Charging system, charging method and power adapter for terminal

Abstract

A charging system, a charging method and a power adapter (1) for a terminal, wherein the charging system comprises the power adapter (1) and the terminal (2), the power adapter (1) comprises a first rectifying unit (101), a transformer (103), a second rectifying unit (104), a sampling unit (106), a modulation control unit (100), an auxiliary winding and a power supply unit (112), the modulation control unit (100) modulates the voltage of the first pulsating waveform according to the voltage sampling value, so that the voltage of the third pulsating waveform output by the second rectifying unit (104) meets the charging demand; the modulation control unit (100) modulates the voltage of the first pulsating waveform by obtaining the voltage detection value through the voltage of the fourth pulsating waveform; the second charging interface (201) of the terminal (2) is connected with the battery (202), when the second charging interface (201) is connected with the first charging interface (105), the second charging interface (201) loads the voltage of the third pulsating waveform to the battery (202).

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of terminal equipment, in particular to a charging system for a terminal, a charging method for a terminal and a power adapter. BACKGROUND

[0002] At present, mobile terminals (such as smart phones) are increasingly favored by consumers, but mobile terminals consume a large amount of power and need to be charged frequently.

[0003] Generally, mobile terminals are charged by power adapters. The power adapter generally includes a primary rectifier circuit, a primary filter circuit, a transformer, a secondary rectifier circuit, a secondary filter circuit and a control circuit, etc. In this way, the power adapter converts the input 220V alternating current into stable low-voltage direct current (such as 5V) suitable for the needs of the mobile terminal, to provide power management devices and batteries of the mobile terminal, so as to realize the charging of the mobile terminal.

[0004] However, as the power of the power adapter increases, for example, from 5W to 10W, 15W, 25W and larger power upgrades, more electronic components capable of withstanding high power and achieving better precision control are needed for adaptation, which not only increases the size of the power adapter, but also increases the production cost and manufacturing difficulty of the adapter. SUMMARY

[0005] The present application is based on the inventor's understanding and research of the following problems:

[0006] The inventor found in the research that as the power of the power adapter increases, the power adapter is prone to cause the battery polarization resistance to increase and the battery temperature to rise when charging the battery of the mobile terminal, thereby reducing the service life of the battery and affecting the reliability and safety of the battery.

[0007] In addition, when an alternating current power supply is generally used, most devices cannot work directly using alternating current, because the alternating current, such as 50Hz 220V mains, is intermittently outputting power, and in order not to be "intermittent", an electrolytic capacitor is needed to store energy, so that when the power supply is at the trough, the continuous dependence of the power supply on the storage energy of the electrolytic capacitor is needed to maintain stable power supply. Therefore, when the alternating current power supply charges the mobile terminal through the power adapter, the alternating current provided by the alternating current power supply, such as 220V alternating current, is first converted into stable direct current to supply the mobile terminal. However, the power adapter charges the battery of the mobile terminal, thereby indirectly supplying power to the mobile terminal, and the continuity of the power supply is guaranteed by the battery, so that the power adapter does not need to continuously output stable direct current when charging the battery.

[0008] To achieve the above object, the first aspect of the present application provides a charging system for a terminal, comprising: a power adapter, the power adapter comprising: a first rectifying unit, the first rectifying unit rectifying input alternating current to output a first pulsating waveform voltage; a transformer; a second rectifying unit, the second rectifying unit rectifying secondary output of the transformer to output a third pulsating waveform voltage; a sampling unit, the sampling unit sampling the third pulsating waveform voltage to obtain a voltage sampling value; a modulation control unit, the modulation control unit modulating the first pulsating waveform voltage according to the voltage sampling value, and loading the modulated first pulsating waveform voltage to a primary of the transformer, so as to transform the modulated first pulsating waveform voltage into a second pulsating waveform voltage through the transformer, so as to make the third pulsating waveform voltage meet charging requirements; an auxiliary winding, the auxiliary winding generating a fourth pulsating waveform voltage according to the modulated first pulsating waveform voltage; a power supply unit, the power supply unit being connected with the auxiliary winding, the power supply unit converting the fourth pulsating waveform voltage to output direct current, and supplying the modulation control unit; the modulation control unit further detecting the fourth pulsating waveform voltage to obtain a voltage detection value, and modulating the first pulsating waveform voltage according to the voltage detection value; a terminal, the terminal comprising a battery, wherein when the power adapter charges the terminal, the power adapter loads the third pulsating waveform voltage to the battery.

[0009] The second object of the present application is to provide a power adapter.

[0010] To achieve the above object, the first aspect of the present application provides a charging system for a terminal, comprising: a power adapter, the power adapter comprising: a first rectifying unit, the first rectifying unit rectifying input alternating current to output a first pulsating waveform voltage; a transformer; a second rectifying unit, the second rectifying unit rectifying secondary output of the transformer to output a third pulsating waveform voltage; a sampling unit, the sampling unit sampling the third pulsating waveform voltage to obtain a voltage sampling value; a modulation control unit, the modulation control unit modulating the first pulsating waveform voltage according to the voltage sampling value, and loading the modulated first pulsating waveform voltage to a primary of the transformer, so as to transform the modulated first pulsating waveform voltage into a second pulsating waveform voltage through the transformer, so as to make the third pulsating waveform voltage meet charging requirements; an auxiliary winding, the auxiliary winding generating a fourth pulsating waveform voltage according to the modulated first pulsating waveform voltage; a power supply unit, the power supply unit being connected with the auxiliary winding, the power supply unit converting the fourth pulsating waveform voltage to output direct current, and supplying the modulation control unit; the modulation control unit further detecting the fourth pulsating waveform voltage to obtain a voltage detection value, and modulating the first pulsating waveform voltage according to the voltage detection value; a terminal, the terminal comprising a battery, wherein when the power adapter charges the terminal, the power adapter loads the third pulsating waveform voltage to the battery.

[0011] The charging system for a terminal according to the embodiment of the present application can realize fast charging of a battery by directly loading the third pulsating waveform voltage output by the power adapter to the battery, wherein the size of the pulsating output voltage / current is periodically changed, which can reduce the lithium precipitation of the lithium battery, prolong the service life of the battery, reduce the probability and intensity of arc drawing of the contact of the charging interface, prolong the service life of the charging interface, reduce the polarization effect of the battery, improve the charging speed, reduce the heat of the battery, and ensure the safety and reliability of the terminal during charging. In addition, since the power adapter outputs the pulsating waveform voltage, no electrolytic capacitor needs to be arranged in the power adapter, which can realize the simplification and miniaturization of the power adapter, and greatly reduce the cost.

[0012] To achieve the above object, the second embodiment of the present application provides a power adapter, comprising: a first rectifying unit, configured to rectify the input alternating current to output a first pulsating waveform voltage; a transformer; a second rectifying unit, configured to rectify the secondary output of the transformer to output a third pulsating waveform voltage, wherein the third pulsating waveform voltage is loaded to the battery of the terminal; a sampling unit, configured to sample the third pulsating waveform voltage to obtain a voltage sampling value; a modulation control unit, configured to modulate the first pulsating waveform voltage according to the voltage sampling value, and load the modulated first pulsating waveform voltage to the primary of the transformer, so that the transformer transforms the modulated first pulsating waveform voltage into a second pulsating waveform voltage, so that the third pulsating waveform voltage meets the charging requirement of the battery; an auxiliary winding, configured to generate a fourth pulsating waveform voltage according to the modulated first pulsating waveform voltage; a power supply unit, connected with the auxiliary winding, configured to convert the fourth pulsating waveform voltage to output direct current to supply the modulation control unit; and the modulation control unit is further configured to detect the fourth pulsating waveform voltage to obtain a voltage detection value, and modulate the first pulsating waveform voltage according to the voltage detection value.

[0013] The power adapter according to the embodiment of the present application can output the third pulsating waveform voltage by converting and modulating the input alternating current, and directly load the third pulsating waveform voltage to the battery of the terminal, so that the pulsating output voltage / current can directly and rapidly charge the battery. The size of the pulsating output voltage / current is periodically changed, compared with the traditional constant voltage and constant current, which can reduce the lithium precipitation of the lithium battery, prolong the service life of the battery, reduce the probability and strength of the arc of the contact of the charging interface, prolong the service life of the charging interface, reduce the polarization effect of the battery, improve the charging speed, reduce the heat of the battery, and ensure the safety and reliability of the terminal during charging. In addition, since the output is the pulsating waveform voltage, the electrolytic capacitor is not needed, which can simplify and miniaturize the power adapter, and greatly reduce the cost.

[0014] To achieve the above object, the third aspect of the present application provides a charging method for a terminal, comprising the following steps: when the power adapter charges the terminal, rectifying the input alternating current once to output a first pulsating waveform voltage; modulating the first pulsating waveform voltage and loading the modulated first pulsating waveform voltage to the primary of a transformer to transform the modulated first pulsating waveform voltage into a second pulsating waveform voltage through the transformer; rectifying the second pulsating waveform voltage twice to output a third pulsating waveform voltage, and loading the third pulsating waveform voltage to the battery of the terminal; sampling the third pulsating waveform voltage to obtain a voltage sampling value, modulating the first pulsating waveform voltage according to the voltage sampling value to make the third pulsating waveform voltage meet the charging requirement; generating a fourth pulsating waveform voltage according to the modulated first pulsating waveform voltage; converting the fourth pulsating waveform voltage to output direct current, detecting the fourth pulsating waveform voltage to obtain a voltage detection value, and modulating the first pulsating waveform voltage according to the voltage detection value.

[0015] According to the charging method for the terminal of the embodiment of the present application, the third pulsating waveform voltage output by the power adapter is directly loaded to the battery of the terminal, so that the pulsating output voltage / current can directly charge the battery quickly. The size of the pulsating output voltage / current is periodically changed, which can reduce the lithium precipitation of the lithium battery, prolong the service life of the battery, reduce the probability and strength of the arc of the contact of the charging interface, prolong the service life of the charging interface, reduce the polarization effect of the battery, improve the charging speed, reduce the heat of the battery, ensure the safety and reliability of the terminal during charging, and the like. In addition, since the power adapter outputs the pulsating waveform voltage, the electrolytic capacitor does not need to be arranged in the power adapter, so that the power adapter can be simplified and miniaturized, and the cost can be greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1A The block schematic diagram of the charging system for the terminal according to an embodiment of the present application adopts a flyback switching power supply;

[0017] Figure 1B The block schematic diagram of the charging system for the terminal according to an embodiment of the present application adopts a forward switching power supply;

[0018] Figure 1C The block schematic diagram of the charging system for the terminal according to an embodiment of the present application adopts a push-pull switching power supply;

[0019] Figure 1D The block schematic diagram of the charging system for the terminal according to an embodiment of the present application adopts a half-bridge switching power supply;

[0020] Figure 1E The block schematic diagram of the charging system for the terminal according to an embodiment of the present application adopts a full-bridge switching power supply;

[0021] Figure 2 The block schematic diagram of the charging system for the terminal according to an embodiment of the present application;

[0022] Figure 3 The charging voltage waveform schematic diagram output by the power adapter to the battery according to an embodiment of the present application;

[0023] Figure 4 The charging current waveform schematic diagram output by the power adapter to the battery according to an embodiment of the present application;

[0024] Figure 5 The control signal schematic diagram output to the switching unit according to an embodiment of the present application;

[0025] Figure 6 a schematic diagram of a fast charging process according to an embodiment of the present application;

[0026] Figure 7A a block diagram of a charging system for a terminal according to an embodiment of the present application;

[0027] Figure 7B a block diagram of a power adapter with LC filter circuit according to an embodiment of the present application;

[0028] Figure 8 a block diagram of a charging system for a terminal according to another embodiment of the present application;

[0029] Figure 9 a block diagram of a charging system for a terminal according to yet another embodiment of the present application;

[0030] Figure 10 a block diagram of a charging system for a terminal according to still another embodiment of the present application;

[0031] Figure 11 a block diagram of a sampling unit according to an embodiment of the present application;

[0032] Figure 12 a block diagram of a charging system for a terminal according to still another embodiment of the present application;

[0033] Figure 13 a block diagram of a terminal according to an embodiment of the present application;

[0034] Figure 14 a block diagram of a terminal according to another embodiment of the present application; and

[0035] Figure 15 a flowchart of a charging method for a terminal according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals and characters throughout the figures denote the same or like components or elements having the same or similar functions. The embodiments described below are exemplary and are intended to provide an explanation of the present application and are not intended to limit the scope of the present application.

[0037] A charging system for a terminal and a power adapter, a charging method for a terminal according to embodiments of the present application are described below with reference to the attached drawings.

[0038] With reference to the attached drawings, a charging system for a terminal according to embodiments of the present application includes a power adapter 1 and a terminal 2.

