Management system for built-in battery of vehicle-mounted terminal

Abstract

The utility model provides a management system for a built-in battery of a vehicle-mounted terminal, which is applied to an electric vehicle and comprises a built-in battery, a comparator connected with a TEMP temperature detection pin of the built-in battery, an MCU microprocessor, a first triode, a D trigger, a discharging MOS field effect transistor, a charging MOS field effect transistor, a discharging loop and a charging loop, by utilizing the input and output characteristics of the D trigger, the charging and discharging management of the battery can be simply realized, and a simple battery management system circuit can be designed according to actual requirements by combining the functions of elements such as the MCU microprocessor, the first triode, the charging MOS field-effect tube and the discharging MOS field-effect tube. And intelligent charging and discharging control and power management of the built-in battery are realized. The system with the design not only can prolong the service life of the battery and guarantee the safe and stable operation of the system, but also can adapt to the requirements of various working scenes, omits a special battery charging and discharging management IC (Integrated Circuit), and is high in precision and low in cost.

Description

Technical Field

[0001] The utility model relates to the technical field of electric vehicles, and more specifically, to a management system for an in-vehicle terminal built-in battery. Background Art

[0002] With the development of automotive electrification and intelligence, more and more in-vehicle terminals need to continue working for a period of time when the main battery of the electric vehicle loses power. At this time, a lithium battery or nickel-metal hydride battery needs to be built into the terminal. During use, the battery will have application modes such as discharging, charging, and shutting down. If not properly managed, it may cause problems such as abnormal battery operation, reduced lifespan, and even affect the performance of the entire machine. Therefore, intelligent management of the built-in battery becomes increasingly important.

[0003] Currently, there are two methods for battery mode management. One is to simply detect the battery voltage through ADC voltage division, and then control the relevant power chips to be enabled and shut down according to different battery voltages. The other is to perform special control through an expensive power charge and discharge management IC.

[0004] However, the first solution overly relies on software and has low accuracy. If the software crashes, it may lead to abnormal battery operating states; the other solution has a high product cost and great software development difficulty. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide a management system for an in-vehicle terminal built-in battery with high accuracy and low cost in view of the deficiencies in the above technical solutions.

[0006] The utility model provides a management system for an in-vehicle terminal built-in battery. The management system is applied to an electric vehicle. The system includes a built-in battery, a comparator connected to the TEMP temperature detection pin of the built-in battery, an MCU microprocessor, a first triode, a D flip-flop, a discharge MOS field-effect transistor, a charging MOS field-effect transistor, a discharge circuit, and a charging circuit; one end of the first triode is connected to the built-in battery, and the other end is electrically connected to the D pin of the D flip-flop. The input end of the comparator is electrically connected to the built-in battery, and the output end is electrically connected to the S pin of the D flip-flop. The MCU microprocessor is electrically connected to the S pin of the D flip-flop. The Q- pin of the D flip-flop is electrically connected to the discharge circuit, and the CP pin of the D flip-flop is electrically connected to the charging circuit; the discharge circuit is electrically connected to the discharge MOS field-effect transistor, and the charging circuit is electrically connected to the charging MOS field-effect transistor;

[0007] When the engine ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from low level to high level, and the VIN input terminal charges the built-in battery through the charging MOS field-effect transistor, so that the control system enters the charging mode, and at the same time, the VOUT output terminal cannot be discharged through the discharging MOS field-effect transistor;

[0008] When the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from high level to low level, and the built-in battery discharges the VOUT output terminal through the discharging MOS field-effect transistor, and the VIN input terminal does not charge the built-in through the charging MOS field-effect transistor, so that the control system enters the discharging mode;

[0009] When the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from high level to low level, and the built-in battery neither discharges through the discharging MOS field-effect transistor nor charges through the charging MOS field-effect transistor, so that both the discharging MOS field-effect transistor and the charging MOS field-effect transistor are in the off state, so that the control system enters the shutdown mode.

[0010] In the management system of the built-in battery of the vehicle-mounted terminal described in the present invention; when the voltage of the built-in battery is lower than 3V and the engine ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from low level to high level, the discharge circuit is not turned on, the discharging MOS field-effect transistor is not turned on either, and the built-in battery does not discharge the VOUT output terminal through the discharging MOS field-effect transistor; at the same time, the engine ignition signal KL15 becomes high level, the charging circuit is turned on, the charging MOS field-effect transistor is turned on, and the VIN input terminal charges the built-in battery through the charging MOS field-effect transistor, so that the control system enters the charging mode.

