A mobile follow-up charging system

Abstract

The present invention relates to the technical field of follow-up charging, and in particular to a mobile follow-up charging system, which includes: a BOOST chip, the electric energy output by the charging power supply is connected to the charging input end of the charging output module through the output pin of the BOOST chip; a charging output module, the charging output module includes at least one charging output submodule, and the output end of the charging output submodule is used to receive charging products; a sampling module, which is used to collect the current value of the negative end of at least one product to be charged, and the output end of the sampling module is connected to the sampling input pin of the MCU control unit; the MCU control unit is used to adjust the duty cycle according to the current value of the negative end of at least one product to be charged, and output a PWM signal according to the duty cycle, and the duty cycle has an initial maximum value and an initial minimum value; an adjustment module, which is used to adjust the output voltage of the output pin of the BOOST chip according to the PWM signal. The present application has the effect of improving the charging conversion efficiency and increasing the number of times the charging box charges the earphone.

Description

Technical Field

[0001] The present invention relates to the technical field of follow-up charging, and in particular to a mobile follow-up charging system. Background Art

[0002] TWS is the abbreviation of True Wireless Stereo, a technology that emerged based on the development of Bluetooth chips. TWS headphones are a new type of smart wearable product that is produced by applying TWS technology to the field of Bluetooth headphones. The basic working principle of TWS headphones is that the mobile device connects to the main headphones, and then the main headphones are connected to the auxiliary headphones via Bluetooth wirelessly to form a stereo system, realizing true wireless separation of Bluetooth left and right channels. Since there is no physical wire connection between the left and right units of TWS headphones, TWS headphones are generally not charged using a microUSB interface, but are equipped with a portable charging box to provide charging and storage functions.

[0003] Thanks to the development of TWS earphones, the design and products of matching charging boxes have become more and more mature. A common way for a charging box to charge earphones is to increase the box battery voltage (BAT) to a constant 5V through a BOOST boost chip inside or outside the chip, and then connect it to the earphones through a POGOPIN to charge the battery of the earphones. This solution is relatively simple and universal, but there is more energy loss and the efficiency of charging conversion is not high. Summary of the invention

[0004] In order to improve the charging conversion efficiency and increase the number of times the charging box charges the earphones, the present application provides a mobile follow-up charging system.

[0005] The above-mentioned invention objective of the present application is achieved through the following technical solutions:

[0006] A mobile follow-up charging system, comprising:

[0007] BOOST chip, the electric energy output by the charging power supply is connected to the charging input terminal of the charging output module through the output pin of the BOOST chip;

[0008] A charging output module, the charging output module includes at least one charging output submodule, and the output end of the charging output submodule is used to receive charging products;

[0009] A sampling module, used to collect the current value of the negative terminal of the at least one product to be charged, the output end of the sampling module being connected to the sampling input pin of the MCU control unit;

[0010] An MCU control unit, configured to adjust a duty cycle according to a current value of a negative terminal of the at least one product to be charged, and output a PWM signal according to the duty cycle, wherein the duty cycle has an initial maximum value and an initial minimum value;

[0011] The regulating module is used to regulate the output voltage of the output pin of the BOOST chip according to the PWM signal.

[0012] In a preferred example, the present application may be further configured as follows: if there is only one output end of the charging output submodule, then adjusting the duty cycle according to the current value of the negative end of the at least one product to be charged includes:

[0013] If the charging current value is greater than a preset current value, reducing the duty cycle between the initial maximum value and the initial minimum value;

[0014] If the charging current value is less than the preset current value, the duty cycle is increased between the initial maximum value and the initial minimum value.

[0015] In a preferred example, the present application may be further configured as follows: if there are at least two current values ​​of the negative terminals of the products to be charged, then adjusting the duty cycle according to the current value of the negative terminal of the at least one product to be charged includes:

[0016] The duty cycle is adjusted according to the highest value of the current values ​​of the negative terminals of at least two products to be charged.

[0017] In a preferred example, the present application can be further configured as follows: adjusting the duty cycle according to the highest value of the current values ​​of the negative terminals of at least two products to be charged, including:

[0018] If the highest value among the current values ​​of the negative terminals of the at least two products to be charged is greater than the preset current value, reducing the duty cycle between the initial maximum value and the initial minimum value;

[0019] If the highest value among the current values ​​of the negative terminals of the at least two products to be charged is less than the preset current value, the duty cycle is increased between the initial maximum value and the initial minimum value.