[0039] As shown in Figure 2 , the power adapter 1 comprises: a first rectifying unit 101, a transformer 103, a second rectifying unit 104, a sampling unit 106 and a modulation control unit 100. The first rectifying unit 101 rectifies the input AC power to output a first pulsating waveform voltage, the second rectifying unit 104 rectifies the secondary output of the transformer 103 to output a third pulsating waveform voltage, the sampling unit 106 samples the third pulsating waveform voltage to obtain a voltage sampling value, and the modulation control unit 100 modulates the first pulsating waveform voltage according to the voltage sampling value and loads the modulated first pulsating waveform voltage to the primary of the transformer 103 to transform the modulated first pulsating waveform voltage into a second pulsating waveform voltage through the transformer 103, so that the third pulsating waveform voltage meets the charging requirement.

[0040] As shown in Figure 2 , the terminal comprises a battery, and when the power adapter charges the terminal, the power adapter loads the third pulsating waveform voltage to the battery.

[0041] The modulation control unit 100 can be integrated with a switching modulation function, a driving switch function, an optical coupling isolation function, a sampling function, a control function, a communication function, etc. Some control functions and communication functions of the modulation control unit 100 are realized by the control unit 107 mentioned below.

[0042] Therefore, further as shown in Figure 1A , the power adapter 1 comprises: a first rectifying unit 101, a switching unit 102, a transformer 103, a second rectifying unit 104, a first charging interface 105, a sampling unit 106 and a control unit 107. The first rectifying unit 101 rectifies the input AC power (mains, for example AC 220V) to output a first pulsating waveform voltage, for example a steamed bun wave voltage, wherein the first rectifying unit 101 can be a full-bridge rectifying circuit composed of four diodes. The switching unit 102 is used to modulate the first pulsating waveform voltage according to a control signal, wherein the switching unit 102 can be composed of MOS tubes, and the steamed bun wave voltage is chopped and modulated by PWM (Pulse Width Modulation) control of the MOS tubes.

[0043] In an embodiment of the present application, as shown in Figure 1AAs shown, the power adapter 1 can adopt a flyback switching power supply. Specifically, the transformer 103 includes a primary winding and a secondary winding, one end of the primary winding is connected with the first output end of the first rectifying unit 101, the second output end of the first rectifying unit 101 is grounded, and the other end of the primary winding is connected with the switching unit 102 (for example, the switching unit 102 is a MOS tube, and here refers to the other end of the primary winding being connected with the drain of the MOS tube), and the transformer 103 is used to output a second pulsating waveform voltage according to the modulated first pulsating waveform voltage.

[0044] The transformer 103 is a high-frequency transformer, and the working frequency thereof can be 50 KHz-2 MHz. The high-frequency transformer couples the modulated first pulsating waveform voltage to the secondary winding for output. In the embodiment of the present application, the high-frequency transformer is adopted, and the high-frequency transformer has a smaller volume compared with a low-frequency transformer (the low-frequency transformer is also referred to as a power-frequency transformer, and is mainly used to refer to the frequency of commercial power, such as 50 Hz or 60 Hz AC power), so that the power adapter 1 can be miniaturized.

[0045] According to one embodiment of the present application, as shown in Figure 1B The power adapter 1 can also adopt a forward switching power supply. Specifically, the transformer 103 includes a first winding, a second winding and a third winding, the same name end of the first winding is connected with the second output end of the first rectifying unit 101 through a reverse diode, the different name end of the first winding is connected with the same name end of the second winding, and then is connected with the first output end of the first rectifying unit 101, the different name end of the second winding is connected with the switching unit 102, and the third winding is connected with the second rectifying unit 104. The reverse diode plays a role of peak clipping, the induced electromotive force generated by the first winding can limit the amplitude of the counter electromotive force through the reverse diode, and return the limited energy to the output of the first rectifying unit to charge the output of the first rectifying unit, and the magnetic field generated by the current flowing through the first winding can demagnetize the core of the transformer, so that the magnetic field intensity in the core of the transformer returns to the initial state. The transformer 103 is used to output a second pulsating waveform voltage according to the modulated first pulsating waveform voltage.

[0046] According to one embodiment of the present application, as shown in Figure 1CAs shown, the power adapter 1 can also adopt a push-pull switching power supply. Specifically, the transformer includes a first winding, a second winding, a third winding and a fourth winding, the same name end of the first winding is connected with the switching unit, the different name end of the first winding is connected with the same name end of the second winding, and then connected with the first output end of the first rectifier unit, the different name end of the second winding is connected with the switching unit, the different name end of the third winding is connected with the same name end of the fourth winding, and the transformer is used to output a second pulsating waveform voltage according to the modulated first pulsating waveform voltage.

[0047] As shown in Figure 1C the switching unit 102 includes a first MOS tube Q1 and a second MOS tube Q2, the transformer 103 includes a first winding, a second winding, a third winding and a fourth winding, the same name end of the first winding is connected with the drain of the first MOS tube Q1 in the switching unit 102, the different name end of the first winding is connected with the same name end of the second winding, and the node between the different name end of the first winding and the same name end of the second winding is connected with the first output end of the first rectifier unit 101, the different name end of the second winding is connected with the drain of the second MOS tube Q2 in the switching unit 102, the source of the first MOS tube Q1 is connected with the source of the second MOS tube Q2, and then connected with the second output end of the first rectifier unit 101, the same name end of the third winding is connected with the first input end of the second rectifier unit 104, the different name end of the third winding is connected with the same name end of the fourth winding, and the node between the different name end of the third winding and the same name end of the fourth winding is grounded, the different name end of the fourth winding is connected with the second input end of the second rectifier unit 104.

[0048] As shown in Figure 1C the first input end of the second rectifier unit 104 is connected with the same name end of the third winding, the second input end of the second rectifier unit 104 is connected with the different name end of the fourth winding, and the second rectifier unit 104 is used to rectify the second pulsating waveform voltage to output a third pulsating waveform voltage. The second rectifier unit 104 can include two diodes, the anode of one diode is connected with the same name end of the third winding, the anode of the other diode is connected with the different name end of the fourth winding, and the cathodes of the two diodes are connected together.

[0049] According to one embodiment of the present application, as shown in Figure 1DAs shown in the figure, the power adapter 1 can also adopt a half-bridge switching power supply. Specifically, the switching unit 102 includes a first MOS tube Q1, a second MOS tube Q2, and a first capacitor C1 and a second capacitor C2 connected in series and then connected in parallel at the output end of the first rectifying unit 101, the first MOS tube Q1 and the second MOS tube Q2 are connected in series and then connected in parallel at the output end of the first rectifying unit 101, the transformer 103 includes a first winding, a second winding, and a third winding, the same name end of the first winding is connected to the node between the first capacitor C1 and the second capacitor C2 connected in series, the different name end of the first winding is connected to the node between the first MOS tube Q1 and the second MOS tube Q2 connected in series, the same name end of the second winding is connected to the first input end of the second rectifying unit 104, the different name end of the second winding is connected to the same name end of the third winding and then grounded, and the different name end of the third winding is connected to the second input end of the second rectifying unit 104. The transformer 103 is used to output a second pulsating waveform voltage according to the modulated voltage of the first pulsating waveform.

[0050] According to one embodiment of the present application, as Figure 1E As shown in the figure, the power adapter 1 can also adopt a full-bridge switching power supply. Specifically, the switching unit 102 includes a first MOS tube Q1, a second MOS tube Q2, and a third MOS tube Q3 and a fourth MOS tube Q4 connected in series and then connected in parallel at the output end of the first rectifying unit 101, the first MOS tube Q1 and the second MOS tube Q2 are connected in series and then connected in parallel at the output end of the first rectifying unit 101, the transformer 103 includes a first winding, a second winding, and a third winding, the same name end of the first winding is connected to the node between the third MOS tube Q3 and the fourth MOS tube Q4 connected in series, the different name end of the first winding is connected to the node between the first MOS tube Q1 and the second MOS tube Q2 connected in series, the same name end of the second winding is connected to the first input end of the second rectifying unit 104, the different name end of the second winding is connected to the same name end of the third winding and then grounded, and the different name end of the third winding is connected to the second input end of the second rectifying unit 104. The transformer 103 is used to output a second pulsating waveform voltage according to the modulated voltage of the first pulsating waveform.

[0051] Therefore, in the embodiments of the present application, the power adapter 1 can adopt any one of a flyback switching power supply, a forward switching power supply, a push-pull switching power supply, a half-bridge switching power supply, and a full-bridge switching power supply to output a pulsating waveform voltage.

[0052] As Figure 1AAs shown, the second rectifying unit 104 is connected with the secondary winding of the transformer 103, and the second rectifying unit 104 is configured to rectify the voltage of the second pulsating waveform to output a third pulsating waveform. The second rectifying unit 104 can be composed of a diode to realize secondary synchronous rectification, so that the third pulsating waveform is synchronous with the modulated first pulsating waveform. It should be noted that the third pulsating waveform is synchronous with the modulated first pulsating waveform, which means that the phase of the third pulsating waveform is consistent with the phase of the modulated first pulsating waveform, and the amplitude of the third pulsating waveform is consistent with the amplitude variation trend of the modulated first pulsating waveform. The first charging interface 105 is connected with the second rectifying unit 104, the sampling unit 106 is configured to sample the voltage and / or current output by the second rectifying unit 104 to obtain a voltage sampling value and / or a current sampling value, and the control unit 107 is connected with the sampling unit 106 and the switching unit 102. The control unit 107 outputs a control signal to the switching unit 102, and adjusts the duty cycle of the control signal according to the voltage sampling value and / or the current sampling value, so that the voltage of the third pulsating waveform output by the second rectifying unit 104 meets the charging requirement.

[0053] As shown in Figure 1A The terminal 2 includes a second charging interface 201 and a battery 202. When the second charging interface 201 is connected with the first charging interface 105, the second charging interface 201 loads the voltage of the third pulsating waveform to the battery 202 to charge the battery 202.

[0054] It should be noted that the voltage of the third pulsating waveform meets the charging requirement, which means that the voltage and current of the third pulsating waveform meet the charging voltage and charging current when charging the battery. That is, the control unit 107 adjusts the duty cycle of the control signal such as the PWM signal according to the sampled voltage and / or current output by the power adapter to adjust the output of the second rectifying unit 104 in real time, realizes closed-loop adjustment control, so that the voltage of the third pulsating waveform meets the charging requirement of the terminal 2, and ensures that the battery 202 is safely and reliably charged. The charging voltage waveform output to the battery 202 is adjusted by the duty cycle of the PWM signal as shown in Figure 3 The charging current waveform output to the battery 202 is adjusted by the duty cycle of the PWM signal as shown in Figure 4 .

[0055] It can be understood that when adjusting the duty cycle of the PWM signal, the adjustment instruction can be generated according to the voltage sampling value, or according to the current sampling value, or according to the voltage sampling value and the current sampling value.

[0056] Therefore, in the embodiment of the present application, by controlling the switch unit 102, the voltage of the first rectified pulsating waveform, i.e. the steamed-bun wave voltage, is directly PWM chopped and modulated, sent to the high-frequency transformer, coupled from the primary to the secondary through the high-frequency transformer, and then restored into the steamed-bun wave voltage / current after synchronous rectification, directly delivered to the battery, to realize the fast charging of the battery. The voltage amplitude of the steamed-bun wave can be adjusted by the duty cycle of the PWM signal, so that the output of the power adapter meets the charging needs of the battery. As can be seen, the power adapter of the embodiment of the present application cancels the electrolytic capacitors of the primary and secondary, directly charges the battery through the steamed-bun wave voltage, so that the size of the power adapter can be reduced, the miniaturization of the power adapter is realized, and the cost can be greatly reduced.

[0057] In one specific example of the present application, the control unit 107 can be an MCU (Micro Controller Unit, micro control processor), i.e. a microprocessor integrated with switch driving control function, synchronous rectification function, voltage and current regulation control function.

[0058] According to one embodiment of the present application, the modulation control unit is further configured to modulate the voltage of the first pulsating waveform according to the voltage sampling value to make the power adapter intermittently output the voltage of the third pulsating waveform. Specifically, the control unit 107 is further configured to adjust the frequency of the control signal according to the voltage sampling value and / or the current sampling value, i.e. to control the PWM signal output to the switch unit 102 to stop outputting after a period of time, and to start outputting the PWM signal again after a predetermined time, so that the voltage loaded to the battery is intermittent, realizing intermittent charging of the battery, thereby avoiding the safety hazard caused by serious heating of the battery during continuous charging, and improving the reliability and safety of battery charging.