[0011] In the management system of the built-in battery of the vehicle-mounted terminal described in the present invention; when the voltage of the built-in battery is lower than 3V and the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from high level to low level, the first triode is not turned on, at this time the D pin of the D flip-flop inputs a high level, and the Q- pin of the D flip-flop also outputs a low level, and the discharge circuit is turned off; at the same time, the engine ignition signal KL15 becomes low level, the charging MOS field-effect transistor is turned off, and the VIN input terminal cannot charge the built-in battery through the charging MOS field-effect transistor, so that the control system enters the shutdown mode.

[0012] In the management system of the built-in battery of the vehicle-mounted terminal described in the present utility model; when the voltage of the built-in battery is higher than 3V and the engine ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from low level to high level, the discharge circuit is not conducting, the discharge MOS field-effect transistor is also not conducting, the built-in battery does not discharge to VOUT through the discharge MOS field-effect transistor, and the discharge circuit is closed; at the same time, the engine ignition signal KL15 becomes high level, the charging circuit is conducting, the charging MOS field-effect transistor is also conducting, the VIN input terminal charges the built-in battery through the charging MOS field-effect transistor, and the control system enters the charging mode; when the voltage of the built-in battery is higher than 3V and the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from high level to low level, the first triode conducts, at this time the D pin of the D flip-flop inputs low level, the Q- pin of the D flip-flop outputs high level, and the discharge circuit is opened; at the same time, the engine ignition signal KL15 becomes low level, the charging circuit is closed, the charging MOS field-effect transistor is synchronously closed, the VIN input terminal cannot charge the built-in battery through the charging MOS field-effect transistor, and the control system enters the discharge mode.

[0013] In the management system of the built-in battery of the vehicle-mounted terminal described in the present utility model; the discharge circuit includes a second triode, a first resistor, a second resistor, a third resistor and a fourth resistor. One end of the first resistor is connected to the Q- pin of the D flip-flop, and the other end is connected to the base of the second triode. One end of the second resistor is connected to the common end of the base of the second triode and the first resistor, and the other end is grounded. One end of the third resistor is connected to the gate of the discharge MOS field-effect transistor, and the other end is connected to the collector of the second triode. One end of the fourth resistor is connected to the source of the discharge MOS field-effect transistor, and the other end is connected to the collector of the second triode. The base-emitter of the second triode is grounded.

[0014] In the management system of the built-in battery of the vehicle-mounted terminal described in the present utility model; the charging circuit includes a third triode, a fifth resistor and a sixth resistor. One end of the fifth resistor is connected to the source of the charging MOS field-effect transistor, and the other end is connected to the collector of the third triode. One end of the sixth resistor is connected to the gate of the discharge MOS field-effect transistor, and the other end is connected to the collector of the third triode. The base-emitter of the third triode is grounded, and the base of the third triode is connected to the CP pin of the D flip-flop.

[0015] In the management system of the in-vehicle terminal built-in battery of the present utility model; the management system of the in-vehicle terminal built-in battery further includes a voltage-dividing circuit, and the voltage-dividing circuit includes an isolation diode, a seventh resistor, an eighth resistor and a ninth resistor. The isolation diode and the seventh resistor are connected in series, one end is connected to the engine ignition signal KL15, and the other end is connected to the output end of the comparator. The common end of the isolation diode and the seventh resistor is connected to the CP pin of the D flip-flop. One end of the eighth resistor is connected to the base of the third triode, and the other end is connected to the CP pin of the D flip-flop. One end of the ninth resistor is grounded, and the other end is connected to the base of the third triode.

[0016] In the management system of the in-vehicle terminal built-in battery of the present utility model; the management system of the in-vehicle terminal built-in battery further includes a pull-down resistor. One end of the pull-down resistor is connected to the common end of the base of the first triode and the D pin of the D flip-flop, and the other end is connected to VCC.

[0017] In the management system of the in-vehicle terminal built-in battery of the present utility model; both the discharge MOS field effect transistor and the charge MOS field effect transistor are P-channel enhancement type.

[0018] By utilizing the input-output characteristics of the D flip-flop, the management system of the in-vehicle terminal built-in battery of the present utility model can simply realize the management of battery charging and discharging. In combination with the functions of components such as the MCU microprocessor, the first triode, the charge MOS field effect transistor, and the discharge MOS field effect transistor, a simple battery management system circuit can be designed according to actual needs to realize intelligent charge and discharge control and power management of the built-in battery. Such a system can not only improve the battery life, ensure the safe and stable operation of the system, but also meet the requirements of various working scenarios. The present utility model not only eliminates the need for a dedicated battery charge and discharge management IC, but also has high precision and low cost. Description of the Drawings

[0019] Figure 1 is the circuit schematic diagram of the management system of the in-vehicle terminal built-in battery of the present utility model;

[0020] Figure 2 is the operation flowchart of the management system of the in-vehicle terminal built-in battery of the present utility model;

