapter of the present invention;

4 is a schematic structural view of an embodiment of an adapter of the present invention.

Description of the reference numerals:

Label name Label name 100 Charging interface R7 Seventh resistor 200 Switching power supply module R8 Eightth resistor 210 Power management circuit R9 Ninth resistor 220 Switch circuit R10 Tenth resistor 230 Constant voltage control circuit R11 Eleventh resistor 240 First rectification filter circuit K1 Transistor 250 Second rectification filter circuit Q1 First MOS tube 260 transformer Q2 Second MOS tube 270 EMI filter circuit Q3 Third MOS tube 300 Communication module C1 First capacitor 400 Discharge module C2 Second capacitor 500 Protection module C3 Third capacitor R1 First resistance J1 Charging interface R2 Second resistance J2 AC input plug R3 Third resistance U1 Optocoupler R4 Fourth resistor U2 Communication control chip R5 Fifth resistor U3 Power management chip R6 Sixth resistor Z1 Voltage reference chip

The implementation, functional features, and advantages of the present invention will be further described in conjunction with the embodiments.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back, ...) in the embodiments of the present invention are only used to explain between components in a certain posture (as shown in the drawing). Relative positional relationship, motion situation, etc., if the specific posture changes, the directional indication also changes accordingly.

In addition, the descriptions of "first", "second", and the like in the present invention are used for the purpose of description only, and are not to be construed as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" or "second" may include at least one of the features, either explicitly or implicitly. In addition, the technical solutions between the various embodiments may be combined with each other, but must be based on the realization of those skilled in the art, and when the combination of the technical solutions is contradictory or impossible to implement, it should be considered that the combination of the technical solutions does not exist. It is also within the scope of protection required by the present invention.

The present invention proposes an adapter.

Referring to FIG. 1 and FIG. 2, in the embodiment of the present invention, the adapter includes a charging interface 100, a switching power supply module 200, and a communication module 300 for connecting with a powered device. When charging, connect the adapter to the powered device; the charging process includes the following steps:

S1: The power device sends a power supply requirement protocol signal to the communication module 300;

S2: The communication module 300 receives the power supply requirement protocol signal and controls the switching power supply module 200 to output a corresponding voltage value and current value according to the power supply demand protocol signal.

It is easy to understand that a protocol communication module is disposed in the power device, and the protocol communication module burns software, and stores information related to charging. When the charging interface 100 of the adapter is inserted into the electrical device, the electrical device sends a power supply requirement protocol signal, and the power supply demand protocol signal includes data such as a rated voltage, a rated current, an overcurrent protection value of the useful electrical device, such as a power supply requirement protocol signal. 01011, representing the power demand of the electrical equipment rated 12V, 1A, overcurrent protection value of 1.5A. After the communication module 300 receives the power supply requirement protocol signal, the voltage and current output by the switching power supply module 200 are controlled to be voltage values and current values required by the protocol communication module. Such protocol signals are common standard signals developed by international regulations. According to this standard, the power supply parameters of the electrical equipment and the output parameters of the adapter are unified to match the power receiving and power supply requirements. The adapter can supply power to a variety of electrical devices such as mobile phones, televisions, and notebook computers.

The technical solution of the present invention forms an adapter by providing the charging interface 100, the switching power supply module 200, and the communication module 300. The voltage threshold range and the current threshold range of the power device are read by the communication module 300, and then the voltage and current corresponding to the required output are controlled by the switching power supply module 200, so that a plurality of different voltage value currents can be output by using only one type of adapter. The value, which can meet a variety of different working voltage power equipment, effectively unifies the standard of most adapters in the market, improves the applicability of the adapter, saves social resources, and reduces the cost of the product adapter.

Further, referring to FIG. 2, the adapter further includes a discharge module 400. When the charging interface 100 pulls out the power device, the communication module 300 controls the discharge module 400 to be turned on. Discharge.

Specifically, the switching power supply module 200 includes a power management circuit 210, a switch circuit 220, a constant voltage control circuit 230, a first rectification and filtering circuit 240, a second rectification and filtering circuit 250, and a transformer 260. The transformer 260 includes a primary coil and a driving end of the power management circuit 210 is connected to a controlled end of the switching circuit 220, and a feedback end of the power management circuit 210 is connected to an output end of the constant voltage control circuit 230; The output end of the circuit 220 is connected to the first end of the primary coil of the transformer 260, the input end of the switch circuit 220 is grounded; the input end of the first rectifying and filtering circuit 240 is connected to the mains, the first rectification An output end of the filter circuit 240 is connected to a second end of the primary coil of the transformer 260; an input end of the second filter rectification circuit is respectively connected to the first end and the second end of the secondary coil, the second rectification An output end of the filter circuit 250 is connected to the charging interface 100; a sampling end of the constant voltage control circuit 230 is connected to an output end of the second rectifying and filtering circuit 250; Adjusting end 230 is connected to the output terminal 300 of the communication module.

