An automobile emergency starting and charging power supply circuit

Abstract

The utility model relates to emergency starting power supply technical field discloses a kind of automobile emergency starting charging power supply circuit with starting and charging function, including the input detection circuit (110) for detecting first current signal, the output detection circuit (140) for detecting second current signal, voltage conversion circuit (130) and main control circuit (200), wherein, main control circuit (200) outputs at least two paths PWM pulse signal, and main control circuit (200) adjusts the level state of output PWM pulse signal according to first current signal or second current signal, to control voltage conversion circuit (130) step-down output or step-up output, power supply to load.

Description

Technical Field

[0001] This utility model relates to the field of emergency starter power supply technology, and more specifically, to a power supply circuit for emergency starter charging of automobiles. Background Technology

[0002] Most common car jump starters on the market use dedicated lithium battery packs as their energy source, which suffers from high cost, large size, inconvenience in carrying, and a relatively high failure rate. Especially during use, if the battery cell's discharge capacity is insufficient or the overcurrent capacity of the charge / discharge protection switch is too low, the large current surge required for car starting can easily lead to insufficient battery cell output and damage to the MOSFET, affecting the reliability and lifespan of the device. Utility Model Content

[0003] The technical problem to be solved by this utility model is to address the shortcomings of the prior art, such as insufficient discharge capacity of the battery cell or low overcurrent capacity of the charge and discharge protection switch, which can easily lead to insufficient battery cell output and damage to the MOSFET under the large current impact required for car starting. This utility model provides a power supply circuit for emergency car starting and charging with starting and charging functions.

[0004] The technical solution adopted by this utility model to solve its technical problem is: to construct a power supply circuit for emergency starting and charging of automobiles, which includes: An input detection circuit, which is configured on the input side of the power supply circuit, is used to detect the first current signal at the input terminal; A voltage conversion circuit, whose power input terminal is connected to the output terminal of the input detection circuit, is used to receive the voltage signal flowing through the input detection circuit; an output detection circuit, whose input terminal is connected to the output terminal of the voltage conversion circuit, is used to detect the second current signal output by the voltage conversion circuit. The main control circuit has its first set of detection terminals connected to both ends of the input detection circuit to acquire the first current signal. The second set of detection terminals of the main control circuit is connected to both ends of the output detection circuit to acquire the second current signal. The signal output terminals of the main control circuit are connected to the signal input terminals of the voltage conversion circuit, respectively, for outputting at least two PWM pulse signals. The main control circuit adjusts the level of the output PWM pulse signal according to the first current signal or the second current signal to control the voltage conversion circuit to output a step-down or step-up voltage to supply power to the load.

[0005] In some embodiments, the main control circuit includes at least a main controller and an output voltage regulation feedback circuit. The first set of detection terminals of the main controller is connected to both ends of the input detection circuit to acquire the first current signal. The second set of detection terminals of the main controller is connected to both ends of the output detection circuit to acquire the second current signal. The signal output terminals of the main controller are connected to the signal input terminals of the voltage conversion circuit, respectively, for outputting at least two PWM pulse signals. One end of the voltage regulation feedback circuit is connected to one end of the load, and is used to obtain the voltage value of the load. The other end of the voltage regulation feedback circuit is connected to the feedback terminal of the main controller. The main controller adjusts the duty cycle of the output PWM pulse signal based on the feedback voltage value, and controls the voltage signal output by the voltage conversion circuit to adapt to the voltage requirements of different batteries.

[0006] In some embodiments, the output voltage regulation feedback circuit includes a twentieth resistor and a twenty-fourth resistor connected in series. One end of the twentieth resistor is connected to one end of the load to obtain the voltage value. The other end of the twentieth resistor and one end of the twenty-fourth resistor are respectively connected to the feedback terminal of the main controller. The other end of the 24th resistor is connected to the common terminal.

[0007] In some embodiments, the voltage conversion circuit includes at least a first switching module, a first inductor, and a second switching module. The input terminal of the first switch module is coupled to the output terminal of the input detection circuit. The output terminal of the first switch module is connected to one end of the first inductor. The input terminal of the second switching module is coupled to the other end of the first inductor. The output terminal of the second switching module is connected to one end of the load. The signal input terminals of the first switching module are respectively connected to a set of signal output terminals of the main controller to receive the PWM pulse signals. The signal input terminal of the second switching module is connected to another set of signal output terminals of the main controller to receive the PWM pulse signal.

