CN114914968A - Charging circuit, charging box, charging system and method and wireless earphone system - Google Patents

Abstract

The invention relates to a charging circuit, a charging box, a charging system and method and a wireless earphone system. The charging circuit includes: a rechargeable battery; the charging management unit is used for performing charging management on the rechargeable battery; the minimum value of the effective output voltage of the rechargeable battery is higher than the full charge voltage of the device battery of the charged portable electronic device, the charging unit is a voltage-reducing charging unit, and the voltage-reducing charging unit is used for reducing the output voltage of the rechargeable battery and then outputting the reduced output voltage through a voltage output end. In the application, the voltage-reducing charging unit is simple in circuit, the number of the included switching devices is small, the structure of the charging circuit is simplified, energy consumption during charging can be reduced, and the energy utilization efficiency of a charging system is improved.

Description

Charging circuit, charging box, charging system and method, and wireless earphone system

Technical Field

The invention relates to the technical field of charging, in particular to a charging circuit, a charging box, a charging system and method and a wireless earphone system.

Background

Compared with wired earphones, wireless earphones have the advantage of being convenient to carry, and are therefore increasingly popular with people. In the prior art, a charging box circuit enables a voltage output end to output a set voltage such as 5V through a booster circuit, and a charging management circuit is arranged in a wireless earphone, so that the earphone battery can be charged and managed by using the 5V voltage, for example, constant current charging or constant voltage charging is performed. Because need design boost circuit in the box circuit that charges and design the management circuit that charges in wireless earphone for whole charging circuit structure is complicated, is unfavorable for reducing energy consumption, improves charge efficiency.

Disclosure of Invention

The present invention is directed to overcome the above problems, and provides a charging circuit, a charging box, a charging system, a wireless headset system, and a charging method, which simplify the structure of the charging circuit, reduce energy consumption during charging, and improve energy utilization efficiency of the charging system.

In order to achieve the above object, an aspect of the present invention provides a charging circuit, including: a rechargeable battery; the charging management unit is used for performing charging management on the rechargeable battery; a charging unit; the minimum value of the effective output voltage of the rechargeable battery is higher than the full charge voltage of the device battery of the charged portable electronic device, the charging unit is a voltage-reducing type charging unit, and the voltage-reducing type charging unit is used for reducing the output voltage of the rechargeable battery and then outputting the reduced output voltage through the voltage output end.

Optionally, the rechargeable battery comprises at least two lithium batteries connected in series; and/or the charging management unit charges the rechargeable battery in a voltage reduction mode and/or a voltage boosting mode.

Optionally, the charging voltage output by the voltage output end is positively correlated with a voltage difference between two poles of a device battery of the portable electronic device coupled to the voltage output end through the voltage input end thereof during charging; and the charging unit is used for dynamically adjusting the charging voltage or the charging current output by the voltage output end based on the output voltage of the rechargeable battery and the charging voltage and/or the charging current output by the voltage output end, so as to realize charging management on the equipment battery of the portable electronic equipment.

Optionally, the charging unit includes a feedback control module, a voltage reduction module, and an output capacitor coupled between the voltage output terminal and a ground terminal, where the feedback control module is configured to sample a charging current and adjust the charging current output by the voltage reduction module through the voltage output terminal according to the sampled charging current, so that the charging current is equal to a predetermined charging current threshold, and a device battery of the portable electronic device is charged at a constant current; and/or the feedback control module is used for sampling charging voltage and controlling and adjusting the charging voltage output by the voltage reduction module through the voltage output end according to the charging voltage obtained by sampling, so that the charging voltage is equal to a preset charging voltage threshold value, and constant voltage charging of a device battery of the portable electronic device is realized.

Optionally, the voltage reducing module includes a first switch, a second switch, and an inductor, the first switch is coupled between an output end of the rechargeable battery and an intermediate node SW, the second switch is coupled between the intermediate node SW and a ground end, the inductor is coupled between the intermediate node and the voltage output end, and the feedback control module controls the first switch and the second switch to be alternately turned on and controls a duty ratio of on and off of the first switch, so as to implement constant current or constant voltage charging.