[0021] Figure 3 is the state flowchart of the management system of the in-vehicle terminal built-in battery of the present utility model. Detailed Embodiments

[0022] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0023] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present utility model are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present utility model described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily limit to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0024] As Figures 1-3 shown, it is a schematic flow chart of an embodiment of the management system of the built-in battery of the vehicle-mounted terminal of the present utility model. A management system of the built-in battery of the vehicle-mounted terminal is provided. The management system is applied to an electric vehicle. The system includes a built-in battery, a comparator connected to the TEMP temperature detection pin of the built-in battery, an MCU microprocessor, a first triode, a D flip-flop, a discharge MOS field effect transistor, a charge MOS field effect transistor, a discharge circuit and a charge circuit; one end of the first triode is connected to the built-in battery and the other end is electrically connected to the D pin of the D flip-flop. The input end of the comparator is electrically connected to the built-in battery and the output end is electrically connected to the S pin of the D flip-flop. The MCU microprocessor is electrically connected to the S pin of the D flip-flop. The Q- pin of the D flip-flop is electrically connected to the discharge circuit. The CP pin of the D flip-flop is electrically connected to the charge circuit; the discharge circuit is electrically connected to the discharge MOS field effect transistor, and the charge circuit is electrically connected to the charge MOS field effect transistor;

[0025] When the engine ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from low level to high level, and the VIN input terminal charges the built-in battery through the charge MOS field effect transistor, so that the control system enters the charging mode, and at the same time, the VOUT output terminal cannot be discharged through the discharge MOS field effect transistor;

[0026] When the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from high level to low level, the built-in battery discharges the VOUT output terminal through the discharge MOS field effect transistor, and the VIN input terminal does not charge the built-in through the charge MOS field effect transistor, so that the control system enters the discharge mode;

[0027] When the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from high level to low level. The built-in battery neither discharges through the discharge MOS field-effect transistor nor charges through the charging MOS field-effect transistor, causing both the discharge MOS field-effect transistor and the charging MOS field-effect transistor to be in the off state, thereby enabling the control system to enter the shutdown mode.

[0028] In this embodiment, when the voltage of the built-in battery is lower than 3V and the engine ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from low level to high level. The discharge circuit is not conducting, and the discharge MOS field-effect transistor is also not conducting. The built-in battery does not discharge to the VOUT output terminal through the discharge MOS field-effect transistor. At the same time, the engine ignition signal KL15 becomes high level, the charging circuit conducts, the charging MOS field-effect transistor conducts, and the VIN input terminal charges the built-in battery through the charging MOS field-effect transistor, thereby enabling the control system to enter the charging mode.

[0029] In this embodiment, when the voltage of the built-in battery is lower than 3V and the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from high level to low level, and the first triode does not conduct. At this time, a high level is input to the D pin of the D flip-flop, and a low level is also output from the Q- pin of the D flip-flop, and the discharge circuit is turned off. At the same time, the engine ignition signal KL15 becomes low level, the charging MOS field-effect transistor is turned off, and the VIN input terminal cannot charge the built-in battery through the charging MOS field-effect transistor, thereby enabling the control system to enter the shutdown mode.

[0030] In this embodiment, when the voltage of the built-in battery is higher than 3V and the engine ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from low level to high level, the discharge circuit is not conducting, the discharge MOS field-effect transistor is also not conducting, the built-in battery does not discharge to VOUT through the discharge MOS field-effect transistor, and the discharge circuit is closed; at the same time, the engine ignition signal KL15 becomes high level, the charging circuit is conducting, the charging MOS field-effect transistor is also conducting, the VIN input terminal charges the built-in battery through the charging MOS field-effect transistor, and the control system enters the charging mode; when the voltage of the built-in battery is higher than 3V and the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from high level to low level, the first triode conducts, at this time the D pin of the D flip-flop inputs low level, the Q- pin of the D flip-flop outputs high level, and the discharge circuit is opened; at the same time, the engine ignition signal KL15 becomes low level, the charging circuit is closed, the charging MOS field-effect transistor is synchronously closed, the VIN input terminal cannot charge the built-in battery through the charging MOS field-effect transistor, and the control system enters the discharge mode.

[0031] In this embodiment, the discharge circuit includes a second triode, a first resistor, a second resistor, a third resistor and a fourth resistor. One end of the first resistor is connected to the Q- pin of the D flip-flop, and the other end is connected to the base of the second triode. One end of the second resistor is connected to the common terminal of the base of the second triode and the first resistor, and the other end is grounded. One end of the third resistor is connected to the gate of the discharge MOS field-effect transistor, and the other end is connected to the collector of the second triode. One end of the fourth resistor is connected to the source of the discharge MOS field-effect transistor, and the other end is connected to the collector of the second triode. The base-emitter of the second triode is grounded.

