Battery charging circuit and Bluetooth audio transceiver

Abstract

The utility model relates to the technical field of audio transceivers, in particular to a battery charging circuit and a Bluetooth audio transceiver. The battery charging circuit comprises a power supply end, a battery end, a voltage reduction module and a voltage division module, the positive electrode of the power supply end is connected with the positive electrode of the voltage reduction module, the negative electrode of the voltage reduction module is connected with the input end of the voltage division module, the output end of the voltage division module is connected with the positive electrode of the battery end, and the negative electrode of the power supply end and the negative electrode of the battery end are both grounded. The negative electrode of the battery end is provided with a sampling resistor, and the sampling resistor is connected with a main control chip of the Bluetooth audio transceiver; according to the scheme, the voltage reduction module is used for reducing the input voltage, linear charging of the battery is achieved through the linear change characteristic of the divided voltage of the voltage dividing module during charging, the circuit is very simple, and the charging requirement of a small-space product is met; and the resistor is connected in series with the negative electrode of the battery end to the grounding end, so that the accurate electric quantity information display can be realized through the detection of the system main control chip.

Description

TECHNICAL FIELD

[0001] The utility model relates to audio frequency transceiver technical field, especially a battery charging circuit and bluetooth audio frequency transceiver. BACKGROUND

[0002] The bluetooth audio frequency transceiver is a device for transmitting audio signals between different audio devices, which realizes wireless connection through bluetooth technology, provides a convenient wireless audio transmission scheme for users, and makes the connection between audio devices simpler and more flexible. The charging management chip in the market is large in size and has many bypass peripheral materials, so it is difficult to realize layout design in the limited space of the bluetooth audio frequency transceiver.

[0003] Therefore, it is crucial for those skilled in the art to design a battery charging circuit suitable for miniaturized bluetooth audio frequency transceiver products and a bluetooth audio frequency transceiver. SUMMARY

[0004] The technical problem to be solved by the embodiments of the utility model lies in providing a battery charging circuit suitable for miniaturized bluetooth audio frequency transceiver products and a bluetooth audio frequency transceiver to solve the problem that the charging management chip is large in size, has many bypass peripheral materials, and is difficult to realize layout design in the bluetooth audio frequency transceiver product.

[0005] The utility model discloses a battery charging circuit, be applied to bluetooth audio frequency transceiver, its scheme lies in, include: power supply end, battery end, voltage reducing module and partial pressure module, the positive pole of power supply end is connected with the positive pole of voltage reducing module, the negative pole of voltage reducing module is connected with the input of partial pressure module, the output of partial pressure module is connected with the positive pole of battery end, the negative pole of power supply end and the negative pole of battery end are all grounded, wherein, the negative pole of battery end is provided with sampling resistance, sampling resistance is connected with the main control chip of bluetooth audio frequency transceiver.

[0006] Optionally, the voltage reducing module is a diode, the partial pressure module is a partial pressure resistance, and the battery charging circuit further includes an indicator light module connected with the negative pole of the diode.

[0007] Optionally, the indicator light module includes a triode, a first resistance and an LED lamp, the emitter of the triode is connected with the negative pole of the diode, the base of the triode is connected with the positive pole of the battery, the collector of the triode is connected with one end of the first resistance, and the other end of the first resistance is connected with the LED lamp.

[0008] Optionally, a second resistor is arranged between the base of the triode and the positive electrode of the battery.

[0009] Optionally, an electrostatic protection element is arranged on the positive electrode of the power supply end.

[0010] To solve the problems in the prior art, the utility model further provides a bluetooth audio transceiver, and the scheme lies in that the utility model comprises the battery charging circuit, further comprises a battery and a master control chip integrated with a bluetooth module, the voltage input end of the master control chip is connected with the power supply end, and the battery is connected with the battery end.

[0011] Optionally, a voltage sampling pin is arranged on the master control chip, and the voltage sampling pin is connected with the sampling resistor to collect the electric quantity.

