Flight control power supply protection circuit

Abstract

The flight control power supply protection circuit comprises a high-reliability switch power supply module, an undervoltage detection module, an electric load module, a resistance voltage division and AD conversion module, a current sampling resistance module, a current AD conversion module and an MCU module. The high-reliability switch power supply circuit is used for transmitting power to the electricity load module; the under-voltage detection circuit is used for outputting a power supply protection signal if the power supply voltage output by the high-reliability switch power supply module is too low; the resistance voltage division and AD conversion module is used for performing resistance voltage division and AD conversion on the output voltage; the current sampling resistor module is used for acquiring a current sampling signal of a power supply; the current AD conversion module is used for amplifying the current sampling signal and then performing AD conversion; and the MCU module is used for receiving and detecting the converted current and voltage, and deciding whether to carry out autonomous power supply protection or to carry out power supply protection by the MCU according to the working state and the flight height of the aircraft. Special application requirements of the aircraft are fully considered, and the circuit is simple and high in reliability.

Description

Technical Field

[0001] The present application relates to the field of rockets, and in particular, to a flight control power supply protection circuit. Background Art

[0002] Flight control refers to the control system of the aircraft. The back end of the flight control system often has huge power-consuming equipment, such as propeller motors or rudder servo motors. In order to make the battery of the aircraft work more safely and have a longer service life, and to ensure that the aircraft itself works more safely, the power supply of the flight control system needs to be protected. At present, there are many aircraft on the market whose power supply circuits are directly controlled by only one switch, and there are basically no power supply protection measures. Most aircraft are equipped with power switches, voltage and current monitoring, and undervoltage and overcurrent protection. This design is relatively conventional. However, since the aircraft is a device flying in the sky, the requirements for power safety are higher. Therefore, in addition to conventional power supply protection, it is necessary to further optimize and improve the reliability of power supply.

[0003] Therefore, how to provide a power supply protection circuit that fully considers the special application requirements of aircraft has become an issue that urgently needs to be solved in the field. Summary of the invention

[0004] The present application proposes a method including: a high-reliability switch power supply module, an undervoltage detection module, a power load module, a resistor voltage division and AD conversion module, a current sampling resistor module, a current AD conversion module, an MCU module and a power supply protection output module; a high-reliability switch power supply circuit for transmitting power to the power load module; an undervoltage detection circuit for directly outputting a power supply protection signal from the power supply protection output module if the power supply voltage output by the high-reliability switch power supply module is too low; a resistor voltage division and AD conversion module for performing resistor voltage division and AD conversion on the voltage output by the high-reliability switch power supply module and then sending it to the MCU module; a current sampling resistor module The module is used to obtain the current sampling signal of the power supply; the current AD conversion module is used to amplify the current sampling signal and perform AD conversion on it, and send it to the MCU module; the MCU module is used to receive the resistor voltage division and the voltage after AD conversion and detect it, as well as receive the current signal after amplification and AD conversion and detect whether the current is within the normal range. The MCU module decides whether to perform power supply protection autonomously or by the MCU according to the working status and flight altitude of the aircraft. If power supply protection is performed autonomously, the power supply protection output module outputs an autonomous protection instruction to the high-reliability switch power supply module, and the high-reliability switch power supply module performs autonomous power supply.

[0005] As above, the high-reliability switch power supply module includes: a power supply (BT1), a Zener diode (Z1), a Zener diode (Z2) and a Zener diode (Z3), a resistor (R1), a resistor (R2), a resistor (R3), a resistor (R4), a resistor (R5), a resistor (R6) and a resistor (R7), a PMOS tube (Q1), a PMOS tube (Q2), a transistor (Q4) and a transistor (Q5), a diode (D1), a capacitor (C1) and a capacitor (C2).

