CN111884276A

CN111884276A - Charging system, charging equipment and charging control method

Info

Publication number: CN111884276A
Application number: CN202010311975.1A
Authority: CN
Inventors: 桑耀; 黄海涛; 许飞
Original assignee: Zhuhai Jieli Technology Co Ltd
Current assignee: Zhuhai Jieli Technology Co Ltd
Priority date: 2020-04-20
Filing date: 2020-04-20
Publication date: 2020-11-03
Anticipated expiration: 2040-04-20
Also published as: CN111884276B

Abstract

The charging system comprises a device to be charged and a power supply device, wherein in the constant current charging stage, a current detection unit detects the current value of a power supply to be charged; when the current value deviates from a preset current range, the current detection unit outputs a current deviation signal, the first control unit generates a control signal according to the deviation direction and the deviation degree of the current deviation signal, and the control signal generation unit generates a rectangular wave signal with a preset period number and a preset duty ratio; the communication identification unit detects the rectangular wave signal through the power supply contact and outputs the rectangular wave signal to the second control unit, the second control unit generates a power supply control signal according to the periodicity and the duty ratio of the rectangular wave signal, and the power supply management unit is controlled to change the power supply voltage of the output end, so that the current value flowing into the power supply to be charged is changed towards a preset current range. The power supply equipment can realize refined constant current charging in the process of charging the equipment to be charged, so that better charging timeliness and lower charging energy consumption can be always kept.

Description

Charging system, charging equipment and charging control method

Technical Field

The invention relates to the technical field of charging management, in particular to a charging system, charging equipment and a charging control method capable of realizing refined constant-current charging.

Background

With the use of TWS (True Wireless Stereo) Wireless devices, users are increasingly demanding Wireless devices, such as TWS headsets and the like. At present, the TWS wireless device is powered by a built-in battery, when the power consumption of the device reaches a certain level (for example, below 10%), it is prompted that charging is needed, and the user connects the TWS wireless device with a charging device to charge the TWS wireless device until the TWS wireless device is fully charged.

Currently, for example, a TWS wireless headset performs charging operation, the TWS headset is usually placed in a matched headset charging box, and the charging process is substantially the same as that of other rechargeable batteries at the present stage, as shown in fig. 1, in the prior art, the charging box performs trickle charging on the TWS headset first, so that the trickle charging is finished after the electric quantity of the headset reaches a certain capacity, and then the charging stage enters a constant-current charging stage, and when the electric quantity of the battery of the headset reaches a certain threshold value, the constant-current charging is finished, and then the constant-voltage charging is started. And finally, the charging equipment performs constant-voltage charging on the earphone until the earphone is fully charged.

However, since the TWS wireless headset and the charging box thereof are required to be small in size so as to be portable, especially, the TWS wireless headset is very small and has a very limited internal space, and it is difficult to place a complex circuit, which also makes it difficult to control the charging process to a desired degree of fineness, especially to control the current in the constant current charging stage, and to achieve a true constant current.

Taking a charging current of 50mA as an optimal charging current in constant current charging as an example, under normal conditions, when the charging current injected into an earphone end reaches 50mA, the charging speed and the charging efficiency should be the highest, but in actual conditions, although the charging box outputs the charging current of 50mA, because other functions exist in the earphone, other functional units may include an LED lamp at the earphone end, a wireless communication unit, an operation memory of a CPU unit inside the earphone, a distributed capacitor, an inductor, a resistor and the like, and these other functional units inevitably shunt a part of current, for example, 10mA is shunted by other functional units, so only 40mA is actually injected into a charging battery of the earphone. The 10mA current shunted by the other functional units is unknown at the charging box end. Moreover, the shunting performed by other functional units at the earphone end is often an uncontrollable and unpredictable sudden event, so that the charging box end cannot be prepared for flow control in advance.

Therefore, the function unit at the earphone end shunts the input charging current uncontrollably, so that the current injected into the rechargeable battery is reduced, the charging box end cannot know in advance or in the future, and the real and expected constant-current charging cannot be realized, so that the charging speed and the charging energy efficiency are reduced.

Disclosure of Invention

Based on the above situation, a main object of the present invention is to provide a charging system and a charging control method, in which an electrical value flow flowing into a to-be-charged power supply in a to-be-charged device is monitored and fed back to a power supply device in a simple manner to adjust a charging voltage in time, so that the power supply device can implement refined constant current charging in a process of charging the to-be-charged device, thereby always maintaining a better charging timeliness and a lower charging energy consumption.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a charging system comprises a device to be charged and a power supply device,

the device to be charged comprises a power supply to be charged, a first control unit, a current detection unit, a signal generation unit and a charging contact, wherein the output end of the signal generation unit is electrically connected with the charging contact, and the control end of the signal generation unit is electrically connected with the first control unit; the detection end of the current detection unit is electrically connected with the charging branch of the power supply to be charged, and the output end of the current detection unit is electrically connected with the first control unit;

the power supply equipment comprises a power supply, a communication identification unit, a second control unit, a power supply management unit and a power supply contact, wherein the identification input end of the communication identification unit is electrically connected with the power supply contact, and the output end of the communication identification unit is electrically connected with the second control unit; the input end of the power management unit is connected with a power supply, the output end of the power management unit is connected with a power supply contact, and the control end of the power management unit is connected with the second control unit;

the charging contact can be connected with the power supply contact so that the output charging current of the power supply equipment flows into the equipment to be charged;

in the constant current charging stage, a current detection unit detects the current value of the current flowing into the power supply to be charged;

when the current value deviates from a preset current range, the current detection unit outputs a current deviation signal, the first control unit generates a control signal according to the deviation direction and the deviation degree of the current deviation signal, and the control signal generation unit generates a rectangular wave signal with a preset period number and a preset duty ratio; the communication identification unit detects the rectangular wave signal through the power supply contact and outputs the rectangular wave signal to the second control unit, the second control unit generates a power supply control signal according to the periodicity and the duty ratio of the rectangular wave signal, and the power supply management unit is controlled to change the power supply voltage of the output end, so that the current value flowing into the power supply to be charged is changed towards a preset current range.

Preferably, when the current value is smaller than the first current threshold, the current detection unit outputs a first current deviation signal, and the first control unit controls the signal generation unit to generate a first rectangular wave signal having a first predetermined cycle number and a first predetermined duty ratio according to the first current deviation signal; the communication identification unit detects a first rectangular wave signal through the power supply contact; the second control unit controls the power supply management unit to increase the power supply voltage according to the first rectangular wave signal detected by the communication identification unit, so that the value of the current flowing into the power supply to be charged is increased.

Preferably, when the current value is greater than the second current threshold, the current detection unit outputs a second current deviation signal, and the first control unit controls the signal generation unit to generate a second rectangular wave signal having a second predetermined cycle number and a second predetermined duty ratio according to the second current deviation signal; the communication identification unit detects a second rectangular wave signal through the power supply contact; the second control unit controls the power supply management unit to reduce the power supply voltage according to the second rectangular wave signal detected by the communication identification unit, so that the current value flowing into the power supply to be charged is reduced.

Preferably, the signal generating unit comprises a triode or a field effect transistor, wherein when the signal generating unit comprises a triode, a base of the triode is connected with the first control unit, one of a collector and an emitter of the triode is connected with the charging contact, and the other is grounded; when the signal generating unit comprises a field effect transistor, the grid electrode of the field effect transistor is connected with the first control unit, one of the drain electrode and the source electrode of the field effect transistor is connected with the charging contact, and the other one of the drain electrode and the source electrode of the field effect transistor is grounded.