[0032] In this embodiment, the charging circuit includes a third triode, a fifth resistor and a sixth resistor. One end of the fifth resistor is connected to the source of the charging MOS field-effect transistor, and the other end is connected to the collector of the third triode. One end of the sixth resistor is connected to the gate of the discharge MOS field-effect transistor, and the other end is connected to the collector of the third triode. The base-emitter of the third triode is grounded, and the base of the third triode is connected to the CP pin of the D flip-flop.

[0033] In this embodiment, the management system of the in-vehicle terminal built-in battery further includes a voltage dividing circuit. The voltage dividing circuit includes an isolation diode, a seventh resistor, an eighth resistor, and a ninth resistor. The isolation diode and the seventh resistor are connected in series, with one end connected to the engine ignition signal KL15 and the other end connected to the output terminal of the comparator. The common terminal of the isolation diode and the seventh resistor is connected to the CP pin of the D flip-flop. One end of the eighth resistor is connected to the base of the third triode, and the other end is connected to the CP pin of the D flip-flop. One end of the ninth resistor is grounded, and the other end is connected to the base of the third triode.

[0034] In this embodiment, the management system of the in-vehicle terminal built-in battery further includes a pull-down resistor. One end of the pull-down resistor is connected to the common terminal of the base of the first triode and the D pin of the D flip-flop, and the other end is connected to VCC.

[0035] In this embodiment, both the discharge MOS field effect transistor and the charge MOS field effect transistor are P-channel enhancement types.

[0036] Specifically, taking the usage scenario of the in-vehicle terminal built-in battery as an example, the present utility model controls the system to enter three modes: charging, discharging, and shutdown respectively through a D flip-flop and peripheral related devices.

[0037] A D flip-flop is an information storage device with a memory function and two stable states. A D flip-flop consists of an integrated flip-flop and a gate circuit. There are two triggering methods: level triggering and edge triggering. The present utility model uses a D flip-flop triggered by a low level, and its working principle is as follows: when the CP pin of the D flip-flop is at a low level, and the inputs of the S terminal and the R terminal of the D flip-flop are both at a high level VCC, at this time, the output level of the Q- of the D flip-flop is determined by the input level of the D pin of the D flip-flop, and the state is opposite. If the D pin of the D flip-flop inputs a high level VCC, then the Q- of the D flip-flop will output a low level 0V. When the CP pin of the D flip-flop is at a high level, and the inputs of the S pin and the R pin of the D flip-flop are both at a high level VCC, at this time, the voltage of the Q- of the D flip-flop will remain unchanged in the previous state. When the input of the S terminal of the D flip-flop is at a low level, regardless of the level of the D pin of the D flip-flop, the output of the Q- of the D flip-flop is a low level 0V. It should be noted that the R pin of the D flip-flop in this application is fixed at a high level VCC.

[0038] A comparator is an electronic component used to compare the magnitudes of currents or voltages at two input terminals and output different voltage results at the output terminal. In the present utility model, when the voltage at the positive input terminal of the comparator U2 is greater than the voltage at the negative input terminal, the output is a high level VCC, otherwise the output is a low level 0V.

[0039] In this application, the symbol of the built-in battery is BAT. The normal voltage range of the built-in battery is between 3V and 4V. BAT+ is used for detecting the voltage input of the built-in battery. TEMP is the temperature detection pin of the built-in battery. There is generally a 10K thermistor pulled down inside it, and the voltage of the built-in battery is judged whether it is in place by the divided voltage resistance.

[0040] In the present utility model, the isolation diode D1 and the seventh resistor R4 are connected in series in the circuit to play an isolation role. When the engine ignition signal KL15 is at a low level of 0V, the third triode Q3 is controlled to turn off through devices such as the seventh resistor R4, the eighth resistor R11, and the ninth resistor R12, and then the charging MOS field effect transistor Q5 in the charging circuit is controlled to turn off through the fifth resistor R9 and the sixth resistor R10, and the state of the Q- pin of the flip-flop will change with the input change of the D pin of the flip-flop. When the engine ignition signal KL15 is at a high level of 9V - 15V, the output state of the Q- pin of the flip-flop will remain unchanged. The first diode D2 and the second diode D3 are connected in series in the circuit. The second diode D3 controls the level of the S pin of the D flip-flop; the first diode D2 provides a VCC pull-up for the eighth resistor R11, the ninth resistor R12, and the third triode Q3 at the subsequent stage through the output of the comparator.