[0006] As above, wherein the positive electrode of the power supply (BT1) is connected to the negative electrode of the Zener diode (Z2), the positive electrode of the Zener diode (Z2) is connected to one end of the resistor (R4), and the other end of the resistor (R4) is connected to the negative electrode of the power supply (BT1); the positive electrode of the Zener diode (Z2) is connected to one end of the resistor (R5), the other end of the resistor (R5) is connected to one end of the capacitor (C2), and the other end of the capacitor (C2) is connected to the negative electrode of the power supply (BT1); the other end of the resistor (R5) is also connected to the base of the triode (Q4), the collector of the triode (Q4) is connected to one end of the resistor (R6), the other end of the resistor (R6) is connected to one end of the resistor (R3), and the emitter of the triode (Q4) is connected to the negative electrode of the power supply (BT1); the other end of the resistor (R5) is also connected to the collector end of the triode (Q5), the emitter end of the triode (Q5) is connected to the negative electrode of the power supply, and the triode (Q4) is connected to the base of the triode (Q4), the collector of the triode (Q4) is connected to one end of the resistor (R6), the other end of the resistor (R6) is connected to one end of the resistor (R3), and the emitter of the triode (Q4) is connected to the negative electrode of the power supply (BT1); The base of the diode (Q5) is connected to one end of the resistor (R9), and the other end of the resistor (R9) is connected to the power-off control signal input end; the positive electrode of the power supply is connected to one end of the resistor (R1), and the other end of the resistor (R1) is connected to one end of the capacitor (C1), and the other end of the capacitor (C1) is connected to the positive electrode of the power supply (BT1); the other end of the resistor (R1) is also connected to the positive electrode of the voltage regulator tube (Z3), the negative electrode of the voltage regulator tube (Z3) is respectively connected to the positive electrode of the power supply and the negative electrode of the voltage regulator tube (Z1), the positive electrode of the voltage regulator tube (Z1) is connected to the s electrode of the PMOS tube (Q1), the d electrode of the PMOS tube (Q1) is connected to the positive electrode of the power supply (BT1), the g electrode of the PMOS tube (Q1) is connected to the other end of the resistor (R2), the b electrode of the PMOS tube (Q1) is connected to the d electrode of the PMOS tube (Q2), and the b electrode of the PMOS tube (Q1) is also connected to the b electrode of the PMOS tube (Q2).

[0007] As described above, the voltage zener diode Z2 and the resistor R4 form a low voltage detection circuit. When the battery voltage is lower than the breakdown voltage of the voltage zener diode (Z2), the transistor (Q4) is in a disconnected state. When the battery voltage is higher than the breakdown voltage of the voltage zener diode (Z2), the transistor (Q4) is in a conducting state. When the transistor (Q4) is in a conducting state, the connection point of the resistors (R2), (R3), and (R6) is in a low voltage state, thereby turning on the PMOS tube (Q1) and the PMOS tube (Q2), and the power supply supplies power to the outside.

[0008] As above, the resistor (R5) and the capacitor (C2) form an RC low-pass filter. When the voltage-stabilizing diode (Z2) is turned on, the transistor (Q4) is turned on after a delay due to the RC filter to prevent power-on shock. When the voltage-stabilizing diode (Z2) is turned off, the capacitor (C2) voltage will quickly fall below the transistor base voltage, thereby turning off the transistor (Q4).

[0009] As mentioned above, the PMOS tube (Q1) and the PMOS tube (Q2) are high current PMOS tubes.

[0010] As mentioned above, the PMOS tube (Q1) and the PMOS tube (Q2) are mutually redundant power switches.

[0011] As mentioned above, the power-off control signal input terminal is the input terminal for the MCU module to send a power-off signal. The power-off signal sent by the MCU module through the power-off control signal input terminal acts on the base of the transistor (Q4) through the resistor (R7) and the transistor (Q5). Once the transistor (Q5) is turned on, the base of the transistor (Q4) is low, and the PMOS switch formed by the connection between the transistor (Q5) and the transistor (Q4) will be disconnected.

[0012] As above, the circuit structure of the MCU module for current detection includes: the positive electrode of the power supply (BT2) is connected to the high-reliability switch power supply circuit module, the high-reliability switch power supply circuit module is connected to the power load, the power load is connected to the current sampling resistor module, the two ends of the current sampling resistor module are respectively connected to the input end of the operational amplifier, and the negative electrode of the power supply (BT2) is connected to the input end of the operational amplifier; the output end of the operational amplifier is connected to one end of the resistor (R8), the other end of the resistor (R8) is connected to one end of the capacitor (C3), and the other end of the capacitor (C3) is connected to the equipotential end; the other end of the resistor (R8) is also connected to the current AD conversion module. The block is connected, the current AD conversion module is connected to the MCU module; the other end of the resistor (R8) is also connected to the + input end of the comparator, the overcurrent reference voltage is connected to the - input end of the comparator, the output end of the comparator is connected to the MCU module, the output end of the comparator is also connected to one end of the resistor (R10), and the other end of the resistor (R10) is connected to the equipotential end; the output end of the comparator is also connected to the single-pole double-throw switch, the single-pole double-throw switch is connected to the automatic power-off protection signal output end, the single-pole double-throw switch is also connected to one end of the resistor (R9), and the other end of the resistor (R9) is connected to the equipotential end; the MCU module is connected to the MCU decision power-off protection signal output end.