[0012] Optionally, the utility model further comprises a nixie tube display circuit, and the nixie tube display circuit is connected with the master control chip to display the electric quantity.

[0013] Optionally, the utility model further comprises a switch key circuit, and the enable end of the switch key circuit is connected with the master control chip.

[0014] Optionally, a filter module is further arranged between the voltage input end of the master control chip and the power supply end.

[0015] Compared with the prior art, the battery charging circuit has the beneficial effects that: by designing a battery charging circuit, the positive electrode of the power supply end is connected with the positive electrode of a step-down module, the negative electrode of the step-down module is connected with the input end of a voltage dividing module, the output end of the voltage dividing module is connected with the positive electrode of a battery end, and the negative electrode of the power supply end and the negative electrode of the battery end are both grounded; the scheme utilizes the step-down module to step down the input voltage, and utilizes the linear variation characteristic of the voltage dividing voltage of the voltage dividing module during charging to realize linear charging of the battery, so that the circuit is very simple and meets the charging demand of small-space products; and by connecting a resistor in series between the negative electrode of the battery end and the ground end, accurate electric quantity information display can be realized through detection of the system master control chip. BRIEF DESCRIPTION OF DRAWINGS

[0016] The technical scheme of the utility model will be further explained in detail below with reference to the drawings and embodiments, and the drawings show:

[0017] Figure 1 is the system block diagram of the battery charging circuit provided by the utility model embodiment;

[0018] Figure 2 is the circuit diagram of the battery charging circuit provided by the utility model embodiment;

[0019] Figure 3is the system block diagram of the Bluetooth audio transceiver provided by the embodiment of the utility model;

[0020] Figure 4 is the circuit diagram of the main control chip provided by the embodiment of the utility model;

[0021] Figure 5 is the circuit diagram of the nixie tube display circuit provided by the embodiment of the utility model;

[0022] Figure 6 is the circuit diagram of the switch key circuit provided by the embodiment of the utility model.

[0023] Reference signs:

[0024] 100, power supply end; 200, battery end; 300, voltage reduction module; 400, voltage division module; 500, indicator light module;

[0025] 1, battery; 10, main control chip; 20, nixie tube display circuit; 21, 188 nixie tube; 30, switch key circuit; 31, switch key; 32, reset key; 11, filter module;

[0026] R4, sampling resistor; Q1, triode; R2, first resistor; D2, LED lamp; D1, diode; R1, voltage division resistor; R3, second resistor; EDS5V, electrostatic protection element. Specific implementation

[0027] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. Now, the preferred embodiments of the utility model will be described in detail with reference to the drawings.

[0028] As Figure 1 shown, the utility model provides a kind of specific embodiment of battery charging circuit.

[0029] A kind of battery charging circuit, applied in Bluetooth audio transceiver, reference Figure 1 , battery charging circuit includes power supply end 100, battery end 200, voltage reduction module 300 and voltage division module 400, the anode V+ of power supply end 100 is connected with the anode of voltage reduction module 300, the cathode of voltage reduction module 300 is connected with the input end of voltage division module 400, the output end of voltage division module 400 is connected with the anode VBAT of battery end 200, the cathode V- of power supply end 100 and the cathode GND of battery end 200 are all grounded, wherein, sampling resistor R4 is provided on the cathode GND of battery end 200.

[0030] Specifically, reference Figure 1The power terminal 100 is used for connecting an external power supply to realize voltage input; the battery terminal 200 is used for connecting a battery to realize charging of the battery; the positive pole of the voltage reduction module 300 is connected with the positive pole V+ of the power terminal 100 for voltage input, the voltage reduction module 300 is used for primary voltage reduction of the external voltage, the negative pole of the voltage reduction module 300 is connected with the input terminal of the voltage division module 400, the voltage after primary voltage reduction by the voltage reduction module 300 will be divided by the voltage division module 400 to realize secondary voltage reduction of the input voltage, the output terminal of the voltage division module 400 is connected with the positive pole VBAT of the battery terminal 200 to output the voltage after secondary voltage reduction to the battery terminal 200; and during the charging process of the battery terminal 200, the voltage division voltage of the voltage division module 400 will change linearly with the linear change of the charging current, so that linear charging of the battery can be realized.