[0041] In the present utility model, the resistors R1 and R2 divide the voltage of BAT and then enter the base of the first triode Q1 to control the conduction and turn-off of the first triode Q1; R3 is a pull-up resistor, providing a high-level pull-up for the D pin of the first triode Q1 and the D flip-flop; the seventh resistor R4 is a series resistor, and together with the isolation diode D1, the eighth resistor R11, and the ninth resistor R12, they form a voltage-dividing circuit to control the input of the CP pin of the D flip-flop and the conduction and turn-off of the third triode Q3; the fifth resistor R9, the sixth resistor R10, and the third triode Q3 control the conduction and turn-off of the charging MOS field effect transistor Q5 in the charging circuit; when the charging MOS field effect transistor Q5 conducts, the input voltage at the front-stage VIN input terminal will charge the built-in battery BAT at the subsequent stage through the charging MOS field effect transistor Q5; the output of the Q- pin of the D flip-flop controls the conduction and turn-off of the second triode Q2 after being divided by the first resistor R5 and the second resistor R6; the fourth resistor R7, the third resistor R8, and the second diode Q2 control the conduction and turn-off of the discharge MOS field effect transistor Q4; when the discharge MOS field effect transistor Q4 conducts, the built-in battery BAT will discharge to the VOUT output terminal at the subsequent stage through the discharge MOS field effect transistor Q4. It should be noted that the resistance values of the resistor R13 and the resistor R14 are the same. VCC enters the non-inverting input terminal of the comparator U2 through R14; VCC provides a pull-up detection for the TEMP pin of the built-in battery through R13.

[0042] A charging MOS field-effect transistor and a discharging MOS field-effect transistor are semiconductor devices that use the electric field effect in the control input circuit to control the current in the output circuit. The discharging MOS field-effect transistor Q4 and the charging MOS field-effect transistor Q5 of the present utility model are P-channel enhancement-mode field-effect transistors. When the Vgs (gate-source voltage) of the discharging MOS field-effect transistor Q4 and the charging MOS field-effect transistor Q5 is higher than the threshold voltage Vth (generally about 1V), they will conduct. Among them, the discharging MOS field-effect transistor Q4 controls the discharging circuit, and the charging MOS field-effect transistor Q5 controls the charging circuit.

[0043] The first triode Q1, the second triode Q2, and the third triode Q3 in the present utility model are all used as switches. Among them, the first triode Q1 is used to control the input voltage of the D pin of the D flip-flop, the third triode Q3 is used to control the gate voltage of the charging MOS field-effect transistor Q5, and the second triode Q2 is used to control the gate voltage of the discharging MOS field-effect transistor Q4.

[0044] The MCU microprocessor is a chip that integrates functions such as a microprocessor core, a memory, and a peripheral interface. The present utility model controls the level of the S pin of the D flip-flop through the IO pin of the MCU microprocessor. When the S pin of the D flip-flop is at a low level, it will control the Q- pin of the D flip-flop to be at a low level all the time, thereby disconnecting the VOUT power supply of the built-in battery in the later stage. At this time, the system will enter the shutdown mode after the engine ignition signal KL15 is in the off state.

[0045] The engine ignition signal KL15 represents the IGN state of the car key and is also the signal to start the electric vehicle. When the electric vehicle is started, the engine ignition signal KL15 is at a high level, and the voltage range is between 9 - 16V. When the engine ignition signal KL15 changes from a low level to a high level, the Q- pin of the D flip-flop will maintain its state unchanged. When the engine ignition signal KL15 changes from a high level to a low level, the output of the Q- pin of the D flip-flop depends on the input level of the D pin of the D flip-flop, and the state is opposite.

[0046] VCC is the symbol of the internal voltage of the system, generally 3.3V or 5V.

[0047] This application has three management modes for built-in battery management, namely charging mode, discharging mode, and shutdown mode. When in the charging mode, the input of the VIN input terminal charges the built-in battery BAT through the charging MOS field-effect transistor Q5, and the built-in battery BAT cannot discharge to the VOUT output terminal through the discharging MOS field-effect transistor Q4. When in the discharging mode, the BAT discharges to the external VOUT output terminal through the discharging MOS field-effect transistor Q4, and the VIN input terminal cannot charge the built-in battery BAT through the charging MOS field-effect transistor Q5. When in the shutdown mode, the built-in battery BAT can neither discharge through the discharging MOS field-effect transistor Q4 nor charge through the charging MOS field-effect transistor Q5. At this time, both the discharging MOS field-effect transistor Q4 and the charging MOS field-effect transistor Q5 are in the off state.