[0008] In some embodiments, the first switching module includes a first MOSFET and a second MOSFET. The drain of the first MOS transistor is connected to the output terminal of the input detection circuit. The gate of the first MOS transistor is connected to the first signal output terminal of the main controller. The gate of the second MOS transistor is connected to the second signal output terminal of the main controller. The source of the first MOSFET and the drain of the second MOSFET are connected to one end of the first inductor. The source of the second MOSFET is connected to the common terminal.

[0009] In some embodiments, the second switching module includes a third MOSFET and a fourth MOSFET. The drain of the third MOS transistor is connected to the input terminal of the output detection circuit. The gate of the third MOS transistor is connected to the third signal output terminal of the main controller. The gate of the fourth MOS transistor is connected to the fourth signal output terminal of the main controller. The source of the third MOS transistor and the drain of the fourth MOS transistor are connected to the other end of the first inductor. The source of the fourth MOS transistor is connected to the common terminal.

[0010] In some embodiments, the first MOSFET, the second MOSFET, the third MOSFET, and the fourth MOSFET are selected as N-channel enhancement-mode MOSFETs.

[0011] In some implementations, input filtering and overcurrent protection circuitry are also included, with the input terminal connected to an external power supply. The output terminal of the input filtering and overcurrent protection circuit is connected to the input terminal of the input detection circuit and an input terminal of the main control circuit.

[0012] The power supply circuit for emergency car start-up charging according to this invention includes an input detection circuit for detecting a first current signal, an output detection circuit for detecting a second current signal, a voltage conversion circuit, and a main control circuit. The main control circuit outputs at least two PWM pulse signals. The main control circuit adjusts the level of the output PWM pulse signals according to the first or second current signal to control the voltage conversion circuit to output a step-down or step-up voltage signal to supply power to the load. Compared with existing technologies, the main control circuit adjusts the level of the output PWM pulse signals according to the first and second current signals to control the voltage conversion circuit to output a step-down or step-up voltage signal, achieving adaptive switching over a wide voltage range to adapt to different battery voltage requirements. On the other hand, by detecting the current in real time through the input / output detection circuit, the main control circuit can achieve cycle-by-cycle current limiting and fast short-circuit protection, effectively preventing device damage caused by excessive starting current or output short circuit. Attached Figure Description

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a circuit diagram of an embodiment of the detection and conversion circuit provided by this utility model; Figure 2 This is a circuit schematic diagram of an embodiment of the main control circuit provided by this utility model. Detailed Implementation

