Unmanned aerial vehicle-mounted servo extension set and power supply circuit and filter circuit thereof

Abstract

The utility model provides an unmanned aerial vehicle servo extension set and a power supply circuit and a filter circuit thereof. The objective of the utility model is to solve the technical problem that an existing unmanned aerial vehicle servo extension set is easily interfered by power supply noise. According to the technical scheme, the filter circuit comprises a common-mode inductor, a common-mode inductor and a common-mode inductor, wherein the input end and the output end of the common-mode inductor are connected; the first capacitor is connected with positive and negative electrodes of the input end; the third capacitor is connected with positive and negative electrodes of the output end; one end of the fifth capacitor is connected with the input end anode and the other end is grounded; one end of the sixth capacitor is connected with the input end cathode and the other end is grounded; one end of the seventh capacitor is connected with the output end anode and the other end is grounded; and one end of the eighth capacitor is connected with the output end cathode and the other end is grounded. The filter circuit can greatly attenuate power supply noise, and improves the stability of a power supply circuit. In addition, the utility model also provides a power supply circuit with the filter circuit and an unmanned aerial vehicle-mounted servo extension set.

Description

TECHNICAL FIELD

[0001] The utility model relates to filter circuit technical field, concretely relates to unmanned aerial vehicle servo branch and power supply circuit, filter circuit thereof. BACKGROUND

[0002] The servo system installed on the unmanned aerial vehicle is sometimes divided into servo host computer and servo branch, and undertakes different tasks in servo motion control. For example, the servo branch can be used for receiving control instructions and controlling the rotation of the antenna with the observation and sighting system; at the same time, the servo branch can also provide direct current power supply for the servo host computer.

[0003] For the servo branch installed on the unmanned aerial vehicle, it is extremely important to ensure its stability and reliability. The power supply noise not only affects the stable operation of the circuit, but also may interfere with other equipment. Therefore, it is necessary to reduce the power supply noise in order to improve the performance and stability of the servo branch and avoid interference with other equipment. SUMMARY

[0004] The utility model discloses a kind of filter circuits, which can greatly attenuate power supply noise, so as to ensure the stable operation of power supply circuit, improve the stability and reliability of servo branch. Based on the same invention concept, another object of the utility model is to provide power supply circuit, unmanned aerial vehicle servo branch with the foregoing filter circuit.

[0005] To achieve the above object, the technical scheme adopted by the utility model is as follows:

[0006] The filter circuit comprises an electromagnetic interference filter circuit arranged at the input end of the power supply circuit. The electromagnetic interference filter circuit comprises a common-mode inductor, a first capacitor, a third capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor and an eighth capacitor. The input end and the output end of the electromagnetic interference filter circuit are connected by the common-mode inductor. The first end of the first capacitor is connected to the positive input end of the electromagnetic interference filter circuit, and the second end of the first capacitor is connected to the negative input end of the electromagnetic interference filter circuit. The first end of the third capacitor is connected to the positive output end of the electromagnetic interference filter circuit, and the second end of the third capacitor is connected to the negative output end of the electromagnetic interference filter circuit. The first end of the fifth capacitor is connected to the positive input end of the electromagnetic interference filter circuit, and the second end of the fifth capacitor is grounded. The first end of the sixth capacitor is connected to the negative input end of the electromagnetic interference filter circuit, and the second end of the sixth capacitor is grounded. The first end of the seventh capacitor is connected to the positive output end of the electromagnetic interference filter circuit, and the second end of the seventh capacitor is grounded. The first end of the eighth capacitor is connected to the negative output end of the electromagnetic interference filter circuit, and the second end of the eighth capacitor is grounded.

[0007] Optionally, it also includes: a second capacitor; a first end of the second capacitor is connected to the positive input terminal of the electromagnetic interference filter circuit, and a second end of the second capacitor is connected to the negative input terminal of the electromagnetic interference filter circuit.

[0008] Optionally, it further includes: a fourth capacitor; a first end of the fourth capacitor is connected to the positive output terminal of the electromagnetic interference filter circuit, and a second end of the fourth capacitor is connected to the negative output terminal of the electromagnetic interference filter circuit.