[0048] The working principle of this utility model is as follows:

[0049] When the system starts to detect, the system VCC starts to supply power. The in-position detection of the built-in battery BAT is started. When the built-in battery BAT is not in position, there is no pull-down resistor at the TEMP terminal. At this time, the voltage at the inverting input terminal of the comparator U2 is VCC, and the voltage at the non-inverting input terminal is also VCC. Therefore, the comparator U2 outputs a low level. At this time, the S pin of the subsequent D flip-flop is at a low level under the action of the first diode D2. According to the characteristics of the D flip-flop, the output of the Q- pin of the D flip-flop is also at a low level, and the built-in battery BAT cannot supply power to the VOUT output terminal. At the same time, the third triode Q3 is also at a low level under the action of the isolation diode D2, the seventh resistor R4, the eighth resistor R11, and the ninth resistor R12 due to the lack of VCC pull-up. Therefore, the VIN input terminal cannot charge the built-in battery BAT through the charging MOS field-effect transistor Q5, so the system will enter the shutdown mode.

[0050] When the built-in battery BAT is in position, at this time, due to the internal resistor voltage division, the voltage at the inverting input terminal of the comparator U2 is less than VCC, and the voltage at the non-inverting input terminal is VCC. Therefore, the comparator U2 outputs a high level. At this time, the voltage of the S pin of the D flip-flop is determined by the IO port of the MCU. When the IO pin of the MCU microprocessor outputs a high level, the output of the Q- pin of the D flip-flop is determined by the states of the CP pin and the D pin of the D flip-flop.

[0051] When the system needs to actively enter the shutdown mode, the MCU microprocessor first outputs a low-level signal to the IO. The S pin of the D flip-flop will be effective. At this time, regardless of the input state of the D pin of the D flip-flop, the Q- of the D flip-flop outputs a low level. At this time, the second triode Q2 will turn off, and the discharge MOS field-effect transistor Q4 will not conduct. Therefore, the built-in battery BAT cannot discharge through the discharge MOS field-effect transistor Q4. At the same time, under the action of the first diode D2, the third triode Q3 is also at a low level under the action of the seventh resistor R4, the eighth resistor R11, and the ninth resistor R12 due to the lack of VCC pull-up. Therefore, the VIN input terminal cannot charge the built-in battery BAT through the charging MOS field-effect transistor Q5. Therefore, the system will enter the shutdown mode.

[0052] After the MCU microprocessor outputs a high level to the IO, it will be divided into two cases according to the state of the built-in battery voltage: when the built-in battery voltage BAT is lower than 3V and when the battery voltage BAT is higher than 3V;

[0053] When the built-in battery voltage BAT is lower than 3V, it includes the following two cases:

[0054] (1) When the built-in battery voltage BAT is lower than 3V and the engine ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from low level to high level. Among them, the CP pin of the D flip-flop is invalid at high level, and the output of the Q- pin of the D flip-flop will maintain the low level of the previous state. Therefore, the base voltage of the second triode Q2 is low level, and the second triode Q2 will not conduct. The discharge MOS field-effect transistor Q4 will not conduct either. The built-in battery BAT will not discharge to the VOUT output terminal through the discharge MOS field-effect transistor Q4; when the engine ignition signal KL15 becomes high level, after the built-in battery BAT is divided by the seventh resistor R4, the eighth resistor R11, and the ninth resistor R12, the base voltage of the third triode Q3 is high level, and the third triode Q3 will conduct. The gate of the charging MOS field-effect transistor Q5 will be pulled to low level. The source voltage of the charging MOS field-effect transistor Q5 is VIN. At this time, the VGS voltage will be greater than the threshold conduction voltage Vth, and the charging MOS field-effect transistor Q5 will conduct. The VIN input terminal will charge the built-in battery BAT through the charging MOS field-effect transistor Q5, so that the system enters the charging mode.

[0055] (2) When the voltage of the built-in battery BAT is lower than 3V and the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from high level to low level. The CP pin of the D flip-flop is active low. At this time, the output of the Q- of the D flip-flop and the input of the D pin of the D flip-flop are in an inverse relationship. At this time, the voltage of the built-in battery BAT is less than 3V. After being divided by R1 and R2, the base voltage of the first triode Q1 is low level, and the first triode Q1 cannot conduct. At this time, the D pin of the D flip-flop will input a high level, and the Q- pin of the D flip-flop will also output a low level, and the discharge circuit will be turned off; at the same time, after the generator ignition signal KL15 becomes low level, the built-in battery BAT is divided by the seventh resistor R4, the eighth resistor R11 and the ninth resistor R12, and the base voltage of the third triode Q3 is low level, and the third triode Q3 will be turned off, and Q5 will be turned off synchronously, and VIN cannot charge the built-in battery BAT through the charging MOS field effect transistor Q5, so that the system enters the shutdown mode.