[0014] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0015] like Figures 1-2 As shown, in the first embodiment of the power supply circuit for emergency car start-up charging of this utility model, the power supply circuit for emergency car start-up charging includes a detection and conversion circuit 100 and a main control circuit 200. The detection and conversion circuit 100 is used to receive external power, boost or increase the voltage of the input power, and feed back the input or output current signal to the main control circuit 200. The main control circuit 200 can output multiple PWM pulse signals according to the current signal and adjust the level / duty cycle of the PWM pulse signal to control the detection and conversion circuit 100 to boost or buck the output voltage signal to adapt to the voltage requirements of different batteries / loads. The detection and conversion circuit 100 includes an input filtering and overcurrent protection circuit 110, an input detection circuit 120, a voltage conversion circuit 130, and an output detection circuit 140. The input filtering and overcurrent protection circuit 110 has the functions of energy storage, buffering, high-frequency decoupling and noise short circuit protection; The input detection circuit 120 is used to acquire the current signal output by the input filtering and overcurrent protection circuit 110, and output the current signal to the main control circuit 200. Among them, the input detection circuit 120 is the detection resistor RCS2; The voltage conversion circuit 130 has the function of buck output and boost output, and can realize bidirectional voltage conversion; The output detection circuit 140 is used to acquire the current signal output by the voltage conversion circuit 130 and output the current signal to the main control circuit 200. Among them, the output detection circuit 140 is the detection resistor RCS1; The main control circuit 200 has the functions of logic operation, signal reception / comparison, output of multiple PWM pulse signals, and adjustment of the level and duty cycle of the PWM pulse signals; The main control circuit 200 includes at least a main controller U1 and an output voltage regulation feedback circuit 210. The main controller U1 has the functions of logic operation, signal reception / comparison, output of multiple PWM pulse signals, and adjustment of the level and duty cycle of the PWM pulse signals; The output voltage regulation feedback circuit 210 is used to obtain the voltage value of the load and feed the voltage value back to the main controller U1; Specifically, the input terminal of the input filtering and overcurrent protection circuit 110 is connected to the external power supply terminal (corresponding to VIN+) to receive the external input voltage signal and perform voltage regulation and filtering on the input voltage signal. The output terminal of the input filtering and overcurrent protection circuit 110 is connected to the input terminal of the input detection circuit 120 and an input terminal of the main control circuit 200, respectively, and outputs the voltage signal after voltage regulation and filtering to the input detection circuit 120 and the main control circuit 200. Furthermore, the input terminal of the input detection circuit 120 is connected to the output terminal of the input filtering and overcurrent protection circuit 110, and is used to detect the first current signal input to the input filtering and overcurrent protection circuit 110, and output the first current signal to the main control circuit 200. Furthermore, the power input terminal of the voltage conversion circuit 130 is connected to the output terminal of the input detection circuit 120 to receive the voltage signal flowing through the input detection circuit 120, perform boost or buck processing on the input voltage signal, and then output it to the output detection circuit 140; furthermore, the input terminal of the output detection circuit 140 is connected to the output terminal of the voltage conversion circuit 130 to detect the second current signal output by the voltage conversion circuit 130 and output the second current signal to the main control circuit 200; Specifically, the first set of detection terminals of the main control circuit 200 is connected to both ends of the input detection circuit 120 to acquire the first current signal; the second set of detection terminals of the main control circuit 200 is connected to both ends of the output detection circuit 140 to acquire the second current signal. Furthermore, the signal output terminal of the main control circuit 200 is connected to the signal input terminal of the voltage conversion circuit 130 respectively, and is used to output at least two PWM pulse signals. The PWM pulse signals are used to control the working state of the voltage conversion circuit 130. The main control circuit 200 adjusts the level of the output PWM pulse signal according to the first current signal or the second current signal to control the voltage conversion circuit 130 to output a step-down or step-up voltage to supply power to the load.

[0016] For example: Input average current signal limit: The main control circuit 200 compares the amplified first current signal with a preset value or threshold. If the first current signal is greater than the preset value or threshold, it indicates that the average input current is too large. The main control circuit 200 will reduce the duty cycle of the PWM pulse signal for power conversion, thereby limiting the input power and protecting the front-end power tool battery from overload discharge. Input peak current limiting / cycle-by-cycle current limiting: The main control circuit 200 monitors the current during each switching cycle. Once a current spike is detected that exceeds the threshold, the currently conducting switch is immediately turned off (within hundreds of nanoseconds) to prevent core saturation and MOSFET overcurrent damage. Output average current signal limiting / constant current mode: When a car battery is severely depleted, it attempts to draw a large current. The main control circuit 200 obtains the voltage across the output detection circuit 140 to ensure that the output current does not exceed the set value. Once the set value is reached, the main control circuit 200 adjusts the duty cycle of the output PWM pulse signal accordingly, controlling the voltage conversion circuit 130 to enter the constant current charging mode to maintain a constant current. At the same time, the voltage may be lower than the set value to adapt to the charging needs of batteries of different models such as cars and trucks.

[0017] Using this technical solution, the main control circuit adjusts the level of the output PWM pulse signal according to the first current signal and the second current signal to control the voltage conversion circuit to output a step-down or step-up voltage signal, thereby achieving adaptive conversion over a wide voltage range to adapt to different battery voltage requirements. On the other hand, by detecting the current in real time through the input / output detection circuit, the main control circuit can achieve cycle-by-cycle current limiting and fast short-circuit protection, effectively preventing device damage caused by excessive starting current or output short circuit.

