Power drive system for high power loads and electronic device

Abstract

The application provides a power driving system of a high-power load and electronic equipment, the power driving system comprising a power limiting circuit, a boost circuit, a switching circuit and a control circuit; a first end of the power limiting circuit is connected with a power supply, and the power limiting circuit is used for limiting the output power of the power supply to be less than a preset power; a first end of the boost circuit is connected with a second end of the power limiting circuit; a first end of the switching circuit is connected with a second end of the boost circuit, and a second end of the switching circuit is connected with the high-power load; a first end of the control circuit is connected with the power supply and the first end of the power limiting circuit, a second end of the control circuit is connected with a controlled end of the switching circuit, and the control circuit is used for controlling the on-off of the switching circuit. The power driving system can limit the output power of the power supply, make the output voltage of the power supply more stable, ensure the power supply reliability of power supply to other external devices, and ensure the working stability of the whole power driving system.

Description

Technical Field

[0001] This application relates to the field of drive circuit technology, and more specifically, to a power drive system and electronic device for high-power loads. Background Technology

[0002] In daily life, some high-power loads require significant power to operate. The common technique involves adding multiple large-capacity capacitors to the output of the input power supply to provide power to these loads and ensure their normal operation. However, this can lead to excessive starting current in the input power supply, potentially pulling down the input voltage and affecting the stability of the power supply to other peripherals, thus impacting the overall system stability. Summary of the Invention

[0003] To address the aforementioned issues, this application provides a power drive system and electronic device for high-power loads, aiming to improve the power supply stability that is affected when the input power supply is pulled low, thus impacting the overall system's operational stability.

[0004] In a first aspect, this application provides a power drive system for a high-power load, applied to a high-power load. The power drive system includes a power limiting circuit, a boost circuit, a switching circuit, and a control circuit. The first terminal of the power limiting circuit is connected to a power supply, and the power limiting circuit is used to limit the output power of the power supply to not exceed a preset power. The first terminal of the boost circuit is connected to the second terminal of the power limiting circuit. The first terminal of the switching circuit is connected to the second terminal of the boost circuit, and the second terminal of the switching circuit is connected to the high-power load. The first terminal of the control circuit is connected to the power supply and the first terminal of the power limiting circuit, and the second terminal of the control circuit is connected to the controlled terminal of the switching circuit, and the control circuit is used to control the switching circuit to turn on and off.

[0005] Based on the power drive system provided in this application, the power limiting circuit limits the output power of the power supply, ensuring that the output power does not exceed a preset power before outputting the voltage to the boost circuit. By limiting the output power of the power supply through the power limiting circuit, the maximum safe power that the small power supply can withstand can be guaranteed, and the power supply will not exceed its own safe power when driving a high-power load, thereby improving the service life of the power supply. Furthermore, limiting the output power of the power supply through the power limiting circuit ensures a more stable output voltage, guaranteeing the reliability of power supply to the control circuit and other peripherals. That is, the control circuit and other peripherals will not be affected by high-power loads, thus ensuring the reliability of the control circuit's control over the switching circuit, and consequently ensuring the operational stability of the entire power drive system. Secondly, the control circuit can control the driving state of the high-power load by controlling the on / off state of the switching circuit, resulting in high control reliability.

[0006] As an optional implementation, the power limiting circuit includes a first diode, a power limiting module, and a first energy storage module; the anode of the first diode is connected to a power supply; the first terminal of the power limiting module is connected to the cathode of the first diode, and the second terminal of the power limiting module is grounded; the first terminal of the first energy storage module is connected to the third terminal of the power limiting module, the second terminal of the first energy storage module is grounded, and the third terminal of the first energy storage module is connected to the first terminal of the boost circuit.

[0007] Based on the aforementioned optional method, the power supply output voltage is transmitted to the power limiting module via the first diode. The power limiting module limits the power supply's output power to a preset level and provides this constant preset power to high-power loads. Combined with the first energy storage module, this achieves a low voltage drop. Secondly, the power limiting module not only limits the power supply's output power to prevent voltage drops, but also addresses the issue of excessive input current during startup. It keeps the input current constant within a preset level, which is a safe current for low-power power supplies. This provides a margin of safety for control circuits and other peripherals, ensuring their normal startup and improving overall system stability. Furthermore, the first diode prevents backflow current from damaging the power supply, extending its lifespan.

[0008] As an optional implementation, the power limiting module includes a first resistor, a second resistor, a second diode, a first switch, and a second switch; one end of the first resistor is connected to the cathode of the first diode, the cathode of the second diode, and the first terminal of the first switch; the other end of the first resistor is connected to one end of the second resistor and the first terminal of the second switch; the other end of the second resistor is connected to the anode of the second diode and the controlled terminal of the first switch; the second terminal of the first switch is connected to the controlled terminal of the second switch and grounded; and the second terminal of the second switch is connected to the first terminal of the first energy storage module.

[0009] As an optional implementation, the boost circuit includes a driver chip, a protection module, and a second energy storage module; a first terminal of the driver chip is connected to a second terminal of the power limiting circuit; a first terminal of the protection module is connected to both the first terminal of the driver chip and the second terminal of the power limiting circuit, a second terminal of the protection module is connected to the second terminal of the driver chip, and a third terminal of the protection module is connected to the third terminal of the driver chip; a first terminal of the second energy storage module is connected to a fourth terminal of the protection module, a second terminal of the second energy storage module is grounded, and a third terminal of the second energy storage module is connected to a first terminal of the switching circuit.

[0010] Based on the above optional methods, the driver chip can use different duty cycles to achieve regulated output to the protection module. The protection module can realize overcurrent protection and output a stable DC current to the second energy storage module to charge the second energy storage module and supply power to the high-power load. By setting the protection module, the stability and efficiency of the voltage output to the high-power load can be guaranteed, so as to ensure the reliability of power supply.

[0011] As an optional implementation, the protection module includes an inductor, a third switch, a third resistor, a first capacitor, and a fourth resistor; one end of the inductor is connected to the first terminal of the driver chip and the second terminal of the power limiting circuit, the other end of the inductor is connected to the first terminal of the third switch and the first terminal of the second energy storage module, one end of the third resistor is connected to the second terminal of the driver chip, the other end of the third resistor is connected to the controlled terminal of the third switch, the second terminal of the third switch is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to the first plate of the first capacitor and the third terminal of the driver chip, and the second plate of the first capacitor is grounded.

