CN106026705A - Adapter - Google Patents

Abstract

The invention discloses an adapter, which comprises a switching power supply module, a communication module and a charging interface; the charging interface is used to connect the adapter with electrical equipment; the electrical equipment sends a power supply demand protocol signal to the communication module; demand protocol signal and control the switching power supply module to output corresponding voltage value and current value according to the power supply demand protocol signal. The technical scheme of the invention unifies the standards of various adapters on the market, improves the applicability of the adapters, saves resources, and realizes fast charging.

Description

adapter

technical field

The invention relates to the technical field of electronic circuits, in particular to an adapter.

Background technique

Traditional adapters can only output a constant voltage, so that the adapter can only be paired with one type of electrical equipment. For example, the output 5V adapter can only supply power to mobile phones; the output 12V adapter can only supply power to TV sets. This makes there are many types of adapters for electrical equipment on the market, resulting in a waste of social resources, and also increases the cost of additional adapters for electronic products.

Contents of the invention

The main purpose of the present invention is to provide an adapter, aiming at unifying the standards of various adapters on the market, improving the applicability of the adapter and saving resources.

In order to achieve the above object, the present invention proposes an adapter, which includes a switching power supply module, a communication module and a charging interface; wherein,

The charging interface connects the adapter with the electrical equipment; the electrical equipment sends a power supply demand protocol signal to the communication module;

The communication module receives the power supply demand 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; the communication module controls the discharge module to be turned on to discharge the switching power supply module when the electrical device is pulled out from the charging interface.

Preferably, the switching power supply module includes a power management circuit, a switching circuit, a transformer, a constant voltage control circuit, a first rectification and filtering circuit, and a second rectification and filtering circuit; the transformer includes a primary coil and a secondary coil; the power management The drive end of the circuit is connected to the controlled end of the switch circuit, the feedback end of the power management circuit is connected to the output end of the constant voltage control circuit; the output end of the switch circuit is connected to the primary coil of the transformer The first end is connected, the input end of the switch circuit is grounded; the input end of the first rectification filter circuit is connected to the mains, and the output end of the first rectification filter circuit is connected to the second end of the primary coil of the transformer connection; the input end of the second filter rectifier circuit is 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 terminal of the said second rectification and filtering circuit is connected to the output terminal; the adjustment terminal of the constant voltage control circuit is connected to the output terminal 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; the anode of the first diode is connected to the first end of the secondary coil, The cathode of the first diode is connected to the first end of the inductor; the second end of the first inductor is connected to the charging interface; the first end of the first capacitor is connected to the first inductor The first terminal of the first capacitor is connected to the ground; the first terminal of the second capacitor is connected to the second terminal of the first inductor, and the second terminal of the second capacitor is grounded.

Preferably, the constant voltage control circuit includes an optocoupler, a first resistor, a second resistor, a third resistor, a fourth resistor, and a voltage reference chip; the execution input terminal of the optocoupler is connected to the power management circuit connected to the feedback end of the optocoupler, the executive output end of the optocoupler is grounded; the first end 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 Two resistors are connected to the output end of the voltage reference chip; the first end of the third resistor is connected to the second end of the first inductor, and the second end of the third resistor is grounded through the fourth resistor ; The input end of the voltage reference chip is grounded, and the reference end of the voltage reference chip is connected to the second end of the third resistor; the control input end of the optocoupler is connected to the second end of the first resistor connected, the control output end of the optocoupler is connected to the second end of the third resistor.

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

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 terminal, a second signal input terminal, a first detection terminal, a second detection terminal, a first An adjustment terminal and a second adjustment terminal; both the first signal input terminal and the second signal input terminal of the communication control chip are grounded, and the sixth resistor is connected to the first signal input terminal and the second signal input terminal Between; the first detection end and the second signal detection end of the communication control chip are connected to the charging interface; the first adjustment end is connected to the control input end of the optocoupler, and the second adjustment The terminal is connected to the control output terminal of the optocoupler via the seventh resistor.

