Large-current on-off control circuit of unmanned aerial vehicle

Abstract

The invention provides an unmanned aerial vehicle large current on-off control circuit, which comprises a DC-DC switching power supply voltage reduction module, a DC-DC linear power supply voltage reduction module and a switch module, and is characterized in that the DC-DC switching power supply voltage reduction module is used for reducing a battery voltage VCC and outputting a 5V direct current to the DC-DC linear power supply voltage reduction module; the DC-DC linear power supply voltage reduction module is used for outputting constant current to the switch module; and the switch module adopts an optocoupler device to drive a plurality of NMOS switch chips and control the output of the battery voltage VCC. The problems that a traditional switch is prone to sparking, poor in vibration resistance, incapable of conducting positive electrode on-off control and the like are solved, the circuit conducts on-off control on the positive electrode of the power source, avionics integration is easy, and extension can be conducted according to the requirement for the magnitude of overcurrent.

Description

Technical Field

[0001] The present invention belongs to the field of unmanned aerial vehicles, and in particular, relates to a high-current on-off control circuit for unmanned aerial vehicles. Background Art

[0002] Traditional industrial drones (pure electric, hybrid, etc.) are mostly powered by direct plug-in batteries, which are prone to ignition during connection and damage to electronic components. Some industrial drones (pure electric, hybrid, etc.) use electromagnetic relays or mechanical hard switches for contact, and there is still a risk of ignition and burning electronic components. On the other hand, electromagnetic relays and mechanical hard switches are not only large in size, but also heavy, which will reduce the payload capacity of drones. At the same time, the strong vibration environment of drones can easily cause switch failure and lead to greater losses. Some industrial drones (pure electric, hybrid, etc.) use electronic switching technology, which basically controls the negative pole of the power supply. Although this method has a relatively simple driving circuit, it is easy to bypass the channel due to the strong coupling of the reference level, and cannot achieve a complete power-off function. Summary of the invention

[0003] An embodiment of the present application provides a high-current on-off control circuit for a UAV, which performs on-off control on the positive pole of a power supply, is not only easy to integrate with avionics, but can also be expanded according to the overcurrent requirements.

[0004] The present application provides a high-current on-off control circuit for an unmanned aerial vehicle, comprising: a DC-DC switching power supply step-down module, a DC-DC linear power supply step-down module and a switch module, wherein the DC-DC switching power supply step-down module is used to step down a battery voltage VCC and output 5V direct current to the DC-DC linear power supply step-down module; the DC-DC linear power supply step-down module is used to output a constant current to the switch module; the switch module uses an optocoupler device to drive multiple NMOS switch chips to control the output of the battery voltage VCC.

[0005] Wherein, the DC-DC switching power supply step-down module includes a chip U1, a pin 1 of the chip U1 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is connected to a pin 8; a pin 2 of the chip U1 is connected to a battery voltage VCC and one end of a resistor R1, the battery voltage VCC is connected to one end of a capacitor C2, and the other end of the capacitor C2 is grounded; a pin 3 of the chip U1 is connected to the other end of the resistor R1, one end of the resistor R4, one end of a capacitor C5, and one end of a resistor R7, and the other end of the resistor R4 and the other end of the capacitor C5 are both grounded; the other end of the resistor R7 is connected to the collector of the transistor Q1, the emitter of the transistor Q1 is grounded, the base of the transistor Q1 is connected to one end of a resistor R10 and one end of a resistor R8, the other end of the resistor R10 is grounded, and the other end of the resistor R8 is connected to TRIG-; TRIG+ is connected to one end of the capacitor C8, the resistor R 9 is connected, the other end of capacitor C8 is grounded, and the other end of resistor R9 is connected to the battery voltage VCC; pin 4 of chip U1 is connected to one end of resistor R5, and the other end of resistor R5 is grounded; the pin of chip U1 is connected to one end of resistor R6 and one end of resistor R2, the other end of resistor R6 is grounded, the other end of resistor R2 is connected to one end of capacitor C3 and one end of capacitor C4, and the other end of capacitor C3 and the other end of capacitor C4 are both grounded; pin 6 of chip U1 is connected to one end of resistor R3 and one end of capacitor C6, the other end of resistor R3 is connected to one end of capacitor C7, and the other end of capacitor C7 and the other end of capacitor C6 are both grounded; pin 7 of chip U1 is grounded, pin 7 is connected to the positive electrode of diode D1, the negative electrode of diode D1 is connected to pin 8 and one end of inductor L1, and the other end of inductor L1 is connected to the other end of resistor R2.