[0012] Based on the above optional method, the third resistor is a current-limiting resistor used to limit the current at the controlled end of the third switch. The fourth resistor and the first capacitor together form a low-pass filter to convert the switching current of the third switch into a more stable DC current. When the current exceeds the threshold current, the fourth resistor and the first capacitor can turn off the third switch, thereby realizing overcurrent protection for the high-power load and the third switch, so as to ensure the reliability of the high-power load and the third switch.

[0013] As an optional implementation, the boost circuit also includes a feedback module, with a first terminal of the feedback module connected to the third terminal of the second energy storage module, a second terminal of the feedback module grounded, and a third terminal of the feedback module connected to the fourth terminal of the driver chip.

[0014] Based on the above optional method, the feedback module continuously monitors the voltage output by the protection module and feeds it back to the driver chip. The driver chip compares and amplifies this feedback voltage with its internal reference voltage. When the feedback voltage is greater than the reference voltage, the driver chip reduces its duty cycle to drive the third switch, causing the output voltage to drop and thus stabilizing the voltage. When the feedback voltage is less than the reference voltage, the driver chip increases its duty cycle to drive the third switch, causing the output voltage to rise and thus stabilizing the voltage. In this way, by continuously monitoring the voltage output by the protection module and adjusting the duty cycle based on the feedback voltage to stabilize the output voltage, the reliability of the voltage output by the boost circuit is ensured.

[0015] As an optional implementation, the switching circuit includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fourth switch, and a fifth switch; one end of the fifth resistor is connected to the second terminal of the boost circuit and the first terminal of the fourth switch, the other end of the fifth resistor is connected to the controlled terminal of the fourth switch and one end of the sixth resistor, the second terminal of the fourth switch is connected to a high-power load, the other end of the sixth resistor is connected to the first terminal of the fifth switch, the second terminal of the fifth switch is grounded, the controlled terminal of the fifth switch is connected to one end of the seventh resistor and one end of the eighth resistor, the other end of the seventh resistor is grounded, and the other end of the eighth resistor is connected to the second terminal of the control circuit.

[0016] Based on the above optional method, when the control circuit outputs an on command to the switching circuit, the fifth switch turns on based on the on command, thereby lowering the voltage at the controlled terminal of the fourth switch. This makes the voltage at the controlled terminal of the fourth switch equal to the voltage output by the boost circuit * (R6 / (R5+R6)). This voltage meets the on-voltage threshold of the fourth switch, causing it to turn on. At this time, the voltage output by the boost circuit can be output to the high-power load through the turned-on fourth switch to achieve driving. When the control circuit does not output an on command to the switching circuit, the fifth switch remains off, and the fourth switch also remains off. In this way, the control circuit can control the driving state by controlling the on / off state of the fifth switch, which is simple to operate and has high control precision.

[0017] As an optional implementation, the power drive system also includes a temperature detection circuit. The first terminal of the temperature detection circuit is connected to the third terminal of the control circuit. The temperature detection circuit is used to detect the current temperature of the power limiting circuit and send it to the control circuit. The control circuit is used to control the switching circuit to turn on or off based on the current temperature.

[0018] Based on the above optional methods, the temperature detection circuit will detect the temperature of the power limiting circuit in real time and send the detected current temperature to the control circuit. This allows the control circuit to determine whether there is a temperature anomaly. When the current temperature of the power limiting circuit received by the control circuit is higher than the temperature threshold, the control circuit can control the switching circuit to disconnect, thereby disconnecting the downstream circuit of the power limiting circuit and preventing the power limiting circuit from burning out due to excessive temperature. This ensures the reliability of the power limiting circuit and improves the safety and reliability of the system.

[0019] As an optional implementation, the temperature detection circuit includes a ninth resistor, a temperature sensor, and a second capacitor; one end of the ninth resistor is connected to the power supply voltage, the other end of the ninth resistor is connected to one end of the temperature sensor, the first plate of the second capacitor, and the third terminal of the control circuit, and the other end of the temperature sensor and the second plate of the second capacitor are grounded.

[0020] Based on the above optional method, when the current temperature of the power limiting circuit rises or falls, the resistance of the temperature detection circuit will change. After being divided by the ninth resistor and filtered by the second capacitor, the temperature is output to the control circuit. The control circuit can read the current temperature and calculate whether the switching transistor of the power limiting circuit is in a safe state, or compare it with a pre-set temperature threshold. When the current temperature exceeds the temperature threshold, that is, the temperature of the power limiting circuit is abnormal, the control circuit controls the switching circuit to turn off, thereby disconnecting the power limiting circuit from the back-end circuit, thus avoiding the problem of the switching transistor burning out due to overheating and improving a certain degree of safety.

[0021] Secondly, embodiments of this application provide an electronic device, including a high-power load and a power drive system as described in any optional manner of the first aspect. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the module structure of an electronic device provided in an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the module structure of another electronic device provided in an embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the module structure of another electronic device provided in the embodiments of this application;

[0026] Figure 4 This is a schematic diagram of the circuit structure of a power limiting circuit provided in an embodiment of this application;

[0027] Figure 5 This is a schematic diagram of the circuit structure of a boost circuit provided in an embodiment of this application;

[0028] Figure 6 This is a schematic diagram of the circuit structure of another boost circuit provided in an embodiment of this application;

[0029] Figure 7 This is a schematic diagram of the circuit structure of a power drive system provided in an embodiment of this application;

[0030] Figure 8 This is a schematic diagram of the module structure of another electronic device provided in an embodiment of this application;

[0031] Figure 9 This is a schematic diagram of the circuit structure of a temperature detection circuit provided in an embodiment of this application;

[0032] Figure 10 This is a schematic diagram of the module structure of another electronic device provided in an embodiment of this application;

[0033] Figure 11 This is a schematic diagram of the circuit structure of a voltage regulator circuit provided in an embodiment of this application.