Preferably, the communication module reads the power of the electrical equipment, and adjusts the output power of the switching power supply module according to the power of the electrical equipment.

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

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

The technical solution of the present invention forms an adapter by arranging a charging interface, a communication module, and a switching power supply module. Read the charging voltage value and charging current value of the electrical equipment through the communication module, and then adjust and control the output voltage and current corresponding to the demand of the switching power supply module, so that only one adapter can output a variety of different voltage and current values, Therefore, it is possible to meet various electrical equipment with different working voltage requirements, improve the applicability of the adapter, and save social resources.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to the structures shown in these drawings without creative effort.

Fig. 1 is the functional module diagram of an embodiment of the adapter of the present invention;

Fig. 2 is a schematic diagram of charging steps of the adapter of the present invention;

Fig. 3 is the functional module diagram of the further embodiment of the adapter of the present invention;

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

Explanation of reference numbers:

label name label name 100 charging port R7 Seventh resistor 200 Switching Power Module R8 Eighth resistor 210 power management circuit R9 Ninth resistance 220 switch circuit R10 Tenth resistor 230 Constant voltage control circuit R11 Eleventh resistor 240 The first rectification filter circuit K1 Triode 250 The second rectification filter circuit Q1 The first MOS tube 260 transformer Q2 The second MOS tube 270 EMI filter circuit Q3 The third MOS tube 300 communication module C1 first capacitor 400 discharge module C2 second capacitor 500 protection module C3 third capacitor R1 first resistor J1 charging port R2 Second resistor J2 AC input plug R3 third resistor U1 optocoupler R4 Fourth resistor U2 Communication control chip R5 fifth resistor U3 power management chip R6 Sixth resistor Z1 voltage reference chip

The realization of the purpose of the present invention, functional characteristics and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection 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 the relationship between the components in a certain posture (as shown in the accompanying drawings). Relative positional relationship, movement conditions, etc., if the specific posture changes, the directional indication will also change accordingly.

In addition, the descriptions involving "first", "second" and so on in the present invention are only for descriptive purposes, and should not be understood as indicating or implying their relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the technical solutions of the various embodiments can be combined with each other, but it must be based on the realization of those skilled in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist , nor within the scope of protection required by the present invention.

The 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 for connecting with an electric device, a switching power supply module 200 , and a communication module 300 . When charging, connect the adapter with the electric device; the charging process includes the following steps:

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

S2: The communication module 300 receives the power supply demand 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 the electrical equipment is provided with a protocol communication module, and the protocol communication module is programmed with software and stores information related to charging. When the charging interface 100 of the adapter is plugged into the electrical equipment, the electrical equipment sends out a power supply demand protocol signal, which contains data such as the rated voltage, rated current, and overcurrent protection value of the electrical equipment, such as the power supply demand protocol signal 01011, representing the power consumption demand of electrical equipment rated at 12V, 1A, and the overcurrent protection value is 1.5A. After the communication module 300 receives the power supply demand protocol signal, it controls the output voltage and current of the switching power supply module 200 to be the voltage value and current value required by the protocol communication module. This type of protocol signal is a general standard signal formulated by international regulations. According to this standard, the demand 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 various electric devices such as mobile phones, TV sets, and notebook computers.

The technical solution of the present invention forms an adapter by setting the charging interface 100 , the switching power supply module 200 , and the communication module 300 . Read the voltage threshold range and current threshold range of the electrical equipment through the communication module 300, and then adjust and control the switching power supply module 200 to output the voltage and current corresponding to the demand, so that only this adapter can output a variety of different voltage values and currents Value, so that it can meet a variety of electrical equipment with different working voltages, effectively unifies the standards of most adapters in the market, improves the applicability of adapters, saves social resources, and reduces the cost of additional adapters for products.

Further, please refer to FIG. 2 , the adapter further includes a discharge module 400; the communication module 300 controls the discharge module 400 to be turned on when the charging interface 100 is pulled out of the electric device, and the switching power supply module 200 to discharge.