[0009] Optionally, it also includes: an output filter circuit provided at the output end of the power supply circuit; the output filter circuit includes: a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, and a twenty-first capacitor; the first end of the sixteenth capacitor is connected to the positive input end of the output filter circuit, and the second end of the sixteenth capacitor is grounded; the first end of the seventeenth capacitor is connected to the negative input end of the output filter circuit, and the second end of the seventeenth capacitor is grounded; the first end of the eighteenth capacitor is connected to the positive output end of the output filter circuit, and the second end of the eighteenth capacitor is connected to the negative output end of the output filter circuit; the twenty-first capacitor is connected in parallel with the eighteenth capacitor.

[0010] Optionally, the output filter circuit also includes: a nineteenth capacitor and a twentieth capacitor; the eighteenth capacitor, the nineteenth capacitor, the twentieth capacitor, and the twenty-first capacitor are connected in parallel; the eighteenth capacitor, the nineteenth capacitor, and the twentieth capacitor are tantalum capacitors, and the sixteenth capacitor, the seventeenth capacitor, and the twenty-first capacitor are ceramic capacitors.

[0011] The present application also provides a power supply circuit having the aforementioned filter circuit.

[0012] Optionally, the power supply circuit also includes: an inrush current suppression circuit, a reverse connection protection circuit, an energy storage circuit, a first DC / DC converter, a second DC / DC converter, a third DC / DC converter, a first voltage regulator, and a second voltage regulator; the output end of the electromagnetic interference filter circuit is connected to the input end of the inrush current suppression circuit; the output end of the inrush current suppression circuit is connected to the input end of the reverse connection protection circuit; the output end of the reverse connection protection circuit has three interfaces, which are respectively connected to the input end of the energy storage circuit, the input end of the second DC / DC converter, and the input end of the third DC / DC converter; the output end of the energy storage circuit is connected to the input end of the first DC / DC converter; the output end of the third DC / DC converter has a first interface, a second interface, and a third interface, the first interface is connected to the input end of the first voltage regulator, and the second interface is connected to the input end of the second voltage regulator; multiple output filter circuits are provided, and the output end of the first DC / DC converter, the output end of the second DC / DC converter, the output end of the first voltage regulator, the output end of the second voltage regulator, and the third interface of the third DC / DC converter are respectively connected to an output filter circuit.

[0013] Optionally, the energy storage circuit includes: a first diode, a second diode, a seventh resistor, and a fourteenth capacitor; the anode of the first diode is connected to the positive input terminal of the energy storage circuit, and the cathode of the first diode is connected to the positive output terminal of the energy storage circuit; the anode of the second diode is connected to the first end of the fourteenth capacitor, and the cathode of the second diode is connected to the cathode of the first diode; the second end of the fourteenth capacitor is connected to the negative input terminal of the energy storage circuit; the seventh resistor is connected in parallel with the second diode.

[0014] Optionally, the energy storage circuit also includes: an eighth resistor, a ninth resistor, and a fifteenth capacitor; the seventh resistor, the eighth resistor, the ninth resistor, and the second diode are connected in parallel; the first end of the fifteenth capacitor is connected to the positive output terminal of the energy storage circuit, and the second end of the fifteenth capacitor is connected to the negative output terminal of the energy storage circuit.

[0015] The present application also provides an unmanned aerial vehicle servo extension, which has the aforementioned filtering circuit or power supply circuit.

[0016] The working principle of this utility model is as follows: at the input end of the electromagnetic interference filter circuit, the first capacitor can suppress differential-mode interference signals; the fifth and sixth capacitors are matched with the common-mode inductor to suppress common-mode interference signals. At the output end of the electromagnetic interference filter circuit, the third capacitor can suppress differential-mode interference signals; the seventh and eighth capacitors are matched with the common-mode inductor to suppress common-mode interference signals. In this way, by providing the first, third, fifth, sixth, seventh, and eighth capacitors, the electromagnetic interference filter circuit can allow DC or low-frequency current to pass through while significantly attenuating high-frequency interference signals.