[0034] Figure label:

[0035] 1. High-power load; 2. Power drive system; 21. Power limiting circuit; 211. Power limiting module; 212. First energy storage module; 22. Boost circuit; 221. Protection module; 222. Second energy storage module; 223. Feedback module; 23. Switching circuit; 24. Control circuit; 25. Temperature detection circuit; 26. Voltage regulator circuit; 3. Power supply;

[0036] D1, First diode; D2, Second diode; D3, Third diode; D4, Fourth diode; R1, First resistor; R2, Second resistor; R3, Third resistor; R4, Fourth resistor; R5, Fifth resistor; R6, Sixth resistor; R7, Seventh resistor; R8, Eighth resistor; R9, Ninth resistor; R10, Tenth resistor; R11, Eleventh resistor; R12, Twelfth resistor; R13, Thirteenth resistor; R14, Fourteenth resistor; Q1, First switch; Q2, Second switch; Q3, Third switch; Q4, Fourth switch Q5, fifth switch; C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; C5, fifth capacitor; C6, sixth capacitor; C7, seventh capacitor; C8, eighth capacitor; C9, ninth capacitor; C10, tenth capacitor; C11, eleventh capacitor; C12, twelfth capacitor; C13, thirteenth capacitor; C14, fourteenth capacitor; C15, fifteenth capacitor; C16, sixteenth capacitor; C17, seventeenth capacitor; U1, driver chip; U2, linear regulator; VCC, power supply voltage. Detailed Implementation

[0037] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, and circuits have been omitted so as not to obscure the description of this application with unnecessary detail.

[0038] In electrical engineering and mechanical design, drive loads are generally categorized into two types: high-power loads and low-power loads. High-power loads typically refer to equipment or systems that consume a relatively high amount of electrical energy. In industrial applications, equipment with power consumption of hundreds of watts (W) or even thousands of watts (kW) is often considered a high-power load. Examples include large motors, heaters, and air conditioning systems. Low-power loads, on the other hand, have lower power requirements and generally refer to equipment or systems that consume a relatively low amount of electrical energy. Equipment with power consumption ranging from milliwatts (mW) to tens of watts (W) is typically considered a low-power load. Examples include light-emitting diodes (LEDs), small electronic devices, and mobile phone chargers.

[0039] Two common driving methods are used in related technologies to drive high-power loads for short periods. The first is to increase the power of the input power supply, ensuring it is greater than or equal to the maximum power required by the high-power load. However, this method is costly and bulky. The second method involves adding multiple large-capacity capacitors to the output of the input power supply to power the high-power load. However, this leads to excessive starting current in the input power supply, which can easily pull down the input power and increase startup time. Since the input power supply also powers other peripherals in the system, when it is pulled down by the high-power load, it affects the stability of the power supply to these peripherals, thus impacting the overall system stability and potentially causing startup failure. Furthermore, the short-term high current in these technologies can reach the 20ms level. This high current is identified as an overload current by the system's control chip, which will directly shut off the input power supply output, disconnecting it from the high-power load and terminating the drive, thus affecting the normal operation of the system.

[0040] Therefore, this application provides a power drive system and electronic device for high-power loads. The power drive system can limit the output power of the power supply, so that the output voltage of the power supply is more stable to ensure the reliability of power supply to other peripherals, thereby ensuring the working stability of the entire power drive system.

[0041] The power drive system and electronic device for high-power loads provided in this application are described below with reference to the accompanying drawings.

[0042] This application provides an electronic device, such as... Figure 1As shown, the electronic device includes a high-power load 1 and a power drive system 2. The power drive system 2 is connected to the high-power load 1 and to a power supply 3. The power drive system 2 is used to provide an output voltage to the high-power load 1 based on the power supply 3, so that the high-power load 1 can operate normally. The high-power load 1 can be a high-power load such as a sound coil, and the power supply 3 can be a low-cost, small-size power supply, such as a battery or a 5V output power supply with weak load capacity. This application does not impose specific limitations on these aspects.

[0043] In one example, such as Figure 2 As shown, the power drive system 2 includes a power limiting circuit 21, a boost circuit 22, a switching circuit 23, and a control circuit 24. The first terminal of the power limiting circuit 21 is connected to the power supply, the first terminal of the boost circuit 22 is connected to the second terminal of the power limiting circuit 21, the first terminal of the switching circuit 23 is connected to the second terminal of the boost circuit 22, the second terminal of the switching circuit 23 is connected to the high-power load 1, the first terminal of the control circuit 24 is connected to the power supply 3 and the first terminal of the power limiting circuit 21, and the second terminal of the control circuit 24 is connected to the controlled terminal of the switching circuit 23.

[0044] The control circuit 24 controls the on / off state of the switching circuit 23 to control the driving state. For example, when the control circuit 24 controls the switching circuit 23 to be on, the branch between the boost circuit 22 and the high-power load 1 is connected, allowing the power supply 3 to output a high voltage to the high-power load 1 via the power limiting circuit 21, the boost circuit 22, and the switching circuit 23, thus enabling high-power driving and driving the high-power load 1 to operate normally. When the control circuit 24 controls the switching circuit 23 to be off, the branch between the boost circuit 22 and the high-power load 1 is disconnected, and the high voltage output by the power supply 3 cannot flow to the high-power load 1, stopping the driving of the high-power load 1. This reduces energy waste during long-term standby and avoids unnecessary energy consumption, which helps improve the energy efficiency of the entire power drive system 2. Thus, the control circuit 24 can control the driving state of the high-power load 1 by controlling the on / off state of the switching circuit 23, resulting in high control reliability.

[0045] Optionally, the control circuit 24 can be a microcontroller unit (MCU). MCUs have high reliability and stability, and they integrate multiple functional modules, reducing the number of external components, thereby reducing the overall cost of the power drive system 2 and improving the reliability of the power drive system 2.