Preferably, the power management unit is further configured to determine whether the power supply voltage reaches a constant voltage charging voltage value, and if so, the charging system enters a constant voltage charging stage.

Preferably, the device to be charged is a TWS headset, and the power supply device is a charging box matched with the TWS headset.

The invention also provides a device to be charged, which comprises a power supply to be charged, a first control unit, a current detection unit, a signal generation unit and a charging contact; the output end of the signal generating unit is electrically connected with the charging contact, and the control end of the signal generating unit is electrically connected with the first control unit; the detection end of the current detection unit is electrically connected with the charging branch of the power supply to be charged, and the output end of the current detection unit is electrically connected with the first control unit;

the charging contact is electrically connected with the power supply equipment so that the output charging current of the power supply equipment flows into the equipment to be charged;

when the current value deviates from the preset current range, the current detection unit outputs a current deviation signal, the first control unit generates a control signal according to the deviation direction and the deviation degree of the current deviation signal, the control signal generation unit generates a rectangular wave signal with a preset period number and a preset duty ratio, and the rectangular wave signal is output through the charging contact to enable the power supply equipment to change the power supply voltage, so that the current value flowing into the power supply to be charged changes towards the preset current range.

Preferably, when the current value is smaller than the first current threshold, the current detection unit outputs a first current deviation signal, the first control unit controls the signal generation unit to generate a first rectangular wave signal with a first predetermined cycle number and a first predetermined duty ratio according to the second current deviation signal, and the first rectangular wave signal is output through the charging contact, so that the charging device increases the power supply voltage.

Preferably, when the current value is greater than the second current threshold, the current detection unit outputs a second current deviation signal, the first control unit controls the signal generation unit to generate a second rectangular wave signal with a second predetermined cycle number and a second predetermined duty ratio according to the second current deviation large signal, and the second rectangular wave signal is output through the charging contact, so that the charging device reduces the power supply voltage.

Preferably, the device to be charged is a TWS headset.

The invention also provides a power supply device, which is used for charging the device to be charged and comprises a communication identification unit, a second control unit, a power supply management unit and a power supply contact; the identification input end of the communication identification unit is electrically connected with the power supply contact, and the output end of the communication identification unit is electrically connected with the second control unit; the input end of the power management unit is connected with a power supply, the output end of the power management unit is connected with a power supply contact, and the control end of the power management unit is connected with the second control unit;

the power supply contact is used for being connected with the equipment to be charged so that the output charging current of the power supply equipment flows into the equipment to be charged;

in the constant current charging stage, the communication identification unit detects a rectangular wave signal output by the equipment to be charged through the power supply contact and outputs the rectangular wave signal to the second control unit, the second control unit generates a power supply control signal according to the periodicity and the duty ratio of the rectangular wave signal, and the power supply management unit is controlled to change the power supply voltage of the output end, so that the current value flowing into the power supply to be charged is changed.

Preferably, when the square wave is a first square wave signal having a first predetermined cycle number and a first predetermined duty ratio, the second control unit controls the power management unit to increase the supply voltage according to the cycle number and the duty ratio of the first square wave signal.

Preferably, when the square wave is a second square wave signal having a second predetermined cycle number and a second predetermined duty ratio, the second control unit controls the power supply management unit to lower the power supply voltage according to the cycle number and the duty ratio of the second square wave signal.

Preferably, the power management unit is further configured to determine whether the power supply voltage reaches a constant voltage charging voltage value, and if so, the power supply device enters a constant voltage charging phase.

Preferably, the power supply device is a charging box providing a charging function for the TWS headset.

The invention relates to a charging control method in a constant current charging process, which is used for charging in the constant current process through a contact between power supply equipment and equipment to be charged and comprises the following steps:

the method comprises the steps that a device to be charged detects the current value of a power supply to be charged flowing into the device to be charged;

when the current value deviates from the preset current range, the equipment to be charged generates a current deviation signal, and generates a rectangular wave signal with a preset period number and a preset duty ratio according to the deviation direction and the deviation degree of the current deviation signal; the power supply equipment detects the rectangular wave signal through the contact, generates a power supply control signal according to the periodicity and the duty ratio of the rectangular wave signal, and controls and changes the power supply voltage, so that the current value flowing into the power supply to be charged is changed towards a preset current range.

Preferably, the device to be charged determines the predetermined number of cycles of the rectangular wave signal according to the current deviation direction, and determines the predetermined duty ratio of the rectangular wave signal according to the current deviation degree.

Preferably, when the current value is smaller than the first current threshold, the device to be charged generates a first current deviation signal, and outputs a first rectangular wave signal having a first predetermined cycle number and a first predetermined duty ratio according to the first current deviation signal; the power supply equipment detects the first rectangular wave signal through the contact, generates a power supply control signal according to the periodicity and the duty ratio of the first rectangular wave signal, and controls and improves the power supply voltage.

Preferably, the device to be charged generates N continuous periods of first rectangular wave signals according to the first current deviation signal, and determines the duty ratio of the first rectangular wave signals according to the difference between the current value and the preset input constant current value of the power supply to be charged.

Preferably, the power supply apparatus generates the boost control signal in accordance with the number of cycles N of the first rectangular wave, and generates the boost value control signal in accordance with the duty ratio of the first rectangular wave.

Preferably, when the current value is greater than the second current threshold, the device to be charged generates a second current deviation signal, and outputs a second rectangular wave signal having a second predetermined cycle number and a second predetermined duty ratio according to the second current deviation signal; the power supply equipment detects the second rectangular wave signal through the contact, generates a power supply control signal according to the periodicity and the duty ratio of the second rectangular wave signal, and controls and reduces the power supply voltage.

Preferably, the device to be charged generates M continuous periods of second rectangular wave signals according to the second current deviation signal, and generates a duty ratio of the second rectangular wave signals according to a difference between a current value and a preset input constant current value of the power supply to be charged.

Preferably, the power supply device generates the step-down control signal according to the number M of cycles of the second rectangular wave, and generates the step-down value control signal according to the duty ratio of the second rectangular wave.

The invention also provides a charging control method executed by the equipment to be charged, and the operation executed by the equipment to be charged in the charging control method in the constant-current charging process is executed.

The invention also provides a charging control method executed by the power supply equipment, which executes the operation executed by the charging equipment in the charging control method in the constant-current charging process.

By adopting the charging system or method provided by the invention, in the constant-current charging stage, the problems of charging speed and charging efficiency reduction caused by shunting caused by functional units in the equipment to be charged are avoided by detecting whether the current value flowing into the equipment to be charged is too low or too high, namely whether the current value is stabilized within the preset charging current value range. The charging voltage value output by the charging equipment is changed through simple electric signal feedback, so that the charging system always keeps better charging timeliness and lower charging energy consumption, the charging times of the charging equipment can be increased, and the user experience is improved.

Other advantages of the present invention will be described in the detailed description, and those skilled in the art will understand the technical features and technical solutions presented in the description.