[0059] For lithium batteries, under low temperature conditions, due to the decline of the ion and electron conductivity of lithium batteries, the polarization degree is easily aggravated during charging, and the continuous charging mode will make this polarization more obvious, and also increase the possibility of lithium precipitation, thereby affecting the safety performance of the battery. In addition, continuous charging will cause continuous accumulation of heat formed during charging, causing continuous rise of the internal temperature of the battery, which will limit the performance of the battery and increase the safety hazard when the temperature exceeds a certain limit.

[0060] In the embodiment of the present application, by adjusting the frequency of the control signal, the power adapter is intermittently output, which is equivalent to introducing a battery resting process during the battery charging process, which can alleviate the lithium precipitation phenomenon caused by polarization during continuous charging, and weaken the influence of continuous accumulation of generated heat, achieve the effect of cooling, and ensure the reliability and safety of battery charging.

[0061] The control signal output to the switch unit 102 can be as shown in the following figure. Figure 5 The control signal output to the switch unit 102 can be as shown in the following figure.

[0062] The power adapter and the terminal are connected through the first charging interface to establish bidirectional communication, the modulation control unit acquires the state information of the terminal according to the bidirectional communication between the power adapter and the terminal, and modulates the voltage of the first pulsating waveform according to the state information of the terminal and the voltage sampling value.

[0063] As shown in the following figure, the control unit 107 is connected with the first charging interface 105, and the control unit 107 is also used to communicate with the terminal 2 through the first charging interface 105 to acquire the state information of the terminal 2. Figure 1A As shown in the following figure, the control unit 107 is connected with the first charging interface 105, and the control unit 107 is also used to communicate with the terminal 2 through the first charging interface 105 to acquire the state information of the terminal 2.

[0064] The state information of the terminal can include the power of the battery, the temperature of the battery, the voltage of the battery, the interface information of the terminal, the information of the access impedance of the terminal, etc.

[0065] Specifically, the first charging interface 105 includes a power line and a data line, the power line is used to charge the battery, and the data line is used to communicate with the terminal. When the second charging interface 201 is connected with the first charging interface 105, the power adapter 1 and the terminal 2 can send communication inquiry instructions to each other, and after receiving the corresponding response instructions, the power adapter 1 and the terminal 2 establish a communication connection, and the control unit 107 can acquire the state information of the terminal 2, so as to negotiate the charging mode and the charging parameters (such as the charging current and the charging voltage) with the terminal 2, and control the charging process.

[0066] The charging mode supported by the power adapter and / or the terminal can include a normal charging mode and a fast charging mode. The charging speed of the fast charging mode is greater than the charging speed of the normal charging mode (for example, the charging current of the fast charging mode is greater than the charging current of the normal charging mode). Generally, the normal charging mode can be understood as a charging mode with a rated output voltage of 5V and a rated output current less than or equal to 2.5A, and in addition, in the normal charging mode, D+ and D- in the data line of the power adapter output port can be short-circuited. The fast charging mode in the embodiment of the application is different. In the fast charging mode, the power adapter can use D+ and D- in the data line to communicate with the terminal to realize data exchange, that is, the power adapter and the terminal can send fast charging instructions to each other: the power adapter sends a fast charging inquiry instruction to the terminal, and after receiving a fast charging response instruction from the terminal, the power adapter obtains the state information of the terminal according to the response instruction of the terminal, and starts the fast charging mode. The charging current in the fast charging mode can be greater than 2.5A, for example, it can reach 4.5A or even more. However, the embodiment of the application does not make specific limitation on the normal charging mode, as long as the power adapter supports two charging modes, and the charging speed (or current) of one of the charging modes is greater than the charging speed of the other charging mode, then the charging mode with slower charging speed can be understood as the normal charging mode. Relative to the charging power, the charging power in the fast charging mode can be greater than or equal to 15W.

[0067] That is, the control unit 107 communicates with the terminal 2 through the first charging interface 105 to determine the charging mode, wherein the charging mode includes a fast charging mode and a normal charging mode.

[0068] Specifically, the power adapter and the terminal are connected through a universal serial bus (USB) interface, which can be a normal USB interface or a micro USB interface. The data line in the USB interface, that is, the data line in the first charging interface, is used for bidirectional communication between the power adapter and the terminal. The data line can be a D+ line and / or a D- line in the USB interface, and the bidirectional communication can mean that the power adapter and the terminal exchange information.

[0069] The power adapter communicates with the terminal through the data line in the USB interface to determine to charge the terminal in the fast charging mode.

[0070] It should be noted that during the process of negotiating with the terminal whether to charge the terminal in the fast charging mode, the power adapter can only keep connected with the terminal, not charge, or charge the terminal in the normal charging mode, or charge the terminal with a small current, and the embodiments of the present application do not make specific limitation.

[0071] The power adapter adjusts the charging current to the charging current corresponding to the fast charging mode to charge the terminal. After the power adapter determines to charge the terminal in the fast charging mode, the charging current can be directly adjusted to the charging current corresponding to the fast charging mode, or the charging current corresponding to the fast charging mode can be negotiated with the terminal, for example, the charging current corresponding to the fast charging mode is determined according to the current power of the battery in the terminal.

[0072] In the embodiments of the present application, the power adapter does not blindly increase the output current for fast charging, but needs to communicate with the terminal bidirectionally to negotiate whether the fast charging mode can be used, compared with the prior art, the safety of the fast charging process is improved.

[0073] Optionally, as an embodiment, when the control unit 107 determines to charge the terminal in the fast charging mode through the bidirectional communication with the terminal through the data line in the first charging interface, the control unit sends a first instruction to the terminal, and the first instruction is used to inquire whether the terminal starts the fast charging mode; the control unit receives a reply instruction of the first instruction from the terminal, and the reply instruction of the first instruction is used to indicate that the terminal agrees to start the fast charging mode.

[0074] Optionally, as an embodiment, before the control unit sends the first instruction to the terminal, the power adapter charges the terminal through the normal charging mode, and after the control unit determines that the charging time of the normal charging mode is greater than a preset threshold, the control unit sends the first instruction to the terminal.

[0075] It should be understood that when the power adapter determines that the charging time of the normal charging mode is greater than the preset threshold, the power adapter can consider that the terminal has recognized itself as the power adapter and can start the fast charging inquiry communication.

[0076] Optionally, as an embodiment, the power adapter determines to charge for a preset time length with a charging current greater than or equal to a preset current threshold, and then sends the first instruction to the terminal.

[0077] Optionally, as an embodiment, the control unit is further configured to control the switch unit to control the power adapter to adjust the charging current to the charging current corresponding to the fast charging mode, and before the power adapter charges the terminal with the charging current corresponding to the fast charging mode, the control unit is configured to communicate with the terminal through the data line in the first charging interface to determine the charging voltage corresponding to the fast charging mode, and control the power adapter to adjust the charging voltage to the charging voltage corresponding to the fast charging mode.

[0078] Optionally, as an embodiment, when the control unit communicates with the terminal through the data line in the first charging interface to determine the charging voltage corresponding to the fast charging mode, the control unit is configured to send a second instruction to the terminal, the second instruction is used to inquire whether the current output voltage of the power adapter is suitable as the charging voltage of the fast charging mode; the control unit is configured to receive a reply instruction of the second instruction sent by the terminal, the reply instruction of the second instruction is used to indicate that the current output voltage of the power adapter is suitable, too high or too low; and the control unit is configured to determine the charging voltage of the fast charging mode according to the reply instruction of the second instruction.

[0079] Optionally, as an embodiment, before the control unit controls the switch unit to control the power adapter to adjust the charging current to the charging current corresponding to the fast charging mode, the control unit is further configured to communicate with the terminal through the data line in the first charging interface to determine the charging current corresponding to the fast charging mode.

[0080] Optionally, as an embodiment, when the control unit communicates with the terminal through the data line in the first charging interface to determine the charging current corresponding to the fast charging mode, the control unit is configured to send a third instruction to the terminal, the third instruction is used to inquire the maximum charging current currently supported by the terminal; the control unit is configured to receive a reply instruction of the third instruction sent by the terminal, the reply instruction of the third instruction is used to indicate the maximum charging current currently supported by the terminal; and the control unit is configured to determine the charging current of the fast charging mode according to the reply instruction of the third instruction.

[0081] The power adapter can directly determine the above-mentioned maximum charging current as the charging current of the fast charging mode, or set the charging current to a certain current value less than the maximum charging current.

[0082] Optionally, as an embodiment, during the process that the power adapter charges the terminal using the fast charging mode, the control unit further communicates with the terminal through the data line in the first charging interface to continuously adjust the charging current output from the power adapter to the battery by controlling the switch unit.

[0083] The power adapter can continuously inquire the current state information of the terminal, such as inquiring the battery voltage and the battery capacity of the terminal, so as to continuously adjust the charging current output from the power adapter to the battery.

[0084] Optionally, as an embodiment, during the process that the control unit communicates with the terminal through the data line in the first charging interface to continuously adjust the charging current output from the power adapter to the battery by controlling the switch unit, the control unit sends a fourth instruction to the terminal, the fourth instruction is used to inquire the current voltage of the battery in the terminal; the control unit receives the reply instruction of the fourth instruction sent by the terminal, the reply instruction of the fourth instruction is used to indicate the current voltage of the battery in the terminal; the control unit adjusts the charging current output from the power adapter to the battery by controlling the switch unit according to the current voltage of the battery.

[0085] Optionally, as an embodiment, the control unit adjusts the charging current output from the power adapter to the battery to the charging current value corresponding to the current voltage of the battery by controlling the switch unit according to the current voltage of the battery and the preset corresponding relationship between the battery voltage value and the charging current value.

[0086] Specifically, the power adapter can pre-store the corresponding relationship between the battery voltage value and the charging current value, and the power adapter can also acquire the corresponding relationship between the battery voltage value and the charging current value stored in the terminal from the terminal side by communicating with the terminal through the data line in the first charging interface.

[0087] Optionally, as an embodiment, during the process that the power adapter charges the terminal using the fast charging mode, the control unit further communicates with the terminal through the data line in the first charging interface to determine whether the contact between the first charging interface and the second charging interface is poor, wherein, when it is determined that the contact between the first charging interface and the second charging interface is poor, the control unit controls the power adapter to exit the fast charging mode.

[0088] Optionally, as an embodiment, before determining whether the first charging interface and the second charging interface are in poor contact, the control unit further receives information indicating the terminal's pass-through impedance from the terminal, wherein the control unit sends a fourth instruction to the terminal, the fourth instruction being used to inquire the voltage of the battery in the terminal; the control unit receives a reply instruction of the fourth instruction sent by the terminal, the reply instruction of the fourth instruction being used to indicate the voltage of the battery in the terminal; the control unit determines the pass-through impedance from the power adapter to the battery according to the output voltage of the power adapter and the voltage of the battery; and the control unit determines whether the first charging interface and the second charging interface are in poor contact according to the pass-through impedance from the power adapter to the battery, the pass-through impedance of the terminal, and the pass-through impedance of the charging line between the power adapter and the terminal.

[0089] The terminal can pre-record its pass-through impedance. For example, terminals of the same model have the same structure, and thus the pass-through impedance of the terminals is set to the same value when the terminals are set at the factory. Similarly, the power adapter can pre-record the pass-through impedance of the charging line. When the power adapter obtains the voltage across the battery of the terminal, the pass-through impedance of the entire pass-through path can be determined according to the voltage drop from the power adapter to the battery and the current of the pass-through path. When the pass-through impedance of the entire pass-through path is greater than the pass-through impedance of the terminal plus the pass-through impedance of the charging line, or the pass-through impedance of the entire pass-through path is greater than the pass-through impedance of the terminal plus the pass-through impedance of the charging line by an impedance threshold, it can be considered that the first charging interface and the second charging interface are in poor contact.

[0090] Optionally, as an embodiment, before the power adapter exits the fast charging mode, the control unit further sends a fifth instruction to the terminal, the fifth instruction being used to indicate that the first charging interface and the second charging interface are in poor contact.

[0091] After the power adapter sends the fifth instruction, the power adapter can exit the fast charging mode or be reset.

[0092] The above describes the fast charging process according to an embodiment of the present application from the perspective of the power adapter. The fast charging process according to an embodiment of the present application is described below from the perspective of the terminal.

[0093] It should be understood that the interaction between the power adapter and the terminal and the related characteristics and functions described from the perspective of the terminal correspond to those described from the perspective of the power adapter. For brevity, repeated descriptions are appropriately omitted.

[0094] According to an embodiment of the present application, as Figure 13As shown, the terminal 2 further comprises a charging control switch 203 and a controller 204, the charging control switch 203, for example, a switch circuit composed of an electronic switch device, is connected between the second charging interface 201 and the battery 202, and the charging control switch 203 is used to shut off or open the charging process of the battery 202 under the control of the controller 204, so that the charging process of the battery 202 can also be controlled from the terminal side, and the safety and reliability of the charging of the battery 202 are ensured.