[0020] In a preferred example, the present application can be further configured as follows: the adjustment module includes:

[0021] A first resistor and a second resistor, the output pin of the BOOST chip is connected in series with the first resistor and the second resistor in sequence and then grounded, and the feedback pin of the BOOST chip is connected between the first resistor and the second resistor;

[0022] A first MOS tube, wherein the drain of the first MOS tube is connected to the BOOST output terminal through the seventh resistor, the source of the first MOS tube is grounded, and the gate of the first MOS tube is connected to the MCU control unit; the drain of the first MOS tube is connected in series with the fifth resistor and the sixth resistor in sequence, and then connected between the first resistor and the second resistor.

[0023] In a preferred example, the present application can be further configured as follows: the charging output submodule includes a second MOS tube, the source of the second MOS tube is connected to the charging input end of the charging output module, the gate of the second MOS tube is connected to the charging input end of the charging output module via the third resistor, and the drain of the second MOS tube is used to receive the charging product.

[0024] In a preferred example, the present application can be further configured as follows: the charging output module also includes a transistor, the collector of the transistor is connected to the charging input terminal of the charging output module via a third resistor, the emitter of the transistor is grounded, and the base of the transistor is connected to the MCU control unit via a fourth resistor.

[0025] In a preferred example, the present application can be further configured as follows: the MCU control unit is connected to the enable pin of the BOOST chip.

[0026] In summary, the present application includes at least one of the following beneficial technical effects:

[0027] Through the original sampling circuit, the charging current of both ears is obtained, the charging stage of the earphones is judged, and then the corresponding PWM duty cycle is output. Therefore, by controlling the boost output of the BOOST chip through PWM, the charger can use a more appropriate voltage according to different charging stages in a wide voltage mode, thereby improving the charging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the application principle of the LP6261AB6F chip in one embodiment of the present application;

[0029] Figure 2 This is a PWM wide voltage charging structure diagram in an embodiment of the present application;

[0030] Figure 3 This is a schematic diagram of the PWM wide voltage output principle in one embodiment of the present application;

[0031] Figure 4 is a schematic diagram of the implementation principle of the charging output module in one embodiment of the present application;

[0032] Figure 5 This is a flow chart of PWM duty cycle adjustment control implementation in one embodiment of the present application;

[0033] Figure 6 This is a test data diagram of an embodiment of the present application in which a follow-up charging circuit is not used;

[0034] Figure 7 This is a test data diagram of a PWM follower charging circuit in an embodiment of the present application.

[0035] Figure numerals: R36, first resistor; R50, second resistor; Q9, first MOS tube; Q6, second MOS tube; RH1, third resistor; Q2, triode; RH2, fourth resistor; R52, fifth resistor; R53, sixth resistor; R54, seventh resistor. DETAILED DESCRIPTION

[0036] The following is a description of exemplary embodiments of the present application in conjunction with the accompanying drawings, including various details of the embodiments of the present application to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0037] It should be noted that the terms "first", "second", etc. in the present invention are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure.

[0038] In addition, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article, unless otherwise specified, generally means that the associated objects before and after are in an "or" relationship.

[0039] At present, the process of charging the earphones by the charging box is as follows: the battery voltage Vbat0 of the charging box is boosted to a Vout value through Boost, and then the Vout connection is used to charge the left and right earphone batteries. Since the battery voltage Vbat of TWS earphones generally varies in the range of 3.0-4.2V, and the maximum voltage is generally 4.2V, the power output by the charging power supply is boosted to 5V through the BOOST chip before charging the earphones. What we actually need here is to convert the battery power of the charging box to the battery power of the earphones, and the process of voltage increase and decrease in the middle, that is, the Boost process, is particularly critical, which is related to the problem of power conversion efficiency for charging the earphones.

[0040] Specifically, according to the relevant formula for electric energy: W=Pt=UIt, the following conversion efficiency calculation is obtained: BOOST chip output to earphone charging conversion efficiency: (P2 / P1)×100%=(U2×I2 / U1×I1)×100%; where P2 is the power input to the earphone battery, P1 is the power output by BOOST, U2 and I2 are the earphone battery voltage and input current, and U1 and I1 are the voltage and current of the BOOST chip boost output.