[0017] It can be seen from this that the beneficial effects of the present invention are: it can greatly attenuate the power supply noise, thereby ensuring the stable operation of the power supply circuit, improving the stability and reliability of the servo extension, extending the service life of the servo extension, and avoiding malfunction of the servo extension. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 This is a circuit structure diagram of an electromagnetic interference filter circuit;

[0020] Figure 2Schematic diagram of another circuit structure of the electromagnetic interference filter circuit;

[0021] Figure 3 A circuit structure diagram of an output filter circuit;

[0022] Figure 4 Schematic diagram of another circuit structure of the output filter circuit;

[0023] Figure 5 is a schematic diagram of the power supply circuit;

[0024] Figure 6 1 is a schematic diagram of a first circuit structure of an energy storage circuit;

[0025] Figure 7 Schematic diagram of the second circuit structure of the energy storage circuit;

[0026] Figure 8 Schematic diagram of the third circuit structure of the energy storage circuit;

[0027] Figure 9 Schematic diagram of the fourth circuit structure of the energy storage circuit;

[0028] Figure 10 Schematic diagram of the first circuit structure of the inrush current suppression circuit;

[0029] Figure 11 Schematic diagram of the second circuit structure of the inrush current suppression circuit;

[0030] Figure 12 This is a schematic diagram of the third circuit structure of the inrush current suppression circuit;

[0031] Figure 13 Schematic diagram of the first circuit structure of the reverse connection protection circuit;

[0032] Figure 14 Schematic diagram of the second circuit structure of the reverse connection protection circuit;

[0033] Figure 15 Schematic diagram of the third circuit structure of the reverse connection protection circuit;

[0034] Reference numerals: 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; C18, eighteenth capacitor; C1 9. The nineteenth capacitor; C20, the twentieth capacitor; C21, the twenty-first capacitor; R1, the first resistor; R2, the second resistor; R3, the third resistor; R4, the fourth resistor; R5, the fifth resistor; R6, the sixth resistor; R7, the seventh resistor; R8, the eighth resistor; R9, the ninth resistor; V1, the first field-effect transistor; V2, the second field-effect transistor; D1, the first diode; D2, the second diode; ZD1, the first voltage-regulating diode; ZD2, the second voltage-regulating diode; L1, the common-mode inductor. DETAILED DESCRIPTION

[0035] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0036] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0037] like Figure 1 、 Figure 2As shown, an embodiment of the present invention provides a filter circuit, which includes: an electromagnetic interference filter circuit provided at the input end of the power supply circuit. The electromagnetic interference filter circuit includes: a common-mode inductor L1, a first capacitor C1, a third capacitor C3, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, and an eighth capacitor C8. It should be understood that the first capacitor C1, the third capacitor C3, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, and the eighth capacitor C8 can be ceramic capacitors. The input end and the output end of the electromagnetic interference filter circuit are connected through the common-mode inductor L1. It should be understood that the first pin of the common-mode inductor L1 is connected to the positive input end of the electromagnetic interference filter circuit, the second pin of the common-mode inductor L1 is connected to the negative input end of the electromagnetic interference filter circuit, the third pin of the common-mode inductor L1 is connected to the positive output end of the electromagnetic interference filter circuit, and the fourth pin of the common-mode inductor L1 is connected to the negative output end of the electromagnetic interference filter circuit. The first end of the first capacitor C1 is connected to the positive input terminal of the electromagnetic interference filter circuit, and the second end of the first capacitor C1 is connected to the negative input terminal of the electromagnetic interference filter circuit. The first end of the third capacitor C3 is connected to the positive output terminal of the electromagnetic interference filter circuit, and the second end of the third capacitor C3 is connected to the negative output terminal of the electromagnetic interference filter circuit. The first end of the fifth capacitor C5 is connected to the positive input terminal of the electromagnetic interference filter circuit, and the second end of the fifth capacitor C5 is grounded. The first end of the sixth capacitor C6 is connected to the negative input terminal of the electromagnetic interference filter circuit, and the second end of the sixth capacitor C6 is grounded. The first end of the seventh capacitor C7 is connected to the positive output terminal of the electromagnetic interference filter circuit, and the second end of the seventh capacitor C7 is grounded. The first end of the eighth capacitor C8 is connected to the negative output terminal of the electromagnetic interference filter circuit, and the second end of the eighth capacitor C8 is grounded.

[0038] The following describes a specific implementation of the filter circuit: At the input of the electromagnetic interference filter circuit, the first capacitor C1 can suppress differential-mode interference signals; the fifth and sixth capacitors C5 and C6 match the common-mode inductor L1 to suppress common-mode interference signals. At the output of the electromagnetic interference filter circuit, the third capacitor C3 can suppress differential-mode interference signals; the seventh and eighth capacitors C7 and C8 match the common-mode inductor L1 to suppress common-mode interference signals. Thus, by providing the first capacitor C1, the third capacitor C3, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, and the eighth capacitor C8, the electromagnetic interference filter circuit allows DC or low-frequency current to pass through while significantly attenuating high-frequency interference signals. This filter circuit can significantly attenuate power supply noise, thereby ensuring stable operation of the power supply circuit, improving the stability and reliability of the servo extension, extending the service life of the servo extension, and preventing malfunctions of the servo extension.