[0046] In this example, power supply 3 has two outputs: one to power limiting circuit 21 and the other to control circuit 24. When the power supply output voltage reaches power limiting circuit 21, power limiting circuit 21 limits the output power of the power supply, ensuring that the output power of power supply 3 does not exceed a preset power. The voltage is then output to boost circuit 22, which raises the low voltage output from power limiting circuit 21 to a high voltage and outputs it to switching circuit 23. When control circuit 24 controls switching circuit 23 to conduct, the high voltage output from boost circuit 22 is output to high-power load 1 via switching circuit 23 to complete high-power drive. Thus, by limiting the output power of power supply 3 through power limiting circuit 21, the maximum safe power that small power supply 3 can withstand is guaranteed, and it will not exceed its own safe power when driving high-power load 1, thereby improving the service life of power supply 3. Secondly, by limiting the output power of the power supply 3 through the power limiting circuit 21, the output voltage of the power supply 3 can be made more stable to ensure the reliability of power supply to the control circuit 24 and other peripherals. That is, the control circuit 24 and other peripherals will not be affected by the high-power load 1, thereby ensuring the reliability of the control circuit 24 in controlling the switching circuit 23, and thus ensuring the working stability of the entire power drive system 2.

[0047] In one example, such as Figure 3 As shown, the power drive system 21 includes a first diode D1, a power limiting module 211, and a first energy storage module 212. The positive terminal of the first diode D1 is connected to the power supply 3. The first terminal of the power limiting module 211 is connected to the negative terminal of the first diode D1. The second terminal of the power limiting module 211 is grounded. The first terminal of the first energy storage module 212 is connected to the third terminal of the power limiting module 211. The second terminal of the first energy storage module 212 is grounded. The third terminal of the first energy storage module 212 is connected to the first terminal of the boost circuit 22.

[0048] In this example, the voltage output from power supply 3 is transmitted to power limiting module 21 via the first diode D1. Power limiting module 21 limits the output power of power supply 3 to a preset power and provides this constant preset power to the high-power load 1. Combined with the first energy storage module 212, this achieves a low voltage drop. Furthermore, power limiting module 21 not only limits the output power of power supply 3 to prevent its output voltage from dropping, but also addresses the issue of excessive input current at startup, ensuring the input current is kept constant at a preset current. This preset current is the safe current for low-power power supply 3, providing a margin for power to peripherals such as control circuit 24, allowing them to start normally and improving the overall system stability. Additionally, the first diode D1 prevents backflow current from damaging power supply 3, thus extending its lifespan.

[0049] Optionally, the first diode D1 is a reverse current protection diode. Since there is a first energy storage module 212 in the subsequent stage, the reverse current protection diode can prevent the reverse current from flowing from the subsequent stage to the previous stage, thereby preventing the power supply 3 from being damaged due to overvoltage or short circuit caused by reverse current. When the power supply 3 is turned off or the voltage drops, the reverse current protection diode can automatically block the reverse current to ensure the safety of the entire system.

[0050] In one example, such as Figure 4 As shown, the power limiting module 211 includes a first resistor R1, a second resistor R2, a second diode D2, a first switch Q1, and a second switch Q2. One end of the first resistor R1 is connected to the cathode of the first diode D1, the cathode of the second diode D2, and the first end of the first switch Q1. The other end of the first resistor R1 is connected to one end of the second resistor R2 and the first end of the second switch Q2. The other end of the second resistor R2 is connected to the anode of the second diode D2 and the controlled end of the first switch Q1. The second end of the first switch Q1 is connected to the controlled end of the second switch Q2 and grounded. The second end of the second switch Q2 is connected to the first end of the first energy storage module 212.

[0051] In this circuit, the first resistor R1 is a current sampling resistor, the second resistor R2 is a current-limiting resistor for the first switch Q1, and the second diode D2 is used to protect the first switch Q1 from large reverse voltage surges, ensuring its safe operation. When driving a high-power load 1, the voltage flowing through the first resistor R1 will exceed a preset voltage (e.g., 0.7V). At this time, the first switch Q1 will conduct, causing the voltage at the first terminal of the second switch Q2 and the controlled terminal of the second switch Q2 to approach 0V, thus turning off the second switch Q2. The current is then limited to 0.7V / the resistance of the first resistor R1, with the remaining current provided by the first energy storage module 212. It is worth noting that in short-term high-power driving scenarios, the voltage drop of the first energy storage module 212 is relatively low and does not affect the output of the high-power load 1.

[0052] In this example, the first resistor R1, the second resistor R2, the second diode D2, the first switch Q1, and the second switch Q2, in addition to protecting the voltage of the power supply 3 from dropping, also ensure that the input current is not too large at the moment of startup. This ensures that the maximum input current is kept constant at 0.7 / the resistance value of the first resistor R1. This current is within the safe current range of the low-power power supply 3, allowing the low-power power supply 3 to have a margin to provide power to peripherals such as the control circuit 24, enabling the control circuit 24 and other peripherals to start normally, thereby improving the stability of the entire system.

[0053] Optionally, the first switch Q1 and the second switch Q2 can be hardware switches, N-Metal Oxide Semiconductor (NMOS) field-effect transistors, P-Metal Oxide Semiconductor (PMOS) field-effect transistors, IGBTs, transistors, relay circuits, or other devices or circuits capable of switching on and off. This application does not impose specific limitations on these.

[0054] For example, such as Figure 4 As shown, the first switch Q1 can be a PNP transistor. The emitter of the PNP transistor serves as the first terminal of the first switch Q1 and is connected to one end of the first resistor R1. The base of the PNP transistor serves as the controlled terminal of the first switch Q1 and is connected to the positive terminal of the second diode D2 and the other end of the second resistor R2. The collector of the PNP transistor serves as the second terminal of the first switch Q1 and is grounded. The second switch Q2 can be a PMOS transistor. The source of the PMOS transistor serves as the first terminal of the second switch Q2 and is connected to the other end of the first resistor R1. The gate of the PMOS transistor serves as the controlled terminal of the second switch Q2 and is connected to the collector of the PNP transistor. The drain of the PMOS transistor serves as the second terminal of the second switch Q2 and is connected to the first terminal of the first energy storage module 212.

[0055] In one example, such as Figure 4 As shown, the power drive system 21 also includes a tenth resistor R10. One end of the tenth resistor R10 is connected to the second terminal of the first switch Q1 and the controlled terminal of the second switch Q2, and the other end of the tenth resistor R10 is grounded.

[0056] In one example, such as Figure 4 As shown, the first energy storage module 212 includes a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5. The first plate of the third capacitor C3 is connected to the second terminal of the second switch Q2, the first plate of the fourth capacitor C4, the first plate of the fifth capacitor C5, and the first terminal of the boost circuit 22. The second plates of the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 are grounded. In this example, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 serve as energy storage capacitors to provide energy for short-term driving of the high-power load 1, thereby reducing the output power of the power supply 3.