[0041] The current demand of the load headphones will affect the size of the BOOST chip output current. When the headphone current demand is large, the BOOST chip can provide more current to meet the load demand. The current I1 output by the BOOST chip is the sum of the current consumed by the internal circuit of the headphone and the current input to the battery. Here, it can be simplified to equal currents I1 and I2 to calculate the conversion efficiency. Therefore, the conversion efficiency can be regarded as U2 / U1; that is, the conversion efficiency can be optimized by controlling the output voltage U1 of the BOOST chip.

[0042] The lithium battery of the headset will go through the stages of trickle charging, constant current charging and constant voltage charging during charging, while the BOOST voltage of the box is always a constant voltage, so the energy loss is different in different stages. The additional follow-up charging function of this solution reduces the energy loss of the headset charging process and improves the charging efficiency of the headset.

[0043] Combination Figure 1 Specifically, in a BOOST chip such as the LP6261AB6F chip, the output voltage Vout of the BOOST is determined by the resistors Rup, Rdn and the voltage Vfb of the feedback pin FB, and there is the following formula: V_out = (R_up / R_dn+1) × V_fb, where the voltage of Vfb is 1.36V. In the charging compartment circuit, if only a fixed 5V is output to charge the earphones, the usual settings are Rup = 820K, Rdn = 300K, Vfb = 1.36V. According to the above calculation formula, the output voltage Vout of the BOOST is 5.07V. That is, a stable output of a 5V charging voltage is obtained.

[0044] Adding a PWM control circuit can change the feedback voltage received by the FB pin by changing the resistor branch on the feedback resistor network, thereby changing the control loop inside the chip and ultimately changing the output voltage U1 of BOOST. At the same time, through the original sampling circuit, the charging current of both ears is obtained, the charging stage of the headphones is determined, and then the corresponding PWM duty cycle is output. Therefore, by controlling the boost output of the BOOST chip through PWM, the charger can use a more appropriate voltage according to different charging stages in a wide voltage manner to improve charging efficiency.

[0045] Reference Figures 2 to 4The mobile follow-up charging system in this application includes a BOOST chip, a charging output module, a sampling module, an MCU control unit and a regulating module. The BOOST chip is a BOOST chip with a feedback function. The electric energy output by the charging power supply is connected to the charging input end of the charging output module through the output pin of the BOOST chip.

[0046] The charging output module includes at least one charging output submodule, and the output end of the charging output submodule is used to receive charging products; the charging output submodule includes a second MOS tube Q6, the source of the second MOS tube Q6 is connected to the charging input end of the charging output module, the gate of the second MOS tube Q6 is connected to the charging input end of the charging output module via the third resistor RH1, and the drain of the second MOS tube Q6 is used to receive charging products.

[0047] The charging output module also includes a transistor Q2, the collector of the transistor Q2 is connected to the charging input terminal of the charging output module via a third resistor RH1, the emitter of the transistor Q2 is grounded, and the base of the transistor Q2 is connected to the MCU control unit via a fourth resistor RH2.

[0048] When charging, the MCU control unit sends an enable output signal to control the transistor Q2 to turn on. In addition, the charging box can also be configured to switch to communication mode when a switch cover or button is detected, use the communication circuit to send instructions to the headset, and then switch back to charging mode after communication to resume charging.

[0049] Among them, there can be multiple charging output sub-modules. When used for charging TWS headphones, two charging output sub-modules are configured to charge the left earphone and the right earphone respectively; the sampling module is used to collect the current value of the negative end of at least one product to be charged. When there are multiple charging output sub-modules, the sampling module collects the current values ​​of the negative ends of multiple products to be charged.

[0050] The output end of the sampling module is connected to the sampling input pin of the MCU control unit; the sampling module may also have multiple output ends, which are respectively connected to multiple sampling input pins of the MCU control unit to correspondingly transmit the current values ​​of the negative ends of multiple products to be charged.

[0051] Taking TWS earphone charging as an example, the sampling module has two acquisition input terminals respectively connected to the output terminals of the two charging output sub-modules, and the sampling module has two output terminals respectively connected to the two sampling input pins of the MCU control unit to realize separate sampling of the charging current of the left and right earphones.

[0052] The MCU control unit is used to adjust the duty cycle according to the current value of the negative end of at least one product to be charged, and output a PWM signal according to the duty cycle. The duty cycle has an initial maximum value and an initial minimum value. The MCU control unit adopts a chip with charge and discharge management, ADC sampling, a timer (output PWM) and some general IO port control functions. The MCU control unit is connected to the enable pin of the BOOST chip.