[0039] Furthermore, the device further includes a second capacitor C2; a first end of the second capacitor C2 is connected to the positive input terminal of the electromagnetic interference filter circuit, and a second end of the second capacitor C2 is connected to the negative input terminal of the electromagnetic interference filter circuit. It should be understood that the second capacitor C2 can suppress differential mode interference signals at the input terminal of the electromagnetic interference filter circuit, and a ceramic capacitor can be selected for the second capacitor C2.

[0040] Furthermore, the system further includes a fourth capacitor C4; a first end of the fourth capacitor C4 is connected to the positive output terminal of the electromagnetic interference filter circuit, and a second end of the fourth capacitor C4 is connected to the negative output terminal of the electromagnetic interference filter circuit. It should be understood that the fourth capacitor C4 can suppress differential mode interference signals at the output terminal of the electromagnetic interference filter circuit, and a ceramic capacitor can be used for the fourth capacitor C4.

[0041] like Figure 3 、 Figure 4 As shown, the filter circuit also includes: an output filter circuit provided at the output end of the power supply circuit. The output filter circuit includes: a sixteenth capacitor C16, a seventeenth capacitor C17, an eighteenth capacitor C18, and a twenty-first capacitor C21. The first end of the sixteenth capacitor C16 is connected to the positive input terminal of the output filter circuit, and the second end of the sixteenth capacitor C16 is grounded. The first end of the seventeenth capacitor C17 is connected to the negative input terminal of the output filter circuit, and the second end of the seventeenth capacitor C17 is grounded. The first end of the eighteenth capacitor C18 is connected to the positive output terminal of the output filter circuit, and the second end of the eighteenth capacitor C18 is connected to the negative output terminal of the output filter circuit. The twenty-first capacitor C21 is connected in parallel with the eighteenth capacitor C18. It should be understood that the sixteenth capacitor C16 and the seventeenth capacitor C17 can suppress common-mode interference signals at the output end of the output filter circuit.

[0042] Furthermore, the output filter circuit further includes a nineteenth capacitor C19 and a twentieth capacitor C20; the eighteenth capacitor C18, the nineteenth capacitor C19, the twentieth capacitor C20, and the twenty-first capacitor C21 are connected in parallel; the eighteenth capacitor C18, the nineteenth capacitor C19, and the twentieth capacitor C20 are tantalum capacitors, and the sixteenth capacitor C16, the seventeenth capacitor C17, and the twenty-first capacitor C21 are ceramic capacitors. It should be understood that the eighteenth capacitor C18, the nineteenth capacitor C19, and the twentieth capacitor C20 can suppress low-frequency ripple, while the twenty-first capacitor C21 can suppress high-frequency ripple.

[0043] like Figure 5 As shown, an embodiment of the present invention further provides a power supply circuit having the aforementioned filter circuit.

[0044] Furthermore, the power supply circuit also includes: an inrush current suppression circuit, a reverse connection protection circuit, an energy storage circuit, a first DC / DC converter, a second DC / DC converter, a third DC / DC converter, a first voltage regulator, and a second voltage regulator; the output end of the electromagnetic interference filter circuit is connected to the input end of the inrush current suppression circuit; the output end of the inrush current suppression circuit is connected to the input end of the reverse connection protection circuit; the output end of the reverse connection protection circuit has three interfaces, respectively connected to the input end of the energy storage circuit, the input end of the second DC / DC converter, and the input end of the third DC / DC converter; the output end of the energy storage circuit is connected to the input end of the first DC / DC converter; the output end of the third DC / DC converter has a first interface, a second interface, and a third interface, the first interface is connected to the input end of the first voltage regulator, and the second interface is connected to the input end of the second voltage regulator; multiple output filter circuits are provided, and the output end of the first DC / DC converter, the output end of the second DC / DC converter, the output end of the first voltage regulator, the output end of the second voltage regulator, and the third interface of the third DC / DC converter are respectively connected to an output filter circuit.