The power management circuit 210 drives the switch circuit 220 to be turned on or off, converts the DC power input by the first rectification and filtering circuit 240 into a pulsating DC power, and converts the pulsating DC power into another voltage through the transformer 260. The value of the pulsating direct current is rectified and filtered by the second rectifying and filtering circuit 250, and the voltage and current outputted by the transformer are stabilized by the constant voltage control loop, and finally the stable direct current is output.

In this embodiment, the charging interface 100 is a USB Type-C interface. USB The Type-C interface is a new USB standard interface that is hot swappable and can be plugged in and out. Easy to understand, USB The Type-C interface may be a plug or a socket, which is correspondingly set according to whether the interface on the powered device is a socket or a plug. The USB The Type-C interface includes a power terminal VBUS, a ground terminal SGND, a first detection terminal CC1, and a second detection terminal CC2.

Referring to FIG. 3, specifically, the second rectifying and filtering circuit 250 includes a first diode D1, a first inductor L1, a first capacitor C1, and a first capacitor C2; an anode and a cathode of the first diode D1. a first end of the secondary coil is connected, a cathode of the first diode D1 is connected to a first end of the first inductor L1, and a second end of the first inductor L1 is connected to the charging interface 100 The first end of the first capacitor C1 is connected to the first end of the first inductor L1, the second end of the first capacitor C1 is grounded, and the first end of the first capacitor C2 is opposite to the first A second end of the inductor L1 is connected, and a second end of the first capacitor C2 is grounded.

Specifically, the constant voltage control circuit 230 includes a photocoupler U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a voltage reference chip Z1; execution of the optocoupler U1 The input end is connected to the feedback end of the power management circuit 210, the output end of the optical coupler U1 is grounded; the first end of the first resistor R1 is connected to the cathode of the first diode D1, The second end of the first resistor R1 is connected to the output end of the voltage reference chip Z1 via the second resistor R2; the first end of the third resistor R3 is connected to the second end of the first inductor L1 The second end of the third resistor R3 is grounded via the fourth resistor R4; the input end of the voltage reference chip Z1 is grounded, the reference end of the voltage reference chip Z1 and the second end of the third resistor R3 The control input of the optical coupler U1 is connected to the second end of the first resistor R1, and the control output of the optical coupler U1 is connected to the second end of the third resistor R3.

It should be noted that the first resistor R1 and the second resistor R2 are both used for current limiting, wherein the first resistor R1 is a power supply current limiting resistor, and the second resistor R2 is a pre-start current limiting resistor of the voltage reference chip Z1. The third resistor R3 and the fourth resistor R4 are voltage dividing sampling resistors. The divided voltage sampling resistor supplies the detected sampled voltage to the voltage reference terminal of the voltage reference chip Z1 to control the magnitude of the current of the optocoupler, thereby controlling the duty ratio of the PWM control signal outputted by the power management circuit 210 to the switch circuit 220, so that The output voltage is constant. For example, when the output voltage of the transformer T (ie, the transformer 260 in FIG. 2) is lowered, the voltages sampled by the third resistor R3 and the fourth resistor R4 become low, thereby controlling the current of the voltage reference chip Z1 from the cathode to the anode to be reduced, so that the light coupling is performed. The current flowing in the U1 control input is reduced, thereby causing the optocoupler U1 to perform an increase in the voltage at the input terminal, and the power management circuit 210 controls the duty ratio of the PWM control signal outputted to the switch circuit 220 to increase, and finally the transformer T is The output voltage is increased to achieve a voltage stabilization effect. When the output voltage of the transformer T is too large, the adjustment process is the same, and will not be described here.

Further, the constant voltage control circuit 230 further includes a fifth resistor R5 and a third capacitor C3; a first end of the fifth resistor R5 is connected to an output end of the voltage reference chip Z1, and the fifth resistor R5 The second end of the third capacitor C3 is connected to the second end of the third capacitor C3, and the second end of the third capacitor C3 is connected to the second end of the third resistor R3; Connected to the control output of the optocoupler U1.

