Circuit for automatically identifying number of battery strings

Abstract

The utility model particularly relates to a circuit capable of automatically identifying the number of battery strings, which comprises an input connector, a detection connector, a charging management circuit and a singlechip U1, and is characterized in that the input connector and the detection connector are respectively connected onto the charging management circuit; the charging management circuit comprises a first field effect transistor Q1, a second field effect transistor Q2, a third field effect transistor Q3, a fourth field effect transistor Q4, a fifth field effect transistor Q5, a sixth field effect transistor Q6 and a charging management chip U2, and a pin 9 of the single chip microcomputer U1 is connected with the resistance voltage division circuit. The beneficial effects of the utility model are that through the voltage value of the battery obtained by the resistor voltage division circuit, the single-chip microcomputer U1 calculates the voltage value, the number of the currently installed battery strings is judged, the single-chip microcomputer U1 adjusts the charging voltage of the charging management circuit, automatically switches the voltage value of the adaptive battery, implements the charging voltage function, and reduces the cost of the circuit board.

Description

Technical Field

[0001] This utility model specifically relates to a circuit for automatically identifying the number of battery cells in a series. Background Technology

[0002] With the advancement of battery technology, utility batteries are becoming increasingly common and their prices are decreasing. However, adjusting the charging cutoff voltage during charging requires the charging management circuit to adapt to the number of batteries connected in series. Currently, the main approach is to use charging management chips with communication configuration interfaces. These chips are generally expensive and require Buck driver circuits, enable logic circuits, LDO circuits, communication interfaces, LED display circuits, and BMS modules, increasing overall manufacturing costs and hindering product adoption. We need a simple solution and circuitry to adapt the number of rechargeable batteries connected in series. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. Therefore, one objective of this invention is to provide a circuit that automatically identifies the number of battery cells in series, enables automatic switching of charging voltage, and reduces circuit board costs.

[0004] According to this utility model, a circuit for automatically identifying the number of battery cells includes an input connector and a detection connector, as well as a charging management circuit and a microcontroller U1. The input connector and the detection connector are respectively connected to the charging management circuit. The charging management circuit includes a first field-effect transistor Q1, a second field-effect transistor Q2, a third field-effect transistor Q3, a fourth field-effect transistor Q4, a fifth field-effect transistor Q5, and a sixth field-effect transistor Q6, and a charging management chip U2. Pin 16 of the microcontroller U1 is connected to the base of the first field-effect transistor Q1. The collector of the first field-effect transistor Q1 is connected to the base of the second field-effect transistor Q2 and the base of the third field-effect transistor Q3. The third field-effect transistor Q3... The collector of the microcontroller is connected to pin 9 of the charging management chip U2. Pin 10 of the charging management chip U2 is connected to the base of the fourth field-effect transistor Q4. The emitter of the fourth field-effect transistor Q4 is connected to the collector of the third field-effect transistor Q3. The detection connector is connected to the collector of the fourth field-effect transistor Q4. Pin 6 of the charging management chip U2 is connected to the collectors of the fifth field-effect transistor Q5 and the sixth field-effect transistor Q6. Pin 2 of the microcontroller U1 is connected to the base of the fifth field-effect transistor Q5. Pin 7 of the microcontroller U1 is connected to the base of the sixth field-effect transistor Q6. Pin 14 of the microcontroller U1 is connected to pin 3 of the charging management chip U2. Pin 9 of the microcontroller U1 is connected to a resistor voltage divider circuit.

[0005] Specifically, the input connector includes a first connector J1 and a second connector J2; the detection connector includes a third positive connector J3 and a fourth negative connector J4. Pin 16 of the microcontroller U1 is connected to the base of the first field-effect transistor Q1 through a first resistor R1. The first resistor R1 is connected to a second resistor R2, which is connected to the first connector J1. The second connector J2 is connected to the collector of the second field-effect transistor Q2. A sixth capacitor C6 and a second electrolytic capacitor EC2 are provided between the third positive connector J3 and the fourth negative connector J4. The sixth capacitor C6 and the second electrolytic capacitor EC2 are connected in parallel. One common terminal of the sixth capacitor C6 and the second electrolytic capacitor EC2 is connected to the third positive connector J3, and the other common terminal of the sixth capacitor C6 and the second electrolytic capacitor EC2 is connected to the fourth negative connector J4. The other common terminal of the sixth capacitor C6 and the second electrolytic capacitor EC2 is also connected to the ground wire GND.