[0031] Taking a 5V power supply as an example, the 5V power supply is used to supply power to the voltage reduction module 300, and the primary voltage reduction by the voltage reduction module 300 can reduce the voltage to 3.9V-4.2V, and then the voltage division module 400 is used for voltage division, and the voltage division voltage of the voltage division module 400 will change linearly with the linear change of the charging current, so that linear charging of the battery can be realized.

[0032] Further, by arranging a sampling resistor R4 at the negative pole GND of the battery terminal 200, when the battery of the Bluetooth audio transceiver is connected with the battery terminal 200, the sampling resistor R4 is electrically connected with the battery of the Bluetooth audio transceiver, so that a voltage division circuit is formed during the whole charging or discharging process of the battery, and the voltage of the sampling resistor R4 is detected in real time by the master control chip of the Bluetooth audio transceiver, so that the real-time input and output current of the battery can be obtained.

[0033] For the Bluetooth audio transceiver product, due to the miniaturized design, the internal design space is very limited, and the charging management chip on the market at present has a large size and many bypass peripheral materials, so it is difficult to realize layout design in the limited space of the Bluetooth audio transceiver.

[0034] In the embodiment, a battery charging circuit is designed, which comprises a power supply end 100, a battery end 200, a voltage reduction module 300 and a voltage division module 400. The positive pole V+ of the power supply end 100 is connected with the positive pole of the voltage reduction module 300, the negative pole of the voltage reduction module 300 is connected with the input end of the voltage division module 400, the output end of the voltage division module 400 is connected with the positive pole VBAT of the battery end 200, and the negative pole V- of the power supply end 100 and the negative pole GND of the battery end 200 are grounded. The scheme utilizes the voltage reduction module 300 to reduce the input voltage, and then utilizes the linear variation characteristic of the voltage division voltage of the voltage division module 400 during charging to realize linear charging of the battery. The circuit is very simple and meets the charging demand of small-space products. Moreover, by connecting a resistor in series at the negative pole of the battery end to the ground end, accurate power information display can be realized through detection of a system main control chip.

[0035] In one of the embodiments, referring to Figure 1 and Figure 2 , the voltage reduction module 300 is specifically a diode D1, and the voltage division module is specifically a voltage division resistor R1. The positive pole of the diode D1 is connected with the positive pole V+ of the power supply end 100 for voltage input. The diode D1 has the characteristic of linear voltage reduction, and the voltage after voltage reduction can be output at the negative pole of the diode D1. The negative pole of the diode D1 is connected with one end of the voltage division resistor R1. The voltage after voltage reduction by the diode D1 is divided by the voltage division resistor R1, which can realize re-reduction of the input voltage. The other end of the voltage division resistor R1 is connected with the positive pole VBAT of the battery end 200 to output the voltage after secondary voltage reduction to the battery end 200. During charging, the voltage division voltage of the voltage division resistor R1 will linearly change with the linear variation of the charging current, which can realize linear charging of the battery.

[0036] In one of the embodiments, referring to Figure 1 and Figure 2 , the battery charging circuit further comprises an indicator light module 500, which is connected with the negative pole of the diode D1.

[0037] Specifically, referring to Figure 2 , the indicator light module 500 can be used to display the running state of the product, such as the on-off state, the power supply state, the connection state and the like. Through the light-off of the indicator light module 500, the user can intuitively understand the current running state of the product. In the embodiment, the indicator light module 500 is mainly used to display the charging state of the product.