[0057] To stabilize the output voltage of power supply 3, in one example, such as Figure 4As shown, the power drive system 21 also includes a sixth capacitor C6 and a seventh capacitor C7. The first plate of the sixth capacitor C6 is connected to the power supply 3, the first plate of the seventh capacitor C7, and the positive terminal of the first diode D1. The second plates of the sixth capacitor C6 and the seventh capacitor C7 are grounded. In this example, the sixth capacitor C6 and the seventh capacitor C7 are filter capacitors used to stabilize the output voltage of the power supply 3. The sixth capacitor C6, the third capacitor C3, and the fourth capacitor C4 can be large-capacity capacitors.

[0058] In one example, such as Figure 5 As shown, the boost circuit 22 includes a driver chip U1, a protection module 221, and a second energy storage module 222. The first terminal of the driver chip U1 is connected to the second terminal of the power limiting circuit 21 (i.e., as shown in the diagram). Figure 4 The first plate of the fifth capacitor C5 shown is connected. The first terminal of the protection module 221 is connected to the first terminal of the driver chip U1 and the second terminal of the power limiting circuit 21. The second terminal of the protection module 221 is connected to the second terminal of the driver chip U1. The third terminal of the protection module 221 is connected to the third terminal of the driver chip U1. The first terminal of the second energy storage module 222 is connected to the fourth terminal of the protection module 221. The second terminal of the second energy storage module 222 is grounded. The third terminal of the second energy storage module 222 is connected to the first terminal of the switching circuit 23. It is worth noting that "VIN" in the figure is the output voltage of the power limiting circuit 21 to which the boost voltage 22 is connected.

[0059] The driver chip U1 is configured with multiple pins, including the first pin of the driver chip U1 (e.g., Figure 5 The “VIN” pin shown is connected as the first terminal of the driver chip U1 to the second terminal of the power limiting circuit 21 (not shown in the figure). The second pin of the driver chip U1 (as shown in the figure) is connected as the second terminal of the power limiting circuit 21. Figure 5 The "ISENSE" pin shown is connected to the second terminal of the protection module 221 as the second terminal of the driver chip U1. The third pin of the driver chip U1 (as shown) Figure 5 The “GATE” shown is connected to the third terminal of the protection module 221 as the third terminal of the driver chip U1.

[0060] In this example, the driver chip U1 can use different duty cycles to achieve regulated output to the protection module 221. The protection module 221 can achieve overcurrent protection and output a stable DC current to the second energy storage module 222 to charge the second energy storage module 222 and supply power to the high-power load 1. By setting the protection module 221, the stability and efficiency of the voltage output to the high-power load 1 can be guaranteed, so as to ensure the reliability of power supply.

[0061] like Figure 5As shown, the boost circuit 22 also includes an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, an eleventh resistor R11, a twelfth resistor R12, and a thirteenth resistor R13, driving the fourth pin of the chip U1 (as shown). Figure 5 The "GND" pin shown is connected to the first plate of the eighth capacitor C8 and one end of the twelfth resistor R12, and the fifth pin of the driver chip U1 (as shown in the image) is connected to the first plate of the eighth capacitor C8 and one end of the twelfth resistor R12. Figure 5 The "RT" shown is connected to the other end of the twelfth resistor R12, driving the sixth pin of chip U1 (as shown in the image). Figure 5 The "COMP" pin is connected to one end of the thirteenth resistor R13, and the other end of the thirteenth resistor R13 is connected to the second plate of the eighth capacitor C8. The twelfth resistor R12 is used to adjust the switching frequency of the driver chip U1. By adjusting the resistance value of the twelfth resistor R12, the driver chip U1 can have different pulse width modulation (PWM) carrier frequencies. The eighth capacitor C8 and the thirteenth resistor R13 are used to compensate for the frequency of the driver chip U1, stabilizing the internal operation of the driver chip U1 and ensuring its reliability. The seventh pin of the driver chip U1 (as shown)... Figure 5 The "EN / SYNC" pin is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to the power supply voltage VCC. The eleventh resistor R11 is a pull-up resistor used to enable the driver chip U1 to operate. The eighth pin of the driver chip U1 (as shown...) Figure 5 The capacitor C10 (represented by "SS") is connected to the first plate of the tenth capacitor R10, and the second plate of the tenth capacitor C10 is grounded. The tenth capacitor C10 is a soft-start capacitor used to control the startup speed of the driver chip U1. The ninth pin of the driver chip U1 (as shown...) Figure 5 The capacitor C9 (represented by "VCC") is connected to the first plate of the ninth capacitor C9 and supplied with the power supply voltage VCC. The second plate of the ninth capacitor C9 is grounded. The ninth capacitor C9 is a filter capacitor. The driver chip U1 can also use other chips capable of performing the above functions; this application does not impose specific limitations on this.

[0062] It is worth noting that directly grounding the "ISENSE" pin of the aforementioned driver chip U1 may lead to short circuits and other abnormal situations. Therefore, in one example, such as Figure 5As shown, the power drive system 2 also includes a fourteenth resistor R14. One end of the fourteenth resistor R14 is connected to the "ISENSE" pin of the driver chip U1, and the other end is grounded. In this example, the fourteenth resistor R14 can limit the current to a certain extent to avoid excessive current damaging the driver chip U1 or causing a short circuit in the external circuit, thereby ensuring the reliability of the driver chip U1 and the external circuit. Secondly, the "ISENSE" pin usually has a high input impedance. By setting the fourteenth resistor R14, the impedance characteristics of the entire loop can be adjusted to improve the reliability and stability of signal transmission.

[0063] In one example, such as Figure 6 As shown, the protection module 221 includes an inductor L, a third switch Q3, a third resistor R3, a first capacitor C1, and a fourth resistor R4. One end of the inductor L is connected to the first terminal of the driver chip U1 and the second terminal of the power limiting circuit 21. The other end of the inductor L is connected to the first terminal of the third switch Q3 and the first terminal of the second energy storage module 222. One end of the third resistor R3 is connected to the second terminal of the driver chip U1. The other end of the third resistor R3 is connected to the controlled terminal of the third switch Q3. The second terminal of the third switch Q3 is connected to one end of the fourth resistor R4. The other end of the fourth resistor R4 is connected to the first plate of the first capacitor C1 and the third terminal of the driver chip U1. The second plate of the first capacitor C1 is grounded.