Drawings

Preferred embodiments of a charging system, apparatus and method according to the present invention will be described below with reference to the accompanying drawings. In the figure:

FIG. 1 is a schematic diagram of a charging process in the prior art;

FIG. 2 is a schematic diagram of a charging system in accordance with a preferred embodiment of the present invention;

FIG. 3 is a schematic diagram of a charging system according to another preferred embodiment of the present invention;

fig. 4 is a schematic view of the connection of the earphone and the charging box according to a preferred embodiment of the present invention;

FIG. 5 is a schematic diagram of a first square wave in accordance with a preferred embodiment of the present invention;

FIG. 6 is a second schematic illustration of a square wave according to a preferred embodiment of the present invention;

fig. 7 is a schematic diagram illustrating output power supply voltage adjustment during charging of the earphone by the charging box in fig. 4;

fig. 8 is a flowchart of a charging control method in a constant current charging process according to a preferred embodiment of the present invention.

Fig. 9 is a flowchart of a charging control method in a constant current charging process according to another preferred embodiment of the present invention.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

Fig. 2 is a schematic diagram of an embodiment of a charging system composed of a power supply device 20 and a device to be charged 10 according to the present invention, which monitors a charging current flowing into a power supply to be charged in real time, feeds the charging current back to the power supply device 20 in a simple manner, adjusts a supply voltage output by the power supply device 20 in real time, and communicates with the device to be charged 10 through the power supply device 20, so that an injection current of the device to be charged 10 is fed back to the power supply device 20 when the injection current does not meet a preset range value, and the power supply device 20 dynamically adjusts the charging voltage, so that the power supply device 20 can realize refined constant current charging during the charging process of the device to be charged 10, and always maintain a better charging timeliness and a lower charging energy consumption.

Wherein, the output end of the signal generating unit 13 is electrically connected with the charging contact, and the control end of the signal generating unit 13 is electrically connected with the first control unit 12; the detection end of the current detection unit 11 is electrically connected with the charging branch of the power supply to be charged, and the output end of the current detection unit 11 is electrically connected with the first control unit 12. The identification input end of the communication identification unit 21 is electrically connected with the power supply contact, and the output end of the communication identification unit 21 is electrically connected with the second control unit 22; the input end of the power management unit 23 is connected with the power supply, the output end is connected with the power supply contact, and the control end is connected with the second control unit 22. The charging branch of the power source to be charged generally refers to a circuit directly connected to the power source to be charged during normal charging, such as a branch from a charging contact to the power source to be charged in fig. 2.

When the device to be charged 10 needs to be charged, the device to be charged 10 is connected to the power supply contact of the power supply device 20 through the charging contact, and the two contacts may be a direct contact connection or an indirect contact connection, for example, through a charging wire. During charging, a shunt may be generated in the functional unit 14 of the device to be charged 10, such as an LED lamp, a wireless communication unit, an operating memory of a CPU unit inside the headset, a distributed capacitor, an inductor, a resistor, and the like, so that the current actually flowing into the power source to be charged becomes small.

In performing the charging process, in order to ensure the charging efficiency, when entering the constant current charging phase, the current detection unit 11 in the device to be charged 10 detects the current value I flowing into the power source to be charged in real time. When the detected current value I deviates from the predetermined current range, the current detection unit 11 outputs a current deviation signal, the first control unit 12 generates a control signal according to the deviation direction and the deviation degree of the current deviation signal, the control signal generation unit 13 generates a rectangular wave signal with a predetermined cycle number and a predetermined duty ratio, the communication identification unit 21 detects the rectangular wave signal through the power supply contact and outputs the rectangular wave signal to the second control unit 22, the second control unit 22 generates a power supply control signal according to the cycle number and the duty ratio of the rectangular wave signal, and the power supply management unit 23 is controlled to change the power supply voltage of the output terminal, so that the current value I flowing into the power supply to be charged changes toward the predetermined current range.

The predetermined current range may be an error value that the device to be charged can receive by floating up and down on the basis of the optimal input constant current value of the power supply to be charged, and the present invention is not limited thereto. The deviation direction of the current deviation signal refers to that the current value I is larger than a preset current range or smaller than the preset current range, and the deviation degree of the current deviation signal refers to that the current value I is larger than the preset current range or smaller than a specific value of the preset current range, and preferably refers to the difference value of the current value I and the optimal input constant current value of the power supply to be charged.

In one embodiment, when the detected present current value I is smaller than the first current threshold Ith1, the current detecting unit 11 outputs a first current deviation signal, that is, the current is smaller, the first control unit 12 controls the signal generating unit 13 to generate a first rectangular wave signal having a first predetermined cycle number and a first predetermined duty ratio according to the first current deviation signal, and typically, the first rectangular wave signal includes a boost signal and a boost value signal; the first rectangular wave signal is output to the power supply device 20 through the charging contact, the communication identification unit 21 of the power supply device 20 can detect the first rectangular wave signal through the power supply contact, and the second control unit 22 controls the power supply management unit 23 to increase the power supply voltage according to the first rectangular wave signal detected by the communication identification unit 21, so that the value of the current flowing into the power supply to be charged becomes large.

In one embodiment, when the detected present current value I is greater than the second current threshold Ith2, the current detection unit 11 outputs a second current deviation signal, that is, a current large signal, the first control unit 12 controls the signal generation unit 13 to generate a second rectangular wave signal having a second predetermined cycle number and a second predetermined duty ratio according to the second current deviation signal, and typically, the second rectangular wave signal includes a voltage reduction signal and a voltage reduction value signal, the second rectangular wave signal is output to the charging device 20 through the charging contact, the communication identification unit 21 of the power supply device 20 can detect the second rectangular wave signal through the power supply contact, and the second control unit 22 controls the power supply management unit 23 to reduce the power supply voltage according to the second rectangular wave signal detected by the communication identification unit 21, so that the current value flowing into the power supply to be charged becomes small.

The current detection unit 11, the first control unit 12, the signal generation unit 13, the communication identification unit 21, the second control unit 22, the power management module 23, the power supply contact and the charging contact form a feedback closed-loop system, and in the constant-current charging stage, the current value flowing into the device to be charged is detected to be too low or too high, namely, whether the current value is stabilized in a preset charging current value range, so that the problems of reduction of charging speed and charging energy efficiency caused by shunting of the functional units in the device to be charged 10 are solved. The power supply voltage output by the power supply equipment 20 is changed through simple electric signal feedback, so that the equipment to be charged always keeps better charging timeliness and lower charging energy consumption in the charging process, the charging times of the power supply equipment 20 can be increased, and the user experience is improved.

In the charging system of the present invention, the current detection unit 11 in the device to be charged 10 may be a circuit component conventionally used for current detection in the prior art, and when used in a small electronic device, a current detection circuit with a simple circuit may be used, and the present invention is not limited thereto. The first control unit 12 in the device to be charged is typically a processor that may be used for data signal communication processing, and the invention is not limited thereto.

In one embodiment, the first current threshold Ith1 and the second current threshold Ith2 may be set appropriately according to production experience, for example, the optimal charging current flowing into the power source to be charged is 50mA, Ith1 may be set to 45mA and Ith2 may be set to 55mA, respectively, and this range ensures that the charging requirement of the power source to be charged can be considered at the same time, and other factors such as the charging efficiency of the power source to be charged can also be considered.

As a preferred embodiment, the signal generating unit 13 may be a triode or a field effect transistor. When a triode is adopted, the base electrode of the triode is connected with the first control unit 12, one of the collector electrode and the emitter electrode of the triode is connected with the charging contact, and the other is grounded; when a field effect transistor is used, the gate of the field effect transistor is connected to the first control unit 12, one of the drain and source of the field effect transistor is connected to the charging contact, and the other is grounded.