Optionally, an input end of the feedback control module is coupled to the intermediate node SW, and the feedback control module obtains the charging current according to a voltage difference between the intermediate node SW and the ground terminal and a resistance of the second switch or obtains the charging current according to a voltage difference between an output end of the rechargeable battery and the intermediate node SW and a resistance of the first switch; the other input end of the feedback control module is coupled with the voltage output end, and the feedback control module obtains the charging voltage of the equipment battery according to the voltage output end; and/or the second switch coupled between the intermediate node SW and the ground terminal is replaced by a diode, the anode of the diode is coupled to the ground terminal, the cathode of the diode is coupled to the intermediate node SW, the on or off state of the diode is consistent with the on or off state of the second switch, and the on or off state of the diode is not controlled by the feedback control module but is determined by whether the voltage difference between the two ends of the diode exceeds the on threshold value.

A second aspect of the present invention provides a charging box comprising the charging circuit of the first aspect described above.

A third aspect of the present invention provides a charging circuit for a portable electronic device, the charging circuit comprising a device battery and a voltage input terminal, the device battery being coupled between the voltage input terminal and a ground terminal, the voltage of the voltage input terminal directly reflecting the voltage of the device battery, the voltage input terminal being directly coupled to a voltage output terminal of an external charging device having the charging circuit of the first aspect when charging, so as to charge the device battery by a charging unit in the external charging device.

A fourth aspect of the present invention provides a charging system comprising: a wireless headset circuit comprising a headset battery as a device battery and a voltage input coupled to the headset battery; the charging circuit of the first aspect, wherein a voltage output terminal of the charging circuit is coupled to the voltage input terminal.

A fifth aspect of the present invention provides a wireless headset system, comprising: the charging cartridge of the second aspect described above; a wireless headset that can be placed into the charging box and that includes a voltage input and a headset battery coupled to the voltage input; when the wireless earphone is placed in the charging box, the voltage output end of the charging circuit is electrically coupled with the voltage input end of the wireless earphone.

A sixth aspect of the present invention provides a charging method, including: the charging circuit of the external charging equipment reduces the output voltage of a rechargeable battery through a charging unit and then outputs the reduced output voltage through a voltage output end, wherein the minimum value of the effective output voltage of the rechargeable battery is higher than the full charge voltage of an equipment battery of the charged portable electronic equipment, and the charging unit is a step-down charging unit; and/or the equipment battery directly receives the charging voltage and/or the charging current output by the voltage output end of the charging circuit for charging.

In the above technical solution, the minimum value of the effective output voltage of the rechargeable battery is higher than the full charge voltage of the device battery of the portable electronic device to be charged, the charging unit is a voltage-reducing charging unit for reducing the output voltage of the rechargeable battery and then outputting the reduced output voltage through the voltage output terminal, compared with the scheme of twice conversion in which the voltage of the rechargeable battery is firstly boosted (first conversion) by the voltage boosting circuit in the charging device such as a charging box and then the boosted voltage is adjusted to the voltage required by the device battery (second conversion) by the charging management unit in the portable electronic device such as a wireless headset, the present application only needs the voltage-reducing charging unit to adjust the voltage of the rechargeable battery to the voltage required by the device battery, that is, only one conversion is needed to obtain the required voltage, and because the circuit of the voltage-reducing charging unit is simple, the number of switching devices is small, therefore, the structure of the charging circuit is simplified, the energy consumption during charging can be reduced, and the energy utilization efficiency of the charging system is improved.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a conventional wireless headset charging system;

fig. 2 is a schematic structural diagram of a charging circuit according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a charging unit of the charging circuit of FIG. 2;

fig. 4 is a schematic structural diagram of a charging circuit of a portable electronic device according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a charging system according to an embodiment of the present application;

fig. 6 is a flowchart of a charging method according to an embodiment of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that as used herein, the meaning of "coupled" includes direct connections between two or more circuit objects without any intervening circuit objects, as well as indirect connections between two or more circuit objects made through one or more intervening circuit objects. For example, two circuit objects that are directly connected to each other are said to be "coupled" to each other. Likewise, two circuit objects are also referred to as being "coupled" to each other if one or more intervening circuit objects are connected therebetween. That is, the term "coupled" may refer to a direct electrical connection or an indirect electrical connection, which means that other components, such as a resistor, a capacitor, etc., are spaced therebetween.