[0095] And, as Figure 14 shown, the terminal 2 further comprises a communication unit 205, the communication unit 205 is used to establish bidirectional communication between the controller 204 and the control unit 107 through the second charging interface 201 and the first charging interface 105. That is, the terminal 2 and the power adapter 1 can perform bidirectional communication through the data line in the USB interface, the terminal 2 supports a normal charging mode and a fast charging mode, the charging current of the fast charging mode is greater than that of the normal charging mode, the communication unit 205 and the control unit 107 perform bidirectional communication so that the power adapter 1 determines to charge the terminal 2 in the fast charging mode, and the control unit 107 controls the power adapter 1 to output the charging current corresponding to the fast charging mode to charge the battery 202 in the terminal 2.

[0096] In the embodiment of the application, the power adapter 1 does not blindly increase the output current for fast charging, but needs to perform bidirectional communication with the terminal 2 to negotiate whether the fast charging mode can be used, compared with the prior art, the safety of the fast charging process is improved.

[0097] Optionally, as one embodiment, the controller receives a first instruction sent by the control unit through the communication unit, the first instruction is used to inquire whether the terminal starts the fast charging mode; the controller sends a reply instruction of the first instruction to the control unit through the communication unit, and the reply instruction of the first instruction is used to indicate that the terminal agrees to start the fast charging mode.

[0098] Optionally, as one embodiment, before the controller receives the first instruction sent by the control unit through the communication unit, the power adapter charges the battery in the terminal through the normal charging mode, and the control unit sends the first instruction to the communication unit in the terminal after determining that the charging time of the normal charging mode is greater than a preset threshold, and the controller receives the first instruction sent by the control unit through the communication unit.

[0099] Optionally, as one embodiment, the controller receives a second instruction sent by the control unit, the second instruction is used to inquire whether the current output voltage of the power adapter is suitable as the charging voltage of the fast charging mode; the controller sends a reply instruction of the second instruction to the control unit, the reply instruction of the second instruction is used to indicate that the current output voltage of the power adapter is suitable, too high or too low.

[0100] Optionally, as one embodiment, the controller receives a second instruction sent by the control unit, the second instruction is used to inquire whether the current output voltage of the power adapter is suitable as the charging voltage of the fast charging mode; the controller sends a reply instruction of the second instruction to the control unit, the reply instruction of the second instruction is used to indicate that the current output voltage of the power adapter is suitable, too high or too low.

[0101] Optionally, as one embodiment, the controller receives a second instruction sent by the control unit, the second instruction is used to inquire whether the current output voltage of the power adapter is suitable as the charging voltage of the fast charging mode; the controller sends a reply instruction of the second instruction to the control unit, the reply instruction of the second instruction is used to indicate that the current output voltage of the power adapter is suitable, too high or too low.

[0102] Optionally, as one embodiment, the controller receives a third instruction sent by the control unit, the third instruction is used to inquire the maximum charging current currently supported by the terminal; the controller sends a reply instruction of the third instruction to the control unit, the reply instruction of the third instruction is used to indicate the maximum charging current currently supported by the battery in the terminal, so that the power adapter determines the charging current corresponding to the fast charging mode according to the maximum charging current.

[0103] Optionally, as one embodiment, during the process that the power adapter charges the terminal using the fast charging mode, the controller communicates with the control unit bidirectionally, so that the power adapter constantly adjusts the charging current output by the power adapter to the battery.

[0104] Optionally, as one embodiment, during the process that the power adapter charges the terminal using the fast charging mode, the controller communicates with the control unit bidirectionally, so that the power adapter constantly adjusts the charging current output by the power adapter to the battery.

[0105] Optionally, as one embodiment, during the process that the power adapter charges the terminal using the fast charging mode, the controller communicates with the control unit bidirectionally, so that the power adapter determines whether the contact between the first charging interface and the second charging interface is poor.

[0106] The controller receives a fourth instruction from the control unit, which is used to query the current voltage of the battery in the terminal; the controller sends a reply instruction to the control unit, which is used to indicate the current voltage of the battery in the terminal, so that the control unit can determine whether there is poor contact between the first charging interface and the second charging interface based on the output voltage of the power adapter and the current voltage of the battery.

[0107] Optionally, as an embodiment, the controller receives a fifth instruction sent by the control unit, the fifth instruction being used to indicate poor contact between the first charging interface and the second charging interface.

[0108] To enable and use fast charging mode, the power adapter can initiate a fast charging communication process with the device, negotiating through one or more handshakes to achieve fast battery charging. The following section combines... Figure 6 This document describes in detail the fast charging communication process of embodiments of the present invention, as well as the various stages included in the fast charging process. It should be understood that... Figure 6 The communication steps or operations shown are merely examples; other operations or procedures may be performed in embodiments of the present invention. Figure 6 Variations of various operations within it. Furthermore, Figure 6 The various stages in can be arranged according to... Figure 6 The different orders in which they are presented may be executed, and may not even be intended to be executed. Figure 6 All operations within. It should be noted that... Figure 6 The curve shown is the trend of the peak or average value of the charging current, not the actual charging current curve.

[0109] like Figure 6 As shown, the fast charging process can include five stages:

[0110] Phase 1:

[0111] After the terminal is connected to the power supply device, the terminal can detect the type of the power supply device through the data lines D+ and D-. When the power supply device is detected to be a power adapter, the current absorbed by the terminal can be greater than a preset current threshold I2 (e.g., 1A). When the power adapter detects that the power adapter output current is greater than or equal to I2 within a preset time period (e.g., a continuous time T1), the power adapter considers that the terminal has completed the identification of the power supply device type. The power adapter then initiates handshake communication between the adapter and the terminal, and sends instruction 1 (corresponding to the first instruction mentioned above) to ask the terminal whether to enable fast charging mode (or flash charging).

[0112] When the power adapter receives the reply instruction from the terminal indicating that the terminal does not agree to start the fast charging mode, the output current of the power adapter is detected again. When the output current of the power adapter is still greater than or equal to I2 within a preset continuous time (for example, the continuous T1 time), the step of inquiring whether the terminal starts the fast charging mode is initiated again, and the above steps of stage 1 are repeated until the terminal replies to agree to start the fast charging mode, or the output current of the power adapter no longer meets the condition of being greater than or equal to I2.

[0113] When the terminal agrees to start the fast charging mode, the fast charging process starts, and the fast charging communication flow enters stage 2.

[0114] Stage 2:

[0115] The output voltage of the power adapter can include multiple gears. The power adapter sends instruction 2 (corresponding to the second instruction described above) to the terminal to inquire whether the output voltage of the power adapter matches the current voltage of the battery (or whether it is appropriate, that is, whether it is suitable as the charging voltage in the fast charging mode), that is, whether it meets the charging requirement.

[0116] When the terminal replies that the output voltage of the power adapter is too high or too low or matches, when the power adapter receives the feedback from the terminal that the output voltage of the adapter is too high or too low, the control unit adjusts the duty cycle of the PWM signal to adjust the output voltage of the power adapter by one gear, and sends instruction 2 to the terminal again to inquire whether the output voltage of the power adapter matches.

[0117] The above steps of stage 2 are repeated until the terminal replies that the output voltage of the power adapter is in the matching gear, and stage 3 is entered.

[0118] Stage 3:

[0119] When the power adapter receives the feedback from the terminal that the output voltage of the power adapter matches, the power adapter sends instruction 3 (corresponding to the third instruction described above) to the terminal to inquire about the maximum charging current currently supported by the terminal. The terminal replies to the power adapter about the maximum charging current value currently supported by the terminal, and enters stage 4.

[0120] Stage 4:

[0121] After the power adapter receives the feedback of the maximum charging current value currently supported by the terminal in reply to the terminal, the power adapter can set its output current reference value, and the control unit 107 adjusts the duty cycle of the PWM signal according to the current reference value, so that the output current of the power adapter meets the charging current requirement of the terminal, that is, enters the constant current stage. The constant current stage here refers to that the peak or average value of the output current of the power adapter basically remains unchanged (that is, the change range of the peak or average value of the output current is very small, such as within 5% of the peak or average value of the output current), that is, the peak of the current of the third pulsating waveform remains constant in each period.

[0122] Stage 5:

[0123] When entering the constant current variation stage, the power adapter sends instruction 4 (corresponding to the fourth instruction described above) every interval to inquire the current voltage of the terminal battery, and the terminal can feed back the current voltage of the terminal battery to the power adapter. The power adapter can determine whether the USB contact, that is, the contact between the first charging interface and the second charging interface, is good and whether the current charging current value of the terminal needs to be reduced according to the feedback of the terminal about the current voltage of the terminal battery. When the power adapter determines that the USB contact is not good, it sends instruction 5 (corresponding to the fifth instruction described above), and then resets to re-enter stage 1.

[0124] Optionally, in some embodiments, in stage 1, when the terminal replies to instruction 1, the data corresponding to instruction 1 can be accompanied by the data (or information) of the terminal's path impedance. The terminal path impedance data can be used to determine whether the USB contact is good in stage 5.

[0125] Optionally, in some embodiments, in stage 2, the time from the terminal agreeing to start the fast charging mode to the power adapter adjusting the voltage to the appropriate value can be controlled within a certain range. If the time exceeds the predetermined range, the terminal can determine that the request is abnormal and perform a fast reset.

[0126] Optionally, in some embodiments, in stage 2, the terminal can feed back to the power adapter that the output voltage of the power adapter is appropriate / matched when the output voltage of the power adapter is adjusted to be higher than the current voltage of the battery by ΔV (ΔV is about 200-500 mV). When the terminal feeds back to the power adapter that the output voltage of the power adapter is not appropriate (i.e., too high or too low), the control unit 107 adjusts the duty cycle of the PWM signal according to the voltage sampling value, thereby adjusting the output voltage of the power adapter.

[0127] Optionally, in some embodiments, in stage 4, the adjustment speed of the output current value of the power adapter can be controlled within a certain range, so that fast charging abnormal interruption caused by too fast adjustment speed can be avoided.

[0128] Optionally, in some embodiments, in stage 5, the magnitude of the change in the output current value of the power adapter can be controlled within 5%, which can be considered as a constant current stage.

[0129] Optionally, in some embodiments, in stage 5, the power adapter monitors the charging circuit impedance in real time, that is, by measuring the power adapter's output voltage, the current charging current, and the read terminal battery voltage, the impedance of the entire charging circuit is monitored. When the measured charging circuit impedance is greater than the terminal path impedance plus the fast charging data line impedance, it can be considered that the USB contact is poor, and a fast charging reset is performed.

[0130] Optionally, in some embodiments, after fast charging mode is enabled, the communication time interval between the power adapter and the terminal can be controlled within a certain range to avoid fast charging reset.

[0131] Optionally, in some embodiments, the termination of the fast charging mode (or fast charging process) can be divided into two types: recoverable termination and non-recoverable termination.

[0132] For example, when the terminal detects that the battery is fully charged or the USB connection is faulty, fast charging stops and resets, entering stage 1. The terminal does not agree to enable fast charging mode, and the fast charging communication process does not enter stage 2. At this time, the stopped fast charging process can be an irreversible stop.

[0133] For example, when a communication error occurs between the terminal and the power adapter, fast charging stops and resets to enter phase 1. After the requirements of phase 1 are met, the terminal agrees to enable fast charging mode to resume the fast charging process. At this time, the stopped fast charging process can be a recoverable stop.

[0134] For example, when the terminal detects a battery malfunction, fast charging stops and resets to enter Phase 1. In Phase 1, the terminal does not allow fast charging to resume. Only after the battery returns to normal and the requirements of Phase 1 are met does the terminal allow fast charging to resume. In this case, the stopped fast charging process can be a reversible stop.

[0135] It should be specifically noted that the above refers to... Figure 6 The communication steps or operations shown are merely examples. For instance, in stage 1, after the terminal connects to the adapter, the handshake communication between the terminal and the adapter can also be initiated by the terminal. That is, the terminal sends instruction 1 to ask the adapter whether to enable fast charging mode (or flash charging). When the terminal receives a reply instruction from the power adapter indicating that the power adapter agrees to enable fast charging mode, the fast charging process begins.