Specifically, when an NPN-type transistor is used, a base of the NPN-type transistor is connected to the first control unit 12, a collector of the NPN-type transistor is connected to the charging contact, and an emitter is grounded; when the PNP type triode is used, the base of the PNP triode is connected to the first control unit 12, the emitter of the PNP triode is connected to the charging contact, and the collector is grounded. When an NMOS tube is adopted, the grid electrode of the NMOS tube is connected with the first control unit 12, the drain electrode of the NMOS tube is connected with the charging contact, and the source electrode is grounded; when a PMOS transistor is used, the gate of the PMOS transistor is connected to the first control unit 12, the source of the PMOS transistor is connected to the charging contact, and the drain is grounded. The above connection manner can be implemented such that when the current value I deviates from the preset current range, the first control unit 12 controls the triode or the field effect transistor to generate a rectangular wave signal with a predetermined cycle number and a predetermined duty ratio.

For example, as shown in fig. 3, using a field effect transistor as the signal generating unit 13, the first control unit 12 controls the field effect transistor 13 to perform on and off operations, thereby forming a first rectangular wave signal or a second rectangular wave signal. Only adopt this kind of simple semiconductor device of triode or field effect transistor, can realize exporting first square wave signal or second square wave signal to can carry out accurate constant current charging process, circuit structure is simple, and control is accurate, and cost reduction, when in the charging system to small-size electronic equipment especially, can guarantee to control accurately, need not electronic equipment's volume design oversize.

In one embodiment, the first control unit 12 controls the signal generating unit 13 to generate the rectangular wave electrical signal with N consecutive cycles and a specific duty ratio, wherein the duty ratio is determined according to a difference value between the current value I and a preset input constant current value of the power to be charged, which generally refers to an optimal input charging current value flowing into the power to be charged. The number N of consecutive cycles may represent that the current value input to the power source to be charged is less than Ith1, and represents that the charging voltage value to be output needs to be increased for the power supply device 20; the duty ratio represents a difference between a current value currently input to the power source to be charged and a preset input constant current value of the power source to be charged, for example, if the duty ratio of the rectangular wave is 90%, it represents that the current value is smaller than the preset input constant current value of the power source to be charged by 10mA, that is, the charging voltage needs to be increased so that the charging current is increased by 10mA, if the duty ratio of the rectangular wave is 85%, it represents that the current value is smaller than the preset input constant current value of the power source to be charged by 15mA by a unit amount, the charging voltage needs to be increased so that the charging current is increased by 15mA, and so on. When the power supply device 20 recognizes the rectangular wave signal, it can perform a corresponding boosting operation.

In one embodiment, the first control unit 12 controls the signal generating unit 13 to generate M rectangular wave electrical signals with continuous cycles and a specific duty ratio, wherein the duty ratio is determined according to a difference between the current value I and a preset input constant current value of the power source to be charged, which generally refers to an optimal input charging current value flowing into the power source to be charged. The number M of consecutive cycles may represent that the current value input to the power source to be charged is greater than Ith2, and represents that the charging voltage value to be output needs to be reduced for the power supply device 20; the duty ratio represents a difference between a current value currently input to the power source to be charged and a preset input constant current value of the power source to be charged, for example, if the duty ratio of the rectangular wave is 90%, it represents that the current value is 10mA more than the preset input constant current value of the power source to be charged, that is, the charging voltage needs to be reduced to reduce the charging current by 10mA, if the duty ratio of the rectangular wave is 85%, it represents that the current value is 15mA more than the preset input constant current value of the power source to be charged by a unit amount, the charging voltage needs to be reduced to reduce the charging current by 15mA, and so on. After recognizing the rectangular wave signal, the power supply device 20 may perform a corresponding step-down operation.

In the charging system of the present invention, the communication identification unit 21 in the power supply device 20 may be a circuit component conventionally used for receiving or detecting a rectangular wave signal in the prior art, and when the charging system is used for a small electronic device, a communication identification circuit with a simple circuit may be used, and the present invention is not limited thereto. The second control unit 22 in the power supply apparatus 20 is typically a processor that may be used for data signal communication processing, and the invention is not limited thereto. The power management unit 23 is also a conventional power management circuit that can be used to regulate the value of the output voltage, and the invention is not limited.

In one embodiment, the communication identifying unit 21 of the power supply device 20 receives the first rectangular wave signal or the second rectangular wave signal output by the device to be charged 10, identifies the communication signal of the first rectangular wave signal or the second rectangular wave signal, that is, identifies the number of cycles in the rectangular wave and the duty ratio of each cycle in the rectangular wave, and feeds back the communication signal to the second control unit 22, the second control unit 22 sends out the voltage boosting or reducing control signal according to the received communication signal, and the voltage boosting value or reducing value control signal is sent to the power management unit 23, and the power management unit 23 performs the voltage boosting or reducing operation according to the voltage boosting or reducing control signal and the voltage boosting value or reducing value control signal.

In another embodiment, after the communication identifying unit 21 receives the first rectangular wave signal or the second rectangular wave signal output by the device to be charged 10, the first rectangular wave signal or the second rectangular wave signal may also be output to the second control unit 22, the second control unit 22 identifies the communication signal of the first rectangular wave signal or the second rectangular wave signal, that is, identifies the number of cycles in the rectangular wave and the duty ratio of each cycle in the rectangular wave, the second control unit 22 further generates the voltage boosting or reducing control signal according to the number of cycles in the rectangular wave and the duty ratio of each cycle in the rectangular wave, and the voltage boosting or reducing control signal is provided to the power management unit 23.

The boost value or the buck value control signal is determined according to the duty ratio of the first rectangular wave signal or the second rectangular wave signal.

Through discerning the rectangular wave signal that has specific cycle, power supply unit 20 can learn to carry out step-up or step-down, and then combines specific duty cycle, and power supply unit 20 is steerable specific step-up value or step-down value again, has realized the accurate control of constant current charging through extremely simple circuit structure, has improved the energy efficiency of charging.

In an embodiment, the power management unit 23 may further determine whether the power supply voltage reaches the voltage value of the constant voltage charging, and if the power supply voltage reaches the voltage value of the constant voltage charging, the charging system enters the constant voltage charging stage to finally complete charging of the device to be charged 10.

In the charging system described above, the device to be charged may be a TWS headset, and the power supply device may be a charging box that provides a charging function for the TWS headset. Through adopting above-mentioned charging system to realize the constant current charging process of TWS earphone, the electric current that has accurately controlled in the power that flows into the earphone keeps at the invariable scope for in the constant current charging stage, keep better charging ageing, lower charging energy consumption all the time, and then make the number of times of charging of box increase, promote user experience and feel.

Next, a charging system formed by the TWS headset and the charging box will be described in detail. As shown in fig. 4, when the TWS headset 100 is charged, it is usually placed in the charging box 200 for charging, and it is also common to perform trickle charging first, then perform constant-current charging, and finally perform constant-voltage charging until the charging is completed. In the constant current charging phase, the output charging current of the preset charging box 200 is 50mA, the output charging voltage of the constant voltage charging (maximum output voltage) of the preset charging box 200 is 5V, the optimal input charging current of the charging power supply in the preset earphone 100 is 50mA, the input charging current value range of the charging power supply in the preset earphone 100 is 50mA ± 5mA, and the full electric quantity of the preset earphone 100 is 4.2V.