[0064] In this example, the third resistor R3 is a current-limiting resistor used to limit the current at the controlled terminal of the third switch Q3. The fourth resistor R4 and the first capacitor C1 together form a low-pass filter to convert the switching current of the third switch Q3 into a more stable DC current. When the current exceeds the threshold current, the fourth resistor R4 and the first capacitor C1 can turn off the third switch Q3, thereby achieving overcurrent protection for the high-power load and the third switch Q3, ensuring the reliability of the high-power load and the third switch Q3. In this example, one end of the fourteenth resistor R14 is connected to the second terminal of the third switch Q3 and one end of the fourth resistor R4, and the other end of the fourteenth resistor R14 is grounded. At this time, the driver chip U1 can collect the switching current of the third switch Q3 through the fourteenth resistor R14.

[0065] Optionally, the third switch Q3 can be a hardware switch, an NMOS field-effect transistor, a PMOS field-effect transistor, an IGBT, a transistor, a relay circuit, or other devices or circuits capable of switching on and off. This application does not impose specific limitations on this. For example, such as... Figure 6As shown, the third switch Q3 can be an NMOS transistor. The gate of the NMOS transistor is connected to the other end of the third resistor R3, the source of the NMOS transistor is connected to one end of the fourth resistor R4, and the drain of the NMOS transistor is connected to the other end of the inductor L and the first end of the second energy storage module 222.

[0066] In one example, such as Figure 6 As shown, the protection module 221 also includes an eleventh capacitor C11, a twelfth capacitor C12, a third diode D3, and a fourth diode D4. The first plates of the eleventh capacitor C11 and the twelfth capacitor C12 are connected to the first terminal of the driver chip U1. The second plates of the eleventh capacitor C11 and the twelfth capacitor C12 are grounded. The positive terminal of the third diode D3 is connected to the other end of the third resistor R3 and the controlled terminal of the third switch Q3. The negative terminal of the third diode D3 is connected to the third terminal of the driver chip U1. The positive terminal of the fourth diode D4 is connected to the other end of the inductor L. The negative terminal of the fourth diode D4 is connected to the first terminal of the second energy storage module 222. In this example, the eleventh capacitor C11 and the twelfth capacitor C12 are filter capacitors, the third diode D3 is used to quickly turn off the third switch Q3, and the fourth diode D4 can be a Schottky diode, which functions as unidirectional conduction. That is, through the fourth diode D4, the driver chip U1 can charge the second energy storage module 222 and supply power to the high-power load 1, but the second energy storage module 222 will not discharge to the third switch Q3, so as to ensure the stability and efficiency of the output voltage.

[0067] In one example, such as Figure 6 As shown, the second energy storage module 222 may include a thirteenth capacitor C13, a fourteenth capacitor C14, and a fifteenth capacitor C15. The first plate of the thirteenth capacitor C13 is connected to the negative terminal of the fourth diode D4, the first plate of the fourteenth capacitor C14, the first plate of the fifteenth capacitor C15, and the first terminal (not shown) of the switching circuit 23. The second plates of the thirteenth capacitor C13, the fourteenth capacitor C14, and the fifteenth capacitor C15 are grounded. In this example, the thirteenth capacitor C13, the fourteenth capacitor C14, and the fifteenth capacitor C15 serve as energy storage and filtering capacitors to provide a short-term high current when driving the high-power load 1. Thus, the first energy storage module 212 and the second energy storage module 222 can provide energy for driving the high-power load 1 for a short time, thereby reducing the power input of the power supply 1.

[0068] In one example, such as Figure 6As shown, the boost circuit 22 also includes a feedback module 223. The first terminal of the feedback module 223 is connected to the third terminal of the second energy storage module 222, the second terminal of the feedback module 223 is grounded, and the third terminal of the feedback module 223 is connected to the fourth terminal of the driver chip U1. The tenth pin of the driver chip U1 (as shown) Figure 6 The “FB” shown is connected to the third terminal of the feedback module 223 as the fourth terminal of the driver chip U1.

[0069] In this example, the feedback module 223 detects the voltage output by the protection module 222 in real time and feeds it back to the driver chip U1. The driver chip U1 compares and amplifies this feedback voltage with its internal reference voltage. When the feedback voltage is greater than the reference voltage, the driver chip U1 reduces its duty cycle to drive the third switch Q3, causing the output voltage to drop and thus stabilizing the voltage. When the feedback voltage is less than the reference voltage, the driver chip U1 increases its duty cycle to drive the third switch Q3, causing the output voltage to rise and thus stabilizing the voltage. In this way, by having the feedback module 223 detect the voltage output by the protection module 222 in real time and adjust the duty cycle based on the feedback voltage to stabilize the output voltage, the reliability of the voltage output by the boost circuit 22 is ensured.

[0070] Optionally, the feedback module 223 may include two resistors connected in series. One end of the first resistor serves as the first terminal of the feedback module 223 and is connected to the third terminal of the second energy storage module 222. The node where the two resistors are directly connected serves as the third terminal of the feedback module 223 and is connected to the fourth terminal of the driver chip U1. Other devices or circuits capable of achieving the above functions may also be used for the feedback module 223; this application does not impose specific limitations on this.

[0071] In one example, the switching circuit 23 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a fourth switch Q4, and a fifth switch Q5. One end of the fifth resistor R5 is connected to the second terminal of the boost circuit 22 and the first terminal of the fourth switch Q4. The other end of the fifth resistor R5 is connected to the controlled terminal of the fourth switch Q4 and one end of the sixth resistor R6. The second terminal of the fourth switch Q4 is connected to the high-power load 1. The other end of the sixth resistor R6 is connected to the first terminal of the fifth switch Q5. The second terminal of the fifth switch Q5 is grounded. The controlled terminal of the fifth switch Q5 is connected to one end of the seventh resistor R7 and one end of the eighth resistor R8. The other end of the seventh resistor R7 is grounded. The other end of the eighth resistor R8 is connected to the second terminal of the control circuit 24.

