Charging device of vehicle-mounted terminal T-BOX standby battery

Abstract

The utility model provides a charging device for a T-BOX standby battery of a vehicle-mounted terminal. The charging device comprises a power supply, a DC-DC conversion module, a switch module and a constant current output module, wherein the input end of the DC-DC conversion module is electrically connected with the output end of the power supply, and the output end of the DC-DC conversion module is electrically connected with the input end of the switch module; the output end of the switch module is electrically connected with the input end of the constant current output module; the output end of the constant current output module is electrically connected with the input end of the vehicle-mounted terminal T-BOX standby battery. A BOOST chip and an LDO chip are replaced by the constant current output module, the material cost is reduced, the use area of a PCB is reduced, miniaturization design and heat dissipation performance are facilitated, power is directly supplied by the power supply, the process of boosting and reducing voltage is not needed any more, and power loss is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of charging of backup batteries for in-vehicle terminals of electric vehicles, and particularly to a charging device for a backup battery of an in-vehicle terminal T-BOX. Background Art

[0002] An important function of a Telematics BOX (abbreviated as in-vehicle T-BOX) is that after a vehicle collision, its backup battery can be enabled to make a call for rescue. Therefore, the backup battery is crucial in the application of in-vehicle T-BOX, and the charging circuit of the backup battery is also an important part of the in-vehicle T-BOX product. The working principle of the existing backup battery charging circuit is as follows: after the micro-control unit MCU of the in-vehicle T-BOX issues a charging signal, first, a primary power supply DC-DC converts the vehicle body voltage from 9V - 16V to 5V, then a secondary power supply boost chip BOOST boosts the 5V to about 10V, and then a tertiary power supply chip LDO drops it to 5.5V. By controlling the current limit value of the LDO, a constant current is provided to the backup battery of the in-vehicle T-BOX for charging.

[0003] However, for the charging circuit of the backup battery of the above-mentioned in-vehicle T-BOX, its electronic material cost is high, it occupies a large area of the printed circuit board PCB, and there are many voltage conversions, with boosting first and then bucking, resulting in large power losses. Therefore, how to reduce the area occupied by the charging circuit of the in-vehicle T-BOX backup battery and reduce the power loss of the charging circuit of the in-vehicle T-BOX backup battery has become a technical problem that cannot be underestimated. Summary of the Utility Model

[0004] In view of this, the purpose of the present application is to provide a charging device for a backup battery of an in-vehicle terminal T-BOX. By replacing two chips, BOOST and LDO, with a constant current output module, the material cost is reduced, the PCB usage area is reduced, which is beneficial to miniaturized design and heat dissipation performance, and it is directly powered by the power supply, without the process of boosting and then bucking, reducing the power loss.

[0005] The embodiment of the present application provides a charging device for a backup battery of an in-vehicle terminal T-BOX, and the charging device includes a power supply, a DC-DC conversion module, a switch module, and a constant current output module; wherein,

[0006] The input end of the DC-DC conversion module is electrically connected to the output end of the power supply, and the output end of the DC-DC conversion module is electrically connected to the input end of the switch module;

[0007] The output end of the switch module is electrically connected to the input end of the constant current output module;

[0008] The output terminal of the constant current output module is electrically connected to the input terminal of the backup battery of the vehicle-mounted terminal T-BOX.

[0009] In a possible implementation manner, the constant current output module includes a voltage dividing circuit, an amplifying circuit, and a constant current circuit; wherein,

[0010] The output terminal of the voltage dividing circuit is electrically connected to the input terminal of the amplifying circuit, and the output terminal of the amplifying circuit is electrically connected to the input terminal of the constant current circuit.

[0011] In a possible implementation manner, the voltage dividing circuit includes a first resistor and a second resistor; wherein,

[0012] The first resistor is connected in series with the second resistor.

[0013] In a possible implementation manner, the amplifying circuit includes a first triode and a third resistor; wherein,

[0014] The base of the first triode is electrically connected to the output terminal of the voltage dividing circuit, the collector of the first triode is electrically connected to one end of the third resistor, and the emitter of the first triode is electrically connected to the input terminal of the constant current circuit;

[0015] The other end of the third resistor is electrically connected to the output terminal of the voltage dividing circuit.

[0016] In a possible implementation manner, the other end of the third resistor is also electrically connected to the output terminal of the switch module.