In the first case, the electric quantity of the battery (to-be-charged power supply) in the earphone 100 is 3.1V, the output charging voltage value of the charging box 200 is 3.6V, the charging voltage does not reach the constant voltage charging voltage value of 5V, the current detection unit 11 in the earphone 100 obtains the input charging current value i of the battery in the earphone to be 48mA, the current detection unit 11 judges that i is within the preset charging current range value, and the charging voltage is kept at 3.6V for constant current charging.

In the second case, the electric quantity of the battery in the earphone 100 is 3.1V, the output charging voltage value of the charging box 200 is 3.6V, and the charging voltage does not reach the constant voltage charging voltage value of 5V, because the functional unit 14 in the earphone 100 shunts 3mA to the input charging current of the earphone, the current detection unit 11 detects that the charging current value i of the battery in the earphone is 45mA, the current detection unit 11 judges that i is within the preset charging current range value, and the charging voltage is kept at 3.1V for constant current charging.

In the third case, the electric quantity of the battery in the earphone 100 is 3.1V, the output charging voltage value of the charging box 200 is 3.6V, and the charging voltage does not reach the constant voltage charging voltage value of 5V, at this time, the functional unit 14 in the earphone 100 shunts 10mA to the input charging current of the earphone, the current detection unit 11 detects that the charging current value i of the battery in the earphone is 40mA, the current detection unit 11 determines that i is not within the preset charging current range value, that is, less than the threshold value of 45mA, and the current detection unit 11 sends a signal to the first control unit 12 in the earphone, according to the information that "10 mA unit quantity is missing". The first control unit 12 of the earphone controls the field effect transistor to be switched on and off according to the information of the '10 mA unit quantity missing' to form a waveform corresponding to the unit quantity and feed the waveform back to the charging box, the communication identification unit 21 of the charging box identifies the communication information of the '10 mA unit quantity missing' and sends the communication information to the second control unit 22 of the charging box, the second control unit 22 outputs a boosting control signal and a boosting value control signal according to the communication information of the '10 mA unit quantity missing', and the power management unit performs boosting operation corresponding to the unit quantity according to the boosting control signal and the boosting value control signal.

Specifically, setting the communication information "lack of 10mA unit amount" as shown in fig. 5 enables to form a waveform of a certain duty ratio by the operation of switching the MOS transistor on and off, switching the fet on and off N times, for example, 10 times, to form a 10 cycle 90% duty ratio, and then switching the fet off. The 90% duty cycle of the 10 cycles, i.e., corresponds to the communication information "lacking the 10mA unit amount".

By analogy, the 10 periods are marked as "lack of XmA units", which in turn correspond to: taking integers as examples, 10 mA-90%, 20 mA-80%, 30 mA-70%, 80 mA-20%, 10 mA-90%.

That is, the communication identifying unit of the charging box 200 can identify that the charging current of the rechargeable battery "lacks XmA units" in the headset 100 when detecting the duty ratio of 10 cycles, and the specific missing unit amount can be referred to as the ratio of the duty ratio.

In a fourth case, on the basis of the third case, the charging box 200 increases the power supply voltage for the communication information output by the earphone 100, so that the input charging current of the rechargeable battery in the earphone 100 reaches 50mA, when the function unit 14 in the earphone 100 finishes working and stops shunting, at this time, the input charging current of the battery in the earphone 100 reaches 60mA, the current detection unit 11 detects that the charging current value i is 60mA, the current detection unit 11 determines that i is not within the preset charging current range value, that is, greater than the second current threshold value 55mA, and the current detection unit 11 sends a "communication information with an excess of 10mA unit amount" to the first control unit 12 of the earphone. The first control unit 12 controls the field effect transistor to be opened and closed according to the communication information of the 'excess 10mA unit amount', a waveform corresponding to the unit amount is formed and fed back to the charging box, the communication identification unit 21 of the charging box identifies the communication information of the 'excess 10mA unit amount' and sends the communication information to the second control unit of the charging box, the second control unit 22 outputs a voltage reduction control signal and a voltage reduction value control signal according to the communication information of the 'excess 10mA unit amount', and the power management unit performs voltage reduction operation corresponding to the unit amount according to the voltage reduction control signal and the voltage reduction value control signal.

Specifically, setting the communication information of "the amount of excess 10mA units", as in the operation of opening and closing the field effect transistor of fig. 6, enables the formation of a waveform of a certain duty ratio. The switching fet was operated 5 times to form 5 cycles with a 90% duty cycle. The 90% duty cycle of the 5 periods, i.e., corresponds to the communication information of the "10 mA unit amount more".

By analogy, the 5 periods are marked as 'excess XmA unit quantity', and the following are corresponded in sequence: taking integers as examples, 10 mA-90%, 20 mA-80%, 30 mA-70%, 80 mA-20%, 10 mA-90%.

That is, the communication identifying unit 21 of the charging box 200 can identify the charging current as "XmA unit amount excess" of the battery in the headset 100 when detecting the duty ratio of 5 cycles, and the specific unit amount missing can be seen as the ratio of the duty ratio.

In case five, when the output charging voltage of the charging box 200 reaches 5V, the charging box 200 enters a stage of constant voltage charging to the earphone 100 regardless of the "XmA unit excess amount" or "XmA unit amount missing" communication signal fed back by the earphone 100.

It is understood that in the art, when the charging box 200 charges the earphone 100, the current distribution of the functional units in the earphone 100 is not particularly large, which makes it difficult for the charging box 200 to greatly increase the output charging voltage to increase the input charging current of the rechargeable battery in the earphone 100. Therefore, even if the charging box 200 is raised to the 5V output charging voltage because of the communication information fed back by the headset 100, it can be understood that the amount of power of the headset 100 is close to the range of the constant voltage charging.

Fig. 7 is a graph showing the variation trend of the output charging voltage U of the charging box 200 and the input charging current i of the battery in the earphone 100 along with the increase of the earphone power in the charging process of the wireless earphone 100 by the charging box 200 in fig. 4, wherein the time periods t3 and t4 correspond to the feedback adjustment processes of the third case and the fourth case, respectively.

The invention also provides a device to be charged, such as the device to be charged 10 in fig. 2, which comprises a power supply to be charged, a first control unit 12, a current detection unit 11, a signal generation unit 13 and a charging contact, wherein the output end of the signal generation unit is electrically connected with the charging contact, and the control end of the signal generation unit is electrically connected with the first control unit; the detection end of the current detection unit is electrically connected with the charging branch of the power supply to be charged, and the output end of the current detection unit is electrically connected with the first control unit; the charging contact is electrically connected with the power supply equipment so that the output charging current of the power supply equipment flows into the equipment to be charged, in a constant current charging stage, the current detection unit 11 detects the current value I flowing into the power supply to be charged, when the current value I deviates from a preset current range, the current detection unit 11 outputs a current deviation signal, the first control unit 12 generates a control signal according to the deviation direction and the deviation degree of the current deviation signal, the control signal generation unit 13 generates a rectangular wave signal with a preset period number and a preset duty ratio, and the rectangular wave signal is output through the charging contact so that the power supply equipment changes the power supply voltage and the current value flowing into the power supply to be charged changes towards the preset current range. The device to be charged 10 of the present invention can detect the current value of the power supply to be charged in real time, and when the current value of the power supply to be charged is not within the preset current value range, the first control unit 12 controls the signal generating unit 13 to generate a rectangular wave signal, so that the charging device can adjust the output power supply voltage according to the rectangular wave signal, thereby adjusting the current value of the power supply to be charged to the preset input constant current value of the power supply to be charged, that is, the optimal input charging current, and accurately controlling the current flowing into the power supply to be charged to be kept within the constant range, so that the highest charging time efficiency is always kept in the constant current charging stage.