[0006] Specifically, the resistor divider circuit includes a sixteenth resistor R16, a fifteenth resistor R15, a ninth capacitor C9, a Zener diode ZD2, and a BAT-V terminal. The sixteenth resistor R16 and the fifteenth resistor R15 are connected in series, the ninth capacitor C9 and the Zener diode ZD2 are connected in parallel, one end of the ninth capacitor C9 and the Zener diode ZD2 are connected to the other end of the fifteenth resistor R15, and the other end of the ninth capacitor C9 and the Zener diode ZD2 are connected to the BAT-V terminal.

[0007] Specifically, pin 6 of the charging management chip U2 is connected to the collector of the fifth field-effect transistor Q5 through a ninth resistor R9, and the collector of the sixth field-effect transistor Q6 is connected to pin 6 of the charging management chip U2 through a tenth resistor R10.

[0008] Specifically, the collector of the fifth field-effect transistor Q5 is connected to pin 2 of the microcontroller U1 through an eleventh resistor R11, and pin 7 of the microcontroller U1 is connected to the base of the sixth field-effect transistor Q6 through a thirteenth resistor R13.

[0009] Specifically, the collector of the fourth field-effect transistor Q4 is connected to the third positive terminal J3 through an inductor L1, and the inductor L1 is connected to a sixth resistor R6.

[0010] The beneficial effects of this utility model are as follows: This circuit obtains the battery voltage value through a resistor voltage divider circuit, the microcontroller U1 calculates the voltage value, determines the number of battery cells currently installed, and coordinates with the microcontroller U1 to adjust the charging voltage of the charging management circuit, automatically switching to the appropriate battery voltage value to implement the charging voltage function; in addition, the combination of the resistor voltage divider circuit, the microcontroller U1, and the charging management circuit further reduces the number of circuits, thereby reducing manufacturing costs. Attached Figure Description

[0011] The above and / or additional aspects and advantages of this invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings.

[0012] Figure 1 This is the charging management circuit diagram of this utility model.

[0013] Figure 2 This is a schematic diagram of the microcontroller of this utility model.

[0014] Figure 3 This is the resistor voltage divider circuit diagram of this utility model. Detailed Implementation

[0015] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0016] The following is for reference. Figures 1 to 3 The present invention describes a circuit for automatically identifying the number of battery cells according to an embodiment of the present invention, and the method based thereon is as follows.

[0017] Step 1: Detect the current battery voltage using a resistor divider circuit.

[0018] Step 2: The voltage value of the battery is obtained by the resistor voltage divider circuit and fed back to the microcontroller U1. The microcontroller U1 calculates the voltage value and determines the number of battery cells currently installed.

[0019] Step 3: The microcontroller U1 adjusts the charging voltage of the charging management circuit according to the battery voltage value.

[0020] Specifically, the FB pin of the charging management chip U2 monitors and detects the peak voltage of the connector.

[0021] This method obtains the battery voltage value through a resistor voltage divider circuit, feeds the voltage value back to the microcontroller U1, calculates the voltage value, determines the number of battery cells currently installed, and realizes automatic switching to adapt to the battery voltage value, implementing the charging voltage function and reducing the cost of the circuit board.

[0022] Specifically: This circuit connects to a resistor voltage divider circuit (such as...) via the BAT-V pin of the microcontroller U1. Figure 3Connect the BAT-V terminal of the circuit (as shown) to the detection connector on the charging management circuit using the BAT+ terminal of the resistor voltage divider circuit. This detects the battery voltage and feeds the battery voltage value obtained by the resistor voltage divider circuit back to the microcontroller U1. The microcontroller U1 calculates the battery voltage value to determine the number of battery cells (e.g., this circuit can be configured to be compatible with 3-cell and 5-cell batteries). Based on the battery voltage value, the microcontroller U1 adjusts the charging voltage of the charging management circuit to charge the battery.

[0023] The charging voltage adjustment is achieved by using the microcontroller U1 to adjust the resistance values ​​of the ninth sampling resistor R9 and the tenth sampling resistor R10 on the charging management circuit, thereby adjusting the battery charging cut-off voltage setting. Specifically, by using the high-level output of the microcontroller's BAT-1-CN terminal and / or BAT-2-CN terminal, the collectors of the fifth and sixth field-effect transistors Q5 and Q are controlled to conduct to ground (GND), thus adjusting the resistance values ​​of the ninth and tenth sampling resistors R9 and R10. Combined with another seventh resistor R7, various resistance values ​​are applied to change the resistance of the FB pin of the charging management chip U2 to ground, further altering the battery voltage when the FB pin of the charging management chip U2 reaches 1.25V, thereby achieving different charging cut-off voltages.