[0018] In some implementations, such as Figure 2 As shown, the main control circuit 200 includes at least a main controller U1 and an output voltage regulation feedback circuit 210. The main controller U1 is equipped with preset values / thresholds and features current protection, cycle-by-cycle peak current limiting, input / output average current limiting, and short-circuit protection (OSP). Voltage protection includes input undervoltage (UVLO), input overvoltage (OVP), and output overvoltage (OVP). The functions of temperature protection over-temperature shutdown and thermal regulation loop (automatic load reduction when temperature exceeds the limit); and It can output multiple PWM pulse signals; The output voltage regulation feedback circuit 210 is used to obtain the voltage value at the load end and feed the voltage value back to the main controller U1; Specifically, the first set of detection terminals of the main controller U1 (corresponding to pins 26 and 27) are connected to the two ends of the input detection circuit 120 respectively to obtain the first current signal. The main controller U1 continuously reads the induced voltage / current signal at both ends of the input detection circuit 120 and compares it with a preset current limit threshold voltage (V-threshold). This threshold can be fixed by the main controller U1 or can be set by programming through an external resistor. The second set of detection terminals of the main controller U1 (corresponding to pins 13 and 14) are connected to the two ends of the output detection circuit 140 respectively to obtain the second current signal. The main controller U1 continuously reads the induced voltage / current signal at both ends of the output detection circuit 140 and compares it with a preset current limit threshold voltage (V-threshold). This threshold can be fixed by the main controller U1 or can be set by programming through an external resistor. One signal terminal (corresponding to pin 25) of the main controller U1 is connected to the output terminal of the input filtering and overcurrent protection circuit 110 through the 80th resistor R80, and is used to receive voltage signals; The signal output terminals of the main controller U1 (corresponding to pins 21, 24, 16, and 19) are connected to the signal input terminals of the voltage conversion circuit 130, respectively. The main controller U1 can output at least two PWM pulse signals and adjust the duty cycle based on the comparison result of the first current signal / second current signal and the preset value. One end of the voltage regulation feedback circuit 210 is connected to one end of the load to obtain the voltage value of the load. The other end of the voltage regulation feedback circuit 210 is connected to the feedback terminal (corresponding to pin 12) of the main controller U1, and outputs the voltage value to the main controller U1. The main controller U1 adjusts the duty cycle of the output PWM pulse signal according to the feedback voltage value, and controls the voltage signal output by the voltage conversion circuit 130 to adapt to the voltage requirements of different batteries.

[0019] In some implementations, such as Figure 2 As shown, the output voltage regulation feedback circuit 210 includes a twentieth resistor R20 and a twenty-fourth resistor R24 ​​connected in series. One end of the twentieth resistor R20 is connected to one end of the load to obtain the voltage value. The other end of the twentieth resistor R20 and one end of the twenty-fourth resistor R24 ​​are respectively connected to the feedback terminal (corresponding to pin 12) of the main controller U1. The other end of the twenty-fourth resistor R24 ​​is connected to the common terminal.

[0020] Specifically, the voltage value at the load end is acquired through the twentieth resistor R20 and the twenty-fourth resistor R24, and is fed back to the main controller U1 after voltage division. The FB2 pin of the main controller U1 continuously "monitors" the midpoint voltage V-FB (voltage value) from the feedback voltage divider network (the twentieth resistor R20 and the twenty-fourth resistor R24). This V-FB is the "miniature" or "report" of the current actual output voltage Vout-actual, and the input voltage value is compared by the error amplifier inside the main controller U1 (with a reference voltage V-REF, usually 0.8V); If V-FB < V-REF → it means that the output voltage is on the low side; If V-FB > V-REF → it means that the output voltage is on the high side; If V-FB = V-REF → it means that the output voltage is exactly correct, and the circuit is in a balanced state; When the main controller U1 determines that the output voltage is on the low side, the control logic will increase the on-time (duty cycle) of the switching tubes (corresponding to Q2, Q3, Q6, Q7) of the voltage conversion circuit 130, and command the power stage to acquire more energy from the input end and transmit it to the output end; When the main controller U1 determines that the output voltage is on the high side, the control logic will reduce the on-time (duty cycle) of the switching tubes, reduce the energy transmitted to the output end, and by adjusting the energy transmission, the final actual output voltage Vout-actual will approach the set Vout-target, realizing the precise regulation of "beginning with the end in mind".