[0013] As mentioned above, the MCU module decides whether to perform power-off protection output according to different working conditions, which are mainly divided into the following working conditions: when the aircraft is on the ground, the MCU controls SPDT1 to switch to the automatic power-off protection signal output path, and the circuit performs protection autonomously; when the aircraft has taken off, the high-reliability switch power supply circuit module switches to the floating state. If the flight altitude is lower than 1 meter, the MCU needs to make a decision based on the overcurrent duration; when the overcurrent signal duration is less than t, the power will not be shut down, and when the overcurrent signal duration is greater than t, an emergency shutdown will be performed; when the aircraft altitude is greater than 1 meter, even if an overcurrent abnormality occurs, the MCU module will not send an overcurrent protection signal, but instead notify the flight control to enter the abnormal working mode; when the aircraft is on the ground or has just taken off, if the voltage and current sampled by the MCU module are not within the normal range, power-off protection will be performed immediately.

[0014] This application has the following beneficial effects:

[0015] The power supply reliability design of this application fully considers the special application requirements of the aircraft. At the same time, the circuit is simple, the principle is clear, the circuit protection mechanisms are complete, and the reliability is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic diagram of the internal structure of the flight control power supply protection circuit provided according to an embodiment of the present application;

[0018] Figure 2 1 is a circuit structure diagram of a flight control power supply protection circuit provided according to an embodiment of the present application;

[0019] Figure 3 It is another circuit structure diagram of the flight control power supply protection circuit provided according to the embodiment of the present application. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0021] The present application provides a flight control power supply protection circuit, which introduces the flight status and flight altitude of the aircraft into the power supply protection decision. The power switch MOS is prone to failure, so a redundant MOS power switch is provided. The MOS switch is also protected from overvoltage, soft power-on, and reverse peak elimination of the power load.

[0022] Embodiment 1

[0023] like Figure 1 As shown, this embodiment provides a flight control power supply protection circuit, which specifically includes: a high-reliability switch power supply module 101, an undervoltage detection module 102, a power load module 103, a resistor voltage divider and AD conversion module 104, a current sampling resistor module 105, a current AD conversion module 106, an MCU module 107 and a power supply protection output module 108.

[0024] The high-reliability switch power supply circuit 101 is used to deliver power to the power load module 103 .

[0025] The undervoltage detection circuit 102 is connected to the high-reliability switch power supply module 101 and the power supply protection output module 108 respectively, and is used for the power supply protection output module 108 to directly output a power supply protection signal if the power supply voltage output by the high-reliability switch power supply module 101 is too low.

[0026] The resistor voltage division and AD conversion module 104 is connected to the high-reliability switch power supply module 101 , and is used to perform resistor voltage division and AD conversion on the voltage outputted by the high-reliability switch power supply module 101 , and then send the result to the MCU module 107 .

[0027] The current sampling resistor module 105 is connected to the power load module 103 and is used to obtain a current sampling signal of the power supply.

[0028] The current AD conversion module 106 is connected to the current sampling resistor module 105 and is used to amplify the current sampling signal, perform AD conversion, and send the amplified current sampling signal to the MCU module 107 .

[0029] The MCU module 107 is respectively connected to the resistor voltage division and AD conversion module 104, the current AD conversion module 106 and the power supply protection output module 108, and is used to receive the resistor voltage division and the voltage after AD conversion and perform detection, as well as receive the current signal after amplification and AD conversion and detect whether the current is within a normal range. If the voltage and current sampled by the MCU module are not within the normal range, power-off protection is immediately performed.

[0030] The MCU module 107 also decides whether to perform power supply protection autonomously or by the MCU's code logic according to the aircraft's operating status and flight altitude. If power supply protection is performed autonomously, the power supply protection output module 108 outputs autonomous protection instructions to the high-reliability switch power supply module 101.