[0045] It should be understood that one implementation of the power supply circuit is as follows: the input voltage of the power supply circuit is set to 28V; the output voltage of the first DC / DC converter is set to 7V, and the output current is set to 2.5A; the output voltage of the second DC / DC converter is set to 5V, and the output current is set to 1A; the output voltage of the first voltage regulator is set to 12V, and the output current is set to 0.2A; the output voltage of the second voltage regulator is set to 5V, and the output current is set to 0.15A; the output voltage of the third interface of the third DC / DC converter is set to 24V, and the output current is set to 2.4A.

[0046] like Figures 6 to 9As shown, the energy storage circuit includes: a first diode D1, a second diode D2, a seventh resistor R7, and a fourteenth capacitor C14. The anode of the first diode D1 is connected to the positive input terminal of the energy storage circuit, and the cathode of the first diode D1 is connected to the positive output terminal of the energy storage circuit. The anode of the second diode D2 is connected to the first end of the fourteenth capacitor C14, and the cathode of the second diode D2 is connected to the cathode of the first diode D1. The second end of the fourteenth capacitor C14 is connected to the negative input terminal of the energy storage circuit. The seventh resistor R7 is connected in parallel with the second diode D2. It should be understood that when the input voltage is supplied, after the input voltage passes through the first diode D1, one path supplies power to the subsequent module circuit, and the other path charges the fourteenth capacitor C14 through the seventh resistor R7. When the input voltage is powered off, due to the limitation of the first diode D1, the fourteenth capacitor C14 will supply power to the subsequent module circuit through the second diode D2. The seventh resistor R7 protects the fourteenth capacitor C14. By providing a second diode D2 in parallel with the seventh resistor R7, the fourteenth capacitor C14 supplies power to the subsequent module circuit via the second diode D2, significantly reducing power losses in the fourteenth capacitor C14. This path of the first DC / DC converter provides DC power to the servo host. By incorporating a tank circuit, this circuit can maintain power for a short period of time in the event of an unexpected power outage, preserving the servo host's internal information.

[0047] Furthermore, the energy storage circuit further includes: an eighth resistor R8, a ninth resistor R9, and a fifteenth capacitor C15; the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, and the second diode D2 are connected in parallel; a first end of the fifteenth capacitor C15 is connected to the positive output terminal of the energy storage circuit, and a second end of the fifteenth capacitor C15 is connected to the negative output terminal of the energy storage circuit. It should be understood that the fifteenth capacitor C15 can also be used for charging and discharging to increase the total capacitance and extend the duration of power supply to the subsequent module circuit during a power outage.

[0048] like Figures 10 to 12 As shown, the power supply circuit can adopt the inrush current suppression circuit with the following structure:

[0049] The inrush current suppression circuit includes: a first field-effect transistor (FET) V1, a first resistor R1, a second resistor R2, a fourth resistor R4, a first voltage-stabilizing transistor (ZD1), and a ninth capacitor C9. The first end of the second resistor R2 is connected to the positive input terminal of the inrush current suppression circuit, and the second end of the second resistor R2 is connected to the gate of the first FET V1. The source of the first FET V1 is connected to the negative input terminal of the inrush current suppression circuit, and the drain of the first FET V1 is connected to the negative output terminal of the inrush current suppression circuit. The first end of the first resistor R1 is connected to the source of the first FET V1, and the second end of the first resistor R1 is connected to the drain of the first FET V1. The anode of the first voltage-stabilizing transistor (ZD1) is connected to the source of the first FET V1 and the first end of the first resistor R1, and the cathode of the first voltage-stabilizing transistor (ZD1) is connected to the gate of the first FET V1 and the second end of the second resistor R2. The fourth resistor R4 and the ninth capacitor C9 are connected in parallel with the first voltage-stabilizing transistor (ZD1).

[0050] The first field-effect transistor V1 is preferably an N-channel field-effect transistor. The gate of the first field-effect transistor V1 is also called the G-stage of the first field-effect transistor V1, the source of the first field-effect transistor V1 is also called the S-stage of the first field-effect transistor V1, and the drain of the first field-effect transistor V1 is also called the D-stage of the first field-effect transistor V1. The voltage between the gate and source of the first field-effect transistor V1 is also called the GS voltage of the first field-effect transistor V1.