[0024] The resistor divider circuit is used to determine whether it is compatible with three-cell or five-cell batteries. The voltage range for three-cell batteries is 9V-12.6V, and the voltage range for five-cell batteries is 15-21V.

[0025] If the battery voltage is greater than 13.5V before charging, it can be determined that it is a five-cell battery configuration. If the battery voltage is lower than 13V, it can be determined that it is a three-cell battery configuration. After the resistor divider circuit determines whether it is a three-cell or five-cell battery configuration, the FB pin of the charging management chip U2 is the full charge detection pin. The principle is that when the voltage on this pin reaches 1.25V, the system determines that the battery is fully charged. Additionally, the charging management chip U2 is model CN3765; the microcontroller U1 is model SC92F73A1.

[0026] Specifically, the STATE pin of the microcontroller U1 changes the clock frequency and voltage of the charging management chip U2, and controls the sleep state of the charging management chip U2. The STATE pin of the microcontroller U1 can be divided into a running state and a stopped state. In the running state, the microcontroller can execute various instructions and complete various tasks. In the stopped state, the microcontroller pauses the execution of instructions and waits for the next startup. The switching between the running state and the stopped state is completed by the internal control circuit and instruction control of the microcontroller.

[0027] The state pin of microcontroller U1 can be divided into working state and sleep state. In working state, microcontroller U1 is in normal working condition, executing various instructions and completing various tasks. In sleep state, microcontroller U1 controls the charging management chip U2 of the charging management circuit to enter a low-power mode to reduce energy consumption.

[0028] This utility model discloses a circuit for automatically identifying the number of battery cells in series. It includes an input connector and a detection connector, as well as a charging management circuit and a microcontroller U1. The input connector and the detection connector are respectively connected to the charging management circuit. The charging management circuit includes a first field-effect transistor Q1, a second field-effect transistor Q2, a third field-effect transistor Q3, a fourth field-effect transistor Q4, a fifth field-effect transistor Q5, and a sixth field-effect transistor Q6, and a charging management chip U2. Pin 16 of the microcontroller U1 is connected to the base of the first field-effect transistor Q1, and the collector of the first field-effect transistor Q1 is connected to the second field-effect transistor Q2. The base of the first field-effect transistor Q1 is connected to the base of the third field-effect transistor Q3. Pin 16 of the microcontroller U1 controls the conduction or disconnection of the first field-effect transistor Q1, and performs the conduction or disconnection of the second field-effect transistor Q2 and the third field-effect transistor Q3, thus completing the front-end voltage input of the input connector. One voltage is input to pin 9 of the charging management chip U2 to provide voltage to the charging management chip U2, so that the charging management chip U2 is in standby mode or in working mode. In addition, a +3.6V DC voltage is input to pin 1 of the microcontroller U1, so that the microcontroller U1 is in working mode and controls the usage status of the charging management circuit.

[0029] The collector of the third field-effect transistor Q3 is connected to pin 9 of the charging management chip U2. Pin 10 of the charging management chip U2 is connected to the base of the fourth field-effect transistor Q4. The emitter of the fourth field-effect transistor Q4 is connected to the collector of the third field-effect transistor Q3. When the third field-effect transistor Q3 is turned on, the voltage supplied to the charging management chip U2 also supplies power to the fourth field-effect transistor Q4. When the fourth field-effect transistor Q4 is turned on, it needs to be supplied with power from pin 10 of the charging management chip U2 to turn on. The detection connector is connected to the collector of the fourth field-effect transistor Q4, and the voltage enters the detection connector to implement the charging effect on the battery.

