12V-driven step-down circuit constructed by eight strings of battery packs

Abstract

The utility model discloses a 12V driven step-down circuit constructed by eight strings of battery packs, which relates to the PACK battery pack step-down field, and comprises a main control unit, a step-down unit, an amplification unit and a power supply unit, the input end of the power supply unit is electrically connected with the output end of a lithium battery pack, and the output end of the power supply unit is electrically connected with the output end of the lithium battery pack through a step-down chip arranged in the step-down unit. Voltage adjustment after voltage reduction in different occasions can be realized only through the voltage reduction chip and resistors in a peripheral circuit of the voltage reduction chip, and the voltage reduction efficiency is adjusted; through a main single-chip microcomputer arranged in the main control unit, the circuit has flexibility and programmability, the single-chip microcomputer simulation booster circuit is controlled by the single-chip microcomputer and can be programmed and adjusted according to needs, so that an operator can change parameters and working modes of the booster circuit more flexibly to meet different requirements, and the working efficiency of the booster circuit is improved. Meanwhile, the main single-chip microcomputer is matched with the step-down chip and is provided with an adjusting feedback circuit, so that the stability, adjustability and safety of the step-down circuit are ensured.

Description

Technical Field

[0001] The utility model relates to the field of voltage reduction of a Pack battery pack, and in particular to a voltage reduction circuit for constructing a 12V drive using an eight-string battery pack. Background Art

[0002] With the popularity of electric vehicles, portable devices, etc., there is a growing demand for 12V-driven buck circuits for battery packs. Eight-string battery packs usually output higher voltages, which need to be converted to 12V by a buck circuit for use in specific devices. The buck circuit can stabilize the output voltage, ensure the normal operation of the device, and improve battery utilization. At the same time, a well-designed buck circuit can reduce power consumption and improve system efficiency. Therefore, it is particularly important to build a 12V-driven buck circuit for various application scenarios.

[0003] The existing step-down circuit has high stability requirements and is limited by the specifications and functions of the chip. A dedicated step-down chip is needed to implement a boost circuit for a specific number of batteries. The flexibility is relatively low and the adjustability is not strong enough. Therefore, it is necessary to provide an eight-string battery pack to construct a 12V driven step-down circuit to solve the above-mentioned problems. Utility Model Content

[0004] In order to improve the versatility and step-down efficiency of the solution, the present technical solution solves the problems mentioned above that the existing step-down circuit has high stability requirements and is limited by the specifications and functions of the chip. It needs to use a dedicated step-down chip to implement the boost circuit for a specific number of batteries, which has relatively low flexibility and insufficient adjustability.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A 12V driven buck circuit constructed with an eight-string battery pack includes a main control unit, a buck unit, an amplifying unit and a power supply unit, wherein the input end of the power supply unit is electrically connected to the output end of the lithium battery pack, the output end of the power supply module is electrically connected to the input end of the main single-chip microcomputer in the main control unit, the main single-chip microcomputer, the amplifying unit and the buck chip are all electrically connected to the power supply unit, the power supply end of the buck chip is electrically connected to the output end of the power supply unit, the fourth pin of the buck chip is connected in series with a thirty-fourth resistor and is electrically connected to the thirteenth pin of the main single-chip microcomputer, the thirteenth pin of the main single-chip microcomputer is electrically connected to the thirty-fourth resistor in the buck unit The thirty-third resistor is electrically connected to the base of the fourth transistor, the collector of the fourth transistor is serially connected to the thirty-second resistor and is electrically connected to the gate of the sixth PMOS tube, the drain of the sixth PMOS tube is electrically connected to the anode of the seventh diode, the cathode of the seventh diode is electrically connected to the fifth pin of the buck chip, the sixth pin of the buck chip is electrically connected to the first inductor, one end of the first inductor is serially connected to the thirty-ninth resistor and the seventh resistor and is electrically connected to the third pin of the buck chip, and the third pin of the buck chip is electrically connected between the seventh resistor and the eighth resistor.

[0007] Optionally, a thirty-first resistor is connected in series between the source and the gate of the sixth PMOS tube in the buck chip, a fourth capacitor and a fifth capacitor are electrically connected between the cathode of the seventh diode and the fifth pin of the buck chip, and one end of the fourth capacitor and the fifth capacitor are both grounded.

[0008] Optionally, the third pin of the buck chip is connected in series with an eighth resistor and grounded, the third pin of the buck chip is connected in series with a seventh resistor and a thirty-ninth resistor and then electrically connected to a fourteenth capacitor, and one end of the fourteenth capacitor away from the buck chip is grounded.

[0009] Optionally, an eleventh capacitor is connected in series to the first pin of the main single-chip computer, and one end of the eleventh capacitor away from the main single-chip computer is grounded and electrically connected to the second pin of the main single-chip computer.