[0038] In one of the embodiments, referring to Figure 2The indicator light module 500 comprises a triode Q1, a first resistor R2 and an LED lamp D2, the emitter E of the triode Q1 is connected with the negative pole of the diode D1, the base B of the triode Q1 is connected with the positive pole of the battery, the collector C of the triode Q1 is connected with one end of the first resistor R2, and the other end of the first resistor R2 is connected with the LED lamp D2.

[0039] Specifically, referring to Figure 1 , the triode Q1 is used as a control switch of the LED lamp D2, and the triode Q1 is a PNP triode Q1; the base B of the triode Q1 is connected with the positive pole of the battery for obtaining the battery voltage; the emitter E of the triode Q1 is connected with the negative pole of the diode D1 for obtaining the voltage after the voltage drop of the diode D1; when the PNP triode Q1 is turned on when the Vbe voltage difference is less than 0.3V, when the battery voltage is less than 3.9V, the Vbe voltage difference of the PNP triode Q1 is less than 0.3V, the triode Q1 is turned on, and the LED lamp D2 is bright; when the battery voltage is charged to 3.9V, the Vbe voltage difference of the PNP triode Q1 is equal to 0.3V, the triode Q1 will be dimmed slowly; when the battery voltage is charged to 4.2V, the Vbe voltage difference of the PNP triode Q1 is 0V, the triode Q1 is cut off, and the LED lamp D2 is extinguished.

[0040] The first resistor R2 is a protection resistor, which can limit the size of the current flowing through the circuit, prevent the elements in the circuit from being damaged due to excessive current, help stabilize the working state of the circuit, prevent the circuit from being abnormal due to external factors, and ensure the normal operation of the circuit.

[0041] In one of the embodiments, referring to Figure 2 , the base B of the triode Q1 is connected with the positive pole VBAT of the battery end.

[0042] Specifically, referring to Figure 1 , the second resistor R3 is also used as a protection resistor, which can limit the size of the current flowing through the circuit, prevent the elements in the circuit from being damaged due to excessive current, help stabilize the working state of the circuit, prevent the circuit from being abnormal due to external factors, and ensure the normal operation of the circuit.

[0043] In one of the embodiments, referring to Figure 1 , the positive pole V+ of the power supply end 100 is provided with an electrostatic protection element EDS5V; the electrostatic protection element EDS5V is an ESD static impedance resistor, which is used to avoid the influence of static electricity on the circuit, thereby improving the stability and safety of the circuit.

[0044] As shown in Figures 3-6 , the utility model also provides a specific embodiment of a Bluetooth audio transceiver.

[0045] A Bluetooth audio transceiver, reference Figure 3 The Bluetooth audio transceiver includes the battery charging circuit as described above, and also includes a battery 1 and a main control chip 10 integrated with a Bluetooth module. The voltage input terminal of the main control chip 10 is connected to the power terminal 100, and the battery 1 is connected to the battery terminal 200.

[0046] Specifically, refer to Figure 3 The main control chip 10 is an MCU Bluetooth chip. The MCU Bluetooth chip is a chip that integrates a microcontroller and Bluetooth communication functions. The chip combines the processing power of the microcontroller and the Bluetooth communication capabilities. The voltage input end of the main control chip 10 is connected to the power supply end 100 to obtain a 5V voltage, and the battery 1 is connected to the battery end 200 to obtain a stepped-down voltage, thereby realizing charging of the battery 1.

[0047] In one embodiment, reference Figure 3 and Figure 4 The main control chip 10 is provided with a voltage sampling pin, and the voltage sampling pin is connected to the sampling resistor R4 to collect power.

[0048] Specifically, refer to Figure 3 and Figure 4 By setting a sampling resistor R4 at the negative electrode GND of the battery terminal 200, when the battery is connected to the battery terminal 200, the sampling resistor R4 is electrically connected to the battery, so that a voltage divider circuit is formed during the entire battery charging or discharging process. The voltage of the sampling resistor R4 is detected in real time through the voltage sampling pin of the main control chip 10, thereby obtaining the real-time input and output current of the battery.