In one embodiment, when the current value I is smaller than the first current threshold Ith1, the current detection unit 11 outputs a first current deviation signal, and the first control unit 12 controls the signal generation unit 13 to generate a first rectangular wave signal having a first predetermined cycle number and a first predetermined duty ratio according to the first current deviation signal, where the first rectangular wave signal includes a boost signal and a boost value signal, and the first rectangular wave signal is output through the charging contact to enable the power supply apparatus to increase the power supply voltage.

In one embodiment, when the current value I is greater than the second current threshold Ith2, the current detection unit 11 outputs a second current deviation signal, and the first control unit 12 controls the signal generation unit 13 to generate a second rectangular wave signal having a second predetermined cycle number and a second predetermined duty ratio according to the second current deviation signal, wherein the second rectangular wave signal generally includes a step-down signal and a step-down value signal, and the second rectangular wave signal is output through the charging contact to enable the power supply device to reduce the charging voltage.

In one embodiment, the signal generating unit 13 may be a transistor or a field effect transistor. When a triode is adopted, the base electrode of the triode is connected with the first control unit 12, one of the collector electrode and the emitter electrode of the triode is connected with the charging contact, and the other is grounded; when a field effect transistor is used, the gate of the field effect transistor is connected to the first control unit 12, one of the drain and source of the field effect transistor is connected to the charging contact, and the other is grounded.

For example, as shown in the device to be charged 10 in fig. 3, using a field effect transistor as the signal generating unit 13, the first control unit 12 controls the field effect transistor 13 to perform on and off operations, thereby forming a first rectangular wave signal or a second rectangular wave signal. Only adopt this kind of simple semiconductor device of triode or field effect transistor, can realize exporting first square wave signal or second square wave signal to can carry out accurate constant current charging process, circuit structure is simple, and control is accurate, and cost reduction, when in the charging system to small-size electronic equipment especially, can guarantee to control accurately, need not electronic equipment's volume design oversize.

In one embodiment, the first control unit 12 controls the signal generating unit 13 to generate the rectangular wave electrical signal with N consecutive cycles and a specific duty ratio, wherein the duty ratio is determined according to a difference value between the current value I and a preset input constant current value of the power to be charged, which generally refers to an optimal input charging current value flowing into the power to be charged. The number N of the continuous cycles may represent that a current value input to the power supply to be charged is smaller than Ith1, and the duty ratio represents a difference value between the current value currently input to the power supply to be charged and a preset input constant current value of the power supply to be charged.

In one embodiment, the first control unit 12 controls the signal generating unit 13 to generate M continuous periods of rectangular wave electrical signals with specific duty ratios, wherein the duty ratios are determined according to the difference between the current value I and the preset input constant current value of the power source to be charged. The number M of consecutive cycles may represent that the current value input to the power source to be charged is greater than Ith2, and the duty ratio represents the difference between the current value currently input to the power source to be charged and the preset input constant current value of the power source to be charged.

The device to be charged can be small-sized electronic equipment such as a TWS earphone and the like, constant current charging is carried out in the TWS earphone by adopting the technical scheme, the current value flowing into a battery can be detected in real time, and when the current value is not in a preset range, overlarge or undersize current information is fed back to a charging box through different rectangular wave signals, so that the current flowing into a power supply of the earphone is accurately controlled to be kept in a constant range, better charging timeliness and lower charging energy consumption are always kept in a constant current charging stage, and the circuit is simple to realize and is particularly suitable for small-sized electronic equipment with high volume requirement.

The invention also provides a power supply device, such as the power supply device 20 in fig. 2, which comprises a communication identification unit 21, a second control unit 22, a power management unit 23 and a power supply contact, wherein the identification input end of the communication identification unit is electrically connected with the power supply contact, and the output end of the communication identification unit is electrically connected with the second control unit; the input end of the power management unit is connected with a power supply, the output end of the power management unit is connected with a power supply contact, and the control end of the power management unit is connected with the second control unit; the power supply contact is connected with the device to be charged so that the output power supply current of the power supply device 20 flows into the device to be charged, in the constant current charging stage, the communication identification unit 21 detects a rectangular wave signal output by the device to be charged through the power supply contact and outputs the rectangular wave signal to the second control unit 22, the second control unit 22 generates a power supply control signal according to the period number and the duty ratio of the rectangular wave signal, and the power supply management unit 23 is controlled to change the power supply voltage of the output end so that the current value flowing into the power supply to be charged changes towards a preset current range.

The power supply device 20 of the invention can receive the rectangular wave information of the real-time charging condition of the device to be charged through the power supply contact, and adjust the output power supply voltage in real time according to the rectangular wave information, thereby adjusting the current value flowing into the device to be charged to the preset input constant current value of the power supply to be charged, namely the optimal input charging current, and accurately controlling the current flowing into the power supply to be kept in a constant range, so that better charging timeliness and lower charging energy consumption are always kept in the constant current charging stage.

In one embodiment, when the square wave is a first square wave signal having a first predetermined cycle number and a first predetermined duty ratio, the second control unit 22 controls the power management unit 23 to increase the supply voltage according to the cycle number and the duty ratio of the first square wave signal, and the first square wave signal generally includes a boost signal and a boost value signal.

In one embodiment, when the square wave is a second square wave signal having a second predetermined cycle number and a second predetermined duty ratio, the second control unit 22 controls the power management unit 23 to decrease the supply voltage according to the cycle number and the duty ratio of the second square wave signal, and typically, the second square wave signal includes a step-down signal and a step-down value signal.

In one embodiment, the communication identification unit 21 in the power supply device 20 may be a circuit component conventionally used in the prior art for receiving or detecting a rectangular wave signal, and when used in a small electronic device, a communication identification circuit with a simple circuit may be used, and the present invention is not limited thereto. The second control unit 22 in the power supply apparatus 20 is typically a processor that may be used for data signal communication processing, and the invention is not limited thereto. The power management unit 23 is also a conventional power management circuit that can be used to regulate the value of the output voltage, and the invention is not limited.

In an embodiment, the power management unit 23 may further determine whether the charging voltage reaches a voltage value for constant voltage charging, and if the charging voltage reaches the voltage value for constant voltage charging, the power supply device enters a constant voltage charging phase.

The power supply apparatus of the present invention may be a charging box providing a charging function for a TWS headset. The current charging information that the box that charges can receive TWS earphone feedback in real time to according to the accurate control output charging voltage of different rectangular wave signals, make in the constant current charging stage, keep the highest ageing, the best charging voltage of charging all the time, and then make the number of times of charging of box that charges increase, promote user experience and feel.

The invention also provides a charging control method in the constant current charging process, which is used for charging in the constant current process through the contact between the power supply equipment and the equipment to be charged. As shown in fig. 8, S301: the method comprises the steps that a device to be charged detects the current value of a power supply to be charged flowing into the device to be charged; s302: judging whether the current value deviates from a preset current range, if so, executing the step S303: the device to be charged generates a current deviation signal, and generates a rectangular wave signal with a preset period number and a preset duty ratio according to the deviation direction and the deviation degree of the current deviation signal; otherwise, continuously detecting the current value of the power supply to be charged flowing into the equipment to be charged; s304: the power supply equipment detects the rectangular wave signal through the contact and generates a power supply control signal according to the periodicity and the duty ratio of the rectangular wave signal; s305: the control changes the supply voltage such that a value of a current flowing into the power source to be charged changes toward a predetermined current range.