The fifth resistor R5 and the third capacitor C3 form a voltage compensation loop, which effectively eliminates external electromagnetic interference, so that the output voltage of the transformer T is more stable.

Specifically, the communication module 300 includes a communication control chip U2, a sixth resistor R6, and a seventh resistor R7. The communication control chip U2 includes a first signal input terminal SEN, a second signal input terminal SEP, and a first detection terminal CC1. a second detecting end CC2, a first adjusting end FB and a second adjusting end VCONN; the first signal input end SEN and the second signal input end SEP of the communication control chip U2 are grounded, and the sixth resistor R6 is connected to Between the first signal input terminal SEN and the second signal input terminal SEP; the first detection terminal CC1 and the second signal detection terminal of the communication control chip U2 are both connected to the charging interface 100; A regulating terminal GP is connected to the control input end of the optical coupler U1, and the second regulating terminal VCONN is connected to the control output end of the optical coupler U1 via the seventh resistor R7.

It should be noted that the first detecting end CC1 and the second detecting end CC2 of the communication control chip U2 are respectively connected to the USB. The first detection terminal CC1 of the Type-C interface is connected to the second detection terminal CC2, and the ground terminal SGND of the USB Type-C interface is grounded, USB. The power terminal VBUS of the Type-C interface is connected to the second end of the first inductor L1.

In this embodiment, the communication control chip U2 adopts the Roma semiconductor BM92T series chip, and the chip of the model BM92T20MWV is preferably used. The sixth resistor R6 is a load overcurrent detecting resistor, and the seventh resistor R7 is a current limiting resistor.

Specifically, the discharge module 400 includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and a transistor K1. The communication control chip U2 further includes a first driving end DRI1; a base of the transistor K1 The first driving end DRI is connected, the emitter of the transistor K1 is grounded; the first end of the eighth resistor R8 is connected to the second end of the first inductor L1, and the second end of the eighth resistor R8 is The terminal is connected to the collector of the transistor K1; the ninth resistor R9 and the tenth resistor R10 are both connected in parallel to the first end of the eighth resistor R8 and the second end of the eighth resistor R8. between.

When the adapter pulls out the power device, the first driving end DRI of the communication control chip U2 outputs a high level, and the control transistor K1 is turned on, and the electric energy stored in the first capacitor C1 and the first capacitor C2 passes through the eighth resistor R8, The nine resistors R9 and the tenth resistor R10 are discharged to prevent the excessive excessive voltage of the capacitor from causing damage to the subsequently charged electrical equipment.

Further, the communication module 300 reads the power of the power device, and adjusts the output power of the switching power module according to the power consumption of the power device.

It should be noted that when the power demand of the powered device is large, the protocol communication module in the powered device records the power demand of the corresponding powered device, and the requirement is transmitted to the communication module 300 through the Type-C interface, specifically Via USB The first detecting end CC1 and the second detecting end CC2 of the Type-C interface are transmitted to the communication control chip U2. After receiving the maximum current required by the powered device, the communication control chip U2 controls the power management circuit 210 through the constant voltage control circuit 230. In turn, the transformer 260 can output the corresponding required maximum power to speed up the charging speed of the powered device with the power storage function.

Further, the adapter further includes a protection module 500, and an input end of the protection module 500 is connected to an output end of the second rectification and filtering circuit 250, and an output end of the protection module 500 is connected to the charging interface 100. The controlled end of the protection module 500 is connected to the control end of the communication module 300.

The protection module 500 includes a first MOS transistor Q1 and a second MOS transistor Q2. The communication control chip U2 further includes a second driving terminal DRI2, a third driving terminal DRI3, a power input terminal VEX, and a detection control terminal SRC. a gate of the first MOS transistor Q1 is connected to the second driving terminal DRI2, a source of the first MOS transistor Q1 is connected to a second end of the first inductor L1, and a drain of the first MOS transistor Q1 a pole is connected to a drain of the second MOS transistor Q2; a source of the second MOS transistor Q2 is connected to the charging interface 100, and a gate of the second MOS transistor Q2 and the third driving terminal DRI3 The power input terminal VEX is connected to the source of the first MOS transistor Q1, and the detection control terminal SRC is connected to the drain of the second MOS transistor Q2.

It should be noted that the sixth resistor R6 in the communication module 300 is used to detect the load circuit current.