[0049] In one embodiment, reference Figure 3 and Figure 5 The Bluetooth audio transceiver further includes a digital tube display circuit 20, which is connected to the main control chip 10 to display the power level.

[0050] Specifically, refer to Figure 3 and Figure 5 The digital tube display circuit 20 includes a 188 digital tube 21. When the sampling pin of the main control chip 10 detects the voltage of the sampling resistor R4 in real time, thereby obtaining the real-time input and output current of the battery, the 188 digital tube can display the real battery power information in real time; it can solve the current problem of inaccurate power display caused by disordered digital jumps.

[0051] In one embodiment, reference Figure 3 and Figure 6 The Bluetooth audio transceiver further includes a switch button circuit 30 , and an enable terminal EN of the switch button circuit 30 is connected to the main control chip 10 .

[0052] Specifically, referring to Figure 3 and Figure 6 , the switch key circuit 30 comprises a switch key 31 and a reset key 32, the input end of the switch key 31 is taken as the enable end EN of the switch key circuit 30 and is connected with the master control chip 10 to transmit corresponding control instructions.

[0053] In one of the embodiments, referring to Figure 4 , the voltage input end of the master control chip 10 is further provided with a filter module 11 between the power supply end 100; the filter module 11 is used to process the noise or interference in the electrical signal so as to make the signal more smooth.

[0054] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them, for those skilled in the art, the technical solutions recorded in the above embodiments can be modified, or some technical features can be replaced equivalently; all these modifications and replacements shall belong to the protection scope of the present application.

Claims

1. A battery charging circuit applied in a Bluetooth audio transceiver, characterized in that, The battery charging circuit comprises a power supply end, a battery end, a voltage reduction module and a voltage division module, the positive pole of the power supply end is connected with the positive pole of the voltage reduction module, the negative pole of the voltage reduction module is connected with the input end of the voltage division module, the output end of the voltage division module is connected with the positive pole of the battery end, and the negative pole of the power supply end and the negative pole of the battery end are both grounded, wherein the negative pole of the battery end is provided with a sampling resistor connected with a master control chip of a Bluetooth audio transceiver. The voltage reduction module is a diode, the voltage division module is a voltage division resistor, and the battery charging circuit further comprises an indicating lamp module connected with the negative pole of the diode.

2. The battery charging circuit of claim 1, wherein, The indicating lamp module comprises a triode, a first resistor and an LED lamp, the emitter of the triode is connected with the negative pole of the diode, the base of the triode is connected with the positive pole of the battery, the collector of the triode is connected with one end of the first resistor, and the other end of the first resistor is connected with the LED lamp.

3. The battery charging circuit of claim 2, wherein, A second resistor is arranged between the base of the triode and the positive pole of the battery.

4. The battery charging circuit of claim 3, wherein, An electrostatic protection element is arranged on the positive pole of the power supply end.

5. The battery charging circuit of claim 1, wherein, The battery charging circuit comprises a battery and a master control chip integrated with a Bluetooth module, the voltage input end of the master control chip is connected with the power supply end, and the battery is connected with the battery end.

6. A Bluetooth audio transceiver, characterized in that A voltage sampling pin is arranged on the master control chip and connected with the sampling resistor to collect the electric quantity.

7. The Bluetooth audio transceiver of claim 6, wherein, A digital tube display circuit is further arranged and connected with the master control chip to display the electric quantity.

8. The Bluetooth audio transceiver of claim 6, wherein, A switch key circuit is further arranged and connected with the master control chip.

9. The Bluetooth audio transceiver of claim 6, wherein, A filter module is further arranged between the voltage input end of the master control chip and the power supply end.

10. The Bluetooth audio transceiver of claim 6, wherein, ​

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