Fig. 1 is a schematic structural diagram of a conventional wireless headset charging system. The wireless earphone charging system is characterized in that the wireless earphone charging system generally comprises a charging box and a wireless earphone, and the wireless earphone can be charged by the charging box when placed in the charging box. The Wireless headset may be a True Wireless Stereo (TWS) headset. As shown in fig. 1, the charging system comprises a first partial circuit 100 located in the TWS headset and a second partial circuit 200 located in the charging box. The first partial circuit 100 includes a first battery BAT1, a first charge management circuit 101, a setting module 102, an analog-to-digital converter ADC 103, and a radio frequency circuit RF 104. The first charging management circuit 101 is configured to charge the first battery BAT1, the setting module 102 is configured to set a charging current of the first charging management circuit 101, the ADC 103 is configured to measure an electric quantity of the first battery BAT1, and the RF 104 is configured to implement wireless communication and receive an audio signal. The second sub-circuit 200 includes a second battery BAT2, a second charge pipe circuit 201, and a booster circuit 202. The second charging tube circuit 201 is used for charging the second battery BAT2, the voltage boost circuit 202 is used for boosting the second battery BAT2 to a set voltage and outputting the voltage to the charging terminal VCHG, the set voltage is 5V, for example, the voltage of VCHG is 5V, and the first charging management circuit 101 in the TWS headset charges the first battery BAT1 through the 5V voltage. Above-mentioned scheme needs designing boost circuit and charge management circuit simultaneously for the charging circuit structure is complicated, is unfavorable for reducing energy consumption, improves charge efficiency.

In view of this, embodiments of the present application provide a charging circuit, a charging box, a charging system, a wireless headset system, and a charging method, which simplify the structure of the charging circuit, reduce energy consumption during charging, and are beneficial to improving the energy utilization efficiency of the charging system.

Fig. 2 is a schematic structural diagram of a charging circuit according to an embodiment of the present disclosure. As shown in fig. 2, the charging circuit includes a rechargeable battery, a charging management unit 11, and a charging unit 12. The charging management unit 11 is used for performing charging management on the rechargeable battery. The minimum value of the effective output voltage of the rechargeable battery is higher than the full charge voltage of the device battery of the portable electronic device to be charged, and the charging unit 12 is a voltage-reducing charging unit for reducing the output voltage of the rechargeable battery and outputting the reduced output voltage through a voltage output terminal.

It should be noted that, in general, the voltage at which the battery can charge the device battery needs to be higher than a certain voltage threshold, for example, the discharge voltage of the lithium battery is 0 to 4.2V, but the voltage at which the device battery can be charged is usually 3V or more, and therefore, the voltage at which the device battery can be charged is defined as an effective output voltage.

As the rechargeable battery in the charging circuit usually adopts a lithium battery to provide 3-4.2V effective charging voltage, the voltage of the equipment battery needs to be reduced when the voltage is too low, and the voltage of the rechargeable battery needs to be increased when the voltage is low. The buck and boost circuits both need switches, which can cause energy loss and cause low charging efficiency. In the above solution of the present application, voltage reduction is only needed, that is, the charging unit 12 is a voltage reduction type charging unit, and is configured to reduce the output voltage of the rechargeable battery and output the reduced output voltage through the voltage output end.

In addition, the charging circuit can be used for a charging box, a charger and other charging devices which can provide charging service for the portable electronic equipment. The charging circuit is physically separated from the portable electronic device, that is, the portable electronic device is separated from the charging circuit when in use, and the portable electronic device can be combined with the charging circuit when charging is needed or other needs. The following description will take an example in which the charging circuit is applied to a charging box. The portable electronic device is now a wireless headset.

In one embodiment, the charging voltage output by the voltage output terminal VO is positively correlated with a voltage difference between two terminals of a device battery of the portable electronic device coupled to the voltage output terminal through the voltage input terminal thereof when charging. Namely, the charging voltage output by the voltage output end VO changes along with the voltage difference between two electrodes of the equipment battery, the voltage difference is increased, and the charging voltage output by the voltage output end VO is increased; the voltage difference is reduced and the charging voltage output by the voltage output terminal VO is reduced.

The charging unit 12 is configured to dynamically adjust the charging voltage or the charging current output by the voltage output terminal based on the output voltage of the rechargeable battery and the charging voltage and/or the charging current output by the voltage output terminal VO, so as to implement charging management on the device battery of the portable electronic device. That is, the charging unit 12 of the charging circuit can adjust the charging voltage and/or the charging current output from the voltage output terminal in accordance with the charging management requirement for the device battery in the portable electronic device using the output voltage of the charging battery, for example, adjust the charging current output from the voltage output terminal when constant current charging is performed, and adjust the charging voltage output from the voltage output terminal when constant voltage charging is performed, so that the device battery can be directly charged using the charging voltage and/or the charging current output from the voltage output terminal of the charging circuit, and it is not necessary to provide a charging management circuit in the portable electronic device, thereby simplifying the circuit configuration in the portable electronic device, facilitating the design for miniaturization of the portable electronic device or installing a battery with a larger capacity in the portable electronic device.