[0053] Specifically, if there is only one output end of the charging output submodule, the duty cycle is adjusted only according to the current value of the negative end of the product to be charged. The specific adjustment method is: if the charging current value is greater than the preset current value, the duty cycle is reduced between the initial maximum value and the initial minimum value; if the charging current value is less than the preset current value, the duty cycle is increased between the initial maximum value and the initial minimum value.

[0054] If there are at least two current values ​​of the negative terminals of the products to be charged, the duty cycle is adjusted according to the highest value of the current values ​​of the negative terminals of the at least two products to be charged. The specific adjustment method is: if the highest value of the current values ​​of the negative terminals of the at least two products to be charged is greater than the preset current value, the duty cycle is reduced between the initial maximum value and the initial minimum value; if the highest value of the current values ​​of the negative terminals of the at least two products to be charged is less than the preset current value, the duty cycle is increased between the initial maximum value and the initial minimum value.

[0055] Taking TWS earphone charging as an example, the charging current value I(L) of the left earphone and the charging current value I(R) of the right earphone are read through the ADC sampling circuit respectively, and the highest current value of the two is selected for judgment. This highest value is compared with the preset current value I1. If the highest value at this time is greater than the preset current value I1, it means that the earphone battery voltage is still relatively small during the constant current charging stage, then the duty cycle value can be reduced to reduce the Vout voltage; similarly, if the highest value is less than the set preset current value I1, it means that the battery voltage of the earphone is increasing, and we increase the duty cycle value accordingly to increase the Vout voltage.

[0056] The initial value may be initially set to a maximum duty cycle to maximize the BOOST output voltage, and then a larger preset current value I1 for earphone charging may be set.

[0057] The regulating module is used to regulate the output voltage of the output pin of the BOOST chip according to the PWM signal. The regulating module includes: a first resistor R36 and a second resistor R50, the output pin of the BOOST chip is connected in series with the first resistor R36 and the second resistor R50 in sequence and then grounded, and the feedback pin of the BOOST chip is connected between the first resistor R36 and the second resistor R50; a first MOS tube Q9, the drain of the first MOS tube Q9 is connected to the BOOST output end through the seventh resistor R54, the source of the first MOS tube Q9 is grounded, and the gate of the first MOS tube Q9 is connected to the MCU control unit; the drain of the first MOS tube Q9 is connected in series with the fifth resistor R52 and the sixth resistor R53 in sequence and then connected between the first resistor R36 and the second resistor R50.

[0058] The present application adds PWM control to change the resistance values ​​of Rdn and Rup through a resistor branch, and according to the above formula principle, the Vout voltage output of BOOST is changed. In the circuit, the fifth resistor R52 and the sixth resistor R53 are connected in series. When the PWM control output is high, the first MOS tube Q9 is turned on, and the voltage value at the drain D is 0. At this time, the total resistance of the fifth resistor R52, the sixth resistor R53 connected in series and the second resistor R50 in parallel is Rdn. After parallel connection, the resistance of Rdn is less than the resistance of the original second resistor R50. According to the formula, Vout is inversely proportional to Rdn, so the BOOST output voltage Vout increases. When the PWM control output is low, the first MOS tube Q9 is turned off, and the total resistance of the fifth resistor R52, the sixth resistor R53, and the seventh resistor R54 connected in series and in parallel with R36 is Rup. At this time, Rup is less than the original resistance of the first resistor R36. According to the above formula, Vout is proportional to Rup, so the output voltage Vout decreases; therefore, the corresponding voltage can be obtained by controlling the time ratio of the two circuit switches, and then the voltage can be output stably by quickly switching the two circuits. Figure 5 , use different PWM duty cycles to control the time occupied by the two circuits. From the above analysis, we know that the larger the duty cycle, that is, the longer the high level time, the larger the voltage output by Vout, and the two are in direct proportion; the PWM frequency needs to be determined according to the actual circuit debugging so that Vout can stably output the required voltage.

[0059] After the BOOST chip outputs voltage, it charges the earphones. Figure 4 The schematic diagram shows that after the Vbus control enable output is high, the transistor Q2 and the second MOS tube Q6-A and the second MOS tube Q6-B are turned on respectively, so that the BOOST chip outputs voltage to the left and right earphone terminals to charge the earphones.