[0136] It should be specifically noted that the above refers to... Figure 6The illustrated communication steps or operations are only examples. For example, after stage 5, a constant-voltage charging stage can also be included. That is, in stage 5, the terminal can feed back the current voltage of the terminal battery to the power adapter. As the voltage of the terminal battery continuously rises, when the current voltage of the terminal battery reaches a constant-voltage charging voltage threshold, the charging enters the constant-voltage charging stage. The control unit 107 adjusts the duty cycle of the PWM signal according to the voltage reference value (i.e., the constant-voltage charging voltage threshold) so that the output voltage of the power adapter meets the terminal charging voltage requirement, i.e., the voltage basically remains constant. In the constant-voltage charging stage, the charging current gradually decreases, and when the current decreases to a certain threshold, the charging is stopped, at which time it is identified that the battery has been fully charged. Here, the constant-voltage charging refers to the fact that the peak voltage of the third pulsating waveform basically remains constant.

[0137] It can be understood that, in the embodiments of the present application, the output voltage of the power adapter refers to the peak voltage or the average voltage of the third pulsating waveform, and the output current of the power adapter refers to the peak current or the average current of the third pulsating waveform.

[0138] In one embodiment of the present application, as shown in Figure 7A The power adapter 1 further includes a controllable switch 108 and a filter unit 109 connected in series, and the controllable switch 108 and the filter unit 109 are connected to the first output end of the second rectifying unit 104. The control unit 107 is further configured to control the controllable switch 108 to be closed when it is determined that the charging mode is the ordinary charging mode, and to be opened when it is determined that the charging mode is the fast charging mode. In addition, one or more groups of small capacitors are connected in parallel to the output end of the second rectifying unit 104, which not only can play a role in reducing noise, but also can reduce the occurrence of inrush phenomenon. Alternatively, an LC filter circuit or a π-type filter circuit can be connected to the output end of the second rectifying unit 104 to filter out ripple interference. As shown in Figure 7B It should be noted that the capacitors in the LC filter circuit or the π-type filter circuit are small capacitors, which occupy very small space. That is, the filter unit is configured to perform filtering processing on the voltage of the third pulsating waveform, and the controllable switch is configured to control whether the filter unit performs filtering work. The modulation control unit is further configured to control the controllable switch to be closed to make the filter unit work when it is determined that the charging mode is the ordinary charging mode, and to be opened to make the filter unit stop working when it is determined that the charging mode is the fast charging mode.

[0139] The filter unit 109 comprises a filter capacitor, which can support 5V normal charging, i.e., corresponding to the normal charging mode, and the controllable switch 108 can be composed of a semiconductor switching device, such as a MOS tube. When the power adapter charges the battery in the terminal in the normal charging mode (or normal charging), the control unit 107 controls the controllable switch 108 to be closed, and the filter unit 109 is connected to the circuit, so that the output of the second rectifier unit can be filtered, which can better adapt to the direct current charging technology, i.e., direct current is loaded to the battery of the terminal, and direct current charging of the battery is realized. For example, in general, the filter unit comprises a parallel electrolytic capacitor and a normal capacitor, i.e., a small capacitor (such as a solid-state capacitor) supporting 5V normal charging. Since the electrolytic capacitor occupies a relatively large volume, in order to reduce the size of the power adapter, the electrolytic capacitor in the power adapter can be removed, and a capacitor with a smaller capacity is retained. When the normal charging mode is used, the branch in which the small capacitor is located can be controlled to be conductive, the current is filtered, small power stable output is realized, and direct current charging of the battery is realized; when the fast charging mode is used, the branch in which the small capacitor is located can be controlled to be disconnected, the output of the second rectifier unit 104 is not filtered, and a pulsating waveform voltage / current is directly output, which is applied to the battery, and fast charging of the battery is realized.

[0140] According to one embodiment of the present application, the control unit 107 is further configured to acquire a charging current and / or a charging voltage corresponding to the fast charging mode according to the state information of the terminal when it is determined that the charging mode is the fast charging mode, and adjust the duty cycle of the control signal, such as the PWM signal, according to the charging current and / or the charging voltage corresponding to the fast charging mode. That is, when it is determined that the current charging mode is the fast charging mode, the control unit 107 acquires the charging current and / or the charging voltage corresponding to the fast charging mode according to the acquired state information of the terminal, such as the voltage, capacity, temperature of the battery, operating parameters of the terminal, and power consumption information of the application program running on the terminal, and then adjusts the duty cycle of the control signal according to the acquired charging current and / or charging voltage, so that the output of the power adapter meets the charging demand, and fast charging of the battery is realized.

[0141] The state information of the terminal comprises the temperature of the battery. When the temperature of the battery is greater than a first preset temperature threshold or the temperature of the battery is less than a second preset temperature threshold, if the current charging mode is the fast charging mode, the fast charging mode is switched to the normal charging mode, wherein the first preset temperature threshold is greater than the second preset temperature threshold. That is, when the temperature of the battery is too low (e.g., less than the second preset temperature threshold) or too high (e.g., greater than the first preset temperature threshold), it is not suitable for fast charging, so the fast charging mode needs to be switched to the normal charging mode. In the embodiments of the present application, the first preset temperature threshold and the second preset temperature threshold can be set according to the actual situation or written into the storage of the control unit (such as the MCU of the power adapter).

[0142] In one embodiment of the present application, the control unit 107 is further configured to control the switch unit 102 to be turned off when the temperature of the battery is greater than a preset high-temperature protection threshold, i.e., when the temperature of the battery exceeds the high-temperature protection threshold, the control unit 107 needs to adopt a high-temperature protection strategy, and controls the switch unit 102 to be in an off state, so that the power adapter stops charging the battery, thereby achieving high-temperature protection of the battery and improving the safety of charging. The high-temperature protection threshold and the first temperature threshold can be different or the same. Preferably, the high-temperature protection threshold is greater than the first temperature threshold.

[0143] In another embodiment of the present application, the controller is further configured to obtain the temperature of the battery, and control the charging control switch to be turned off when the temperature of the battery is greater than a preset high-temperature protection threshold, i.e., the charging control switch is turned off from the terminal side, thereby turning off the charging process of the battery and ensuring the safety of charging.

[0144] In one embodiment of the present application, the control unit is further configured to obtain the temperature of the first charging interface, and control the switch unit to be turned off when the temperature of the first charging interface is greater than a preset protection temperature, i.e., when the temperature of the charging interface exceeds a certain temperature, the control unit 107 also needs to execute a high-temperature protection strategy, and controls the switch unit 102 to be turned off, so that the power adapter stops charging the battery, thereby achieving high-temperature protection of the charging interface and improving the safety of charging.

[0145] Of course, in another embodiment of the present application, the controller obtains the temperature of the first charging interface through bidirectional communication with the control unit, and controls the charging control switch (see Figure 13 and Figure 14 ) to be turned off when the temperature of the first charging interface is greater than a preset protection temperature, i.e., the charging control switch is turned off from the terminal side, thereby turning off the charging process of the battery and ensuring the safety of charging.

[0146] Specifically, in one embodiment of the present application, as shown in Figure 8 the power adapter 1 further includes a driving unit 110, such as a MOSFET driver, which is connected between the switch unit 102 and the control unit 107, and is configured to drive the switch unit 102 to be turned on or turned off according to a control signal. It should be noted that in other embodiments of the present application, the driving unit 110 can also be integrated in the control unit 107.

[0147] In addition, as shown in Figure 8As shown, the power adapter 1 further comprises an isolation unit 111 connected between the driving unit 110 and the control unit 107, to realize signal isolation between the primary and the secondary of the power adapter 1 (or signal isolation between the primary winding and the secondary winding of the transformer 103). The isolation unit 111 can be in the form of optical coupling isolation, or other isolation forms. By arranging the isolation unit 111, the control unit 107 can be arranged at the secondary side of the power adapter 1 (or the secondary winding side of the transformer 103), so as to facilitate communication with the terminal 2, and make the space design of the power adapter 1 simpler and easier.

[0148] Of course, it can be understood that in other embodiments of the present application, the control unit 107 and the driving unit 110 can be arranged at the primary side, and the isolation unit 111 can be arranged between the control unit 107 and the sampling unit 106 to realize signal isolation between the primary and the secondary of the power adapter 1.

[0149] It should be noted that in the embodiments of the present application, when the control unit 107 is arranged at the secondary side, the isolation unit 111 needs to be arranged, and the isolation unit 111 can also be integrated in the control unit 107. That is, when the signal is transmitted from the primary to the secondary or from the secondary to the primary, the isolation unit needs to be arranged to realize signal isolation.

[0150] In one embodiment of the present application, as shown in Figure 9 As shown, the power adapter 1 further comprises an auxiliary winding and a power supply unit 112, the auxiliary winding generates a voltage of a fourth pulsating waveform according to the voltage of the modulated first pulsating waveform, and the power supply unit 112 is connected with the auxiliary winding. The power supply unit 112 (for example, comprising a filter and voltage stabilizing module, a voltage conversion module, etc.) is used to convert the voltage of the fourth pulsating waveform to output direct current, to supply power to the driving unit 110 and / or the control unit 107. The power supply unit 112 can be composed of a filter small capacitor, a voltage stabilizing chip, etc., to process and convert the voltage of the fourth pulsating waveform, to output low voltage direct current such as 3.3V or 5V.

[0151] That is, the power supply of the driving unit 110 can be converted from the voltage of the fourth pulsating waveform by the power supply unit 112, and when the control unit 107 is arranged at the primary side, the power supply thereof can also be converted from the voltage of the fourth pulsating waveform by the power supply unit 112. As shown in Figure 9 When the control unit 107 is arranged at the primary side, the power supply unit 112 provides two paths of direct current output to supply power to the driving unit 110 and the control unit 107 respectively, and the optical coupling isolation unit 111 is arranged between the control unit 107 and the sampling unit 106 to realize signal isolation between the primary and the secondary of the power adapter 1.

[0152] When the control unit 107 is arranged at the primary side and integrated with the driving unit 110, the power supply unit 112 separately supplies power to the control unit 107. When the control unit 107 is arranged at the secondary side and the driving unit 110 is arranged at the primary side, the power supply unit 112 separately supplies power to the driving unit 110, and the control unit 107 is supplied with power by the secondary, for example, by a power supply unit converting the voltage of the third pulsating waveform output by the second rectifying unit 104 into a direct current power source.

[0153] Also, in the embodiment of the present application, the output end of the first rectifying unit 101 is also connected in parallel with a plurality of small capacitors, which play a filtering role. Alternatively, the output end of the first rectifying unit 101 is connected with an LC filter circuit.

[0154] In another embodiment of the present application, as shown in Figure 10 The power adapter 1 further comprises a first voltage detection unit 113 connected with the auxiliary winding and the control unit 107 respectively, and the first voltage detection unit 113 is used to detect the voltage of the fourth pulsating waveform to generate a voltage detection value, wherein the control unit 107 is further used to adjust the duty cycle of the control signal according to the voltage detection value.

[0155] That is, the control unit 107 can reflect the voltage output by the second rectifying unit 104 according to the voltage output by the auxiliary winding detected by the first voltage detection unit 113, and then adjust the duty cycle of the control signal according to the voltage detection value, so that the output of the second rectifying unit 104 matches the charging demand of the battery.

[0156] Specifically, in one embodiment of the present application, as shown in Figure 11 The sampling unit 106 comprises a first current sampling circuit 1061 and a first voltage sampling circuit 1062. The first current sampling circuit 1061 is used to sample the current output by the second rectifying unit 104 to obtain a current sampling value, and the first voltage sampling circuit 1062 is used to sample the voltage output by the second rectifying unit 104 to obtain a voltage sampling value.

[0157] Alternatively, the first current sampling circuit 1061 can sample the current output by the second rectifying unit 104 by sampling the voltage across a resistance (current sensing resistance) connected to the first output end of the second rectifying unit 104. The first voltage sampling circuit 1062 can sample the voltage output by the second rectifying unit 104 by sampling the voltage between the first output end and the second output end of the second rectifying unit 104.

[0158] Also, in one embodiment of the present application, as shown in Figure 11As shown, the first voltage sampling circuit 1062 comprises a peak voltage sampling and holding unit, a zero-crossing sampling unit, a bleeder unit and an AD sampling unit. The peak voltage sampling and holding unit is used to sample and hold the peak voltage of the voltage of the third pulsating waveform, the zero-crossing sampling unit is used to sample the zero-crossing point of the voltage of the third pulsating waveform, the bleeder unit is used to bleed the peak voltage sampling and holding unit at the zero-crossing point, and the AD sampling unit is used to sample the peak voltage in the peak voltage sampling and holding unit to obtain a voltage sampling value.

[0159] By arranging the peak voltage sampling and holding unit, the zero-crossing sampling unit, the bleeder unit and the AD sampling unit in the first voltage sampling circuit 1062, the voltage output by the second rectifying unit 104 can be accurately sampled, and the voltage sampling value can be kept in phase synchronization with the voltage of the first pulsating waveform, i.e., the amplitude variation trend is kept consistent.