As a specific embodiment, the charging circuit may further include an analog-to-digital converter ADC1 and a radio frequency unit RF1, and the ADC1 is used for measuring the voltage of the charging battery. At this time, the wireless headset circuit may include a radio frequency unit RF2, and voltage information of the rechargeable battery in the charging box may be transmitted to the wireless headset through communication between RF1 and RF 2.

With continued reference to fig. 2, the rechargeable battery may include at least two lithium batteries BAT1 and BAT2 connected in series. In the circuit configuration shown in fig. 1, since the booster circuit 202 and the first charge management circuit 101 for the earphone battery are separately designed, there is an efficiency loss in both the booster circuit 202 and the charge management circuit 101, resulting in a low charging efficiency. The voltage of the rechargeable battery can be directly used for charging the earphone battery after being reduced by the voltage reduction type charging unit, and only the efficiency loss of the voltage reduction type charging unit exists, so that the energy efficiency of the charging system is higher.

Further, since a general universal input voltage is 5V, for example, a power supply is performed using a general Adapter (Adapter) or USB, a full charge voltage of each lithium battery is usually 4.2V, and when two lithium batteries BAT1 and BAT2 are connected in series, the full charge voltage is 4.2Vx2 to 8.4V, and a voltage is required to be increased from 5V to a higher voltage for charging, whereas when the voltages of both batteries are very low, for example, each is 1V, a voltage reduction method is required for charging. Therefore, the charging management unit 11 can charge the rechargeable battery in a step-down mode and/or a step-up mode.

Fig. 3 is a schematic structural diagram of an embodiment of the charging unit 12 of the charging circuit in fig. 2. As shown in fig. 3, the charging unit 12 includes a feedback control module 121, a voltage-reducing module 122, and an output capacitor C coupled between the voltage output terminal VO and a ground terminal. The feedback control module 121 is configured to sample a charging current and adjust the charging current output by the voltage reduction module 122 through the voltage output end VO according to the sampled charging current, so that the charging current is equal to a predetermined charging current threshold, thereby implementing constant current charging on a device battery of the portable electronic device. The feedback control module 121 is configured to sample a charging voltage and adjust the charging voltage output by the voltage reduction module 122 through the voltage output terminal VO according to the sampled charging voltage, so that the charging voltage is equal to a predetermined charging voltage threshold, thereby implementing constant voltage charging on a device battery of the portable electronic device.

In one embodiment, as shown in fig. 3, the voltage-reducing module 122 includes a first switch S1, a second switch S2, and an inductor L, the first switch S1 is coupled between the output terminal of the rechargeable battery, such as BAT2, and the intermediate node SW, the second switch S2 is coupled between the intermediate node SW and the ground terminal, the inductor L is coupled between the intermediate node SW and the voltage output terminal VO, and the feedback control module 121 controls the first switch S1 and the second switch S2 to be alternately turned on and off, and controls the on/off duty ratio of the first switch S1, so as to implement constant-current or constant-voltage charging. Here, the "duty ratio of on and off of the first switch S1" refers to a ratio of on time of the first switch S1 with respect to one period in which the first switch S1 and the second switch S2 are alternately turned on. The first switch S1 and the second switch S1 may be GaAs switches having a smaller on-resistance than that of a common silicon-based switch.

In another embodiment, the second switch coupled between the intermediate node SW and the ground terminal is replaced by a diode, an anode of the diode is coupled to the ground terminal, a cathode of the diode is coupled to the intermediate node SW, and the on or off state of the diode is consistent with the on or off state of the second switch, and the on or off state of the diode is not controlled by the feedback control module 121 but is determined by whether the voltage difference between the two ends of the diode exceeds the on threshold. That is, the second switch S2 can be replaced by a diode, so that the feedback control module 121 only needs to control the on state of the first switch S1, and thus the on duty ratio of the first switch S1, to realize constant current or constant voltage charging.