[0060] Figure 6 This is a test data diagram of an embodiment of the present application in which a follow-up charging circuit is not used. Figure 7This is a test data chart of the PWM following charging circuit used in one embodiment of the present application. It can be seen that by adopting the mobile following charging system of the present application, the number of charging times is increased from the original 2.5 times to 3.5 times, and the charging time and the amount of electricity each time are basically the same, thereby improving the charging conversion efficiency and increasing the number of times the charging box charges the earphones.

[0061] Various implementations of the systems and techniques described herein can be realized in digital electronic circuit systems, integrated circuit systems, dedicated ASICs (application specific integrated circuits), computer hardware, firmware, software, and / or combinations thereof. These various implementations may include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0062] These computer programs (also referred to as programs, software, software applications, or code) include machine instructions for programmable processors and can be implemented using high-level procedural and / or object-oriented programming languages ​​and / or assembly / machine languages. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, device, and / or means (e.g., disk, optical disk, memory, programmable logic device (PLD)) for providing machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal for providing machine instructions and / or data to a programmable processor.

[0063] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0064] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communications network). Examples of communications networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0065] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution disclosed in this application can be achieved, and this document is not limited here.

[0066] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. Mobile follow-up charging system, characterized in that: include: BOOST chip, the electric energy output by the charging power supply is connected to the charging input terminal of the charging output module through the output pin of the BOOST chip; A charging output module, the charging output module includes at least one charging output submodule, and the output end of the charging output submodule is used to receive charging products; A sampling module, used to collect the current value of the negative terminal of at least one product to be charged, the output end of the sampling module being connected to the sampling input pin of the MCU control unit; An MCU control unit, configured to adjust a duty cycle according to a current value of a negative terminal of the at least one product to be charged, and output a PWM signal according to the duty cycle, wherein the duty cycle has an initial maximum value and an initial minimum value; A regulating module, used for regulating the output voltage of the output pin of the BOOST chip according to the PWM signal; The regulating module comprises: a first resistor and a second resistor, the output pin of the BOOST chip is connected in series with the first resistor and the second resistor in sequence and then grounded, and the feedback pin of the BOOST chip is connected between the first resistor and the second resistor; a first MOS tube, the drain of the first MOS tube is connected to the BOOST output end through a seventh resistor, the source of the first MOS tube is grounded, and the gate of the first MOS tube is connected to the MCU control unit; the drain of the first MOS tube is connected in series with a fifth resistor and a sixth resistor in sequence and then connected between the first resistor and the second resistor; Wherein, if there is only one output end of the charging output submodule, the step of adjusting the duty cycle according to the current value of the negative end of the at least one product to be charged includes: If the charging current value is greater than a preset current value, reducing the duty cycle between the initial maximum value and the initial minimum value; If the charging current value is less than the preset current value, increasing the duty cycle between the initial maximum value and the initial minimum value; Furthermore, if there are at least two current values ​​of the negative terminals of the products to be charged, then adjusting the duty cycle according to the current value of the negative terminal of the at least one product to be charged includes: The duty cycle is adjusted according to the highest value of the current values ​​of the negative terminals of at least two products to be charged.

2. The mobile follow-up charging system according to claim 1, characterized in that: The duty cycle is adjusted according to the highest value of the current values ​​of the negative terminals of at least two products to be charged, including: If the highest value among the current values ​​of the negative terminals of the at least two products to be charged is greater than the preset current value, reducing the duty cycle between the initial maximum value and the initial minimum value; If the highest value among the current values ​​of the negative terminals of the at least two products to be charged is less than the preset current value, the duty cycle is increased between the initial maximum value and the initial minimum value.

3. The mobile follow-up charging system according to claim 1, characterized in that: The charging output submodule includes a second MOS tube, the source of the second MOS tube is connected to the charging input end of the charging output module, the gate of the second MOS tube is connected to the charging input end of the charging output module via a third resistor, and the drain of the second MOS tube is used to receive charging products.

4. The mobile follow-up charging system according to claim 3, characterized in that: The charging output module also includes a transistor, the collector of the transistor is connected to the charging input end of the charging output module via a third resistor, the emitter of the transistor is grounded, and the base of the transistor is connected to the MCU control unit via a fourth resistor.

5. The mobile follow-up charging system according to claim 1, characterized in that: The MCU control unit is connected to the enable pin of the BOOST chip.

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