It should be noted that when the output voltage of the transformer T detected by the detection control terminal SRC is the same as the voltage set by the communication control chip U2, the second MOS transistor is controlled to be turned on to supply power to the electrical equipment.

After the first detecting terminal CC1 and the second detecting terminal CC2 detect the insertion of the power-consuming device, the communication control chip controls the first MOS transistor to be turned on, and outputs power to the power-consuming device after being output through the second MOS transistor Q2. When the Type-C connector is unplugged, the communication control chip controls the second NMOS transistor to be turned off, preventing the voltage from being reversed due to excessive voltage when plugging in other different powered devices, thereby causing damage to the front end adapter.

In this embodiment, the power management circuit 210 includes a power management chip U3, and the power management chip U3 is implemented by using a BM1P061FJ chip of Roma Semiconductor. The switch circuit 220 includes a third MOS transistor Q3 and an eleventh resistor R11. The gate of the third MOS transistor Q3 is connected to the driving terminal OUT of the power management chip U3, and the drain of the third MOS transistor Q3 is A second end of the primary winding of the transformer T is connected, and a source of the third MOS transistor Q3 is grounded via the eleventh resistor R11.

In this embodiment, the switching power supply module 200 further includes an EMI filter circuit 270 and an AC input plug J2. The input end of the EMI filter circuit 270 is electrically connected to the AC input plug J2, and the output of the EMI filter circuit 270 is The terminal is connected to the first rectifying and filtering circuit 240. The AC plug J2 is used to plug into a common outlet to access the mains, and the EMI filter circuit 270 is used to filter out electromagnetic interference.

This embodiment is described by a television set, and the present invention will be further described with reference to FIG. 4:

When the demand for electrical equipment is 12V, a protocol communication module is designed on the main board of the TV. The software is programmed in the module to record the rated voltage of the TV set at 12V, the rated current value of 2A and the overcurrent protection value of 3A. .

When the charging interface of the adapter is inserted into the power device, the protocol communication module in the power device controls the rated voltage value 12V and the rated current value 2A through the first detecting terminal CC1 and the second detecting terminal CC2 under the control of its internal software. The stream protection value 3A informs the communication control chip U2 in the adapter. The communication module 300 in the adapter also burns the corresponding software, and through the first detection terminal CC1 and the second detection terminal CC2, the rated voltage and current and the overcurrent protection value 3A required by the protocol communication module in the television are obtained, so that the first adjustment is passed. The terminal FB and the second regulating terminal VCONN control the constant voltage control circuit, thereby controlling the power management chip U3, so that the transformer T outputs the voltage value and current value required by the power device.

The technical solution of the present invention reads the voltage parameter and the current parameter of the electrical equipment through the communication module 300, and then adjusts the voltage and current output by the switching power supply module 200, so that the adapter outputs a large range of voltage and current, thereby being able to satisfy a plurality of different The working voltage of the electrical equipment, such as mobile phones, computers, televisions, etc., improves the applicability of the adapter, so that the adapters between different electrical equipment can be universal, reducing the idleness of different types of adapters, saving social resources.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the invention, and the equivalent structural transformation, or direct/indirect use, of the present invention and the contents of the drawings are used in the inventive concept of the present invention. It is included in the scope of the patent protection of the present invention in other related technical fields.

Claims (13)