[0017] In a possible implementation manner, the first triode is a PNP type triode.

[0018] In a possible implementation manner, the constant current circuit includes a second triode and a fourth resistor; wherein,

[0019] The base of the second triode is electrically connected to the output terminal of the amplifying circuit, the collector of the second triode is electrically connected to the power supply, and the emitter of the second triode is electrically connected to one end of the fourth resistor;

[0020] The other end of the fourth resistor is electrically connected to the positive pole of the backup battery of the vehicle-mounted terminal T-BOX.

[0021] In a possible implementation manner, the second triode is an NPN type triode.

[0022] In a possible implementation manner, the negative pole of the backup battery of the vehicle-mounted terminal T-BOX is grounded.

[0023] In a possible implementation, the DC-DC conversion module converts a DC voltage of 9V to 16V into a DC voltage of 5V.

[0024] A charging device for a spare battery of an in-vehicle terminal T-BOX provided by an embodiment of the present application. The charging device includes a power supply, a DC-DC conversion module, a switch module, and a constant current output module. Among them, the input end of the DC-DC conversion module is electrically connected to the output end of the power supply, and the output end of the DC-DC conversion module is electrically connected to the input end of the switch module. The output end of the switch module is electrically connected to the input end of the constant current output module. The output end of the constant current output module is electrically connected to the input end of the spare battery of the in-vehicle terminal T-BOX. By replacing the BOOST and LDO chips with a constant current output module, the material cost is reduced, the PCB usage area is reduced, which is beneficial to miniaturized design and heat dissipation performance, and it is directly powered by the power supply, without the process of boosting and then bucking, reducing the power loss.

[0025] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. Description of the Drawings

[0026] To more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0027] Figure 1 One of the structural schematic diagrams of a charging device for a spare battery of an in-vehicle terminal T-BOX provided by an embodiment of the present application;

[0028] Figure 2 The structural schematic diagram of a charging device for a spare battery of an in-vehicle terminal T-BOX in the prior art provided by an embodiment of the present application;

[0029] Figure 3 Another structural schematic diagram of a charging device for a spare battery of an in-vehicle terminal T-BOX provided by an embodiment of the present application;

[0030] Figure 4 The circuit schematic diagram of a charging device for a spare battery of an in-vehicle terminal T-BOX provided by an embodiment of the present application.

[0031] Main Component Symbol Explanation:

[0032] Icons: 100 - Charging device for the backup battery of in - vehicle terminal T - BOX; 110 - Power supply; 120 - DC - DC conversion module; 130 - Switch module; 140 - Constant - current output module; 141 - Voltage - dividing circuit; 142 - Amplification circuit; 143 - Constant - current circuit; 1411 - First resistor; 1412 - Second resistor; 1421 - First triode; 1422 - Third resistor; 1431 - Second triode; 1432 - Fourth resistor. Detailed implementation manners

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be understood that the accompanying drawings in the present application are only for the purposes of illustration and description, and are not used to limit the protection scope of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present application illustrate the operations implemented according to some embodiments of the present application. It should be understood that the operations in the flowchart may not be implemented in sequence, and steps without a logical context relationship may be reversed or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart or remove one or more operations from the flowchart under the guidance of the content of the present application.

[0034] In addition, the described embodiments are only some embodiments of the present application, rather than all embodiments. The components of the embodiments of the present application described and illustrated in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0035] To enable those skilled in the art to use the content of the present application, the following implementation manners are given in combination with the specific application scenario "Charging device for the backup battery of in - vehicle terminal T - BOX". For those skilled in the art, without departing from the spirit and scope of the present application, the general principles defined here can be applied to other embodiments and application scenarios.

[0036] First, an application scenario applicable to the present application is introduced. The present application can be applied to the technical field of charging the backup battery of electric vehicle in - vehicle terminals.