[0021] In some embodiments, as shown in Figure 1 , the voltage conversion circuit 130 at least includes a first switching module 131, a first inductor L1 and a second switching module 132, wherein, the first inductor L1 is used for energy storage and filtering. During the step-up / step-down voltage conversion process, the inductor stores energy when there is surplus energy, and releases the previously stored energy when outputting energy, so as to improve the efficiency of power conversion; Specifically, the input end of the first switching module 131 is coupled to the output end of the input detection circuit 120, and is configured to receive the voltage signal input by the input detection circuit 120, and perform step-up / step-down processing on the input voltage signal; The output end of the first switching module 131 is connected to one end of the first inductor L1, The input end of the second switching module 132 is coupled to the other end of the first inductor L1, and the voltage signal output by the first switching module 131 is input to the second switching module 132 through the first inductor L1, The output end of the second switching module 132 is connected to one end of the load, The signal input terminals of the first switch module 131 are respectively connected to a set of signal output terminals (corresponding to pins 26 and 27) of the main controller U1 to receive PWM pulse signals. The input PWM pulse signals are used to control the on / off state of the first switch module 131. The signal input terminals of the second switch module 132 are connected to another set of signal output terminals (corresponding to pins 13 and 14) of the main controller U1 to receive PWM pulse signals. The input PWM pulse signals are used to control the on / off state of the second switch module 132.

[0022] In some implementations, such as Figure 1 As shown, the first switching module 131 includes a first MOSFET Q3 and a second MOSFET Q7, wherein the first MOSFET Q3 and the second MOSFET Q7 are selected as N-channel enhancement-mode MOSFETs, which have the function of switching; Specifically, the drain of the first MOSFET Q3 is connected to the output terminal of the input detection circuit 120 to receive the voltage signal input to the input detection circuit 120. The gate of the first MOSFET Q3 is connected to the first signal output terminal (corresponding to pin 24) of the main controller U1 through the seventh resistor R7, which is used to receive the first PWM pulse signal. The input first PWM pulse signal is used to control the on / off state of the first MOSFET Q3. The gate of the second MOSFET Q7 is connected to the second signal output terminal (corresponding to pin 21) of the main controller U1 through the forty-second resistor R42, which is used to receive the second PWM pulse signal. The input second PWM pulse signal is used to control the on / off state of the second MOSFET Q7. The source of the first MOSFET Q3 and the drain of the second MOSFET Q7 are connected to one end of the first inductor L1. The source of the second MOSFET Q7 is connected to the common terminal.

[0023] In some implementations, such as Figure 1 As shown, the second switching module 132 includes a third MOSFET Q2 and a fourth MOSFET Q6, wherein the third MOSFET Q2 and the fourth MOSFET Q6 are selected as N-channel enhancement-mode MOSFETs, which have the function of switching; Specifically, the drain of the third MOSFET Q2 is connected to the input terminal of the output detection circuit 140. The gate of the third MOSFET Q2 is connected to the third signal output terminal (corresponding to pin 16) of the main controller U1 through the sixth resistor R6, which is used to receive the third PWM pulse signal. The input third PWM pulse signal is used to control the on / off state of the third MOSFET Q2. The gate of the fourth MOS transistor Q6 is connected to the fourth signal output terminal (corresponding to pin 19) of the main controller U1 via the thirteenth resistor R13, for receiving a fourth PWM pulse signal, and the input fourth PWM pulse signal is used to control the on / off state of the fourth MOS transistor Q6; The source of the third MOS transistor Q2 and the drain of the fourth MOS transistor Q6 are connected to the other end of the first inductor L1, The source of the fourth MOS transistor Q6 is connected to the common terminal.

[0024] Specifically, Buck Mode Applicable condition: VIN>VBUS (for example, charging a 12V battery with a 24V battery) In this mode, the circuit is equivalent to a synchronous Buck step-down converter, and the first inductor L1 acts as a filtering and energy transfer element; Third MOS transistor Q2 (high-side input transistor): PWM switch It is turned on at the beginning of the switching cycle, and the current path is: VIN→third MOS transistor Q2→first inductor L1→output capacitor & load; In this phase, the first inductor L1 stores energy, and the current rises linearly; Second MOS transistor Q7 (low-side output transistor), synchronous rectifier, which is turned on complementarily to the third MOS transistor Q2, It is turned on when the third MOS transistor Q2 is turned off, providing a low-impedance loop for the freewheeling current of the first inductor L1: first inductor L1→output→second MOS transistor Q7→GND. In this phase, the first inductor L1 releases energy, and the current decreases linearly; First MOS transistor Q3 (high-side output transistor): normally off It remains off at all times, blocking the possibility of reverse flow of output voltage back to the input side, Fourth MOS transistor Q6 (low-side input transistor): normally off It remains off at all times, Buck mode simplified method: (The third MOS transistor Q2 and the second MOS transistor Q7) operate as a pair of complementary switches, and (the first MOS transistor Q3 and the fourth MOS transistor Q6) are turned off; Boost Mode Applicable condition: VIN<VBUS (for example, charging a 24V battery with a 12V battery) In this mode, the circuit is equivalent to a synchronous Boost step-up converter, and the inductor L1 acts as an energy storage element.