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

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

In this embodiment, the charging interface 100 is a USB Type-C interface. The USB Type-C interface is a new type of USB standard interface, which is characterized by supporting hot plugging, and can be plugged in forward and reverse directions. It is easy to understand that the USB Type-C interface may be a plug or a socket, which is set correspondingly according to whether the interface on the electric device is a socket or a plug. The USB Type-C interface includes a power supply 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; the anode of the first diode D1 is connected to the first capacitor C2. The first end of the secondary coil is connected, the cathode of the first diode D1 is connected to the first end of the first inductor L1; the second end of the first inductor L1 is connected to the charging interface 100 ; The first terminal of the first capacitor C1 is connected to the first terminal of the first inductor L1, and the second terminal of the first capacitor C1 is grounded; the first terminal of the first capacitor C2 is connected to the first terminal of the first capacitor C2. The second end of an inductor L1 is connected, and the second end of the first capacitor C2 is grounded.

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

It should be noted that both the first resistor R1 and the second resistor R2 are 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 voltage-dividing sampling resistor sends the detected and sampled voltage to the voltage reference terminal of the voltage reference chip Z1 to control the current of the optocoupler, and then controls the duty cycle of the PWM control signal output from 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 (that is, the transformer 260 in FIG. 2 ) decreases, the voltage sampled by the third resistor R3 and the fourth resistor R4 becomes lower, thereby controlling the current from the cathode to the anode of the voltage reference chip Z1 to decrease, so that the optical coupling The current flowing into the control input terminal of the optocoupler U1 decreases, and then the voltage at the input terminal of the optocoupler U1 increases, and the power management circuit 210 controls the duty cycle of the PWM control signal output to the switch circuit 220 to increase, and finally the transformer T The output voltage increases to achieve a voltage stabilization effect. When the output voltage of the transformer T is too high, the adjustment process is the same, and will not be repeated here.

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

The fifth resistor R5 and the third capacitor C3 form a voltage compensation loop, which effectively eliminates external electromagnetic interference and makes the output voltage of the transformer T 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, a first detection terminal CC1 , the second detection terminal CC2, the first adjustment terminal FB and the second adjustment terminal VCONN; the first signal input terminal SEN and the second signal input terminal SEP of the communication control chip U2 are both 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 terminal of the optocoupler U1, and the second regulating terminal VCONN is connected to the control output terminal of the optocoupler U1 via the seventh resistor R7.

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

In this embodiment, the communication control chip U2 adopts the BM92T series chips of Rohm Semiconductor, and the chips of the model BM92T20MWV are preferred. The sixth resistor R6 is a load overcurrent detection 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, and the communication control chip U2 also includes a first drive terminal DRI1; the base of the transistor K1 is connected to The first drive terminal DRI is connected, the emitter of the triode 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 connected to the collector of the triode K1; the ninth resistor R9 and the tenth resistor R10 are connected in parallel between the first end of the eighth resistor R8 and the second end of the eighth resistor R8 between.

When the adapter is pulled out of the electrical equipment, the first drive terminal DRI of the communication control chip U2 outputs a high level, and the triode K1 is controlled to conduct, and the electric energy stored in the first capacitor C1 and the first capacitor C2 passes through the eighth resistor R8, the first The nine resistors R9 and the tenth resistor R10 are discharged to prevent the remaining excessive voltage of the capacitor from causing damage to the electrical equipment for subsequent charging.

Further, the communication module 300 reads the power of the electrical equipment, and adjusts the output power of the switching power supply module according to the power of the electrical equipment.

It should be noted that when the power demand of the electric device is large, the protocol communication module in the electric device will record the corresponding power demand of the electric device, and pass this demand to the communication module 300 through the Type-C interface, specifically The first detection terminal CC1 and the second detection terminal CC2 of the USB Type-C interface transmit to the communication control chip U2, and the communication control chip U2 controls the power management circuit through the constant voltage control circuit 230 after receiving the maximum current required by the electrical equipment 210, so that the transformer 260 can output the corresponding maximum power required, so as to speed up the charging speed of the electric equipment with the power storage function.