[0051] The inrush current suppression circuit operates as follows: When DC power is first applied, the DC input voltage slowly charges the GS voltage of the first FET V1 through the RC circuit formed by the second resistor R2 and the ninth capacitor C9. The first voltage regulator diode ZD1 clamps the GS voltage of the first FET V1. Before the GS voltage of the first FET V1 reaches the turn-on voltage, current flows through the first resistor R1 to power the subsequent module circuit. At this point, the current is limited to below the maximum peak current Ipk = Vdc / R1, effectively suppressing inrush current. After the GS voltage of the first FET V1 reaches the turn-on voltage, the first FET V1 gradually turns on, and the current gradually transfers from the first resistor R1 to the first FET V1 until the first FET V1 is fully turned on. At this point, because the on-resistance of the first FET V1 is much smaller than that of the first resistor R1, the majority of the current flows through the first FET V1 to power the subsequent module circuit. This significantly reduces the energy consumption of the first resistor R1, thereby reducing circuit losses.

[0052] Furthermore, the inrush current suppression circuit further includes a third resistor R3; the third resistor R3 is connected in series with the second resistor R2 and is disposed between the first end of the second resistor R2 and the positive input terminal of the inrush current suppression circuit. The first end of the second resistor R2 is connected to the positive input terminal of the inrush current suppression circuit via the third resistor R3.

[0053] Furthermore, it includes a tenth capacitor C10; a first end of the tenth capacitor C10 is connected to the positive output terminal of the inrush current suppression circuit, and a second end of the tenth capacitor C10 is connected to the negative output terminal of the inrush current suppression circuit.

[0054] Furthermore, an eleventh capacitor C11 is included; a first end of the eleventh capacitor C11 is connected to the positive output terminal of the inrush current suppression circuit, and a second end of the eleventh capacitor C11 is connected to the negative output terminal of the inrush current suppression circuit. The tenth capacitor C10 and the eleventh capacitor C11 can suppress differential-mode interference signals at the output terminal of the inrush current suppression circuit.

[0055] like Figures 13 to 15 As shown, the power supply circuit can adopt the reverse connection protection circuit with the following structure:

[0056] The input end of the reverse connection protection circuit is connected to the output end of the surge current suppression circuit. The reverse connection protection circuit includes: a second field effect transistor V2, a second voltage regulator ZD2, and a fifth resistor R5. The first end of the fifth resistor R5 is connected to the positive input end of the reverse connection protection circuit, and the second end of the fifth resistor R5 is connected to the gate of the second field effect transistor V2; the drain of the second field effect transistor V2 is connected to the negative input end of the reverse connection protection circuit, and the source of the second field effect transistor V2 is connected to the negative output end of the reverse connection protection circuit; the positive electrode of the second voltage regulator ZD2 is connected to the source of the second field effect transistor V2, and the negative electrode of the second voltage regulator ZD2 is connected to the gate of the second field effect transistor V2 and the second end of the fifth resistor R5.

[0057] The second FET V2 is preferably an N-channel FET to reduce circuit losses. When the input is correctly powered, the DC input voltage first conducts through the body diode of the second FET V2, simultaneously charging the gate of the second FET V2. When the turn-on voltage of the second FET V2 is reached, the second FET V2 conducts, and the body diode of the second FET V2 is deactivated. If the input is reverse polarity, the body diode of the second FET V2 is reversely blocked, preventing the DC input voltage from entering the subsequent module circuit, thus achieving reverse polarity protection. The second voltage regulator ZD2 protects the gate of the second FET V2.

[0058] Furthermore, the reverse polarity protection circuit further includes a sixth resistor R6; the sixth resistor R6 is connected in series with the fifth resistor R5 and is disposed between the first end of the fifth resistor R5 and the positive input terminal of the reverse polarity protection circuit. The first end of the fifth resistor R5 is connected to the positive input terminal of the reverse polarity protection circuit via the sixth resistor R6.

[0059] Furthermore, the device further includes: a twelfth capacitor C12 and a thirteenth capacitor C13; a first end of the twelfth capacitor C12 is connected to the positive output terminal of the reverse connection protection circuit, and a second end of the twelfth capacitor C12 is connected to the negative output terminal of the reverse connection protection circuit; and the thirteenth capacitor C13 is connected in parallel with the twelfth capacitor C12. The twelfth capacitor C12 and the thirteenth capacitor C13 can suppress differential mode interference signals at the output terminal of the reverse connection protection circuit.