[0160] According to one embodiment of the present application, as Figure 12 As shown, the power adapter 1 further comprises a second voltage sampling circuit 114, which is used to sample the voltage of the first pulsating waveform, and is connected to the control unit 107. When the voltage value sampled by the second voltage sampling circuit 114 is greater than a first preset voltage value, the control unit 107 controls the switch unit 102 to be turned on for a first preset time to discharge the inrush voltage and the peak voltage in the first pulsating waveform.

[0161] As shown in Figure 12 The second voltage sampling circuit 114 can be connected to the first output end and the second output end of the first rectifying unit 101 to sample the voltage of the first pulsating waveform. The control unit 107 judges the voltage value sampled by the second voltage sampling circuit 114. If the voltage value sampled by the second voltage sampling circuit 114 is greater than the first preset voltage value, it means that the power adapter 1 is disturbed by lightning, and an inrush voltage occurs. At this time, the inrush voltage needs to be discharged to ensure the safety and reliability of charging. The control unit 107 controls the switch unit 102 to be turned on for a period of time to form a bleeder path to discharge the inrush voltage caused by lightning, prevent the interference caused by lightning on the power adapter when charging the terminal, and effectively improve the safety and reliability of the terminal when charging. The first preset voltage value can be calibrated according to actual conditions.

[0162] In one embodiment of the present application, during the process of charging the battery 202 of the terminal 2 by the power adapter 1, the control unit 107 is further configured to control the switch unit 102 to be off when the voltage value sampled by the sampling unit 106 is greater than a second preset voltage value, i.e., the control unit 107 is further configured to determine the magnitude of the voltage value sampled by the sampling unit 106, and if the voltage value sampled by the sampling unit 106 is greater than the second preset voltage value, it indicates that the voltage output by the power adapter 1 is too high, and at this time, the control unit 107 controls the switch unit 102 to be off so as to stop the power adapter 1 from charging the battery 202 of the terminal 2, i.e., the control unit 107 controls the switch unit 102 to be off to realize overvoltage protection of the power adapter 1, thereby ensuring charging safety.

[0163] Of course, in one embodiment of the present application, the controller 204 acquires the voltage value sampled by the sampling unit 106 by bidirectional communication with the control unit 107 ( Figure 13 and Figure 14 ), and controls the charging control switch 203 to be off when the voltage value sampled by the sampling unit 106 is greater than the second preset voltage value, i.e., the charging control switch 203 is controlled to be off on the terminal 2 side, thereby stopping the charging process of the battery 202, and ensuring charging safety.

[0164] In addition, the control unit 107 is further configured to control the switch unit 102 to be off when the current value sampled by the sampling unit 106 is greater than a preset current value, i.e., the control unit 107 is further configured to determine the magnitude of the current value sampled by the sampling unit 106, and if the current value sampled by the sampling unit 106 is greater than the preset current value, it indicates that the current output by the power adapter 1 is too large, and at this time, the control unit 107 controls the switch unit 102 to be off so as to stop the power adapter 1 from charging the terminal, i.e., the control unit 107 controls the switch unit 102 to be off to realize overcurrent protection of the power adapter 1, thereby ensuring charging safety.

[0165] Similarly, the controller 204 acquires the current value sampled by the sampling unit 106 by bidirectional communication with the control unit 107 ( Figure 13 and Figure 14 ), and controls the charging control switch 203 to be off when the current value sampled by the sampling unit 106 is greater than the preset current value, i.e., the charging control switch 203 is controlled to be off on the terminal 2 side, thereby stopping the charging process of the battery 202, and ensuring charging safety.

[0166] The second preset voltage value and the preset current value can be set or written into the memory of the control unit (such as the control unit 107 of the power adapter 1, for example, a micro control processor MCU) according to actual conditions.

[0167] In embodiments of the present application, the terminal can be a mobile terminal such as a mobile phone, a mobile power source such as a power bank, a multimedia player, a notebook computer, a wearable device, etc.

[0168] According to the charging system for a terminal in embodiments of the present application, by controlling the power adapter to output a third pulsating waveform voltage and directly loading the third pulsating waveform voltage output by the power adapter to the battery of the terminal, the pulsating output voltage / current can directly charge the battery quickly. The magnitude of the pulsating output voltage / current is periodically changed, which can reduce the lithium precipitation phenomenon of the lithium battery, improve the service life of the battery, reduce the probability and strength of arc drawing of the contact of the charging interface, improve the service life of the charging interface, reduce the polarization effect of the battery, improve the charging speed, reduce the heating of the battery, and ensure the safety and reliability of the terminal during charging. In addition, since the power adapter outputs a pulsating waveform voltage, no electrolytic capacitor needs to be arranged in the power adapter, which can not only simplify and miniaturize the power adapter, but also greatly reduce the cost.

[0169] Furthermore, embodiments of the present application also provide a power adapter, which comprises: a first rectifying unit configured to rectify input alternating current to output a first pulsating waveform voltage; a transformer; a second rectifying unit configured to rectify the secondary output of the transformer to output a third pulsating waveform voltage, wherein the third pulsating waveform voltage is loaded to the battery of the terminal; a sampling unit configured to sample the third pulsating waveform voltage to obtain a voltage sampling value; and a modulation control unit configured to modulate the first pulsating waveform voltage according to the voltage sampling value, and load the modulated first pulsating waveform voltage to the primary of the transformer, so that the transformer transforms the modulated first pulsating waveform voltage into a second pulsating waveform voltage, so that the third pulsating waveform voltage meets the charging requirement of the battery.

[0170] According to an embodiment of the present invention, the power adapter outputs a third pulsating waveform voltage through a first charging interface, and directly applies the third pulsating waveform voltage to the terminal's battery through a second charging interface, thereby enabling rapid charging of the battery directly using a pulsating output voltage / current. The periodic variation in the magnitude of the pulsating output voltage / current, compared to traditional constant voltage and constant current methods, reduces lithium plating in lithium batteries, improves battery lifespan, reduces the probability and intensity of arcing at the charging interface contacts, improves the charging interface's lifespan, and helps reduce battery polarization, increase charging speed, reduce battery heat generation, and ensure safe and reliable charging of the terminal. Furthermore, since the output is a pulsating waveform voltage, there is no need to use electrolytic capacitors, which not only simplifies and miniaturizes the power adapter but also significantly reduces costs.

[0171] Figure 15 This is a flowchart of a charging method for a terminal according to an embodiment of the present invention. Figure 15 As shown, the charging method for the terminal includes the following steps:

[0172] S1, when the first charging interface of the power adapter is connected to the second charging interface of the terminal, that is, when the power adapter charges the terminal, the AC power input to the power adapter is rectified once to output the voltage of the first pulsating waveform.

[0173] In other words, the first rectifier unit in the power adapter rectifies the input AC power (i.e., mains power, such as 220V, 50Hz or 60Hz) and outputs a first pulsating waveform voltage (e.g., 100Hz or 120Hz) as a steampunk voltage.

[0174] S2, the voltage of the first pulsating waveform is modulated by controlling the switching unit, and the voltage of the second pulsating waveform is output by transforming it through a transformer. For example, the voltage of the first pulsating waveform is modulated, and the modulated voltage of the first pulsating waveform is applied to the primary side of the transformer, so that the voltage of the modulated first pulsating waveform is transformed into the voltage of the second pulsating waveform through the transformer.

[0175] The switching unit can be composed of MOSFETs, and the MOSFETs are PWM controlled to chop and modulate the pulsating voltage. Then, the modulated first pulsating waveform voltage is coupled to the secondary winding by a transformer, and the second pulsating waveform voltage is output by the secondary winding.

[0176] In embodiments of the present invention, a high-frequency transformer can be used for conversion, so that the transformer can be very small, thereby enabling the power adapter to be designed with high power and small size.

[0177] S3, secondary rectifying the voltage of the second pulsating waveform to output a voltage of a third pulsating waveform, wherein the voltage of the third pulsating waveform can be loaded to a battery of the terminal through the second charging interface to realize charging of the battery of the terminal.

[0178] In an embodiment of the present application, the voltage of the second pulsating waveform is secondary rectified by a second rectifying unit, which can be composed of a diode or a MOS tube, to realize secondary synchronous rectification, so that the modulated first pulsating waveform and the third pulsating waveform are kept synchronous.

[0179] S4, sampling the voltage and / or current after secondary rectification to obtain a voltage sampling value and / or a current sampling value.

[0180] S5, adjusting a duty cycle of a control signal of the control switching unit according to the voltage sampling value and / or the current sampling value, so that the voltage of the third pulsating waveform meets the charging requirement.

[0181] That is, in an embodiment of the present application, the voltage of the third pulsating waveform can be sampled to obtain a voltage sampling value, and the voltage of the first pulsating waveform is modulated according to the voltage sampling value, so that the voltage of the third pulsating waveform meets the charging requirement.

[0182] It should be noted that the voltage and current of the third pulsating waveform meet the charging requirement, which means that the voltage and current of the third pulsating waveform meet the charging voltage and charging current when the battery is charging. That is, the duty cycle of the control signal such as the PWM signal can be adjusted according to the sampled voltage and / or current output by the power adapter, the output of the power adapter is adjusted in real time, closed-loop adjustment control is realized, so that the voltage of the third pulsating waveform meets the charging requirement of the terminal, and the battery is safely and reliably charged. Specifically, the charging voltage waveform output to the battery is adjusted by the duty cycle of the PWM signal as shown in Figure 3 , and the charging current waveform output to the battery is adjusted by the duty cycle of the PWM signal as shown in Figure 4 .

[0183] Therefore, in the embodiment of the present application, the voltage of the first pulsating waveform after full-bridge rectification, i.e. the steamed-bun wave voltage, is directly PWM chopped modulated by the control switching unit, sent to the high-frequency transformer, coupled from the primary to the secondary through the high-frequency transformer, restored to the steamed-bun wave voltage / current after synchronous rectification, and directly delivered to the battery of the terminal to realize fast charging of the battery. The voltage amplitude of the steamed-bun wave can be adjusted by the duty cycle of the PWM signal to realize that the output of the power adapter meets the charging requirement of the battery. Thus, the electrolytic capacitors in the primary and secondary of the power adapter can be cancelled, the battery is directly charged by the steamed-bun wave voltage, so that the size of the power adapter can be reduced to realize miniaturization of the power adapter, and the cost can be greatly reduced.

[0184] According to one embodiment of the present application, the voltage of the first pulsating waveform is also modulated according to the voltage sampling value to make the power adapter discontinuously output the voltage of the third pulsating waveform. For example, the frequency of the control signal can be adjusted according to the voltage sampling value and / or the current sampling value, i.e. the PWM signal output to the switching unit is controlled to be output for a period of time and then stopped, and the PWM signal output is restarted after a predetermined time, so that the voltage loaded to the battery is discontinuous, realizing discontinuous charging of the battery, thereby avoiding the safety hazard caused by serious heating of the battery when continuously charging, and improving the reliability and safety of battery charging. The control signal output to the switching unit can be as shown in the following table. Figure 5

[0185] Further, the charging method for the terminal described above further comprises: communicating with the terminal through the first charging interface to obtain the state information of the terminal, and adjusting the duty cycle of the control signal according to the state information of the terminal, the voltage sampling value and / or the current sampling value.

[0186] That is, when the second charging interface is connected to the first charging interface, the power adapter and the terminal can send communication inquiry instructions to each other, and after receiving the corresponding response instructions, the power adapter and the terminal establish a communication connection, so that the state information of the terminal can be obtained, thereby negotiating the charging mode and charging parameters (such as charging current and charging voltage) with the terminal, and controlling the charging process.

[0187] According to one embodiment of the present application, the voltage of the fourth pulsating waveform is also generated by transformation of the transformer, and the voltage of the fourth pulsating waveform is detected to generate a voltage detection value, and the duty cycle of the control signal is adjusted according to the voltage detection value.

[0188] Specifically, the transformer can also be provided with an auxiliary winding, and the auxiliary winding can generate the voltage of the fourth pulsating waveform according to the modulated voltage of the first pulsating waveform. In this way, by detecting the voltage of the fourth pulsating waveform, the output voltage of the power adapter can be reflected, so that the duty cycle of the control signal is adjusted according to the voltage detection value, so that the output of the power adapter matches the charging demand of the battery.

[0189] ​In one embodiment of the present application, sampling the voltage after secondary rectification to obtain a voltage sampling value comprises: sampling and holding a peak voltage of the voltage after secondary rectification and sampling a zero-crossing point of the voltage after secondary rectification; bleeding a peak voltage sampling and holding unit that samples and holds the peak voltage at the zero-crossing point; and sampling the peak voltage in the peak voltage sampling and holding unit to obtain the voltage sampling value. In this way, the voltage output by the power adapter can be accurately sampled, and the voltage sampling value can be kept in synchronization with the voltage of the first pulsating waveform, i.e., the phase and amplitude variation trend are kept consistent.