[0037] It should be noted that an important function of the Telematics BOX (abbreviated as in-vehicle T-BOX) is that after a vehicle collision, its backup battery can be activated to make a call for rescue. Therefore, the backup battery is crucial in the application of in-vehicle T-BOX, and the charging circuit of the backup battery is also an important part of the in-vehicle T-BOX product. For the working principle of the existing backup battery charging circuit, please refer to Figure 2 , Figure 2 which is a schematic structural diagram of a charging device for the backup battery of an in-vehicle terminal T-BOX in the prior art provided by an embodiment of the present application. As Figure 2 shown, the existing charging device includes a power supply KL30, a DC-DC converter, a microcontroller unit MCU, a BOOST chip, and an LDO chip. After the microcontroller unit MCU of the in-vehicle T-BOX sends a charging signal, first, the primary power DC-DC converter converts the vehicle body voltage from 9V - 16V to 5V, then the secondary power boost chip BOOST boosts the 5V to about 10V, and then the tertiary power chip LDO reduces it to 5.5V. By controlling the current limit value of the LDO, a constant current is provided to the backup battery of the in-vehicle T-BOX for charging.

[0038] However, for the charging circuit of the backup battery of the above in-vehicle T-BOX, its electronic material cost is high, it occupies a large area of the printed circuit board PCB, and there are many voltage conversions, with boosting first and then bucking, resulting in large power losses. Therefore, how to reduce the area occupied by the charging circuit of the in-vehicle T-BOX backup battery and reduce the power loss of the charging circuit of the in-vehicle T-BOX backup battery has become a technical problem that cannot be underestimated.

[0039] Based on this, an embodiment of the present application provides a charging device for the backup battery of an in-vehicle terminal T-BOX. By replacing the BOOST and LDO chips with a constant current output module, the material cost is reduced, the PCB usage area is reduced, which is beneficial to miniaturization design and heat dissipation performance, and it is directly powered by the power supply, without the process of boosting and then bucking, reducing the power loss.

[0040] Please refer to Figure 1 , Figure 1 which is one of the schematic structural diagrams of a charging device 100 for the backup battery of an in-vehicle terminal T-BOX provided by an embodiment of the present application. As Figure 1 shown in, the charging device 100 for the backup battery of the in-vehicle terminal T-BOX provided by the embodiment of the present application includes a power supply 110, a DC-DC conversion module 120, a switch module 130, and a constant current output module 140.

[0041] Specifically, the input end of the DC-DC conversion module 120 is electrically connected to the output end of the power supply 110, and the output end of the DC-DC conversion module 120 is electrically connected to the input end of the switch module 130; the output end of the switch module 130 is electrically connected to the input end of the constant current output module 140; the output end of the constant current output module 140 is electrically connected to the input end of the standby battery of the vehicle-mounted terminal T-BOX.

[0042] As an example, the power supply 110 can be KL30, providing a voltage of 9-16V. The DC-DC conversion module 120 converts the DC voltage of 9V to 16V into a DC voltage of 5V to provide 5V voltage for the vehicle-mounted T-BOX. The switch module 130 includes a micro control unit MCU and a switch S1. After the MCU is powered on, it can work normally. After the MCU sends a charging signal, the switch S1 closes and conducts.

[0043] Further, please refer to Figure 3 , Figure 3 FIG. 2 is a second schematic structural diagram of a charging device 100 for a standby battery of a vehicle-mounted terminal T-BOX provided by an embodiment of the present application. As shown in Figure 3 FIG. 2, the constant current output module 140 includes a voltage dividing circuit 141, an amplifying circuit 142, and a constant current circuit 143; wherein, the output end of the voltage dividing circuit 141 is electrically connected to the input end of the amplifying circuit 142, and the output end of the amplifying circuit 142 is electrically connected to the input end of the constant current circuit 143.

[0044] Here, after S1 conducts, the voltage output by the switch module 130 is divided by the voltage dividing circuit 141, the divided voltage is amplified by the amplifying circuit 142, and finally a constant current is output through the constant current circuit 143 to charge the standby battery of the vehicle-mounted T-BOX.

[0045] Further, as shown in Figure 3 FIG. 2, the voltage dividing circuit 141 includes a first resistor 1411 and a second resistor 1412; wherein, the first resistor 1411 and the second resistor 1412 are connected in series.

[0046] Here, the voltage dividing circuit 141 includes at least two resistors, namely the first resistor 1411 and the second resistor 1412. Or, the first resistor 1411 includes multiple resistors connected in series, and the second resistor 1412 includes multiple resistors connected in series.

[0047] Further, as shown in Figure 3As shown, the amplifier circuit 142 includes a first triode 1421 and a third resistor 1422. Among them, the base of the first triode 1421 is electrically connected to the output terminal of the voltage dividing circuit 141, the collector of the first triode 1421 is electrically connected to one end of the third resistor 1422, and the emitter of the first triode 1421 is electrically connected to the input terminal of the constant current circuit 143. The other end of the third resistor 1422 is electrically connected to the output terminal of the voltage dividing circuit 141.