[0006] Among them, chip U1 is the TPS54560DDAR buck regulator.

[0007] Among them, the DC-DC linear power supply buck module includes a chip U3, pin 1 of the chip U3 is connected to the constant current end VG1, pin 2 is connected to one end of the resistor R18, the other end of the resistor R18 is connected to the constant current end VG1, pin 3 is connected to the 5V input voltage, pin 3 is also connected to one end of the capacitor C10 and one end of the capacitor C11, the other end of the capacitor C10 and the other end of the capacitor C11 are both grounded; pin 4 is connected to pin 2, pin 4 is also connected to one end of the capacitor C12 and one end of the capacitor C13, the other end of the capacitor C12 and the other end of the capacitor C13 are both grounded.

[0008] Wherein, the chip U3 is a LM317 linear regulator.

[0009] Wherein, the switch module includes an optocoupler device U2, pin 1 of U2 is connected to the constant current end VG1, pin 3 of U2 is grounded, pin 6 of U2 is connected to one end of resistor R17 and one end of resistor R16, the other end of resistor R16 is connected to one end of resistor R11, one end of resistor R12, one end of resistor R13, one end of resistor R14, and one end of resistor R15, the other end of resistor R11 is connected to one end of capacitor C9, the other end of capacitor C9 is connected to VCC, the drain of NMOS transistor Q2, the drain of NMOS transistor Q3, the drain of NMOS transistor Q4, and the drain of NMOS transistor Q5 are connected to VCC, and the drain of NMOS transistor Q6 is connected to VCC. The drain of Q5 is connected to VCC, the other end of the resistor R12 is connected to the gate of the NMOS transistor Q2, the other end of the resistor R13 is connected to the gate of the NMOS transistor Q3, the other end of the resistor R14 is connected to the gate of the NMOS transistor Q4, the other end of the resistor R15 is connected to the gate of the NMOS transistor Q5, the source of the NMOS transistor Q2, the source of the NMOS transistor Q3, the source of the NMOS transistor Q4, and the source of the NMOS transistor Q5 are all connected to the port VCCOUT, and the other end of the resistor R17 is connected to pin 4 of U2 and the source of the NMOS transistor Q2.

[0010] The present application also provides a drone, comprising any of the drone high-current on-off control circuits described above.

[0011] The high current on-off control circuit of the drone in the embodiment of the present application has the following beneficial effects:

[0012] The circuit of the present application performs on-off control on the positive pole of the power supply, which is not only easy to integrate into avionics, but also can be expanded according to the overcurrent requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the structure of a high current on / off control circuit for a drone according to an embodiment of the present application;

[0014] Figure 2 This is a schematic diagram of a DC-DC switching power supply step-down circuit;

[0015] Figure 3 This is a schematic diagram of a DC-DC linear power supply step-down circuit;

[0016] Figure 4 This is a schematic diagram of the switching circuit for the optocoupler to drive the N-channel MOSFET. DETAILED DESCRIPTION

[0017] The present application is further described below in conjunction with the accompanying drawings and embodiments.

[0018] In the following introduction, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The following introduction provides multiple embodiments of the present invention, and different embodiments can be replaced or combined, so this application can also be considered to include all possible combinations of the same and / or different embodiments recorded. Therefore, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then this application should also be considered to include embodiments containing one or more of all other possible combinations of features A, B, C, and D, even though the embodiment may not be clearly recorded in the following text.

[0019] like Figure 1 As shown, the high current on-off control circuit of the drone of the present application includes: a DC-DC switching power supply buck module 10, a DC-DC linear power supply buck module 20 and a switch module 30. The DC-DC switching power supply buck module 10 is used to step down the battery voltage VCC and output 5V DC to the DC-DC linear power supply buck module; the DC-DC linear power supply buck module 20 is used to output a constant current to the switch module; the switch module 30 uses an optocoupler device to drive multiple NMOS switch chips to control the output of the battery voltage VCC.