[0190] Further, in one embodiment of the present application, the charging method for a terminal further comprises: sampling the voltage of the first pulsating waveform, and controlling the switch unit to be turned on for a first preset time to discharge the inrush voltage in the first pulsating waveform when the sampled voltage value is greater than a first preset voltage value.

[0191] By sampling the voltage of the first pulsating waveform, and then judging the sampled voltage value, if the sampled voltage value is greater than a first preset voltage value, it indicates that the power adapter is struck by lightning and an inrush voltage occurs, at this time, the inrush voltage needs to be discharged to ensure the safety and reliability of charging, and the switch unit needs to be controlled to be turned on for a period of time to form a discharge path to discharge the inrush voltage caused by lightning, preventing the interference caused by lightning when the power adapter charges the terminal, effectively improving the safety and reliability of terminal charging. The first preset voltage value can be calibrated according to actual conditions.

[0192] According to one embodiment of the present application, the first charging interface also communicates with the terminal to determine the charging mode, and when it is determined that the charging mode is the fast charging mode, the charging current and / or charging voltage corresponding to the fast charging mode are obtained according to the state information of the terminal, and the duty cycle of the control signal is adjusted according to the charging current and / or charging voltage corresponding to the fast charging mode, wherein the charging mode includes the fast charging mode and the ordinary charging mode.

[0193] That is, when it is determined that the current charging mode is the fast charging mode, the charging current and / or charging voltage corresponding to the fast charging mode can be obtained according to the obtained state information of the terminal, such as the voltage, capacity, temperature of the battery, the operating parameters of the terminal, and the power consumption information of the application running on the terminal, and then the duty cycle of the control signal is adjusted according to the obtained charging current and / or charging voltage, so that the output of the power adapter meets the charging demand and the fast charging of the battery is realized.

[0194] The state information of the terminal includes the temperature of the battery. When the temperature of the battery is greater than a first preset temperature threshold or the temperature of the battery is less than a second preset temperature threshold, if the current charging mode is the fast charging mode, the fast charging mode is switched to the normal charging mode, wherein the first preset temperature threshold is greater than the second preset temperature threshold. That is, when the temperature of the battery is too low (for example, less than the second preset temperature threshold) or too high (for example, greater than the first preset temperature threshold), the fast charging mode is not suitable, and thus the fast charging mode needs to be switched to the normal charging mode. In the embodiment of the application, the first preset temperature threshold and the second preset temperature threshold can be calibrated according to actual conditions.

[0195] In an embodiment of the application, when the temperature of the battery is greater than a preset high-temperature protection threshold, the switch unit is controlled to be turned off. That is, when the temperature of the battery exceeds the high-temperature protection threshold, a high-temperature protection strategy needs to be adopted, the switch unit is controlled to be disconnected, and the power adapter stops outputting to charge the battery, so that high-temperature protection of the battery is realized, and the safety of charging is improved. The high-temperature protection threshold and the first temperature threshold can be different or the same. Preferably, the high-temperature protection threshold is greater than the first temperature threshold.

[0196] In another embodiment of the application, the terminal also acquires the temperature of the battery, and when the temperature of the battery is greater than a preset high-temperature protection threshold, the battery is controlled to stop charging. That is, the charging control switch can be turned off on the terminal side, so that the charging process of the battery is turned off, and the safety of charging is ensured.

[0197] In an embodiment of the application, the charging method for the terminal further includes acquiring the temperature of the first charging interface, and when the temperature of the first charging interface is greater than a preset protection temperature, the switch unit is controlled to be turned off. That is, when the temperature of the charging interface exceeds a certain temperature, the control unit also needs to execute a high-temperature protection strategy, the switch unit is controlled to be disconnected, the power adapter stops charging the battery, high-temperature protection of the charging interface is realized, and the safety of charging is improved.

[0198] Of course, in another embodiment of the application, the terminal performs bidirectional communication with the power adapter through the second charging interface to acquire the temperature of the first charging interface, and when the temperature of the first charging interface is greater than a preset protection temperature, the battery is controlled to stop charging. That is, the charging control switch can be turned off on the terminal side, so that the charging process of the battery is turned off, and the safety of charging is ensured.

[0199] And, during the process that the power adapter charges the terminal, the switch unit is controlled to be turned off when the voltage sampling value is greater than the second preset voltage value. That is to say, during the process that the power adapter charges the terminal, the size of the voltage sampling value is also judged, if the voltage sampling value is greater than the second preset voltage value, it indicates that the voltage outputted by the power adapter is too high, at this time, the switch unit is controlled to be turned off, so that the power adapter stops charging the terminal, that is, the overvoltage protection of the power adapter is realized by controlling the switch unit to be turned off, and the charging safety is ensured.

[0200] Of course, in an embodiment of the present application, the terminal performs bidirectional communication with the power adapter through the second charging interface to obtain the voltage sampling value, and controls the battery to stop charging when the voltage sampling value is greater than the second preset voltage value, that is, the charging control switch can be turned off from the terminal side, so that the charging process of the battery is turned off, and the charging safety is ensured.

[0201] In an embodiment of the present application, during the process that the power adapter charges the terminal, the switch unit is controlled to be turned off when the current sampling value is greater than the preset current value. That is to say, during the process that the power adapter charges the terminal, the size of the current sampling value is also judged, if the current sampling value is greater than the preset current value, it indicates that the current outputted by the power adapter is too large, at this time, the switch unit is controlled to be turned off, so that the power adapter stops charging the terminal, that is, the overcurrent protection of the power adapter is realized by controlling the switch unit to be turned off, and the charging safety is ensured.

[0202] Similarly, the terminal performs bidirectional communication with the power adapter through the second charging interface to obtain the current sampling value, and controls the battery to stop charging when the current sampling value is greater than the preset current value, that is, the charging control switch can be turned off from the terminal side, so that the charging process of the battery is turned off, and the charging safety is ensured.

[0203] Wherein, the second preset voltage value and the preset current value can be calibrated according to actual conditions.

[0204] In the embodiment of the present application, the state information of the terminal can include the power of the battery, the temperature of the battery, the voltage / current of the terminal, the interface information of the terminal, the information of the access impedance of the terminal, etc.

[0205] Specifically, the power adapter and the terminal can be connected through a USB interface, which can be a common USB interface or a micro USB interface. The data line in the USB interface, that is, the data line in the first charging interface, is used for bidirectional communication between the power adapter and the terminal, which can be the D+ line and / or the D- line in the USB interface, and the so-called bidirectional communication can mean that the power adapter and the terminal interact with each other.

[0206] The power adapter determines to charge the terminal using the fast charging mode through the data line in the USB interface and the terminal.

[0207] Optionally, as an embodiment, when the power adapter determines to charge the terminal using the fast charging mode through the first charging interface and the terminal, the power adapter sends a first instruction to the terminal, the first instruction is used to inquire whether the terminal starts the fast charging mode; the power adapter receives a reply instruction of the first instruction from the terminal, the reply instruction of the first instruction is used to indicate that the terminal agrees to start the fast charging mode.

[0208] Optionally, as an embodiment, before the power adapter sends the first instruction to the terminal, the power adapter charges the terminal through the normal charging mode, and after determining that the charging time of the normal charging mode is greater than a preset threshold, the power adapter sends the first instruction to the terminal.

[0209] It can be understood that when the power adapter determines that the charging time of the normal charging mode is greater than a preset threshold, the power adapter can consider that the terminal has recognized itself as a power adapter and can start the fast charging inquiry communication.

[0210] Optionally, as an embodiment, the switch unit is also controlled to control the power adapter to adjust the charging current to the charging current corresponding to the fast charging mode, and before the power adapter charges the terminal with the charging current corresponding to the fast charging mode, the first charging interface is used to communicate with the terminal to determine the charging voltage corresponding to the fast charging mode, and the power adapter is controlled to adjust the charging voltage to the charging voltage corresponding to the fast charging mode.

[0211] Optionally, as an embodiment, the power adapter sends a second instruction to the terminal, the second instruction is used to inquire whether the current output voltage of the power adapter is suitable as the charging voltage of the fast charging mode; the power adapter receives a reply instruction of the second instruction sent by the terminal, the reply instruction of the second instruction is used to indicate that the current output voltage of the power adapter is suitable, too high or too low; the power adapter determines the charging voltage of the fast charging mode according to the reply instruction of the second instruction.

[0212] Optionally, as an embodiment, before the power adapter adjusts the charging current to the charging current corresponding to the fast charging mode, the power adapter also communicates with the terminal through the first charging interface to determine the charging current corresponding to the fast charging mode.

[0213] Optionally, as an embodiment, the communication between the power adapter and the terminal through the first charging interface to determine the charging current corresponding to the fast charging mode includes: the power adapter sends a third instruction to the terminal, the third instruction being used to inquire the maximum charging current currently supported by the terminal; the power adapter receives a reply instruction of the third instruction sent by the terminal, the reply instruction of the third instruction being used to indicate the maximum charging current currently supported by the terminal; and the power adapter determines the charging current of the fast charging mode according to the reply instruction of the third instruction.

[0214] The power adapter can directly determine the maximum charging current as the charging current of the fast charging mode, or set the charging current to a current value less than the maximum charging current.

[0215] Optionally, as an embodiment, during the charging of the terminal by the power adapter using the fast charging mode, the power adapter also communicates with the terminal through the first charging interface to continuously adjust the charging current output by the power adapter to the battery by controlling the switch unit.

[0216] The power adapter can continuously inquire the current state information of the terminal to continuously adjust the charging current, such as inquiring the battery voltage and battery capacity of the terminal.

[0217] Optionally, as an embodiment, the communication between the power adapter and the terminal through the first charging interface to continuously adjust the charging current output by the power adapter to the battery by controlling the switch unit includes: the power adapter sends a fourth instruction to the terminal, the fourth instruction being used to inquire the current voltage of the battery in the terminal; the power adapter receives a reply instruction of the fourth instruction sent by the terminal, the reply instruction of the fourth instruction being used to indicate the current voltage of the battery in the terminal; and the charging current is adjusted by controlling the switch unit according to the current voltage of the battery.

[0218] Optionally, as an embodiment, the adjustment of the charging current by controlling the switch unit according to the current voltage of the battery includes: the charging current output by the power adapter to the battery is adjusted to the charging current value corresponding to the current voltage of the battery by controlling the switch unit according to the current voltage of the battery, and the correspondence between the preset battery voltage value and the charging current value.

[0219] In particular, the power adapter can pre-store the corresponding relationship between the battery voltage value and the charging current value.

[0220] Optionally, as an embodiment, during the process that the power adapter charges the terminal by using the fast charging mode, the power adapter further performs bidirectional communication with the terminal through the first charging interface to determine whether the first charging interface and the second charging interface are in poor contact, wherein when it is determined that the first charging interface and the second charging interface are in poor contact, the power adapter is controlled to exit the fast charging mode.

[0221] Optionally, as an embodiment, before determining whether the first charging interface and the second charging interface are in poor contact, the power adapter receives information indicating the pass-through impedance of the terminal from the terminal, wherein the power adapter sends a fourth instruction to the terminal, the fourth instruction being used to inquire the voltage of the battery in the terminal; the power adapter receives a reply instruction of the fourth instruction sent by the terminal, the reply instruction of the fourth instruction being used to indicate the voltage of the battery in the terminal; according to the output voltage of the power adapter and the voltage of the battery, the pass-through impedance of the power adapter to the battery is determined; and according to the pass-through impedance of the power adapter to the battery, the pass-through impedance of the terminal, and the pass-through impedance of the charging line between the power adapter and the terminal, whether the first charging interface and the second charging interface are in poor contact is determined.

[0222] Optionally, as an embodiment, before controlling the power adapter to exit the fast charging mode, a fifth instruction is further sent to the terminal, the fifth instruction being used to indicate that the first charging interface and the second charging interface are in poor contact.

[0223] After the power adapter sends the fifth instruction, the power adapter can exit the fast charging mode or be reset.

[0224] The above describes the fast charging process according to the embodiment of the application from the perspective of the power adapter, and the following describes the fast charging process according to the embodiment of the application from the perspective of the terminal.

[0225] In the embodiment of the application, the terminal supports the normal charging mode and the fast charging mode, wherein the charging current of the fast charging mode is greater than the charging current of the normal charging mode, the terminal performs bidirectional communication with the power adapter through the second charging interface so that the power adapter determines to charge the terminal by using the fast charging mode, and the power adapter outputs according to the charging current corresponding to the fast charging mode to charge the battery in the terminal.