One input terminal of the feedback control module 121 is coupled to the intermediate node SW, and the feedback control module 121 obtains the charging current according to a voltage difference between the intermediate node SW and the ground terminal and the resistance of the second switch S2. The feedback control module 121 obtains the charging current according to the voltage difference between the output terminal of the rechargeable battery, such as VBAT2, and the intermediate node SW and the resistance of the first switch S1. The other input terminal of the feedback control module 121 is coupled to the voltage output terminal VO, and the feedback control module 121 obtains a charging voltage of a device battery, such as a battery of an earphone, according to the voltage output terminal VO.

That is, first, the feedback control module 121 may obtain the charging current by sampling at the intermediate node SW and combining the ground terminal and the resistance of the second switch S2 or combining the VBAT2 and the resistance of the first switch S1, and obtain the earphone battery voltage, i.e., the charging voltage, by sampling the voltage at the voltage output terminal VO. Then, the feedback control module 121 operates in a negative feedback manner according to the sampled charging current and charging voltage, so that the switches S1 and S2 are alternately turned on, and the duty ratio of the switch S1 is controlled, thereby implementing constant current or constant voltage control.

Fig. 4 is a schematic structural diagram of a charging circuit of a portable electronic device according to an embodiment of the present disclosure. As shown in fig. 4, the charging circuit includes a device battery BAT3 and a voltage input terminal VCHG, the device battery BAT3 is coupled between the voltage input terminal VCHG and a ground terminal GND1, a voltage of the voltage input terminal VCHG can directly reflect a voltage of the device battery BAT3, and the voltage input terminal VCHG is directly coupled to a voltage output terminal of the external charging device, so as to charge the device battery by a charging unit in the external charging device. Wherein, the external charging equipment can be a power bank or a charging box. The charging circuit in the external device may be the charging circuit shown in fig. 2 and 3.

When the external charging device is a charging box, the portable electronic device may be a wireless headset. Since the voltage input terminal VCHG is coupled to the voltage output terminal VO of the charging circuit, the ground terminal of the charging box is coupled to the ground terminal GND1 of the wireless headset, and the battery BAT3 is directly coupled to the voltage input terminal VCHG to obtain power. The circuit in this wireless headset need not set up the charge management unit and comes to carry out charge management to battery BAT3 to simplify wireless headset circuit's structure, can save the space of earphone, be used for installing the battery of bigger capacity with more spaces, perhaps, can reduce the volume of earphone, helped realizing the miniaturization of earphone.

Also the circuitry in the wireless headset comprises an analog to digital converter ADC2, a wireless communication unit such as a radio frequency unit RF2, an application processor AP and an audio unit 21. The analog-to-digital converter ADC2 can be used to obtain the voltage of the battery BAT 3. The radio frequency unit RF2 may be used to transmit data information to a terminal device such as a cellular phone. The data information may include information of the voltage of the battery BAT 3. The audio unit 21 may be used to play information in the application processor AP.

Fig. 5 is a schematic structural diagram of a charging system according to an embodiment of the present application. The charging system includes wireless headset circuitry (shown as circuitry in the right dashed box of fig. 5) and the charging circuitry described above (shown as circuitry in the left dashed box of fig. 5). The wireless headset circuit is located in the wireless headset and includes a headset battery BAT3 as the device battery and a voltage input VCHG coupled to the headset battery BAT 3. The charging circuit is located in the charging box, and the voltage output terminal VO of the charging circuit is coupled to the voltage input terminal VCHG, and the ground terminal GND2 of the charging box is coupled to the ground terminal GND1 of the wireless headset.

The charging circuit in the charging box includes a battery BAT1 and a battery BAT2, a charging management unit 11, a charging unit 12, an analog-to-digital converter ADC1, and a radio frequency unit RF 1. The ADC1 can detect the voltages of the battery BAT1 and the battery BAT2 to obtain the remaining power, and output the remaining power to the RF module RF1, the RF module RF1 sends the remaining power information to the RF2 module of the wireless headset, and the wireless headset can further send the information to the mobile phone for display. The specific structure of the charging unit 12 can be as described above with reference to fig. 3.