[0056] When the voltage of the built-in battery BAT is higher than 3V, it includes the following two situations:

[0057] (1) If the voltage of the built-in battery BAT is higher than 3V and the generator ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from low level to high level, making the CP pin of the D flip-flop high level invalid. The output of the Q- pin of the D flip-flop is the same low level as the previous state. Therefore, the base voltage of the second triode Q2 is low level, and the second triode Q2 will not conduct, and the discharge MOS field effect transistor Q4 will not conduct either. The built-in battery BAT will not discharge to the VOUT output terminal through the discharge MOS field effect transistor Q4, and the discharge circuit will be turned off; at the same time, after the generator ignition signal KL15 becomes high level, the built-in battery BAT is divided by the seventh resistor R4, the eighth resistor R11 and the ninth resistor R12, and the base voltage of the third triode Q3 is high level, and the third triode Q3 will conduct, and the charging MOS field effect transistor Q5 will also conduct. The VIN input terminal charges the built-in battery BAT through the discharge MOS field effect transistor Q5, so that the system enters the charging mode.

[0058] (2) When the voltage BAT of the built-in battery is higher than 3V and the ignition signal KL15 of the generator is in the off state, the CP pin of the D flip-flop changes from high level to low level. The CP pin of the D flip-flop is active low. At this time, the output of the Q- pin of the D flip-flop and the input of the D pin of the D flip-flop are in an inverse relationship. And at this time, the voltage of the built-in battery BAT is greater than 3V. After being divided by R1 and R2, the base voltage of the first triode Q1 is high level, and the first triode Q1 conducts. At this time, the D pin of the D flip-flop will input a low level, and the Q- pin of the D flip-flop will output a high level, and the discharge circuit will be opened; at the same time, after the ignition signal KL15 of the generator becomes low level, after VCC is divided by the seventh resistor R4, the eighth resistor R11 and the ninth resistor R12, the base voltage of the third triode Q3 is low level, and the third triode Q3 will turn off. The charging MOS field effect transistor Q5 will also turn off synchronously, and the VIN input terminal cannot charge the built-in battery BAT through the charging MOS field effect transistor Q5, so that the system enters the discharge mode.

[0059] The beneficial effects of a management system for the built-in battery of a vehicle-mounted terminal provided by an embodiment of the present invention are at least as follows:

[0060] 1. The present invention does not require a dedicated battery charge and discharge management IC, and the cost is lower;

[0061] 2. The present invention utilizes the input and output characteristics of the D flip-flop, and can simply implement the management of battery charge and discharge by using simple discrete devices;

[0062] 3. The present invention will not cause battery feed. When the battery voltage is lower than 3V, the subsequent discharge will be automatically disconnected, which better guarantees the battery life;

[0063] 4. The present invention realizes a shutdown mode that is compatible with software and hardware, and has stronger compatibility.

[0064] 5. The present invention can detect whether the battery is in place by reducing the circuit.

[0065] It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0066] Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present utility model, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disc), and includes several instructions for causing a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present utility model.

[0067] Therefore, as described above, the above are only the preferred specific embodiments of the present utility model, and the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered by the protection scope of the present utility model. The protection scope of the present utility model should be subject to the protection scope of the claims.

Claims

1. A management system for a battery built into a vehicle terminal, which is applied to electric vehicles and is characterized in that: The system includes a built-in battery, a comparator connected to the TEMP temperature detection pin of the built-in battery, an MCU microprocessor, a first triode, a D trigger, a discharge MOS field effect transistor, a charge MOS field effect transistor, a discharge circuit and a charge circuit; One end of the first triode is connected to the built-in battery, and the other end is electrically connected to the D pin of the D flip-flop. The input end of the comparator is electrically connected to the built-in battery, and the output end is electrically connected to the S pin of the D flip-flop. The MCU microprocessor is electrically connected to the S pin of the D flip-flop. The Q-pin of the D flip-flop is electrically connected to the discharge circuit, and the CP pin of the D flip-flop is electrically connected to the charging circuit. The discharge circuit is electrically connected to the discharge MOS field effect tube, and the charging circuit is electrically connected to the charging MOS field effect tube. When the engine ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from low level to high level, and the VIN input end charges the built-in battery through the charging MOS field effect tube, so that the control system enters the charging mode, and at the same time, the VOUT output end cannot be discharged through the discharging MOS field effect tube; When the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from high level to low level, the built-in battery discharges to the VOUT output terminal through the discharge MOS field effect tube, and the VIN input terminal does not charge the built-in through the charging MOS field effect tube, so that the control system enters the discharge mode; When the engine ignition signal KL15 is in the off state, the CP pin of the D trigger changes from a high level to a low level, and the built-in battery is neither discharged through the discharge MOS field effect transistor nor charged through the charge MOS field effect transistor, so that the discharge MOS field effect transistor and the charge MOS field effect transistor are both in the off state, thereby causing the control system to enter the shutdown mode.