[0031] Among them Figure 2 As shown, the specific circuit structure of the high-reliability switch power supply module 101 includes: a power supply BT1, voltage-stabilizing diodes Z1, Z2, and Z3, resistors R1-R7, PMOS tubes Q1 and Q2, transistors Q4 and Q5, a diode D1, and capacitors C1 and C2.

[0032] The positive electrode of the power supply BT1 is connected to the negative electrode of the voltage zener diode Z2, the positive electrode of the voltage zener diode Z2 is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the negative electrode of the power supply BT1.

[0033] The positive electrode of the voltage zener diode Z2 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to one end of the capacitor C2, and the other end of the capacitor C2 is connected to the negative electrode of the power supply BT1.

[0034] The other end of the resistor R5 is also connected to the base of the transistor Q4, the collector of the transistor Q4 is connected to one end of the resistor R6, the other end of the resistor R6 is connected to one end of the resistor R3, and the emitter of the transistor Q4 is connected to the negative electrode of the power supply BT1.

[0035] The other end of the resistor R5 is also connected to the collector end of the transistor Q5, the emitter end of the transistor Q5 is connected to the negative pole of the power supply, the base of the transistor Q5 is connected to one end of the resistor R7, and the other end of the resistor R7 is connected to the power-off control signal input end.

[0036] The positive electrode of the power supply is connected to one end of the resistor R1 , the other end of the resistor R1 is connected to one end of the capacitor C1 , and the other end of the capacitor C1 is connected to the positive electrode of the power supply BT1 .

[0037] The other end of the resistor R1 is also connected to the positive electrode of the voltage regulator tube Z3, the negative electrode of the voltage regulator tube Z3 is respectively connected to the positive electrode of the power supply and the negative electrode of the voltage regulator tube Z1, the positive electrode of the voltage regulator tube Z1 is connected to the s electrode of the PMOS tube Q1, the d electrode of the PMOS tube Q1 is connected to the positive electrode of the power supply BT1, the g electrode of the PMOS tube Q1 is connected to the other end of the resistor R2, the b electrode of the PMOS tube Q1 is connected to the d electrode of the PMOS tube Q2, and the b electrode of the PMOS tube Q1 is also connected to the b electrode of the PMOS tube Q2.

[0038] The other end of the resistor R1 is also connected to one end of the resistor R2 and the resistor R3, the other end of the resistor R3 is connected to the g pole of the PMOS tube Q2, the s pole of the PMOS tube Q2 is connected to one end of the electrical load, the other end of the electrical load is connected to the cathode of the diode D1, the anode of the diode D1 is connected to the output voltage detection end, and the s pole of the PMOS tube Q2 is also connected to the output voltage detection end.

[0039] The working principle of the high-reliability switch power supply module circuit is:

[0040] Z2 is a voltage-stabilizing diode. It and R4 form a reliable low-voltage detection circuit. When the battery voltage is lower than the breakdown voltage of Z2, Q4 is in the disconnected state. When the battery voltage is higher than the breakdown voltage of Z2, Q4 is in the on state. When Q4 is in the on state, the connection point of R2, R3, and R6 is in a low-voltage state, so that Q1 and Q2 are turned on, that is, the power supply is supplied to the outside. R5 and C2 form an RC low-pass filter. When Z2 is turned on, Q4 will be turned on for a period of time due to the RC filter, thereby preventing power-on shock. But when Z2 is disconnected, the C2 voltage will quickly fall below the base voltage of the transistor, causing Q4 to disconnect quickly.

[0041] Q1 and Q2 are high-current PMOS tubes, which can improve reliability as redundant power switches. Z1 is used to protect Q1 and Q2 from being damaged by Vds (source-drain voltage difference) voltage shock, Z3 is used to protect Q1 and Q2 from being damaged by Vgs (source-gate voltage difference) voltage shock, and R2 and R3 are used to prevent damage to one PMOS and affect the normal operation of the other PMOS. R1 and C1 also form an RC circuit, which can make the PMOS turn on slowly, thereby preventing the power supply circuit from generating instantaneous impact current.

[0042] The power-off signal sent by the MCU module through the power-off control signal input terminal acts on the base of Q4 through R7 and Q5. Once Q5 is turned on, the base of Q4 is low, and the PMOS switch formed by the connection of Q5 and Q4 will be disconnected.