[0020] like Figure 2As shown, the DC-DC switching power supply step-down module includes a chip U1, wherein pin 1 of the chip U1 is connected to one end of a capacitor C1, and the other end of the capacitor C1 is connected to pin 8; pin 2 of the chip U1 is connected to a battery voltage VCC and one end of a resistor R1, the battery voltage VCC is connected to one end of a capacitor C2, and the other end of the capacitor C2 is grounded; pin 3 of the chip U1 is connected to the other end of the resistor R1, one end of a resistor R4, one end of a capacitor C5, and one end of a resistor R7, and the other end of the resistor R4 and the other end of the capacitor C5 are both grounded; the other end of the resistor R7 is connected to the collector of the transistor Q1, the emitter of the transistor Q1 is grounded, the base of the transistor Q1 is connected to one end of a resistor R10 and one end of a resistor R8, the other end of the resistor R10 is grounded, and the other end of the resistor R8 is connected to TRIG-; TRIG+ is connected to one end of the capacitor C8 and the resistor R9 The other end of capacitor C8 is connected to the ground, and the other end of resistor R9 is connected to the battery voltage VCC; the pin 4 of chip U1 is connected to one end of resistor R5, and the other end of resistor R5 is grounded; the pin of chip U1 is connected to one end of resistor R6 and one end of resistor R2, and the other end of resistor R6 is grounded, and the other end of resistor R2 is connected to one end of capacitor C3 and one end of capacitor C4, and the other end of capacitor C3 and the other end of capacitor C4 are both grounded; the pin 6 of chip U1 is connected to one end of resistor R3 and one end of capacitor C6, and the other end of resistor R3 is connected to one end of capacitor C7, and the other end of capacitor C7 and the other end of capacitor C6 are both grounded; the pin 7 of chip U1 is grounded, and pin 7 is connected to the positive electrode of diode D1, and the negative electrode of diode D1 is connected to pin 8 and one end of inductor L1, and the other end of inductor L1 is connected to the other end of resistor R2. Chip U1 is a TPS54560DDAR buck regulator.

[0021] like Figure 3 As shown, the DC-DC linear power supply buck module includes a chip U3, wherein the pin 1 of the chip U3 is connected to the constant current end VG1, the pin 2 is connected to one end of the resistor R18, the other end of the resistor R18 is connected to the constant current end VG1, the pin 3 is connected to the 5V input voltage, the pin 3 is also connected to one end of the capacitor C10 and one end of the capacitor C11, the other end of the capacitor C10 and the other end of the capacitor C11 are both grounded; the pin 4 is connected to the pin 2, the pin 4 is also connected to one end of the capacitor C12 and one end of the capacitor C13, the other end of the capacitor C12 and the other end of the capacitor C13 are both grounded. The chip U3 is a LM317 linear regulator.

[0022] like Figure 4As shown, the switch module includes an optocoupler device U2, a pin 1 of U2 is connected to the constant current end VG1, a pin 3 of U2 is grounded, a pin 6 of U2 is connected to one end of a resistor R17 and one end of a resistor R16, the other end of the resistor R16 is connected to one end of a resistor R11, one end of a resistor R12, one end of a resistor R13, one end of a resistor R14, and one end of a resistor R15, the other end of the resistor R11 is connected to one end of a capacitor C9, the other end of the capacitor C9 is connected to VCC, the drain of an NMOS transistor Q2, the drain of an NMOS transistor Q3, the drain of an NMOS transistor Q4, and the drain of an NMOS transistor Q 5 are all connected to VCC, the other end of the resistor R12 is connected to the gate of the NMOS transistor Q2, the other end of the resistor R13 is connected to the gate of the NMOS transistor Q3, the other end of the resistor R14 is connected to the gate of the NMOS transistor Q4, the other end of the resistor R15 is connected to the gate of the NMOS transistor Q5, the source of the NMOS transistor Q2, the source of the NMOS transistor Q3, the source of the NMOS transistor Q4, and the source of the NMOS transistor Q5 are all connected to the port VCCOUT, and the other end of the resistor R17 is connected to the pin 4 of U2 and the source of the NMOS transistor Q2.

[0023] like Figure 2 As shown, the circuit diagram is a DC-DC switching power supply buck circuit, where U1 model is TPS54560DDAR, VCC is the battery voltage (50.4V), and after bucking, it is 5V DC. The EN pin of U1 is the enable end of the buck module. When the level is lower than 1.2V, U1 will stop working. When the transistor Q1 is not working (TRIG- and TRIG+ are disconnected), the voltage division of resistors R1 and R4 can make EN in the enabled state, thereby completing the voltage reduction function from 50.4V to 5V; when the transistor Q1 is working (TRIG- and TRIG+ are connected), the combined voltage division of resistors R1, R4, and R7 can make EN in the disabled state, and U1 will stop working. Among them, R9 and C8 are filter circuits used to suppress the level jitter when TRIG- and TRIG+ are connected; R1 and C5 are used for the delayed enable of EN. C2 is the input power filter capacitor, C3 and C4 are the output power filter capacitors, R2 and R6 are the output voltage divider feedback of the Buck circuit, R3, C6 and C7 are the switching frequency settings of the Buck circuit, L1 is the Buck circuit energy storage inductor, and D1 is the Buck circuit freewheeling diode.