The charge management unit 11 can charge the battery BAT1 and the battery BAT2 by stepping down or stepping up. Also, the charging unit 12 is used to charge the battery BAT3 in a step-down manner. Since the electric quantity of a general lithium battery is mainly in a range of 3V-4.2V, the electric quantity is 4.2V when the lithium battery is fully charged, and the lithium battery has almost no output capacity when the lithium battery is discharged to be lower than 3V. Since the two batteries are connected in series at a voltage of 3V × 2V, which is greater than the voltage of the battery BAT3, a step-down charging circuit may be used. By connecting the two batteries in series, the battery BAT3 can be charged by a relatively simple step-down charging circuit, and the working efficiency is high. Preferably, the power switch in the charging unit 12 is a GaAs switch, which has a smaller on-resistance and higher efficiency than a common silicon-based switch. In addition, the charging circuit of the battery BAT3 in the wireless earphone circuit is designed in the charging unit of the charging box, so that the space in the wireless earphone is saved, more space can be reserved for designing a battery with larger capacity, or the miniaturization of the wireless earphone can be realized.

The wireless headset circuit comprises a battery BAT3, an analog-to-digital converter ADC2, a radio frequency unit RF2, an application processor AP and an audio unit 21. The ADC2 obtains the remaining power information of the battery BAT3 by detecting the voltage of the battery BAT3, outputs the information to the RF unit RF2, and transmits the information to the mobile phone for display through the RF unit RF 2. The application processor AP may control the audio unit 21 and the radio frequency unit RF2 for power consumption optimization, e.g. may operate intermittently to save power consumption.

The charging system of this application has simplified the circuit structure among the wireless headset, can be used for designing the battery of more heavy current with the space in the wireless headset, perhaps, can design the headset more lightly, does benefit to and wears. Meanwhile, the energy efficiency during charging is higher, and the charging system is simple in structure and beneficial to reducing the cost. Specifically, in fig. 1, when the boost circuit 202 and the charging management circuit 101 of the earphone battery are used, the boost circuit outputs a voltage of 5V, and when the voltage of the earphone battery is low, the charging efficiency is low, for example, when the battery voltage is 3V, the efficiency is 3/5 ═ 60%, and at the same time, the boost circuit 202 has an efficiency loss, for example, the efficiency is 90%, and the total efficiency is (60%) × (90%) -54%. In the charging system of the present application, the efficiency of the charging system is mainly related to the efficiency of the charging unit 12, and when the efficiency of the charging unit 12 is 90%, the overall efficiency is 90%.

In addition, the embodiment of the present application further provides a wireless headset system, which includes a charging box and a wireless headset, wherein the charging box includes the charging circuit described above, as shown by a dashed line box on the left side in fig. 5, and the wireless headset includes the wireless headset circuit described above, as shown by a dashed line box on the right side in fig. 5. The wireless earphone can be put into the charging box, and the wireless earphone includes voltage input end and the earphone battery who is coupled with voltage input end, and when the wireless earphone was put into the charging box, charging circuit's voltage output VO and wireless earphone's voltage input end VCHG electrical coupling.

Fig. 6 is a flowchart of a charging method according to an embodiment of the present disclosure. As shown in fig. 6, the charging method includes the steps of:

in step S602, the charging circuit of the external charging device reduces the output voltage of the rechargeable battery through the charging unit and outputs the reduced output voltage through the voltage output terminal, wherein the minimum value of the effective output voltage of the rechargeable battery is higher than the full charge voltage of the device battery of the portable electronic device to be charged, and the charging unit is a step-down charging unit.

In step S604, the device battery of the portable electronic device directly receives the charging voltage and/or the charging current output by the voltage output terminal of the charging circuit for charging.

In summary, the minimum value of the effective output voltage of the rechargeable battery is higher than the full charge voltage of the device battery of the charged portable electronic device, the charging unit is a voltage-reducing charging unit for reducing the output voltage of the rechargeable battery and then outputting the reduced output voltage through the voltage output terminal, and the voltage-reducing charging unit has a simple circuit and contains fewer switching devices, so that the structure of the charging circuit is simplified, the energy consumption during charging can be reduced, and the energy utilization efficiency of the charging system is improved.

Those of skill would further appreciate that the various illustrative components and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (11)

1. A charging circuit having a voltage output, comprising:

a rechargeable battery;

the charging management unit is used for performing charging management on the rechargeable battery;

a charging unit;

the minimum value of the effective output voltage of the rechargeable battery is higher than the full charge voltage of the device battery of the charged portable electronic device, the charging unit is a voltage-reducing type charging unit, and the voltage-reducing type charging unit is used for reducing the output voltage of the rechargeable battery and then outputting the reduced output voltage through the voltage output end.