[0043] Since the aircraft's electrical load includes a high-power motor, in order to prevent the reverse electromotive force generated at the moment of power failure from affecting the power supply circuit, a reverse-electromotive force diode D1 needs to be connected in parallel to the electrical load.

[0044] The output voltage of Q1 and Q2 needs to pass through a resistor divider circuit, followed by AD conversion, and then the output voltage value is transmitted to the MCU through the output voltage detection terminal to determine whether the output voltage is normal.

[0045] like Figure 3 As shown, it is a circuit diagram of the MCU module performing current detection and the circuit autonomously performing overcurrent protection, wherein SPDT2 represents a high-reliability switch power supply circuit module, RL represents a power load module, and Rs represents a current sampling resistor module.

[0046] The positive pole of the power supply BT2 is connected to the high-reliability switch power supply circuit module, the high-reliability switch power supply circuit module is connected to the power load RL, the power load RL is connected to the current sampling resistor module, the two ends of the current sampling resistor module are respectively connected to the input ends of the operational amplifier, and the negative pole of the power supply BT2 is connected to the input end of the operational amplifier.

[0047] The output end of the operational amplifier is connected to one end of the resistor R8 , the other end of the resistor R8 is connected to one end of the capacitor C3 , and the other end of the capacitor C3 is connected to the equipotential terminal.

[0048] The other end of the resistor R8 is also connected to the current AD conversion module, and the current AD conversion module is connected to the MCU.

[0049] The other end of resistor R8 is also connected to the + input end of the comparator, the overcurrent reference voltage is connected to the - input end of the comparator, the output end of the comparator is connected to the MCU module, the output end of the comparator is also connected to one end of resistor R10, and the other end of resistor R10 is connected to the equipotential end.

[0050] The output end of the comparator is also connected to the single-pole double-throw switch SPDT1, the single-pole double-throw switch SPDT1 is connected to the automatic power-off protection signal output end, the single-pole double-throw switch SPDT1 is also connected to one end of the resistor R9, and the other end of the resistor R9 is connected to the equipotential end.

[0051] The MCU module is connected to the MCU decision power-off protection signal output terminal.

[0052] Figure 3 The working principle is: the voltage across the current sampling resistor is first amplified by the operational amplifier, and then filtered by the RC combination of R8 and C3 to remove high-frequency noise and obtain a relatively smooth current signal. The signal is converted by the AD current sampling circuit and received and judged by the MCU.

[0053] The current signal is then compared with the overcurrent reference voltage through a comparator. If an overcurrent occurs, the input voltage of SPDT1 (single-pole double-throw switch) is high, and if no overcurrent occurs, it is low. The R10 resistor is used to pull down the overcurrent signal to prevent the comparator from being in an unstable state at the moment of power-on. The overcurrent signal also needs to be directly input to the MCU pin as an interrupt signal. When the overcurrent state changes, the MCU can sense it immediately and make the next decision.

[0054] SPDT1 is controlled by MCU, which can control the overcurrent signal to be directly connected to the automatic power-off protection signal output terminal, or it can be left floating. When the automatic power-off protection signal output path is used, the circuit will autonomously control the power-off protection. R9 is used to pull down and clamp the automatic power-off protection signal to avoid accidental triggering of the automatic power-off protection signal when the switch is floating.

[0055] The MCU can decide whether to perform power-off protection output according to different input conditions, which are mainly divided into the following working conditions:

[0056] 1. The aircraft is in the ground state, whether it has not taken off, has landed, or has landed unexpectedly, as long as it is in the ground state, the MCU controls SPDT1 to switch to the automatic power-off protection signal output path, and the circuit is autonomously protected.

[0057] 2. When the aircraft has taken off, SPDT1 switches to the floating state. If the flight altitude is less than 1 meter, an emergency shutdown will not seriously damage the aircraft. At this time, the MCU needs to make a decision based on the overcurrent duration. When the overcurrent signal duration is less than t, the aircraft will not be shut down. When the overcurrent signal duration is greater than t, an emergency shutdown will be performed.

[0058] 3. When the aircraft altitude is greater than 1 meter, even if an overcurrent abnormality occurs, the MCU does not send an overcurrent protection signal, but instead notifies the flight control to enter an abnormal working mode.

[0059] 4. When the aircraft is on the ground or just takes off, there is no altitude or the altitude is very low. If the voltage and current sampled by the MCU are not within the normal range, power-off protection will be performed immediately.