In the constant current charging stage, the problem of reduction of charging speed and charging energy efficiency caused by shunting due to the functional units in the device to be charged 10 is avoided by detecting whether the current value of the power supply to be charged flowing into the device to be charged is too low or too high, namely whether the current value is stabilized within a preset charging current value range. The charging voltage value output by the charging equipment is changed through feedback, so that the equipment to be charged always keeps the highest charging timeliness and the lowest charging energy consumption in the charging process.

In one embodiment, the device to be charged determines a predetermined number of cycles of the rectangular wave signal according to the current deviation direction, and determines a predetermined duty ratio of the rectangular wave signal according to the current deviation degree. In a specific embodiment, when the present current value is smaller than the predetermined current range, N rectangular wave periods may be generated, and the difference between the present current value and the predetermined current minimum value may define the duty ratio of the rectangular wave; when the present current value is greater than the predetermined current range, M rectangular wave periods may be generated, and the difference between the present current value and the predetermined current maximum value may define the duty cycle of the rectangular wave, such as the rectangular wave generation process in the charging system formed by the TWS headset and the charging box described above.

In one embodiment, as shown in fig. 9, S401: detecting the current value of a power supply to be charged flowing into equipment to be charged; s402: judging whether the current value is smaller than a first current threshold value, if so, executing S403: the method comprises the steps that a device to be charged generates a first current deviation signal, and outputs a first rectangular wave signal with a first preset period number and a first preset duty ratio according to the first current deviation signal; s404: the power supply equipment detects a first rectangular wave signal through a contact and generates a power supply control signal according to the periodicity and the duty ratio of the first rectangular wave signal; and S405, controlling to increase the power supply voltage.

In an embodiment, the device to be charged generates N continuous periods of first rectangular wave signals according to the first current deviation small signal, and determines a duty ratio of the first rectangular wave signal according to a difference between a current value and a preset input constant current value of the power source to be charged, where the preset input constant current value of the power source to be charged generally refers to an optimal input charging current value flowing into the power source to be charged. The power supply apparatus generates a boost control signal according to the number of cycles N of the first rectangular wave, and generates a boost value control signal according to the duty ratio of the first rectangular wave. Specifically, N consecutive periods of the rectangular wave with a specific duty cycle represent the voltage value to be increased. For example, if the duty ratio of the rectangular wave is 90%, it indicates that the current value is smaller than the preset input constant current value of the power source to be charged by a unit amount of 10mA, that is, the power supply voltage needs to be increased to increase the charging current by 10 mA; the duty ratio is 85%, which means that the current value is smaller than the preset input constant current value of the power supply to be charged by a unit amount of 15mA, the supply voltage needs to be increased to increase the charging current by 15mA, and so on.

In one embodiment, as shown in fig. 9, S401: detecting the current value of a power supply to be charged flowing into equipment to be charged; s402: judging whether the current value is smaller than the first current threshold value, if not, executing S406: judging whether the current value is larger than a second current threshold value, if so, executing S407: the equipment to be charged generates a second current deviation signal and outputs a second rectangular wave signal with a second preset period number and a second preset duty ratio according to the second current deviation signal; s408: the power supply equipment detects a second rectangular wave signal through the contact and generates a power supply control signal according to the periodicity and the duty ratio of the second rectangular wave signal; s409: the control reduces the supply voltage.

In an embodiment, the device to be charged generates M continuous periods of second rectangular wave signals according to the second current deviation signal, and generates a duty ratio of the second rectangular wave signal according to a difference between a current value and a preset input constant current value of the power supply to be charged. The power supply equipment generates a buck-boost control signal according to the period number M of the second rectangular wave and generates a buck value control signal according to the duty ratio of the second rectangular wave. For example, if the duty ratio of the rectangular wave is 90%, it represents that the current value is 10mA greater than the preset input constant current value of the power source to be charged by a unit amount, that is, the charging voltage needs to be decreased to decrease the charging current by 10 mA; the duty ratio is 85%, which means that the current value is larger than the preset input constant current value of the power supply to be charged by a unit amount of 15mA, the charging voltage needs to be reduced to reduce the charging current by 15mA, and so on.

The invention also provides a constant current charging method executed by the equipment to be charged and a constant current charging method executed by the electric equipment, which respectively execute the operation executed by the equipment to be charged and the operation executed by the charging equipment in the technical scheme.

It will be appreciated by those skilled in the art that the above-described preferred embodiments may be freely combined, superimposed, without conflict.

It will be understood that the embodiments described above are illustrative only and not restrictive, and that various obvious and equivalent modifications and substitutions for details described herein may be made by those skilled in the art without departing from the basic principles of the invention.

Claims

1. A charging system comprising a device to be charged and a power supply device,

the power supply equipment comprises a power supply, a communication identification unit, a second control unit, a power management unit and a power supply contact, wherein the identification input end of the communication identification unit is electrically connected with the power supply contact, and the output end of the communication identification unit is electrically connected with the second control unit; the input end of the power management unit is connected with the power supply, the output end of the power management unit is connected with the power supply contact, and the control end of the power management unit is connected with the second control unit;

the charging contact is connected with the power supply contact so that the output charging current of the power supply equipment flows into the equipment to be charged;

in the constant current charging stage, the current detection unit detects the current value of the current flowing into the power supply to be charged;

when the current value deviates from a preset current range, the current detection unit outputs a current deviation signal, the first control unit generates a control signal according to the deviation direction and the deviation degree of the current deviation signal, and the signal generation unit is controlled to generate a rectangular wave signal with a preset period number and a preset duty ratio; the communication identification unit detects the rectangular wave signal through the power supply contact and outputs the rectangular wave signal to the second control unit, the second control unit generates a power supply control signal according to the periodicity and the duty ratio of the rectangular wave signal, and the power supply management unit is controlled to change the power supply voltage of the output end, so that the current value flowing into the power supply to be charged is changed towards the preset current range.

2. The charging system according to claim 1, wherein when the present current value is smaller than a first current threshold value, the current detection unit outputs a first current deviation signal, and the first control unit controls the signal generation unit to generate a first rectangular wave signal having a first predetermined number of cycles and a first predetermined duty ratio according to the first current deviation signal; the communication identification unit detects the first rectangular wave signal through the power supply contact; the second control unit controls the power supply management unit to increase the power supply voltage according to the first rectangular wave signal detected by the communication identification unit, so that the current value flowing into the power supply to be charged is increased.

3. The charging system according to claim 1, wherein when the present current value is greater than a second current threshold value, the current detection unit outputs a second current deviation signal, and the first control unit controls the signal generation unit to generate a second rectangular wave signal having a second predetermined number of cycles and a second predetermined duty ratio according to the second current deviation signal; the communication identification unit detects the second rectangular wave signal through the power supply contact; the second control unit controls the power supply management unit to reduce the power supply voltage according to the second rectangular wave signal detected by the communication identification unit, so that the current value flowing into the power supply to be charged is reduced.

4. The charging system according to claim 1, wherein the signal generating unit comprises a transistor or a field effect transistor, wherein,

when the signal generating unit comprises a triode, the base electrode of the triode is connected with the first control unit, one of the collector electrode and the emitter electrode of the triode is connected with the charging contact, and the other one of the collector electrode and the emitter electrode of the triode is grounded;

when the signal generating unit comprises a field effect transistor, the grid electrode of the field effect transistor is connected with the first control unit, one of the drain electrode and the source electrode of the field effect transistor is connected with the charging contact, and the other one of the drain electrode and the source electrode of the field effect transistor is grounded.