Further, the adapter further includes a protection module 500, the input end of the protection module 500 is connected to the output end of the second rectification and filtering circuit 250, and the output end of the protection module 500 is connected to the charging interface 100, so 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, and the communication control chip U2 also includes a second drive terminal DRI2, a third drive terminal DRI3, a power input terminal VEX, and a detection control terminal SRC; The gate of the first MOS transistor Q1 is connected to the second driving terminal DRI2, the source of the first MOS transistor Q1 is connected to the second end of the first inductor L1, and the drain of the first MOS transistor Q1 The pole is connected to the drain of the second MOS transistor Q2; the source of the second MOS transistor Q2 is connected to the charging interface 100, and the gate of the second MOS transistor Q2 is connected to the third driving terminal DRI3 connection; the power supply 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.

When the first detection terminal CC1 and the second detection terminal CC2 detect that the electric device is plugged in, the communication control chip controls the first MOS transistor to conduct, and supplies power to the electric device after outputting through the second MOS transistor Q2. When the Type-C connector is unplugged, the communication control chip controls the second NMOS tube to cut off to prevent the voltage from being fed back due to excessive voltage when plugging in other different electrical equipment, 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 a BM1P061FJ chip of ROHM 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 drive terminal OUT of the power management chip U3, and the drain of the third MOS transistor Q3 is connected to the drive terminal OUT of the power management chip U3. The second end of the primary coil of the transformer T is connected, and the source of the third MOS transistor Q3 is grounded through 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 The terminal is connected to the first rectifying and filtering circuit 240. The AC plug J2 is used to be inserted into a common socket to connect to the mains, and the EMI filter circuit 270 is used to filter out electromagnetic interference.

The present embodiment is described with TV set, now in conjunction with Fig. 4 the present invention is further elaborated:

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

When the charging interface of the adapter is plugged into the electrical equipment, the protocol communication module in the electrical equipment is controlled by its internal software, through the first detection terminal CC1 and the second detection terminal CC2, the rated voltage value of 12V, the rated current value of 2A and the overvoltage The flow protection value 3A informs the communication control chip U2 in the adapter. The communication module 300 in the adapter is also programmed with the corresponding software. Through the first detection terminal CC1 and the second detection terminal CC2, the rated voltage and current required by the protocol communication module in the TV and the overcurrent protection value of 3A are obtained, so that the first adjustment The terminal FB and the second regulating terminal VCONN control the constant voltage control circuit, and then control the power management chip U3, so that the transformer T outputs the voltage value and current value required by the electrical equipment.

The technical solution of the present invention reads the voltage parameters and current parameters of the electrical equipment through the communication module 300, and then adjusts and controls the voltage and current output by the switching power supply module 200, so that the adapter outputs a larger range of voltage and current, thereby meeting various requirements. Electric devices with working voltage, such as mobile phones, computers, TVs, etc., improve the applicability of adapters, make the adapters between different electric devices universal, reduce the idleness of different types of adapters, and save social resources.

The above is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Under the inventive concept of the present invention, the equivalent structural transformation made by using the description of the present invention and the contents of the accompanying drawings, or direct/indirect use All other relevant technical fields are included in the patent protection scope of the present invention.