[0048] Here, the first triode 1421 can be a PNP type triode. The amplifier circuit 142 includes at least one resistor, i.e., the third resistor 1422, or the third resistor 1422 includes multiple resistors connected in series.

[0049] Further, as Figure 3 shown, the constant current circuit 143 includes a second triode 1431 and a fourth resistor 1432. Among them, the base of the second triode 1431 is electrically connected to the output terminal of the amplifier circuit 142, the collector of the second triode 1431 is electrically connected to the power supply 110, and the emitter of the second triode 1431 is electrically connected to one end of the fourth resistor 1432. The other end of the fourth resistor 1432 is electrically connected to the positive electrode of the in-vehicle terminal T-BOX backup battery.

[0050] Here, the second triode 1431 can be an NPN type triode. The constant current circuit 143 includes at least one resistor, i.e., the fourth resistor 1432, or the fourth resistor 1432 includes multiple resistors connected in series.

[0051] Among them, the resistance value of each resistor in the constant current circuit 143 needs to be selected according to the charging current of the in-vehicle terminal T-BOX backup battery, and the current output by the constant current circuit 143 needs to reach the charging current of the in-vehicle terminal T-BOX backup battery (provided by the battery manufacturer). That is, the following formula needs to be satisfied:

[0052]

[0053] Among them, I is the charging current of the in-vehicle terminal T-BOX backup battery provided by the battery manufacturer, V is the output voltage of the DC-DC conversion module 120, which can be 5V, R 4 is the resistance value of the fourth resistor 1432 (or the sum of the resistance values of all the resistors connected in series in the fourth resistor 1432), R 1 and R 2 are the resistance values of the first resistor 1411 (or the sum of the resistance values of all the resistors connected in series in the first resistor 1411) and the second resistor 1412 (or the sum of the resistance values of all the resistors connected in series in the second resistor 1412) in the voltage dividing circuit 141, respectively.

[0054] It should be noted that for R 1 and R 2 their selection needs to be based on the charging voltage of the backup battery of the vehicle-mounted terminal T-BOX, and it is necessary to make the voltage output by the voltage dividing circuit 141 greater than the charging voltage of the backup battery of the vehicle-mounted terminal T-BOX (provided by the battery manufacturer). That is, the following formula needs to be satisfied:

[0055]

[0056] where U is the charging voltage of the backup battery of the vehicle-mounted terminal T-BOX provided by the battery manufacturer.

[0057] Furthermore, the negative electrode of the backup battery of the vehicle-mounted terminal T-BOX is grounded.

[0058] As an example, please refer to Figure 4 , Figure 4 which is the circuit schematic diagram of a charging device for the backup battery of a vehicle-mounted terminal T-BOX provided by an embodiment of the present application. As shown in Figure 4 , the power supply 110 (KL30) of the vehicle-mounted T-BOX provides a voltage of 9 - 16V. The DC-DC conversion module 120 (power chip DC-DC) converts the vehicle body voltage from 9V - 16V to 5V to provide 5V voltage for the vehicle-mounted T-BOX. After the MCU in the switch module 130 is powered on, it can work normally. After the MCU issues a charging signal, the switch S1 in the switch module 130 closes and conducts. The base voltage of the first triode 1421 (PNP type triode Q1) is 5V×R 2 / (R 1 +R 2 ), which is greater than the turn-on voltage of Q1. The collector voltage is 0V, the collector is forward-biased, the emitter voltage is 5V, and the emitter is reverse-biased. Q1 conducts and operates in the amplification region; the base voltage of the second triode 1431 (NPN type triode Q2) is [5V×R 2 / (R 1 +R 2 )]+0.7V, which is greater than the turn-on voltage of Q2. The collector voltage is the voltage provided by KL30 (i.e., 9 - 16V), the collector is reverse-biased, the emitter voltage is the current voltage of the battery, and the emitter is forward-biased. Q2 conducts and operates in the amplification region. Since the emitter voltage of Q2 after conduction is 5V×R 2 / (R 1 +R 2 ), it is constant and does not change with the KL30 voltage, playing a constant voltage role. The internal resistance of the battery is mostly in the milliohm level and has little influence on the circuit resistance. R 4 can be selected according to the charging current of the backup battery, and constant current charging can be achieved.