[0025] Second MOS transistor Q7 (low-side output transistor): PWM switch At the beginning of the switching cycle, the transistor is turned on. The current path is: VIN → first MOSFET Q3 (body diode or turned on) → first inductor L1 → second MOSFET Q7 → GND. During this stage, all electrical energy is stored in the first inductor L1, and the current rises linearly. The third MOSFET Q2 (high-side input transistor): This transistor is used in the synchronous rectifier and conducts complementaryly with the second MOSFET Q7. It conducts when the second MOSFET Q7 is turned off. The first inductor L1 releases energy, and its induced electromotive force is superimposed on the input voltage VIN, supplying power to the output through the third MOSFET Q2 and the first MOSFET Q3. The path is: VIN → third MOSFET Q2 → first inductor L1 → output. During this stage, inductor L1 releases energy, and the current decreases linearly. First MOSFET Q3 (high-side output transistor): Normally open or synchronous rectification. In this mode, the first MOSFET Q3 is typically driven normally on (or rectified synchronously with the third MOSFET Q2) to provide a path for the boost current with extremely low on-resistance, which is key to achieving high efficiency.

[0026] Fourth MOSFET Q6 (low-side input transistor): Normally off Boost pattern simplification: (The second MOSFET Q7 and the third MOSFET Q2) work as a complementary switch pair, with the first MOSFET Q3 normally open and the fourth MOSFET Q6 off; Buck-Boost Mode Applicable conditions: VIN ≈ VBUS or VIN fluctuates within a wide range around the VBUS value. When the circuit cannot achieve a stable output using only Buck or Boost, the first inductor L1 is activated in this mode as a pure energy storage element, where energy is stored first and then released. In this mode, all four switches are in PWM mode, and one switching cycle is divided into multiple stages (usually at least two): Phase 1 (Energy Storage Phase): Conducting transistors: Third MOSFET Q2 and Second MOSFET Q7, Current path: VIN → third MOSFET Q2 → first inductor L1 → second MOSFET Q7 → GND, Logic: In this stage, energy is stored from the input source into the first inductor L1, and the inductor is charged on the input side; Phase Two (Energy Release Phase): Conducting transistors: First MOSFET Q3 and fourth MOSFET Q6, Current path: GND → fourth MOSFET Q6 → first inductor L1 → first MOSFET Q3 → output. Logic: In this stage, the energy stored in the first inductor L1 is released to the output. The inductor acts as a current source to power the output; By precisely controlling the duty cycle combination of stage one and stage two, the main controller U1 can maintain the stability of the output voltage even if the input voltage is lower than, equal to or higher than the output voltage.

[0027] In some implementations, such as Figure 1 As shown, the input filtering and overcurrent protection circuit 110 includes at least a fuse (FUSE1), an input filtering circuit (composed of capacitors EC1, C52, and C53 connected together), and a fourth diode D4 and a fifth diode D5. Among them, the fuse (FUSE1) is used for overcurrent protection and overcurrent safety protection circuit to prevent reverse voltage and overcurrent from damaging the circuit; The input filter circuit is used to ensure safety protection when the subsequent circuit is in abnormal condition. When there is inrush current due to external interference, the current can be filtered through the filter circuit. The fourth diode D4 and the fifth diode D5 are used to quickly discharge the junction capacitance Cgs of the MOSFET when it is turned off, so as to turn off the MOSFET in time, reduce fast turn-off losses, and improve output efficiency.

[0028] In some implementations, such as Figure 1 As shown, the output filtering circuit uses multiple capacitors (such as capacitor C4, capacitor C5 and capacitor C6) to filter the input and output, ensuring a stable output voltage.