[0010] Optionally, the amplifying unit includes a second PMOS tube, a gate of the second PMOS tube is connected in series with an eleventh resistor and is electrically connected to the collector of the first transistor, and an emitter of the first transistor is grounded and connected in series with a fourteenth resistor.

[0011] Optionally, one end of the fourteenth resistor is electrically connected to the base of the first transistor, and the base of the first transistor is connected in series with a fifteenth resistor, and one end of the fifteenth resistor away from the first transistor is electrically connected to the cathodes of the third diode and the second diode.

[0012] Optionally, the anode of the third diode is connected in series with a thirtieth resistor, and the anode of the second diode is electrically connected to the fifteenth pin of the main microcontroller.

[0013] Optionally, the drain of the second PMOS tube is electrically connected to the anode of the first diode, the cathode of the first diode is connected in series with a tenth resistor and is electrically connected to the second pin of the amplifier chip, and the third pin of the amplifier chip is electrically connected to the ninth capacitor.

[0014] Optionally, the source of the second PMOS tube is electrically connected to the cathode of the second voltage stabilizing diode, and the anode of the second voltage stabilizing diode is connected in series with a forty-eighth resistor and is electrically connected to the cathode of the fourth diode.

[0015] Furthermore, the inductance used by the buck chip can be adjusted to adjust the buck efficiency.

[0016] Furthermore, the voltage-reducing chip can be feedback-regulated through an external voltage-dividing resistor.

[0017] Compared with the prior art, the advantages of the utility model are:

[0018] In the 12V driven buck circuit constructed by an eight-string battery pack proposed in this scheme, the buck chip provided in the buck unit can adjust the voltage after bucking in different occasions and adjust the buck efficiency only through the buck chip and the resistors in its peripheral circuit; the main single-chip microcomputer provided in the main control unit makes the circuit flexible and programmable, and the single-chip microcomputer analog boost circuit is controlled by the single-chip microcomputer, which can be programmed and adjusted as needed, so that the operator can more flexibly change the parameters and working mode of the boost circuit to meet different needs. At the same time, the main single-chip microcomputer cooperates with the buck chip to have an adjustment feedback circuit, which ensures the stability, adjustability and safety of the buck circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the voltage reduction unit in the utility model;

[0020] Figure 2 It is a structural schematic diagram of the main control unit in the utility model;

[0021] Figure 3 It is a structural schematic diagram of the amplification unit in the utility model; DETAILED DESCRIPTION

[0022] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0023] See also Figure 1-3As shown, an eight-string battery pack constructs a 12V driven buck circuit, including a main control unit, a buck unit, an amplifying unit and a power supply unit, the input end of the power supply unit is electrically connected to the output end of the lithium battery pack, the output end of the power supply module is electrically connected to the input end of the main single-chip computer U2 in the main control unit, the main single-chip computer U2, the amplifying unit and the buck chip U6 are all electrically connected to the power supply unit, the power supply end of the buck chip U6 is electrically connected to the output end of the power supply unit, the fourth pin EN of the buck chip U6 is connected in series with the thirty-third resistor R34 and is electrically connected to the thirteenth pin AN1 of the main single-chip computer U2, the thirteenth pin AN1 of the main single-chip computer U2 is electrically connected to the thirty-third resistor R33 and the thirty-third resistor R 34, the thirty-third resistor R33 is electrically connected to the base 1 of the fourth triode Q4, the collector 3 of the fourth triode Q4 is connected in series with the thirty-second resistor R32 and is electrically connected to the gate 1 of the sixth PMOS tube Q6, the drain 3 of the sixth PMOS tube Q6 is electrically connected to the anode of the seventh diode D7, the cathode of the seventh diode D7 is electrically connected to the fifth pin VIN of the buck chip U6, the sixth pin SW of the buck chip U6 is electrically connected to the first inductor L1, one end of the first inductor L1 is connected in series with the thirty-ninth resistor R39 and the seventh resistor R7 and is electrically connected to the third pin FB of the buck chip U6, and the third pin FB of the buck chip U6 is electrically connected between the seventh resistor R7 and the eighth resistor R8.

[0024] Specifically, the main microcontroller U2 is connected to the control terminal EN of the buck chip, the logic high level starts the buck chip, and the logic low level enters the low power mode. The power supply terminal VIN of the buck chip U6 is connected to the positive pole of the system's main discharge circuit; the main microcontroller U2 can use SC92F7352, whose operating voltage range is 2.0~5.5V. It is a fully static 8-bit 1T 8051 core CMOS microcontroller, the instruction set is fully compatible with MCS-51, and has a 2-level priority interrupt configuration; the boost chip U6 can use HE9436, which is a buck IC that supports up to 40V input. The HE9436 device is a high-efficiency, synchronous step-down DC / DC regulator. It has a wide input range and is suitable for various applications, such as power regulation from unregulated sources. It has a low RpsoN (250m2 / 150m2 typical) internal switch to achieve maximum efficiency (92% typical). Supporting PSM mode, the operating frequency is fixed at 1.1MHz, allowing the use of small external components while still being able to have low output voltage ripple. With OVP function, it can withstand input voltages up to 40V. HE9436 supports 1.0A continuous output current and has a 0.8V nominal feedback voltage.