[0060] Beneficial effects of this application:

[0061] The power supply reliability design of this application fully considers the special application requirements of the aircraft. At the same time, the circuit is simple, the principle is clear, the circuit protection mechanisms are complete, and the reliability is high.

[0062] Although the present application is described with reference to examples, this is for illustrative purposes only and is not intended to limit the present application, and changes, additions and / or deletions to the embodiments may be made without departing from the scope of the present application.

[0063] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A flight control power supply protection circuit, characterized in that: include: High-reliability switch power supply module, undervoltage detection module, power load module, resistor voltage division and AD conversion module, current sampling resistor module, current AD conversion module, MCU module and power supply protection output module; High-reliability switch power supply circuit, used to deliver power to the power load module; The undervoltage detection circuit is used for directly outputting a power supply protection signal from the power supply protection output module if the power supply voltage output by the high-reliability switch power supply module is too low; The resistor voltage division and AD conversion module is used to divide the voltage output by the high-reliability switch power supply module by resistors, perform AD conversion, and then send it to the MCU module; A current sampling resistor module is used to obtain a current sampling signal of a power supply; The current AD conversion module is used to amplify the current sampling signal, perform AD conversion, and send it to the MCU module; The MCU module is used to receive and detect the voltage after resistor voltage division and AD conversion, as well as to receive the current signal after amplification and AD conversion and detect whether the current is within the normal range. The MCU module decides whether to perform power supply protection autonomously or by the MCU according to the working status and flight altitude of the aircraft. If power supply protection is performed autonomously, the power supply protection output module outputs an autonomous protection instruction to the high-reliability switch power supply module, and the high-reliability switch power supply module performs autonomous power supply.

2. The flight control power supply protection circuit according to claim 1, characterized in that: The high-reliability switch power supply module includes: a power supply (BT1), a Zener diode (Z1), a Zener diode (Z2) and a Zener diode (Z3), a resistor (R1), a resistor (R2), a resistor (R3), a resistor (R4), a resistor (R5), a resistor (R6) and a resistor (R7), a PMOS tube (Q1), a PMOS tube (Q2), a triode (Q4) and a triode (Q5), a diode (D1), a capacitor (C1) and a capacitor (C2).

3. The flight control power supply protection circuit according to claim 2, characterized in that: The positive electrode of the power supply (BT1) is connected to the negative electrode of the voltage zener diode (Z2), the positive electrode of the voltage zener diode (Z2) is connected to one end of the resistor (R4), and the other end of the resistor (R4) is connected to the negative electrode of the power supply (BT1); The positive electrode of the voltage zener diode (Z2) is connected to one end of the resistor (R5), the other end of the resistor (R5) is connected to one end of the capacitor (C2), and the other end of the capacitor (C2) is connected to the negative electrode of the power supply (BT1); The other end of the resistor (R5) is also connected to the base of the transistor (Q4), the collector of the transistor (Q4) is connected to one end of the resistor (R6), the other end of the resistor (R6) is connected to one end of the resistor (R3), and the emitter of the transistor (Q4) is connected to the negative electrode of the power supply (BT1); The other end of the resistor (R5) is also connected to the collector end of the transistor (Q5), the emitter end of the transistor (Q5) is connected to the negative electrode of the power supply, the base of the transistor (Q5) is connected to one end of the resistor (R9), and the other end of the resistor (R9) is connected to the power-off control signal input end; The positive electrode of the power supply is connected to one end of the resistor (R1), the other end of the resistor (R1) is connected to one end of the capacitor (C1), and the other end of the capacitor (C1) is connected to the positive electrode of the power supply (BT1); The other end of the resistor (R1) is also connected to the positive electrode of the voltage regulator tube (Z3), the negative electrode of the voltage regulator tube (Z3) is respectively connected to the positive electrode of the power supply and the negative electrode of the voltage regulator tube (Z1), the positive electrode of the voltage regulator tube (Z1) is connected to the s electrode of the PMOS tube (Q1), the d electrode of the PMOS tube (Q1) is connected to the positive electrode of the power supply (BT1), the g electrode of the PMOS tube (Q1) is connected to the other end of the resistor (R2), the b electrode of the PMOS tube (Q1) is connected to the d electrode of the PMOS tube (Q2), and the b electrode of the PMOS tube (Q1) is also connected to the b electrode of the PMOS tube (Q2).