[0072] In this example, when the control circuit 24 outputs an enable command to the switching circuit 23, the fifth switch Q5 turns on based on the enable command, thereby lowering the voltage at the controlled terminal of the fourth switch Q4. This makes the voltage at the controlled terminal of the fourth switch Q4 equal to the voltage output by the boost circuit 22 * ​​(R6 / (R5+R6)), where R6 is the resistance value of the sixth resistor R6 and R5 is the resistance value of the fifth resistor R5. This voltage meets the turn-on voltage threshold of the fourth switch Q4, causing the fourth switch Q4 to turn on. At this time, the voltage output by the boost circuit 22 can be output to the high-power load 1 through the turned-on fourth switch Q4 to achieve driving. When the control circuit 24 does not output an enable command to the switching circuit 23, the fifth switch Q5 remains off, and the fourth switch Q4 also remains off. In this way, the control circuit 24 can control the driving state by controlling the on / off state of the fifth switch Q5, which is simple to operate and has high control accuracy.

[0073] Optionally, the fourth switch Q4 and the fifth switch Q5 can be hardware switches, NMOS field-effect transistors, PMOS field-effect transistors, IGBTs, transistors, relay circuits, or other devices or circuits capable of switching on and off. This application does not impose specific restrictions on these.

[0074] When the downstream circuits of the power limiting circuit 21, such as the boost circuit 22 or the high-power load 1, malfunction, a large current will occur. This large current will cause the temperature of the power limiting circuit 21 to rise. In order to monitor the temperature of the power limiting circuit 21 in real time, in one example, such as... Figure 8 As shown, the power drive system 2 also includes a temperature detection circuit 25. The first terminal of the temperature detection circuit 25 is connected to the third terminal of the control circuit 24. The temperature detection circuit 25 detects the current temperature of the power limiting circuit 21 and sends it to the control circuit 24. The control circuit 24 controls the switching circuit 23 based on the current temperature. In this example, the temperature detection circuit 25 detects the temperature of the power limiting circuit 21 in real time and sends the detected current temperature to the control circuit 24. This allows the control circuit 24 to determine if there is a temperature anomaly. When the current temperature of the power limiting circuit 21 received by the control circuit 24 is higher than a temperature threshold, the control circuit 24 can control the switching circuit 23 to disconnect, thus disconnecting the downstream circuit of the power limiting circuit 21 and preventing the power limiting circuit 21 from burning out due to excessive temperature. This ensures the reliability of the power limiting circuit 21 and improves the safety and reliability of the system.

[0075] In this example, to further improve the security and reliability of the system, such as Figure 8As shown, a sixth switch Q6 can be provided between the power limiting circuit 21 and the boost circuit 22. The controlled terminal of the sixth switch Q6 is connected to the control circuit 24. When the current temperature of the power limiting circuit 21 received by the control circuit 24 is higher than the temperature threshold, the control circuit 24 can also control the sixth switch Q6 to turn off, so as to disconnect the branch between the power limiting circuit 21 and the boost circuit 22, thereby further improving the safety and reliability of the system.

[0076] It is worth noting that when the high-power load 1 is short-circuited or other reasons cause a continuous high current, the control circuit 24 can also control the switching circuit 23 to turn off the output, thereby ensuring the safety and reliability of the power drive system 1.

[0077] In one example, the temperature detection circuit 25 includes a ninth resistor R9, a temperature sensor NTC, and a second capacitor C2. One end of the ninth resistor R9 is connected to the power supply voltage VCC, and the other end of the ninth resistor R9 is connected to one end of the temperature sensor NTC, the first plate of the second capacitor C2, and the third end of the control circuit 24. The other end of the temperature sensor NTC and the second plate of the second capacitor C2 are grounded.

[0078] In this example, the temperature detection circuit 25 is positioned near the power limiting circuit 21, specifically near the switching transistor of the power limiting circuit 21. When a short circuit or abnormality occurs in the downstream circuit, causing a continuous high current, the switching transistor of the power limiting circuit 21 will generate heat, and the temperature sensor NTC can detect the current temperature of the power limiting circuit 21. When the current temperature of the power limiting circuit 21 rises or falls, the resistance of the temperature detection circuit 25 changes. After being divided by the ninth resistor R9 and filtered by the second capacitor C2, the voltage is output to the control circuit 24. The control circuit 24 can read the current temperature and calculate whether the switching transistor of the power limiting circuit 21 is in a safe state, or compare it with a pre-set temperature threshold. When the current temperature exceeds the temperature threshold, i.e., the temperature of the power limiting circuit 21 is abnormal, the control circuit 24 controls the switching circuit 24 to turn off, thereby disconnecting the power limiting circuit 21 from the downstream circuit, thus avoiding the problem of the switching transistor burning out due to overheating and improving safety.

[0079] Optionally, the temperature sensor NTC can be a negative temperature coefficient thermistor (NTC) or a positive temperature coefficient thermistor (PTC). This application does not impose specific restrictions on this.

[0080] In one example, such as Figure 10As shown, the power drive system 2 also includes a voltage regulator circuit 26, which is located between the power supply 3 and the control circuit 24. The voltage regulator circuit 26 converts the output voltage provided by the power supply 3 into a stable voltage and outputs it to the control circuit 24, enabling the control circuit 24 to operate under clean power, thereby ensuring the operational stability of the control circuit 24 and further improving the operational stability of the power drive system 2. For example, as... Figure 11 As shown, the voltage regulator circuit 26 may include a sixteenth capacitor C16, a seventeenth capacitor C17, and a linear regulator U2. The sixteenth capacitor C16 and the seventeenth capacitor C17 are filter capacitors. The linear regulator U2 can convert the output voltage provided by the power supply 3 into a stable voltage and output it to the control circuit 24, so that the control circuit 24 can work under a clean power supply, thereby ensuring the working stability of the control circuit 24 and further improving the working stability of the power drive system 2.