[0024] like Figure 3As shown in the figure, the circuit diagram is a DC-DC linear power supply step-down circuit, where U3 is LM317, and the constant current source output mode is used to drive the optocoupler. The output current of VG1 is Vref / R18, and the output current value can be adjusted by changing the size of R18. Among them, C10 and C11 are input voltage filter capacitors, and C12 and C13 are output voltage filter capacitors.

[0025] like Figure 4 As shown in the figure, the circuit diagram is a switch circuit of an optocoupler driving an N-channel MOSFET. An optocoupler device is used to drive multiple NMOS switch chips, where the number of NMOS in parallel can be expanded according to the power demand of the actual load. VCC is connected to the positive pole of the power output, and VCCOUT is connected to the positive pole of the load; a small resistance (such as R12, R13, R14, and R15) is connected in series with the gate end of each NMOS device to prevent the drive signal from oscillating due to impedance problems during the opening process; resistor R16 is used to limit the drive current at the moment of opening; resistor R17 is used to quickly discharge energy during the shutdown process to achieve fast shutdown; R11 and C9 are connected between the gate and drain of the NMOS to adjust the Miller platform time during the opening and closing process and reduce the current spike.

[0026] Figure 2 It is a Buck circuit, which steps down the DC power VCC to output DC 5V; Figure 3 It is the DC 5V input of the linear power supply and the constant current terminal VG1 output; Figure 4 The VG1 input drives the U2 optocoupler to work, generating an isolated voltage (the voltage across R17), which is loaded between the gate and source of the NMOS device to drive the NMOS to turn on.

[0027] The large current on-off control circuit of the present application can realize NMOS parallel on-off control of large current output through the small current on-off of TRIG- and TRIG+.

[0028] When TRIG- and TRIG+ are disconnected, the transistor Q1 does not work, and the EN pin of U1 is connected to the voltage divider of R1 and R4. Figure 2 The Buck circuit works by stepping down the VCC voltage to 5V DC. Figure 3 The linear power supply circuit outputs a constant current, and the constant current output terminal VG1 drives Figure 4 The U2 optocoupler works to generate an isolated output voltage (at both ends of R17), which is loaded on both ends of the GS of the NMOS, driving both ends of the DS of the NMOS to turn on, and VCCOUT outputs the VCC voltage. According to the overcurrent capability of the NMOS device and the number of parallel connections, large current conduction can be achieved.

[0029] When TRIG- and TRIG+ are connected, the transistor Q1 works, and the EN pin of U1 is connected through the voltage divider of R1, R4, and R7. Figure 2 The Buck circuit does not work and cannot output 5V. Figure 3 The linear power supply does not work, Figure 4 The U2 optocoupler does not work and has no isolated voltage output, causing the voltage across the GS of the NMOS to be zero, turning off the NMOS device (the DS of the NMOS is not conducting and there is no output from VCCOUT), thereby achieving a large current shutdown from VCC to VCCOUT.

[0030] This solution uses an optocoupler device to drive multiple parallel NMOS to achieve high current output on-off control of the positive pole of the power supply. The number of parallel NMOS can be expanded according to the actual needs of the load. This solution uses a linear regulated power supply to power the light-emitting diode of the optocoupler device, and adopts an adjustable constant current output control mode; this solution indirectly controls the on-off of the parallel NMOS through the enable control of the switching power supply, which belongs to the electronic switch technology; the electronic switch technology proposed in this solution solves the problems of traditional switches that are easy to spark, poor vibration resistance, and cannot be on-off controlled at the positive pole.

[0031] The present application also provides a drone, comprising any of the above-mentioned drone high-current on-off control circuits.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high current on-off control circuit for drones, characterized in that: include: A DC-DC switching power supply step-down module, a DC-DC linear power supply step-down module and a switch module. The DC-DC switching power supply step-down module is used to step down the battery voltage VCC and output 5V DC to the DC-DC linear power supply step-down module; the DC-DC linear power supply step-down module is used to output a constant current to the switch module; the switch module uses an optocoupler device to drive multiple NMOS switch chips to control the output of the battery voltage VCC.