[0030] Pin 6 of the charging management chip U2 is connected to the collectors of the fifth MOSFET Q5 and the sixth MOSFET Q6, respectively. Pin 2 of the microcontroller U1 is connected to the base of the fifth MOSFET Q5, pin 7 of the microcontroller U1 is connected to the base of the sixth MOSFET Q6, pin 14 of the microcontroller U1 is connected to pin 3 of the charging management chip U2, and pin 9 of the microcontroller U1 is connected to a resistor voltage divider circuit, which detects the battery voltage. The charging voltage is adjusted by the microcontroller U1 adjusting the resistance values ​​of the ninth sampling resistor R9 and the tenth sampling resistor R10 on the charging management circuit, thereby adjusting the battery charging cutoff voltage setting. Specifically, by using the high-level output of the microcontroller's BAT-1-CN pin and / or BAT-2-CN pins, the collectors of the fifth and sixth field-effect transistors Q5 and Q6 are controlled to connect to ground (GND). This allows adjustment of the resistance values ​​of the ninth and tenth sampling resistors R9 and R10, combined with another seventh resistor R7, to change the resistance of the FB pin of the charging management chip U2 to ground. This further alters the battery voltage when the FB pin of the charging management chip U2 reaches 1.25V, thus achieving different charging cutoff voltages.

[0031] Specifically, the input connector includes a first connector J1 and a second connector J2; the detection connector includes a third positive connector J3 and a fourth negative connector J4. Pin 16 of the microcontroller U1 is connected to the base of the first field-effect transistor Q1 via a first resistor R1. The first resistor R1 is connected to a second resistor R2, which is connected to the first connector J1. The second connector J2 is connected to the collector of the second field-effect transistor Q2. A sixth capacitor C6 and a second electrolytic capacitor EC2 are located between the third positive connector J3 and the fourth negative connector J4. The sixth capacitor C6 and the second electrolytic capacitor EC2 are connected in parallel. One common terminal of the sixth capacitor C6 and the second electrolytic capacitor EC2 is connected to the third positive connector J3, and the other common terminal of the sixth capacitor C6 and the second electrolytic capacitor EC2 is connected to the fourth negative connector J4. The other common terminal of the sixth capacitor C6 and the second electrolytic capacitor EC2 is also connected to ground (GND). The combination of the sixth capacitor C6 and the second electrolytic capacitor EC2 is used to stabilize the charging voltage. Figure 1 As shown, a sixth resistor R6 is provided between inductor L1 and the third positive terminal J3. A line is drawn from the common terminal between the sixth resistor R6 and the third positive terminal J3 and input to pins 6 and 7 of the charging management chip U2 respectively. Pin 7 of the charging management chip U2 is used to record the voltage flowing through the sixth resistor R6, and this voltage value is used as the initial base voltage value. A seventh resistor R7 is connected in parallel between pins 6 and 7 of the charging management chip U2. Pin 7 of the charging management chip U2 is used to determine the cutoff voltage value.

[0032] Specifically, the resistor divider circuit includes a sixteenth resistor R16, a fifteenth resistor R15, a ninth capacitor C9, a Zener diode ZD2, and a BAT-V terminal. The sixteenth resistor R16 and the fifteenth resistor R15 are connected in series, and the ninth capacitor C9 and the Zener diode ZD2 are connected in parallel. One common terminal of the ninth capacitor C9 and the Zener diode ZD2 is connected to the other end of the fifteenth resistor R15, and the other common terminal of the ninth capacitor C9 and the Zener diode ZD2 is connected to the BAT-V terminal. The ninth capacitor C9 and the Zener diode ZD2 increase the capacitance, thus stabilizing the voltage. The combination of the sixteenth resistor R16 and the fifteenth resistor R15 limits the voltage, preventing excessive voltage from damaging the microcontroller U1.

[0033] Specifically, pin 6 of the charging management chip U2 is connected to the collector of the fifth field-effect transistor Q5 via a ninth resistor R9, and the collector of the sixth field-effect transistor Q6 is connected to pin 6 of the charging management chip U2 via a tenth resistor R10. The ninth and tenth resistors R9 and R10 are used to adjust the voltage value, and are controlled by the on / off state of the fifth and sixth field-effect transistors Q5 and Q6. The eleventh resistor R11 is used to protect the fifth field-effect transistor Q5; similarly, the thirteenth resistor R13 is used to protect the sixth field-effect transistor Q6.

[0034] Specifically, the collector of the fifth field-effect transistor Q5 is connected to pin 2 of the microcontroller U1 via an eleventh resistor R11, and pin 7 of the microcontroller U1 is connected to the base of the sixth field-effect transistor Q6 via a thirteenth resistor R13. The collector of the fourth field-effect transistor Q4 is connected to the third positive terminal J3 via an inductor L1, which is connected to a sixth resistor R6. The inductor L1, connected to the collector of the fourth field-effect transistor Q4, has the ability to convert energy into magnetic energy for storage and release, reducing DC resistance and altering DC superposition characteristics.