 An adapter, comprising: a switching power supply module, a communication module, and a charging interface; The charging interface connects the adapter with the powered device; the powered device sends a power supply requirement protocol signal to the communication module; The communication module receives the power supply requirement protocol signal and controls the switching power supply module to output a corresponding voltage value and current value according to the power supply demand protocol signal. The adapter according to claim 1, wherein the adapter further comprises a discharge module; the communication module controls the discharge module to be turned on when the charging interface is pulled out of the power device, and the switching power supply module Discharge. The adapter according to claim 2, wherein said switching power supply module comprises a power management circuit, a switching circuit, a transformer, a constant voltage control circuit, a first rectifying and filtering circuit, and a second rectifying and filtering circuit; said transformer comprising a primary a coil and a secondary coil; a driving end of the power management circuit is connected to a controlled end of the switching circuit, and a feedback end of the power management circuit is connected to an output end of the constant voltage control circuit; The output end is connected to the first end of the primary coil of the transformer, the input end of the switch circuit is grounded; the input end of the first rectifying and filtering circuit is connected to the mains, and the output end of the first rectifying and filtering circuit is a second end of the primary winding of the transformer is connected; an input end of the second filter rectifier circuit is respectively connected to the first end and the second end of the secondary coil, and an output end of the second rectifying and filtering circuit is a charging interface connection; a sampling end of the constant voltage control circuit is connected to an output end of the second rectifying and filtering circuit; an adjusting end of the constant voltage control circuit and the The output of the communication module is connected. The adapter of claim 1 wherein said charging interface is a USB Type-C interface. The adapter according to claim 4, wherein said second rectifying and filtering circuit comprises a first diode, a first inductor, a first capacitor and a second capacitor; and an anode and a cathode of said first diode a first end of the secondary coil is connected, a cathode of the first diode is connected to the first end of the inductor; a second end of the first inductor is connected to the charging interface; the first capacitor The first end is connected to the first end of the first inductor, the second end of the first capacitor is grounded; the first end of the second capacitor is connected to the second end of the first inductor, The second end of the second capacitor is grounded. The adapter of claim 5 wherein said constant voltage control circuit comprises An optocoupler, a first resistor, a second resistor, a third resistor, a fourth resistor, and a voltage reference chip; an execution input of the optocoupler is coupled to a feedback end of the power management circuit, the optocoupler The first output of the first resistor is connected to the cathode of the first diode, and the second end of the first resistor is connected to the output of the voltage reference chip via the second resistor The first end of the third resistor is connected to the second end of the first inductor, the second end of the third resistor is grounded via the fourth resistor; the input end of the voltage reference chip is grounded a reference end of the voltage reference chip is coupled to a second end of the third resistor; a control input of the optocoupler is coupled to a second end of the first resistor, and a control output of the optocoupler The end is connected to the second end of the third resistor. The adapter of claim 6 wherein said constant voltage control circuit further comprises a fifth resistor and a third capacitor; said first end of said fifth resistor being coupled to an output of said voltage reference chip The second end of the fifth resistor is connected to the first end of the third capacitor, the second end of the third capacitor is connected to the second end of the third resistor; the output end of the voltage reference chip is further Connected to the control output of the optocoupler. The adapter according to claim 7, wherein the communication module comprises a communication control chip, a sixth resistor and a seventh resistor; the communication control chip comprises a first signal input terminal, a second signal input terminal, and a first a detecting end, a second detecting end, a first adjusting end and a second adjusting end; the first signal input end and the second signal input end of the communication control chip are both grounded, and the sixth resistor is connected to the first signal Between the input end and the second signal input end; the first detecting end and the second signal detecting end of the communication control chip are both connected to the charging interface; the first adjusting end and the optical coupler The control input is connected, and the second adjustment terminal is connected to the control output of the optical coupler via the seventh resistor. The adapter according to claim 1, wherein said communication module reads the power of the power device, and adjusts the power output by said switching power module according to the power consumption of the power device. The adapter according to claim 8, wherein said adapter further comprises a protection module, an input end of said protection module being coupled to said output of said second rectifying filter circuit, said output of said protection module being said The charging interface is connected, and the controlled end of the protection module is connected to the control end of the communication module. The adapter according to claim 10, wherein the protection module comprises a first MOS transistor and a second MOS transistor, the communication control chip further comprising a second driving end, a third driving end, a power input end, and detecting a control terminal; a gate of the first MOS transistor is connected to the second driving end, a source of the first MOS transistor is connected to a second end of the first inductor, and a drain of the first MOS transistor a pole is connected to a drain of the second MOS transistor; a source of the second MOS transistor is connected to the charging interface, and a gate of the second MOS transistor is connected to the third driving end; The input terminal is connected to the source of the first MOS transistor, and the detection control terminal is connected to the drain of the second MOS transistor. The adapter according to claim 2, wherein said discharge module comprises an eighth resistor, a ninth resistor, a tenth resistor, and a triode, and said communication control chip further comprises a first driving end; said base of said triode The pole is connected to the first driving end, the emitter of the transistor is grounded; the first end of the eighth resistor is connected to the second end of the first inductor, and the second end of the eighth resistor is The collector connection of the triode; the ninth resistor and the tenth resistor are both connected in parallel between the first end of the eighth resistor and the second end of the eighth resistor. The adapter of claim 3, wherein the switching power supply module further comprises an EMI filter circuit and an AC input plug, wherein an input end of the EMI filter circuit is electrically connected to the AC input plug, and the EMI filter circuit The output is connected to the first rectifying and filtering circuit.