2. According to claim 1, the UAV high current on-off control circuit is characterized in that: The DC-DC switching power supply step-down module includes a chip U1, wherein a pin 1 of the chip U1 is connected to one end of a capacitor C1, and the other end of the capacitor C1 is connected to a pin 8; a pin 2 of the chip U1 is connected to a battery voltage VCC and one end of a resistor R1, the battery voltage VCC is connected to one end of a capacitor C2, and the other end of the capacitor C2 is grounded; a pin 3 of the chip U1 is connected to the other end of the resistor R1, one end of a resistor R4, one end of a capacitor C5, and one end of a resistor R7, and the other end of the resistor R4 and the other end of the capacitor C5 are both grounded; the other end of the resistor R7 is connected to the collector of the transistor Q1, the emitter of the transistor Q1 is grounded, the base of the transistor Q1 is connected to one end of a resistor R10 and one end of a resistor R8, the other end of the resistor R10 is grounded, and the other end of the resistor R8 is connected to TRIG-; TRIG+ is connected to one end of the capacitor C8 and the resistor R9. One end of the chip U1 is connected, the other end of the capacitor C8 is grounded, and the other end of the resistor R9 is connected to the battery voltage VCC; Pin 4 of the chip U1 is connected to one end of the resistor R5, and the other end of the resistor R5 is grounded; the pin of the chip U1 is connected to one end of the resistor R6 and one end of the resistor R2, the other end of the resistor R6 is grounded, the other end of the resistor R2 is connected to one end of the capacitor C3 and one end of the capacitor C4, and the other end of the capacitor C3 and the other end of the capacitor C4 are both grounded; Pin 6 of the chip U1 is connected to one end of the resistor R3 and one end of the capacitor C6, the other end of the resistor R3 is connected to one end of the capacitor C7, and the other end of the capacitor C7 and the other end of the capacitor C6 are both grounded; Pin 7 of the chip U1 is grounded, Pin 7 is connected to the positive electrode of the diode D1, the negative electrode of the diode D1 is connected to Pin 8 and one end of the inductor L1, and the other end of the inductor L1 is connected to the other end of the resistor R2.

3. According to claim 2, the UAV high current on-off control circuit is characterized in that: Chip U1 is a TPS54560DDAR buck regulator.

4. The UAV high current on-off control circuit according to any one of claims 1 to 3, characterized in that: The DC-DC linear power supply buck module includes a chip U3, pin 1 of the chip U3 is connected to the constant current end VG1, pin 2 is connected to one end of the resistor R18, the other end of the resistor R18 is connected to the constant current end VG1, pin 3 is connected to the 5V input voltage, pin 3 is also connected to one end of the capacitor C10 and one end of the capacitor C11, the other end of the capacitor C10 and the other end of the capacitor C11 are both grounded; pin 4 is connected to pin 2, pin 4 is also connected to one end of the capacitor C12 and one end of the capacitor C13, the other end of the capacitor C12 and the other end of the capacitor C13 are both grounded.

5. The UAV high current on-off control circuit according to claim 4 is characterized in that: The chip U3 is a LM317 linear regulator.

6. The UAV high current on-off control circuit according to any one of claims 1 to 3, characterized in that: The switch module includes an optocoupler device U2, wherein pin 1 of U2 is connected to a constant current end VG1, pin 3 of U2 is grounded, pin 6 of U2 is connected to one end of a resistor R17 and one end of a resistor R16, the other end of the resistor R16 is connected to one end of a resistor R11, one end of a resistor R12, one end of a resistor R13, one end of a resistor R14, and one end of a resistor R15, the other end of the resistor R11 is connected to one end of a capacitor C9, the other end of the capacitor C9 is connected to VCC, the drain of an NMOS transistor Q2, the drain of an NMOS transistor Q3, the drain of an NMOS transistor Q4, and an NMOS transistor Q5 are connected. The drains of the NMOS transistors Q2, Q3, Q4 and Q5 are all connected to VCC, the other end of the resistor R12 is connected to the gate of the NMOS transistor Q2, the other end of the resistor R13 is connected to the gate of the NMOS transistor Q3, the other end of the resistor R14 is connected to the gate of the NMOS transistor Q4, the other end of the resistor R15 is connected to the gate of the NMOS transistor Q5, the source of the NMOS transistor Q2, the source of the NMOS transistor Q3, the source of the NMOS transistor Q4 and the source of the NMOS transistor Q5 are all connected to the port VCCOUT, and the other end of the resistor R17 is connected to the pin 4 of U2 and the source of the NMOS transistor Q2.

7. A drone, characterized in that: The invention comprises the UAV high current on-off control circuit as described in any one of claims 1 to 6.

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