[0025] Reference Figure 1As shown, a thirty-first resistor R31 is connected in series between the source 2 and the gate 1 of the sixth PMOS tube Q6 in the buck chip U6, and a fourth capacitor C4 and a fifth capacitor C5 are electrically connected between the cathode of the seventh diode D7 and the fifth pin SW of the buck chip U6, and one end of the fourth capacitor C4 and the fifth capacitor C5 are both grounded. The third pin SW of the buck chip U6 is connected in series with the eighth resistor R8 and grounded, and the third pin SW of the buck chip U6 is connected in series with the seventh resistor R7 and the thirty-ninth resistor R39 and then electrically connected to the fourteenth capacitor C14, and one end of the fourteenth capacitor C14 away from the buck chip U6 is grounded.

[0026] Reference Figure 2 As shown, the first pin VDD of the main single-chip computer U2 is connected in series with the eleventh capacitor C11, and the end of the eleventh capacitor C11 away from the main single-chip computer U2 is grounded and electrically connected to the second pin VSS of the main single-chip computer U2. The IO port of the main single-chip computer U2 is connected to the buck chip U6 and is connected to the fourth transistor Q6 of the sixth PMOS tube Q6 that controls the buck chip U6 power supply terminal EN to be connected to the power input terminal VIN, so that when the control terminal SW is not turned on, the buck chip U6 enters a low power consumption mode, and at the same time, there is no power input to the power supply terminal VIN, thereby fundamentally achieving a zero power consumption mode.

[0027] Reference Figure 2 and Figure 3 As shown, the amplification unit includes a second PMOS transistor Q2, the gate 1 of the second PMOS transistor Q2 is connected in series with an eleventh resistor R11 and is electrically connected to the collector 3 of the first transistor Q1, the emitter 2 of the first transistor Q1 is grounded and connected in series with a fourteenth resistor R14. One end of the fourteenth resistor R14 is electrically connected to the base 1 of the first transistor Q1, and the base 1 of the first transistor Q1 is connected in series with a fifteenth resistor R15, and one end of the fifteenth resistor R15 away from the first transistor Q1 is electrically connected to the cathode of the third diode D3 and the second diode D2. The anode of the third diode D3 is connected in series with a thirtieth resistor R30, and the anode of the second diode D2 is electrically connected to the fifteenth pin AN4 of the main microcontroller U2.

[0028] Reference Figure 3As shown, the drain 3 of the second PMOS tube Q2 is electrically connected to the anode of the first diode D1, the cathode of the first diode D1 is connected in series with the tenth resistor R10 and is electrically connected to the second pin VIN of the amplifier chip U4, and the third pin OUT of the amplifier chip U4 is electrically connected to the ninth capacitor C9. The source 2 of the second PMOS tube Q2 is electrically connected to the cathode of the second voltage zener diode ZD2, and the anode of the second voltage zener diode ZD2 is connected in series with the forty-eighth resistor R48 and is electrically connected to the cathode of the fourth diode D4. The amplifier chip U4 adopts the SE8550 model. The E8550 is a PNP power triode, which is commonly used in applications such as low-frequency power amplification and switching circuits. The SE8550 has a higher current amplification factor and is suitable for applications that require larger current amplification. The SE8550 has a lower voltage drop in the saturation region, which can reduce power loss and heat generation and improve efficiency. The SE8550 has a higher operating frequency characteristic, and its performance is stable and reliable, and its service life is long.

[0029] Working principle and implementation method: When the circuit is running, the input and output ends of the main single-chip computer U2 are connected to the buck chip U6 and the fourth transistor Q6 of the sixth PMOS tube Q6 that controls the buck chip U6 power supply end EN and the power input end VIN, so that when the control end SW is not turned on, the buck chip U6 enters a low power consumption mode, and the buck chip U6 set in the buck unit only needs to adjust the voltage after bucking in different occasions through the buck chip U6 and several resistors and the first inductor L1 in its peripheral circuit to adjust the buck efficiency. The electric energy input by the power supply unit is stored in the first inductor L1 of the inductor element to form a magnetic field energy storage state. The first inductor L1 releases the stored energy, and the magnetic field collapses to generate a reverse electromotive force, so that the output voltage increases. Several filter capacitors in the circuit are used to provide a more stable output voltage and current, while protecting the circuit components from damage by overvoltage and overcurrent.