[0081] In summary, in the power drive system 1 provided by this application, when the power supply output voltage reaches the power limiting circuit 21, the power limiting circuit 21 limits the output power of the power supply, that is, limits the output power of the power supply 3 to no more than a preset power, and then outputs the voltage to the boost circuit 22. The boost circuit 22 raises the low voltage output by the power limiting circuit 21 to a high voltage and outputs it to the switching circuit 23. When the control circuit 24 controls the switching circuit 23 to be turned on, the high voltage output by the boost circuit 22 will be output to the high-power load 1 through the switching circuit 23 to complete the high-power drive. In this way, by limiting the output power of the power supply 3 through the power limiting circuit 21, the maximum safe power that the small power supply 3 can withstand can be guaranteed, and the power supply 3 will not exceed its own safe power when driving the high-power load 1, thereby improving the service life of the power supply 3. Secondly, by limiting the output power of the power supply 3 through the power limiting circuit 21, the output voltage of the power supply 3 can be made more stable, thereby ensuring the reliability of power supply to the control circuit 24 and other peripherals. That is, the control circuit 24 and other peripherals will not be affected by the high-power load 1, thus ensuring the reliability of the control circuit 24 in controlling the switching circuit 23, and thus ensuring the working stability of the entire power drive system 2. Furthermore, the inductors and switching transistors in the power drive system 2 provided in this application are all low-power devices, eliminating the need for high-power devices, thereby reducing costs and the size of the power drive system 2.

[0082] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0083] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0084] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0085] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0086] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A power drive system for a high-power load, characterized in that, The power drive system includes: A power limiting circuit, wherein the first terminal of the power limiting circuit is connected to a power source, and the power limiting circuit is used to limit the output power of the power source from not exceeding a preset power. A boost circuit, wherein the first terminal of the boost circuit is connected to the second terminal of the power limiting circuit; A switching circuit, wherein a first terminal of the switching circuit is connected to a second terminal of the boost circuit, and the second terminal of the switching circuit is connected to the high-power load; and... A control circuit, wherein a first terminal of the control circuit is connected to the power supply and the first terminal of the power limiting circuit, and a second terminal of the control circuit is connected to the controlled terminal of the switching circuit, and the control circuit is used to control the on / off state of the switching circuit.

2. The power drive system for high-power loads according to claim 1, characterized in that, The power limiting circuit includes: A first diode, the positive terminal of which is connected to the power supply; A power limiting module, wherein a first terminal of the power limiting module is connected to the negative terminal of the first diode, and a second terminal of the power limiting module is grounded; and, The first energy storage module has a first terminal connected to the third terminal of the power limiting module, a second terminal grounded, and a third terminal connected to the first terminal of the boost circuit.

3. The power drive system for high-power loads according to claim 2, characterized in that, The power limiting module includes a first resistor, a second resistor, a second diode, a first switch, and a second switch; One end of the first resistor is connected to the cathode of the first diode, the cathode of the second diode, and the first terminal of the first switch. The other end of the first resistor is connected to one end of the second resistor and the first terminal of the second switch. The other end of the second resistor is connected to the anode of the second diode and the controlled terminal of the first switch. The second terminal of the first switch is connected to the controlled terminal of the second switch and grounded. The second terminal of the second switch is connected to the first terminal of the first energy storage module.

4. The power drive system for high-power loads according to claim 1, characterized in that, The boost circuit includes: A driver chip, wherein a first terminal of the driver chip is connected to a second terminal of the power limiting circuit; A protection module, wherein a first terminal of the protection module is connected to a first terminal of the driver chip and a second terminal of the power limiting circuit, a second terminal of the protection module is connected to a second terminal of the driver chip, and a third terminal of the protection module is connected to a third terminal of the driver chip; and, The second energy storage module has its first terminal connected to the fourth terminal of the protection module, its second terminal grounded, and its third terminal connected to the first terminal of the switching circuit.

5. The power drive system for high-power loads according to claim 4, characterized in that, The protection module includes an inductor, a third switch, a third resistor, a first capacitor, and a fourth resistor; One end of the inductor is connected to the first end of the driver chip and the second end of the power limiting circuit. The other end of the inductor is connected to the first end of the third switch and the first end of the second energy storage module. One end of the third resistor is connected to the second end of the driver chip. The other end of the third resistor is connected to the controlled end of the third switch. The second end of the third switch is connected to one end of the fourth resistor. The other end of the fourth resistor is connected to the first plate of the first capacitor and the third end of the driver chip. The second plate of the first capacitor is grounded.

6. The power drive system for high-power loads according to claim 4, characterized in that, The boost circuit also includes: The feedback module has a first terminal connected to the third terminal of the second energy storage module, a second terminal grounded, and a third terminal connected to the fourth terminal of the driver chip.

7. The power drive system for high-power loads according to claim 1, characterized in that, The switching circuit includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fourth switch, and a fifth switch; One end of the fifth resistor is connected to the second terminal of the boost circuit and the first terminal of the fourth switch. The other end of the fifth resistor is connected to the controlled terminal of the fourth switch and one end of the sixth resistor. The second terminal of the fourth switch is connected to the high-power load. The other end of the sixth resistor is connected to the first terminal of the fifth switch. The second terminal of the fifth switch is grounded. The controlled terminal of the fifth switch is connected to one end of the seventh resistor and one end of the eighth resistor. The other end of the seventh resistor is grounded. The other end of the eighth resistor is connected to the second terminal of the control circuit.

8. The power drive system for a high-power load according to any one of claims 1-7, characterized in that, The power drive system also includes: A temperature detection circuit is provided, wherein a first terminal of the temperature detection circuit is connected to a third terminal of the control circuit. The temperature detection circuit is used to detect the current temperature of the power limiting circuit and send it to the control circuit. The control circuit is used to control the on / off state of the switching circuit based on the current temperature.

9. The power drive system for a high-power load according to claim 8, characterized in that, The temperature detection circuit includes a ninth resistor, a temperature sensor, and a second capacitor. One end of the ninth resistor is connected to the power supply voltage, and the other end of the ninth resistor is connected to one end of the temperature sensor, the first plate of the second capacitor, and the third end of the control circuit. The other end of the temperature sensor and the second plate of the second capacitor are grounded.

10. An electronic device, characterized in that, include: High-power load; as well as, The power drive system for a high-power load as described in claims 1-9, wherein the power drive system is connected to the high-power load.

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