2. The management system for the built-in battery of the vehicle terminal according to claim 1, characterized in that: When the voltage of the built-in battery is lower than 3V and the engine ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from a low level to a high level, the discharge circuit is not turned on, the discharge MOS field effect tube is also not turned on, and the built-in battery does not discharge to the VOUT output terminal through the discharge MOS field effect tube; at the same time, the engine ignition signal KL15 becomes a high level, the charging circuit is turned on, the charging MOS field effect tube is turned on, and the VIN input terminal charges the built-in battery through the charging MOS field effect tube, thereby causing the control system to enter the charging mode.

3. The management system for the built-in battery of the vehicle terminal according to claim 1, characterized in that: When the voltage of the built-in battery is lower than 3V and the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from a high level to a low level, and the first transistor is not turned on. At this time, the D pin of the D flip-flop inputs a high level, and the Q-pin of the D flip-flop also outputs a low level, and the discharge circuit is closed; at the same time, the engine ignition signal KL15 becomes a low level, the charging MOS field effect transistor is turned off, and the VIN input terminal cannot charge the built-in battery through the charging MOS field effect transistor, thereby causing the control system to enter the shutdown mode.

4. The management system for the built-in battery of the vehicle terminal according to claim 3, characterized in that: When the voltage of the built-in battery is higher than 3V and the engine ignition signal KL15 is in the on state, the CP pin of the D flip-flop changes from low level to high level, the discharge circuit is not turned on, the discharge MOS field effect tube is also not turned on, the built-in battery does not discharge to VOUT through the discharge MOS field effect tube, and the discharge circuit is closed; at the same time, the engine ignition signal KL15 becomes high level, the charging circuit is turned on, the charging MOS field effect tube is also turned on, the VIN input end charges the built-in battery through the charging MOS field effect tube, and the control system enters the charging state. Charging mode; when the voltage of the built-in battery is higher than 3V and the engine ignition signal KL15 is in the off state, the CP pin of the D flip-flop changes from a high level to a low level, the first transistor is turned on, at this time, the D pin of the D flip-flop inputs a low level, the Q-pin of the D flip-flop outputs a high level, and the discharge circuit is opened; at the same time, the engine ignition signal KL15 becomes a low level, the charging circuit is closed, the charging MOS field effect tube is synchronously closed, the VIN input terminal cannot charge the built-in battery through the charging MOS field effect tube, and the control system enters the discharge mode.

5. The management system for the built-in battery of the vehicle terminal according to claim 3, characterized in that: The discharge circuit includes a second transistor, a first resistor, a second resistor, a third resistor and a fourth resistor, one end of the first resistor is connected to the Q-pin of the D trigger, and the other end is connected to the base of the second transistor, one end of the second resistor is connected to the common end of the base of the second transistor and the first resistor, and the other end is grounded, one end of the third resistor is connected to the gate of the discharge MOS field effect transistor, and the other end is the collector of the second transistor, one end of the fourth resistor is connected to the source of the discharge MOS field effect transistor, and the other end is connected to the collector of the second transistor, and the base emitter of the second transistor is grounded.

6. The management system for the built-in battery of the vehicle terminal according to claim 5, characterized in that: The charging circuit includes a third transistor, a fifth resistor and a sixth resistor, one end of the fifth resistor is connected to the source of the charging MOS field effect transistor, and the other end is connected to the collector of the third transistor, one end of the sixth resistor is connected to the gate of the discharging MOS field effect transistor, and the other end is connected to the collector of the third transistor, the base emitter of the third transistor is grounded, and the base of the third transistor is connected to the CP pin of the D trigger.

7. The management system for the built-in battery of the vehicle terminal according to claim 6, characterized in that: The management system of the built-in battery of the vehicle terminal also includes a voltage divider circuit, which includes an isolation diode, a seventh resistor, an eighth resistor and a ninth resistor. The isolation diode and the seventh resistor are connected in series, one end of which is connected to the engine ignition signal KL15, and the other end is connected to the output end of the comparator. The common end of the isolation diode and the seventh resistor is connected to the CP pin of the D trigger, one end of the eighth resistor is connected to the base of the third transistor, and the other end is connected to the CP pin of the D trigger, and one end of the ninth resistor is grounded, and the other end is connected to the base of the third transistor.

8. The management system for the built-in battery of the vehicle terminal according to claim 7, characterized in that: The management system of the built-in battery of the vehicle terminal also includes a pull-down resistor, one end of which is connected to the common end of the base of the first transistor and the D pin of the D trigger, and the other end is connected to VCC.

9. The management system for the built-in battery of the vehicle terminal according to claim 8, characterized in that: The discharging MOS field effect transistor and the charging MOS field effect transistor are both P-channel enhancement type.

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