5. The charging system of claim 1, wherein the power management unit is further configured to determine whether the power supply voltage reaches a constant voltage charging voltage value, and if so, the charging system enters a constant voltage charging phase.

6. The charging system according to any one of claims 1 to 5, wherein the device to be charged is a TWS headset, and the power supply device is a charging box that is mated with the TWS headset.

7. The device to be charged is characterized by comprising a power supply to be charged, a first control unit, a current detection unit, a signal generation unit and a charging contact; the output end of the signal generating unit is electrically connected with the charging contact, and the control end of the signal generating unit is electrically connected with the first control unit; the detection end of the current detection unit is electrically connected with the charging branch of the power supply to be charged, and the output end of the current detection unit is electrically connected with the first control unit;

the charging contact is used for being electrically connected with power supply equipment so that the output charging current of the power supply equipment flows into the equipment to be charged;

when the current value deviates from a preset current range, the current detection unit outputs a current deviation signal, the first control unit generates a control signal according to the deviation direction and the deviation degree of the current deviation signal, the signal generation unit is controlled to generate a rectangular wave signal with a preset period number and a preset duty ratio, and the rectangular wave signal is output through the charging contact to enable the power supply equipment to change the power supply voltage, so that the current value flowing into the power supply to be charged changes towards the preset current range.

8. The device to be charged according to claim 7, wherein when the current value is smaller than a first current threshold, the current detection unit outputs a first current deviation signal, the first control unit controls the signal generation unit to generate a first rectangular wave signal having a first predetermined number of cycles and a first predetermined duty ratio according to the first current deviation signal, and the first rectangular wave signal is output through the charging contact to enable the charging device to increase a supply voltage.

9. The apparatus to be charged according to claim 7, wherein when the present current value is greater than a second current threshold value, the current detection unit outputs a second current deviation signal, the first control unit controls the signal generation unit to generate a second rectangular wave signal having a second predetermined number of cycles and a second predetermined duty ratio according to the second current deviation signal, and the second rectangular wave signal is output through the charging contact to cause the charging apparatus to reduce a supply voltage.

10. The device to be charged according to claim 7, wherein the signal generating unit comprises a triode or a field effect transistor, wherein,

11. A device to be charged according to any of claims 7 to 10, characterized in that the device to be charged is a TWS headset.

12. A power supply device is used for charging a device to be charged and is characterized by comprising a communication identification unit, a second control unit, a power management unit and a power supply contact; the identification input end of the communication identification unit is electrically connected with the power supply contact, and the output end of the communication identification unit is electrically connected with the second control unit; the input end of the power management unit is connected with the power supply, the output end of the power management unit is connected with the power supply contact, and the control end of the power management unit is connected with the second control unit;

the power supply contact is used for being connected with equipment to be charged so that output charging current of the power supply equipment flows into the equipment to be charged;

in the constant-current charging stage, the communication identification unit detects a rectangular wave signal output by the device to be charged through the power supply contact and outputs the rectangular wave signal to the second control unit, the second control unit generates a power supply control signal according to the periodicity and the duty ratio of the rectangular wave signal, and the power supply management unit is controlled to change the power supply voltage of the output end so as to change the current value flowing into the power supply to be charged.

13. The power supply apparatus according to claim 12, wherein when the rectangular wave is a first rectangular wave signal having a first predetermined cycle number and a first predetermined duty ratio, the second control unit controls the power supply management unit to increase the supply voltage in accordance with the cycle number and the duty ratio of the first rectangular wave signal.

14. The power supply apparatus according to claim 12, wherein when the rectangular wave is a second rectangular wave signal having a second predetermined cycle number and a second predetermined duty ratio, the second control unit controls the power supply management unit to lower the supply voltage in accordance with the cycle number and the duty ratio of the second rectangular wave signal.

15. The power supply device of claim 12, wherein the power management unit is further configured to determine whether the power supply voltage reaches a constant voltage charging voltage value, and if so, the power supply device enters a constant voltage charging phase.

16. The power supply device of any one of claims 12 to 15, wherein the power supply device is a charging box providing a charging function for a TWS headset.

17. A charging control method in a constant current charging process is used for charging in the constant current process through a contact between power supply equipment and equipment to be charged, and is characterized by comprising the following steps:

the device to be charged detects the current value of a power supply to be charged flowing into the device to be charged;

when the current value deviates from a preset current range, the equipment to be charged generates a current deviation signal, and generates a rectangular wave signal with a preset period number and a preset duty ratio according to the deviation direction and the deviation degree of the current deviation signal; the power supply equipment detects the rectangular wave signal through the contact, generates a power supply control signal according to the periodicity and the duty ratio of the rectangular wave signal, and controls and changes power supply voltage, so that the value of current flowing into the power supply to be charged changes towards the preset current range.

18. The charging control method in the constant-current charging process according to claim 17, wherein the device to be charged determines a predetermined number of cycles of the rectangular wave signal according to the current deviation direction, and determines a predetermined duty ratio of the rectangular wave signal according to the current deviation degree.

19. The charging control method in the constant-current charging process according to claim 17, wherein when the present current value is smaller than a first current threshold value, the device to be charged generates a first current deviation signal, and outputs a first rectangular wave signal having a first predetermined cycle number and a first predetermined duty ratio according to the first current deviation signal; the power supply equipment detects the first rectangular wave signal through the contact, generates a power supply control signal according to the periodicity and the duty ratio of the first rectangular wave signal, and controls and increases power supply voltage.

20. The charging control method in the constant-current charging process according to claim 19, wherein the device to be charged generates N consecutive periods of first rectangular wave signals according to the first current deviation signal, and determines the duty ratio of the first rectangular wave signals according to the difference between the current value and a preset input constant current value of the power source to be charged.

21. The charge control method in the constant-current charging process according to claim 20, wherein the power supply device generates a boost control signal according to a cycle number N of the first rectangular wave signal, and generates a boost value control signal according to a duty ratio of the first rectangular wave.

22. The charging control method in the constant-current charging process according to claim 17, wherein when the present current value is greater than a second current threshold value, the device to be charged generates a second current deviation signal, and outputs a second rectangular wave signal having a second predetermined cycle number and a second predetermined duty ratio according to the second current deviation signal; and the power supply equipment detects the second rectangular wave signal through the contact, generates a power supply control signal according to the periodicity and the duty ratio of the second rectangular wave signal, and controls to reduce the power supply voltage.

23. The charging control method in the constant-current charging process according to claim 22, wherein the device to be charged generates M continuous periods of second rectangular wave signals according to the second current deviation signal, and generates a duty ratio of the second rectangular wave signals according to a difference between the current value and a preset input constant current value of the power source to be charged.

24. The charging control method in the constant-current charging process according to claim 23, wherein the power supply device generates a step-down control signal according to the number M of cycles of the second rectangular wave, and generates a step-down value control signal according to a duty ratio of the second rectangular wave.

25. A charging control method performed by a device to be charged, characterized by performing the operation performed by the device to be charged in the charging control method in the constant-current charging process according to any one of claims 17 to 24.

26. A charging control method performed by a power supply apparatus, characterized by performing an operation performed by the power supply apparatus in the charging control method during constant-current charging according to any one of claims 17 to 24.