2. The charging circuit of claim 1, wherein:

the rechargeable battery comprises at least two lithium batteries connected in series; and/or the presence of a gas in the gas,

and the charging management unit charges the rechargeable battery in a voltage reduction mode and/or a voltage boosting mode.

3. The charging circuit of claim 1, wherein the charging voltage output by the voltage output terminal is positively correlated with a voltage difference between two poles of a device battery of the portable electronic device coupled to the voltage output terminal through the voltage input terminal thereof during charging;

and the charging unit is used for dynamically adjusting the charging voltage or the charging current output by the voltage output end based on the output voltage of the rechargeable battery and the charging voltage and/or the charging current output by the voltage output end, so as to realize charging management on the equipment battery of the portable electronic equipment.

4. The charging circuit according to any of claims 1-3, wherein the charging unit comprises a feedback control module, a voltage reduction module, and an output capacitor coupled between the voltage output terminal and a ground terminal,

the feedback control module is used for sampling a charging current and adjusting the charging current output by the voltage reduction module through the voltage output end according to the charging current obtained by sampling so as to enable the charging current to be stable at a preset charging current threshold value and realize constant-current charging of a device battery of the portable electronic device; and/or the presence of a gas in the gas,

the feedback control module is used for sampling charging voltage and controlling and adjusting the charging voltage output by the voltage reduction module through the voltage output end according to the charging voltage obtained by sampling, so that the charging voltage is stabilized at a preset charging voltage threshold value, and constant-voltage charging of a device battery of the portable electronic device is realized.

5. The charging circuit of claim 4, wherein the voltage dropping module comprises a first switch, a second switch and an inductor, the first switch is coupled between the output terminal of the rechargeable battery and an intermediate node SW, the second switch is coupled between the intermediate node SW and a ground terminal, the inductor is coupled between the intermediate node SW and the voltage output terminal, and the feedback control module controls the first switch and the second switch to be alternately turned on and controls a duty ratio of the first switch to be turned on and off to realize constant current or constant voltage charging.

6. The charging circuit of claim 5, wherein:

one input end of the feedback control module is coupled to the intermediate node SW, and the feedback control module obtains the charging current according to a voltage difference between the intermediate node SW and the ground terminal and a resistance of the second switch or obtains the charging current according to a voltage difference between an output end of the rechargeable battery and the intermediate node SW and a resistance of the first switch; the other input end of the feedback control module is coupled with the voltage output end, and the feedback control module obtains the charging voltage of the equipment battery according to the voltage output end; and/or the presence of a gas in the gas,

the second switch coupled between the intermediate node SW and the ground terminal is replaced by a diode, an anode of the diode is coupled to the ground terminal, a cathode of the diode is coupled to the intermediate node SW, an on or off state of the diode is consistent with an on or off state of the second switch, and the on or off state of the diode is not controlled by the feedback control module but is determined by whether a voltage difference between two ends of the diode exceeds an on threshold.

7. A charging box characterized by comprising a charging circuit according to any one of claims 1 to 6.

8. A charging circuit for a portable electronic device, the charging circuit comprising a device battery and a voltage input, the device battery being coupled between the voltage input and a ground, the voltage at the voltage input directly reflecting the voltage of the device battery, the voltage input being directly coupled to a voltage output of an external charging device having the charging circuit as claimed in one of claims 1 to 6 when charging, for charging the device battery by a charging unit in the external charging device.

9. An electrical charging system, comprising:

a wireless headset circuit comprising a headset battery as a device battery and a voltage input coupled to the headset battery;

the charging circuit of any of claims 1-6, a voltage output of the charging circuit coupled to the voltage input.

10. A wireless headset system, comprising:

a charging cartridge according to claim 7;

a wireless headset that can be placed into the charging box and that includes a voltage input and a headset battery coupled to the voltage input;

when the wireless earphone is placed in the charging box, the voltage output end of the charging circuit is coupled with the voltage input end of the wireless earphone.

11. A method of charging, comprising:

the charging circuit of the external charging equipment reduces the output voltage of a rechargeable battery through a charging unit and then outputs the reduced output voltage through a voltage output end, wherein the minimum value of the effective output voltage of the rechargeable battery is higher than the full charge voltage of an equipment battery of the charged portable electronic equipment, and the charging unit is a step-down charging unit; and/or the presence of a gas in the atmosphere,

the equipment battery directly receives the charging voltage and/or the charging current output by the voltage output end of the charging circuit for charging.

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