4. The flight control power supply protection circuit as claimed in claim 3, characterized in that: The voltage zener diode Z2 and the resistor R4 form a low voltage detection circuit. When the battery voltage is lower than the breakdown voltage of the voltage zener diode (Z2), the transistor (Q4) is in a disconnected state. When the battery voltage is higher than the breakdown voltage of the voltage zener diode (Z2), the transistor (Q4) is in a conducting state. When the transistor (Q4) is in the conducting state, the connection point of the resistors (R2), (R3) and (R6) is in a low voltage state, thereby turning on the PMOS tube (Q1) and the PMOS tube (Q2), and the power supply supplies power to the outside.

5. The flight control power supply protection circuit according to claim 4, characterized in that: The resistor (R5) and the capacitor (C2) form an RC low-pass filter. When the Zener diode (Z2) is turned on, the transistor (Q4) is turned on for a period of time due to the RC filter to prevent power-on shock. When the Zener diode (Z2) is turned off, the capacitor (C2) voltage will quickly fall below the transistor base voltage, causing the transistor (Q4) to turn off.

6. The flight control power supply protection circuit according to claim 5, characterized in that: The PMOS tube (Q1) and the PMOS tube (Q2) are high-current PMOS tubes.

7. The flight control power supply protection circuit according to claim 6, characterized in that: The PMOS tube (Q1) and the PMOS tube (Q2) are mutually redundant power switches.

8. The flight control power supply protection circuit according to claim 7, characterized in that: The power-off control signal input terminal is the input terminal for the MCU module to send a power-off signal. The power-off signal sent by the MCU module through the power-off control signal input terminal acts on the base of the transistor (Q4) through the resistor (R7) and the transistor (Q5). Once the transistor (Q5) is turned on, the base of the transistor (Q4) is low, and the PMOS switch formed by the connection between the transistor (Q5) and the transistor (Q4) will be disconnected.

9. The flight control power supply protection circuit according to claim 1, characterized in that: The circuit structure of the MCU module for current detection includes: The positive electrode of the power supply (BT2) is connected to the high-reliability switch power supply circuit module, the high-reliability switch power supply circuit module is connected to the power load, the power load is connected to the current sampling resistor module, the two ends of the current sampling resistor module are respectively connected to the input end of the operational amplifier, and the negative electrode of the power supply (BT2) is connected to the input end of the operational amplifier; The output end of the operational amplifier is connected to one end of a resistor (R8), the other end of the resistor (R8) is connected to one end of a capacitor (C3), and the other end of the capacitor (C3) is connected to an equipotential terminal; The other end of the resistor (R8) is also connected to the current AD conversion module, and the current AD conversion module is connected to the MCU module; The other end of the resistor (R8) is also connected to the + input end of the comparator, the overcurrent reference voltage is connected to the - input end of the comparator, the output end of the comparator is connected to the MCU module, the output end of the comparator is also connected to one end of the resistor (R10), and the other end of the resistor (R10) is connected to the equipotential terminal; The output end of the comparator is also connected to a single-pole double-throw switch, the single-pole double-throw switch is connected to the automatic power-off protection signal output end, the single-pole double-throw switch is also connected to one end of a resistor (R9), and the other end of the resistor (R9) is connected to an equipotential end; The MCU module is connected to the MCU decision power-off protection signal output terminal.

10. The flight control power supply protection circuit according to any one of claims 1 to 9, characterized in that: The MCU module decides whether to perform power-off protection output according to different working conditions, which are mainly divided into the following working conditions: When the aircraft is on the ground, the MCU controls SPDT1 to switch to the automatic power-off protection signal output path, and the circuit performs protection autonomously; When the aircraft has taken off, the high-reliability switch power supply circuit module switches to the floating state. If the flight altitude is less than 1 meter, the MCU needs to make a decision based on the overcurrent duration. If the overcurrent signal duration is less than t, the device will not shut down. If the overcurrent signal duration is greater than t, an emergency shutdown will be performed. When the aircraft altitude is greater than 1 meter, even if an overcurrent abnormality occurs, the MCU module does not send an overcurrent protection signal, but instead notifies the flight control to enter the abnormal working mode; When the aircraft is on the ground or just taking off, if the voltage and current sampled by the MCU module are not within the normal range, power-off protection will be performed immediately.

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