[0029] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A power supply circuit for emergency car start-up charging, characterized in that, have: An input detection circuit, which is configured on the input side of the power supply circuit, is used to detect the first current signal at the input terminal; A voltage conversion circuit, whose power input terminal is connected to the output terminal of the input detection circuit, is used to receive the voltage signal flowing through the input detection circuit; An output detection circuit, whose input terminal is connected to the output terminal of the voltage conversion circuit, is used to detect the second current signal output by the voltage conversion circuit. The main control circuit has its first set of detection terminals connected to both ends of the input detection circuit to acquire the first current signal. The second set of detection terminals of the main control circuit is connected to both ends of the output detection circuit to acquire the second current signal. The signal output terminals of the main control circuit are connected to the signal input terminals of the voltage conversion circuit, respectively, for outputting at least two PWM pulse signals. The main control circuit adjusts the level of the output PWM pulse signal according to the first current signal or the second current signal to control the voltage conversion circuit to output a step-down or step-up voltage to supply power to the load.

2. The power supply circuit for emergency starting and charging of a car according to claim 1, characterized in that, The main control circuit includes at least a main controller and an output voltage regulation feedback circuit. The first set of detection terminals of the main controller is connected to both ends of the input detection circuit to acquire the first current signal. The second set of detection terminals of the main controller is connected to both ends of the output detection circuit to acquire the second current signal. The signal output terminals of the main controller are connected to the signal input terminals of the voltage conversion circuit, respectively, for outputting at least two PWM pulse signals. One end of the voltage regulation feedback circuit is connected to one end of the load, and is used to obtain the voltage value of the load. The other end of the voltage regulation feedback circuit is connected to the feedback terminal of the main controller. The main controller adjusts the duty cycle of the output PWM pulse signal based on the feedback voltage value, and controls the voltage signal output by the voltage conversion circuit to adapt to the voltage requirements of different batteries.

3. The power supply circuit for emergency car start-up charging according to claim 2, characterized in that, The output voltage regulation feedback circuit includes a twentieth resistor and a twenty-fourth resistor connected in series. One end of the twentieth resistor is connected to one end of the load to obtain the voltage value. The other end of the twentieth resistor and one end of the twenty-fourth resistor are respectively connected to the feedback terminal of the main controller. The other end of the 24th resistor is connected to the common terminal.

4. The power supply circuit for emergency starting and charging of a car according to claim 2, characterized in that, The voltage conversion circuit includes at least a first switching module, a first inductor, and a second switching module. The input terminal of the first switch module is coupled to the output terminal of the input detection circuit. The output terminal of the first switch module is connected to one end of the first inductor. The input terminal of the second switching module is coupled to the other end of the first inductor. The output terminal of the second switching module is connected to one end of the load. The signal input terminals of the first switching module are respectively connected to a set of signal output terminals of the main controller to receive the PWM pulse signals. The signal input terminal of the second switching module is connected to another set of signal output terminals of the main controller to receive the PWM pulse signal.

5. The power supply circuit for emergency starting and charging of a car according to claim 4, characterized in that, The first switching module includes a first MOSFET and a second MOSFET. The drain of the first MOS transistor is connected to the output terminal of the input detection circuit. The gate of the first MOS transistor is connected to the first signal output terminal of the main controller. The gate of the second MOS transistor is connected to the second signal output terminal of the main controller. The source of the first MOSFET and the drain of the second MOSFET are connected to one end of the first inductor. The source of the second MOSFET is connected to the common terminal.

6. The power supply circuit for emergency starting and charging of a car according to claim 5, characterized in that, The second switching module includes a third MOSFET and a fourth MOSFET. The drain of the third MOS transistor is connected to the input terminal of the output detection circuit. The gate of the third MOS transistor is connected to the third signal output terminal of the main controller. The gate of the fourth MOS transistor is connected to the fourth signal output terminal of the main controller. The source of the third MOS transistor and the drain of the fourth MOS transistor are connected to the other end of the first inductor. The source of the fourth MOS transistor is connected to the common terminal.

7. The power supply circuit for emergency starting and charging of a car according to claim 6, characterized in that, The first MOSFET, the second MOSFET, the third MOSFET, and the fourth MOSFET are selected as N-channel enhancement-mode MOSFETs.

8. The power supply circuit for emergency starting and charging of an automobile according to any one of claims 1-6, characterized in that, It also includes input filtering and overcurrent protection circuitry, the input of which is connected to an external power supply. The output terminal of the input filtering and overcurrent protection circuit is connected to the input terminal of the input detection circuit and an input terminal of the main control circuit.

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