[0035] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A circuit for automatically identifying the number of battery cells in a series, comprising an input connector and a detection connector, characterized in that: It also includes a charging management circuit and a microcontroller U1. The input connector and the detection connector are respectively connected to the charging management circuit. The charging management circuit includes a first field-effect transistor Q1, a second field-effect transistor Q2, a third field-effect transistor Q3, a fourth field-effect transistor Q4, a fifth field-effect transistor Q5, and a sixth field-effect transistor Q6, and a charging management chip U2. Pin 16 of the microcontroller U1 is connected to the base of the first field-effect transistor Q1. The collector of the first field-effect transistor Q1 is connected to the bases of the second field-effect transistor Q2 and the third field-effect transistor Q3, respectively. The collector of the third field-effect transistor Q3 is connected to pin 9 of the charging management chip U2. Pin 10 of the charging management chip U2 is connected to the base of the fourth field-effect transistor Q4. The emitter of the fourth field-effect transistor Q4 is connected to the collector of the third field-effect transistor Q3. The detection connector is connected to the collector of the fourth field-effect transistor Q4. Pin 6 of the charging management chip U2 is connected to the collectors of the fifth field-effect transistor Q5 and the sixth field-effect transistor Q6. Pin 2 of the microcontroller U1 is connected to the base of the fifth field-effect transistor Q5. Pin 7 of the microcontroller U1 is connected to the base of the sixth field-effect transistor Q6. Pin 14 of the microcontroller U1 is connected to pin 3 of the charging management chip U2. Pin 9 of the microcontroller U1 is connected to the resistor voltage divider circuit.

2. The circuit for automatically identifying the number of battery cells according to claim 1, characterized in that: The input connectors include a first connector J1 and a second connector J2; the detection connectors include a third positive connector J3 and a fourth negative connector J4. Pin 16 of the microcontroller U1 is connected to the base of the first field-effect transistor Q1 via a first resistor R1. The first resistor R1 is connected to a second resistor R2, which is connected to the first connector J1. The second connector J2 is connected to the collector of the second field-effect transistor Q2. A sixth capacitor C6 and a second electrolytic capacitor EC2 are located between the third positive connector J3 and the fourth negative connector J4. The sixth capacitor C6 and the second electrolytic capacitor EC2 are connected in parallel. One common terminal of the sixth capacitor C6 and the second electrolytic capacitor EC2 is connected to the third positive connector J3, and the other common terminal of the sixth capacitor C6 and the second electrolytic capacitor EC2 is connected to the fourth negative connector J4. The other common terminal of the sixth capacitor C6 and the second electrolytic capacitor EC2 is also connected to the ground wire GND.

3. The circuit for automatically identifying the number of battery cells according to claim 1, characterized in that: The resistor divider circuit includes a sixteenth resistor R16, a fifteenth resistor R15, a ninth capacitor C9, a Zener diode ZD2, and a BAT-V terminal. The sixteenth resistor R16 and the fifteenth resistor R15 are connected in series, the ninth capacitor C9 and the Zener diode ZD2 are connected in parallel, one end of the ninth capacitor C9 and the Zener diode ZD2 is connected to the other end of the fifteenth resistor R15, and the other end of the ninth capacitor C9 and the Zener diode ZD2 is connected to the BAT-V terminal.

4. The circuit for automatically identifying the number of battery cells according to claim 1, characterized in that: The sixth pin of the charging management chip U2 is connected to the collector of the fifth field-effect transistor Q5 through the ninth resistor R9, and the collector of the sixth field-effect transistor Q6 is connected to the sixth pin of the charging management chip U2 through the tenth resistor R10.

5. The circuit for automatically identifying the number of battery cells according to claim 1, characterized in that: The collector of the fifth field-effect transistor Q5 is connected to pin 2 of the microcontroller U1 through the eleventh resistor R11, and pin 7 of the microcontroller U1 is connected to the base of the sixth field-effect transistor Q6 through the thirteenth resistor R13.

6. The circuit for automatically identifying the number of battery cells according to claim 1, characterized in that: The collector of the fourth field-effect transistor Q4 is connected to the third positive terminal J3 through an inductor L1, and the inductor L1 is connected to a sixth resistor R6.

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