[0030] It is worth noting that the MCU model in this embodiment is only used to implement this embodiment, and it is not a limitation of the present invention. The two-string battery pack boost circuit proposed in the present invention can be implemented through the common IO port of any MCU. The boost chip of the present invention is a dedicated chip for implementing this embodiment, and the effect cannot be guaranteed if other chips are used.

[0031] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and the specification only describe the principles of the utility model. The utility model may be subject to various changes and improvements without departing from the spirit and scope of the utility model. These changes and improvements fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A 12V drive buck circuit constructed with eight battery packs, characterized in that: The invention comprises a main control unit, a step-down unit, an amplifying unit and a power supply unit, wherein the input end of the power supply unit is electrically connected to the output end of the lithium battery pack, the output end of the power supply unit is electrically connected to the input end of the main single-chip computer in the main control unit, the main single-chip computer, the amplifying unit and the step-down chip are all electrically connected to the power supply unit, the power supply end of the step-down chip is electrically connected to the output end of the power supply unit, the fourth pin of the step-down chip is connected in series with a thirty-fourth resistor and is electrically connected to the thirteenth pin of the main single-chip computer, and the thirteenth pin of the main single-chip computer is electrically connected to the thirty-third resistor and the thirty-fourth resistor in the step-down unit The thirty-third resistor is electrically connected to the base of the fourth transistor, the collector of the fourth transistor is connected in series with the thirty-second resistor and is electrically connected to the gate of the sixth PMOS tube, the drain of the sixth PMOS tube is electrically connected to the anode of the seventh diode, the cathode of the seventh diode is electrically connected to the fifth pin of the buck chip, the sixth pin of the buck chip is electrically connected to the first inductor, one end of the first inductor is connected in series with the thirty-ninth resistor and the seventh resistor and is electrically connected to the third pin of the buck chip, and the third pin of the buck chip is electrically connected between the seventh resistor and the eighth resistor.

2. According to claim 1, a 12V driven step-down circuit constructed by an eight-string battery pack is characterized in that: A thirty-first resistor is connected in series between the source and gate of the sixth PMOS tube in the buck chip, a fourth capacitor and a fifth capacitor are electrically connected between the cathode of the seventh diode and the fifth pin of the buck chip, and one end of the fourth capacitor and the fifth capacitor are both grounded.

3. According to claim 1, a 12V driven step-down circuit constructed by an eight-string battery pack is characterized in that: The third pin of the buck chip is connected in series with the eighth resistor and grounded. The third pin of the buck chip is connected in series with the seventh resistor and the thirty-ninth resistor and then electrically connected to the fourteenth capacitor. One end of the fourteenth capacitor away from the buck chip is grounded.

4. According to claim 1, a 12V driven step-down circuit constructed by an eight-string battery pack is characterized in that: The first pin of the main single-chip computer is connected in series with an eleventh capacitor, and one end of the eleventh capacitor away from the main single-chip computer is grounded and electrically connected to the second pin of the main single-chip computer.

5. According to claim 1, a 12V driven step-down circuit constructed by an eight-string battery pack is characterized in that: The amplifying unit comprises a second PMOS tube, a gate of the second PMOS tube is connected in series with an eleventh resistor and is electrically connected to the collector of the first transistor, and an emitter of the first transistor is grounded and connected in series with a fourteenth resistor.

6. The eight-string battery pack according to claim 5 constructs a 12V driven buck circuit, characterized in that: One end of the fourteenth resistor is electrically connected to the base of the first transistor, and the base of the first transistor is serially connected with a fifteenth resistor, and one end of the fifteenth resistor away from the first transistor is electrically connected to the cathodes of the third diode and the second diode.

7. The eight-string battery pack according to claim 6 constructs a 12V driven buck circuit, characterized in that: The anode of the third diode is connected in series with a thirtieth resistor, and the anode of the second diode is electrically connected to the fifteenth pin of the main single chip computer.

8. The eight-string battery pack according to claim 5 constructs a 12V driven buck circuit, characterized in that: The drain of the second PMOS tube is electrically connected to the anode of the first diode, the cathode of the first diode is connected in series with a tenth resistor and is electrically connected to the second pin of the amplifier chip, and the third pin of the amplifier chip is electrically connected to the ninth capacitor.

9. The eight-string battery pack according to claim 5 constructs a 12V driven buck circuit, characterized in that: The source of the second PMOS tube is electrically connected to the cathode of the second voltage stabilizing diode, and the anode of the second voltage stabilizing diode is serially connected to a forty-eighth resistor and is electrically connected to the cathode of the fourth diode.

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