[0226] Optionally, as one embodiment, the terminal communicates with the power adapter through the second charging interface in both directions so that the power adapter determines to charge the terminal using the fast charging mode, comprising: the terminal receives a first instruction sent by the power adapter, the first instruction being used to inquire whether the terminal starts the fast charging mode; the terminal sends a reply instruction of the first instruction to the power adapter, the reply instruction of the first instruction being used to indicate that the terminal agrees to start the fast charging mode.

[0227] Optionally, as one embodiment, before the terminal receives the first instruction sent by the power adapter, the terminal and the power adapter charge through the normal charging mode, and the terminal receives the first instruction sent by the power adapter after the power adapter determines that the charging time length of the normal charging mode is greater than a preset threshold.

[0228] Optionally, as one embodiment, before the power adapter outputs the charging current corresponding to the fast charging mode to charge the battery in the terminal, the terminal communicates with the power adapter through the second charging interface in both directions so that the power adapter determines the charging voltage corresponding to the fast charging mode.

[0229] Optionally, as one embodiment, the terminal communicates with the power adapter through the second charging interface in both directions so that the power adapter determines the charging voltage corresponding to the fast charging mode, comprising: the terminal receives a second instruction sent by the power adapter, the second instruction being used to inquire whether the current output voltage of the power adapter is suitable as the charging voltage of the fast charging mode; the terminal sends a reply instruction of the second instruction to the power adapter, the reply instruction of the second instruction being used to indicate that the current output voltage of the power adapter is suitable, too high or too low.

[0230] Optionally, as one embodiment, before the terminal receives the charging current corresponding to the fast charging mode from the power adapter to charge the battery in the terminal, the terminal communicates with the power adapter through the second charging interface in both directions so that the power adapter determines the charging current corresponding to the fast charging mode.

[0231] The terminal communicates with the power adapter through the second charging interface in both directions, so that the power adapter determines the charging current corresponding to the fast charging mode, including: the terminal receives a third instruction sent by the power adapter, the third instruction being used to inquire the maximum charging current currently supported by the terminal; the terminal sends a reply instruction of the third instruction to the power adapter, the reply instruction of the third instruction being used to indicate the maximum charging current currently supported by the terminal, so that the power adapter determines the charging current corresponding to the fast charging mode according to the maximum charging current.

[0232] Optionally, as an embodiment, during the process that the power adapter charges the terminal using the fast charging mode, the terminal communicates with the power adapter through the second charging interface in both directions, so that the power adapter continuously adjusts the charging current output by the power adapter to the battery.

[0233] The terminal communicates with the power adapter through the second charging interface in both directions, so that the power adapter continuously adjusts the charging current output by the power adapter to the battery, including: the terminal receives a fourth instruction sent by the power adapter, the fourth instruction being used to inquire the current voltage of the battery in the terminal; the terminal sends a reply instruction of the fourth instruction to the power adapter, the reply instruction of the fourth instruction being used to indicate the current voltage of the battery in the terminal, so that the charging current output by the power adapter to the battery is continuously adjusted according to the current voltage of the battery.

[0234] Optionally, as an embodiment, during the process that the power adapter charges the terminal using the fast charging mode, the terminal communicates with the power adapter through the second charging interface in both directions, so that the power adapter determines whether the contact between the first charging interface and the second charging interface is poor.

[0235] The terminal communicates with the power adapter through the second charging interface in both directions, so that the power adapter determines whether the contact between the first charging interface and the second charging interface is poor, including: the terminal receives a fourth instruction sent by the power adapter, the fourth instruction being used to inquire the current voltage of the battery in the terminal; the terminal sends a reply instruction of the fourth instruction to the power adapter, the reply instruction of the fourth instruction being used to indicate the current voltage of the battery in the terminal, so that the power adapter determines whether the contact between the first charging interface and the second charging interface is poor according to the output voltage of the power adapter and the current voltage of the battery.

[0236] Optionally, as an embodiment, the terminal also receives a fifth instruction sent by the power adapter, the fifth instruction being used to indicate poor contact between the first charging interface and the second charging interface.

[0237] To enable and use fast charging mode, the power adapter can initiate a fast charging communication process with the device, negotiating through one or more handshakes to achieve fast battery charging. See details below. Figure 6 This description details the fast charging communication process of embodiments of the present invention, as well as the various stages included in the fast charging process. It should be understood that... Figure 6 The communication steps or operations shown are merely examples; other operations or procedures may be performed in embodiments of the present invention. Figure 6 Variations of various operations within it. Furthermore, Figure 6 The various stages in can be arranged according to... Figure 6 The different orders in which they are presented may be executed, and may not even be intended to be executed. Figure 6 All operations within.

[0238] In summary, the charging method for a terminal according to embodiments of the present invention controls the power adapter to output a voltage of a third pulsating waveform that meets the charging requirements, and directly applies this voltage to the terminal's battery, thereby enabling rapid charging of the battery directly through a pulsating output voltage / current. The periodic variation in the magnitude of the pulsating output voltage / current, compared to traditional constant voltage and constant current methods, reduces lithium plating in lithium batteries, improves battery lifespan, reduces the probability and intensity of arcing at the charging interface contacts, improves the lifespan of the charging interface, and helps reduce battery polarization, increase charging speed, reduce battery heat generation, and ensure safe and reliable charging of the terminal. Furthermore, since the power adapter outputs a pulsating waveform voltage, there is no need to include electrolytic capacitors in the power adapter, which not only simplifies and miniaturizes the power adapter but also significantly reduces costs.

[0239] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0240] In addition, the terms "first", "second", etc. are used herein only to describe different instances, and do not imply or suggest relative importance or a number of the technical features indicated. Thus, the features defined with "first", "second" can include at least one of the features explicitly or implicitly. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0241] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0242] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0243] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or features of different embodiments or examples described in the present application without contradiction.

[0244] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0245] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0246] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0247] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0248] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically independently, or two or more units can be integrated into one unit.

[0249] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the present application that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of software products. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the various embodiments of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0250] Although the embodiments of the present application have been shown and described above, it should be understood that the above-described embodiments are exemplary and should not be construed as limiting the present application, and those of ordinary skill in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A charging system for a terminal, characterized by, The power adapter comprises: a first rectifying unit for rectifying input alternating current to output a first pulsating waveform voltage; a transformer; a second rectifying unit for rectifying a secondary output of the transformer to output a third pulsating waveform voltage; a sampling unit for sampling the third pulsating waveform voltage to obtain a voltage sampling value; a modulation control unit for modulating the first pulsating waveform voltage according to the voltage sampling value, and loading the modulated first pulsating waveform voltage to a primary of the transformer, so as to transform the modulated first pulsating waveform voltage into a second pulsating waveform voltage through the transformer, so that the third pulsating waveform voltage meets a charging requirement; an auxiliary winding for generating a fourth pulsating waveform voltage according to the modulated first pulsating waveform voltage; a power supply unit connected with the auxiliary winding, for converting the fourth pulsating waveform voltage to output direct current to supply the modulation control unit; the modulation control unit is further configured to detect the fourth pulsating waveform voltage to obtain a voltage detection value, and modulate the first pulsating waveform voltage according to the voltage detection value; the terminal comprises a battery, wherein when the power adapter charges the terminal, the power adapter loads the third pulsating waveform voltage to the battery. The power adapter comprises:

2. A power adapter, characterized by a first rectifying unit for rectifying input alternating current to output a first pulsating waveform voltage; a transformer; a second rectifying unit for rectifying a secondary output of the transformer to output a third pulsating waveform voltage, wherein the third pulsating waveform voltage is loaded to a battery of a terminal; a sampling unit for sampling the third pulsating waveform voltage to obtain a voltage sampling value; a modulation control unit for modulating the first pulsating waveform voltage according to the voltage sampling value, and loading the modulated first pulsating waveform voltage to a primary of the transformer, so as to transform the modulated first pulsating waveform voltage into a second pulsating waveform voltage through the transformer, so that the third pulsating waveform voltage meets a charging requirement of the battery; an auxiliary winding for generating a fourth pulsating waveform voltage according to the modulated first pulsating waveform voltage; a power supply unit connected with the auxiliary winding, for converting the fourth pulsating waveform voltage to output direct current to supply the modulation control unit; the modulation control unit is further configured to detect the fourth pulsating waveform voltage to obtain a voltage detection value, and modulate the first pulsating waveform voltage according to the voltage detection value. The power adapter comprises a first charging interface, and the power adapter and the terminal are connected through the first charging interface to establish bidirectional communication.

3. The power adapter of claim 2, wherein, The power adapter comprises: a first rectifying unit for rectifying input alternating current to output a first pulsating waveform voltage; a transformer; a second rectifying unit for rectifying a secondary output of the transformer to output a third pulsating waveform voltage, wherein the third pulsating waveform voltage is loaded to a battery of a terminal; a sampling unit for sampling the third pulsating waveform voltage to obtain a voltage sampling value; a modulation control unit for modulating the first pulsating waveform voltage according to the voltage sampling value, and loading the modulated first pulsating waveform voltage to a primary of the transformer, so as to transform the modulated first pulsating waveform voltage into a second pulsating waveform voltage through the transformer, so that the third pulsating waveform voltage meets a charging requirement of the battery; an auxiliary winding for generating a fourth pulsating waveform voltage according to the modulated first pulsating waveform voltage; a power supply unit connected with the auxiliary winding, for converting the fourth pulsating waveform voltage to output direct current to supply the modulation control unit; the modulation control unit is further configured to detect the fourth pulsating waveform voltage to obtain a voltage detection value, and modulate the first pulsating waveform voltage according to the voltage detection value. The power adapter comprises a first charging interface, and the power adapter and the terminal are connected through the first charging interface to establish bidirectional communication.

4. The power adapter of claim 3, wherein, The modulation control unit obtains state information of the terminal through bidirectional communication between the power adapter and the terminal, and modulates the voltage of the first pulsating waveform according to the state information of the terminal and the voltage sampling value.

5. The power adapter of claim 3, wherein, The power adapter further comprises a controllable switch and a filter unit connected in series, The modulation control unit determines a charging mode through bidirectional communication between the power adapter and the terminal, wherein the charging mode comprises a fast charging mode and a normal charging mode; The filter unit is configured to filter the voltage of the third pulsating waveform, and the controllable switch is configured to control whether the filter unit works or not, wherein the modulation control unit is further configured to control the controllable switch to be closed to make the filter unit work when the charging mode is determined to be the normal charging mode, and control the controllable switch to be opened to make the filter unit stop working when the charging mode is determined to be the fast charging mode.

6. The power adapter of claim 4, wherein, When the temperature of the battery is greater than a first preset temperature threshold or the temperature of the battery is less than a second preset temperature threshold, if the current charging mode is the fast charging mode, the fast charging mode is switched to the normal charging mode, wherein the first preset temperature threshold is greater than the second preset temperature threshold.

7. The power adapter of claim 2, wherein, The modulation control unit is further configured to control the power adapter to stop outputting when the voltage sampling value is greater than a second preset voltage value.

8. The power adapter of claim 5, wherein, The modulation control unit determines whether to charge the terminal using the fast charging mode through bidirectional communication between the data line in the first charging interface and the terminal, The modulation control unit sends a first instruction to the terminal, and the first instruction is used to inquire whether the terminal opens the fast charging mode; The modulation control unit receives a reply instruction of the first instruction from the terminal, and the reply instruction of the first instruction is used to indicate that the terminal agrees to open the fast charging mode.

9. The power adapter of claim 8, wherein, Before the modulation control unit sends the first instruction to the terminal, the power adapter and the terminal charge through the normal charging mode, and after the modulation control unit determines that the charging time length of the normal charging mode is greater than a preset threshold, the modulation control unit sends the first instruction to the terminal.

10. A charging method for a terminal, characterized by, The method comprises the following steps: When the power adapter charges the terminal, the input alternating current is rectified once to output the voltage of the first pulsating waveform; The voltage of the first pulsating waveform is modulated, and the modulated voltage of the first pulsating waveform is loaded to the primary of the transformer to transform the modulated voltage of the first pulsating waveform into the voltage of the second pulsating waveform through the transformer; The voltage of the second pulsating waveform is rectified twice to output the voltage of the third pulsating waveform, and the voltage of the third pulsating waveform is loaded to the battery of the terminal; The voltage of the third pulsating waveform is sampled to obtain a voltage sampling value, and the voltage of the first pulsating waveform is modulated according to the voltage sampling value to make the voltage of the third pulsating waveform meet the charging demand; The voltage of the fourth pulsating waveform is generated according to the modulated voltage of the first pulsating waveform; The voltage of the fourth pulsating waveform is converted to output direct current, the voltage of the fourth pulsating waveform is detected to obtain a voltage detection value, and the voltage of the first pulsating waveform is modulated according to the voltage detection value.

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