Claims (10)

1. An adapter, characterized in that it comprises a switching power supply module, a communication module and a charging interface; The charging interface connects the adapter with the electrical equipment; the electrical equipment sends a power supply demand protocol signal to the communication module; The communication module receives the power supply demand 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. 2. The adapter according to claim 1, characterized in that, 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 electric device, and the switch The power module is discharging. 3. The adapter according to claim 2, wherein the switching power supply module includes a power management circuit, a switching circuit, a transformer, a constant voltage control circuit, a first rectification filter circuit and a second rectification filter circuit; the transformer It includes a primary coil and a secondary coil; the drive end of the power management circuit is connected to the controlled end of the switch circuit, and the feedback end of the power management circuit is connected to the output end of the constant voltage control circuit; the switch The output end of the circuit 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 rectification filter circuit is connected to the mains, and the output of the first rectification filter circuit end is connected with the second end of the primary coil of the transformer; the input end of the second filter rectifier circuit is connected with the first end and the second end of the secondary coil respectively, and the output end of the second rectification filter circuit is connected with The charging interface is connected; the sampling terminal of the constant voltage control circuit is connected with the output terminal of the second rectification filter circuit; the adjustment terminal of the constant voltage control circuit is connected with the output terminal of the communication module. 4. The adapter according to any one of claims 1-3, wherein the charging interface is a USB Type-C interface. 5. The adapter according to claim 4, wherein the second rectifying and filtering circuit comprises a first diode, a first inductor, a first capacitor and a second capacitor; the anode of the first diode connected to the first end of the secondary coil, the cathode of the first diode is connected to the first end of the inductance; the second end of the first inductance is connected to the charging interface; the first The first end of a capacitor 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. 6. The adapter according to claim 5, wherein the constant voltage control circuit comprises an optical coupler, a first resistor, a second resistor, a third resistor, a fourth resistor, and a voltage reference chip; the optical The execution input end of the coupler is connected to the feedback end of the power management circuit, the execution output end of the optocoupler is grounded; the first end of the first resistor is connected to the cathode of the first diode, so The second end of the first resistor is connected to the output end of the voltage reference chip through the second resistor; the first end of the third resistor is connected to the second end of the first inductor, and the third The second end of the resistor is grounded through the fourth resistor; the input end of the voltage reference chip is grounded, and the reference end of the voltage reference chip is connected to the second end of the third resistor; the control of the optocoupler The input end is connected to the second end of the first resistor, and the control output end of the optocoupler is connected to the second end of the third resistor. 7. The adapter according to claim 6, wherein the constant voltage control circuit further comprises a fifth resistor and a third capacitor; the first end of the fifth resistor is connected to the output end of the 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 of the voltage reference chip terminal is also connected with the control output terminal of the optocoupler. 8. The adapter according to claim 7, wherein the communication module includes a communication control chip, a sixth resistor, and a seventh resistor; the communication control chip includes a first signal input terminal, a second signal input terminal, The first detection terminal, the second detection terminal, the first adjustment terminal and the second adjustment terminal; the first signal input terminal and the second signal input terminal of the communication control chip are both grounded, and the sixth resistor is connected to the first Between a signal input terminal and the second signal input terminal; the first detection terminal and the second signal detection terminal of the communication control chip are both connected to the charging interface; the first adjustment terminal is coupled to the optical connected to the control input end of the optocoupler, and the second adjustment end is connected to the control output end of the optocoupler via the seventh resistor. 9. The adapter according to claim 1, wherein the communication module reads the power of the electrical equipment, and adjusts the output power of the switching power supply module according to the power of the electrical equipment. 10. The adapter according to claim 8, characterized in that, the adapter further comprises a protection module, the input end of the protection module is connected to the output end of the second rectification and filtering circuit, and the output end of the protection module is connected to the output end of the second rectification filter circuit. The charging interface is connected, and the controlled terminal of the protection module is connected to the control terminal of the communication module; The protection module includes a first MOS tube and a second MOS tube, and the communication control chip also includes a second drive terminal, a third drive terminal, a power input terminal, and a detection control terminal; the gate of the first MOS tube is connected to the The second driving terminal is connected, the source of the first MOS transistor is connected to the second end of the first inductor, and the drain of the first MOS transistor is connected to the drain of the second MOS transistor; The source of the second MOS transistor is connected to the charging interface, the gate of the second MOS transistor is connected to the third drive terminal; the power input terminal is connected to the source of the first MOS transistor , the detection control terminal is connected to the drain of the second MOS transistor.