[0059] In summary, in this embodiment, discrete components are used to replace the two chips of BOOST and LDO, reducing the material cost. It is directly powered by the power supply 110 (KL30), and there is no longer a process of step-down, step-up, and then step-down, reducing the power loss. It realizes constant voltage and constant current charging for the in-vehicle T-BOX backup battery. Using the charging device 100 provided in this embodiment can also reduce the PCB usage area, which is beneficial for heat dissipation and miniaturization design.

[0060] A charging device for an in-vehicle terminal T-BOX backup battery provided by an embodiment of the present application, the charging device includes a power supply, a DC-DC conversion module, a switch module, and a constant current output module; wherein, the input end of the DC-DC conversion module is electrically connected to the output end of the power supply, and the output end of the DC-DC conversion module is electrically connected to the input end of the switch module; the output end of the switch module is electrically connected to the input end of the constant current output module; the output end of the constant current output module is electrically connected to the input end of the in-vehicle terminal T-BOX backup battery. By replacing the two chips of BOOST and LDO with a constant current output module, the material cost is reduced, the PCB usage area is reduced, which is beneficial for miniaturization design and heat dissipation performance, and it is directly powered by the power supply, and there is no longer a process of step-up and then step-down, reducing the power loss.

[0061] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described systems, devices, and units can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0062] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection may be through some communication interfaces, and the indirect coupling or communication connection of the devices or units may be in an electrical, mechanical, or other form.

[0063] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0064] In addition, in each embodiment of the present application, each functional unit may be integrated into a processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.

[0065] If the above-mentioned function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks, or optical discs.

[0066] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0067] Finally, it should be noted that the above-described embodiments are only specific implementation manners of the present application, used to illustrate the technical solutions of the present application, and are not intended to limit them. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the art within the technical scope disclosed in the present application can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes, or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A charging device for a backup battery of a vehicle-mounted terminal T-BOX, characterized in that: The charging device includes a power supply, a DC-DC conversion module, a switch module and a constant current output module; wherein, The input end of the DC-DC conversion module is electrically connected to the output end of the power supply, and the output end of the DC-DC conversion module is electrically connected to the input end of the switch module; The output end of the switch module is electrically connected to the input end of the constant current output module; The output end of the constant current output module is electrically connected to the input end of the backup battery of the vehicle-mounted terminal T-BOX.

2. The charging device according to claim 1, characterized in that: The constant current output module includes a voltage divider circuit, an amplifier circuit and a constant current circuit; wherein, The output end of the voltage divider circuit is electrically connected to the input end of the amplifier circuit, and the output end of the amplifier circuit is electrically connected to the input end of the constant current circuit.

3. The charging device according to claim 2, characterized in that: The voltage divider circuit includes a first resistor and a second resistor; wherein, The first resistor is connected in series with the second resistor.

4. The charging device according to claim 2, characterized in that: The amplifying circuit includes a first transistor and a third resistor; wherein, The base of the first transistor is electrically connected to the output end of the voltage divider circuit, the collector of the first transistor is electrically connected to one end of the third resistor, and the emitter of the first transistor is electrically connected to the input end of the constant current circuit; The other end of the third resistor is electrically connected to the output end of the voltage divider circuit.

5. The charging device according to claim 4, characterized in that: The other end of the third resistor is also electrically connected to the output end of the switch module.

6. The charging device according to claim 4, characterized in that: The first transistor is a PNP transistor.

7. The charging device according to claim 2, characterized in that: The constant current circuit includes a second triode and a fourth resistor; wherein, The base of the second transistor is electrically connected to the output end of the amplifier circuit, the collector of the second transistor is electrically connected to the power supply, and the emitter of the second transistor is electrically connected to one end of the fourth resistor; The other end of the fourth resistor is electrically connected to the positive electrode of the backup battery of the vehicle-mounted terminal T-BOX.

8. The charging device according to claim 7, characterized in that: The second transistor is an NPN transistor.

9. The charging device according to claim 7, characterized in that: The negative pole of the backup battery of the vehicle-mounted terminal T-BOX is grounded.

10. The charging device according to claim 1, characterized in that: The DC-DC conversion module converts a DC voltage of 9V to a DC voltage of 16V to a DC voltage of 5V.

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