[0060] The embodiment of the present utility model further provides an unmanned aerial vehicle servo extension, which has the aforementioned filter circuit or power supply circuit.

[0061] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that various changes or modifications can be made to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A filter circuit, characterized in that: include: An electromagnetic interference filter circuit provided at the input end of the power circuit; The electromagnetic interference filtering circuit includes: a common mode inductor, a first capacitor, a third capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, and an eighth capacitor; The input end and the output end of the electromagnetic interference filter circuit are connected via a common mode inductor; A first end of the first capacitor is connected to the positive input terminal of the electromagnetic interference filter circuit, and a second end of the first capacitor is connected to the negative input terminal of the electromagnetic interference filter circuit; A first end of the third capacitor is connected to the positive output terminal of the electromagnetic interference filter circuit, and a second end of the third capacitor is connected to the negative output terminal of the electromagnetic interference filter circuit; A first end of the fifth capacitor is connected to the positive input terminal of the electromagnetic interference filter circuit, and a second end of the fifth capacitor is grounded; A first end of the sixth capacitor is connected to the negative input terminal of the electromagnetic interference filter circuit, and a second end of the sixth capacitor is grounded; A first end of the seventh capacitor is connected to the positive output terminal of the electromagnetic interference filter circuit, and a second end of the seventh capacitor is grounded; A first end of the eighth capacitor is connected to the negative output terminal of the electromagnetic interference filter circuit, and a second end of the eighth capacitor is grounded.

2. The filter circuit according to claim 1, wherein: Also included: a second capacitor; A first end of the second capacitor is connected to the positive input terminal of the electromagnetic interference filter circuit, and a second end of the second capacitor is connected to the negative input terminal of the electromagnetic interference filter circuit.

3. The filter circuit according to claim 2, wherein: Also included: a fourth capacitor; A first end of the fourth capacitor is connected to the positive output terminal of the electromagnetic interference filter circuit, and a second end of the fourth capacitor is connected to the negative output terminal of the electromagnetic interference filter circuit.

4. The filter circuit according to any one of claims 1 to 3, characterized in that: It also includes: an output filter circuit provided at the output end of the power supply circuit; The output filter circuit includes: a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, and a twenty-first capacitor; A first end of the sixteenth capacitor is connected to the positive input terminal of the output filter circuit, and a second end of the sixteenth capacitor is grounded; A first end of the seventeenth capacitor is connected to the negative input terminal of the output filter circuit, and a second end of the seventeenth capacitor is grounded; A first end of the eighteenth capacitor is connected to the positive output terminal of the output filter circuit, and a second end of the eighteenth capacitor is connected to the negative output terminal of the output filter circuit; The twenty-first capacitor is connected in parallel with the eighteenth capacitor.

5. The filter circuit according to claim 4, wherein: The output filter circuit further includes: a nineteenth capacitor and a twentieth capacitor; The eighteenth capacitor, the nineteenth capacitor, the twentieth capacitor, and the twenty-first capacitor are connected in parallel; The eighteenth capacitor, the nineteenth capacitor, and the twentieth capacitor are tantalum capacitors, and the sixteenth capacitor, the seventeenth capacitor, and the twenty-first capacitor are ceramic capacitors.

6. A power supply circuit, characterized in that: A filter circuit according to claim 4 or 5.

7. The power supply circuit according to claim 6, wherein: It also includes: an inrush current suppression circuit, a reverse connection protection circuit, an energy storage circuit, a first DC / DC converter, a second DC / DC converter, a third DC / DC converter, a first voltage stabilizer, and a second voltage stabilizer; The output end of the electromagnetic interference filter circuit is connected to the input end of the surge current suppression circuit; The output end of the inrush current suppression circuit is connected to the input end of the reverse connection protection circuit; The output end of the reverse connection protection circuit has three interfaces for connecting to the input end of the energy storage circuit, the input end of the second DC / DC converter, and the input end of the third DC / DC converter respectively; The output end of the energy storage circuit is connected to the input end of the first DC / DC converter; The output end of the third DC / DC converter has a first interface, a second interface, and a third interface, the first interface is connected to the input end of the first voltage regulator, and the second interface is connected to the input end of the second voltage regulator; There are multiple output filter circuits, and the output end of the first DC / DC converter, the output end of the second DC / DC converter, the output end of the first voltage regulator, the output end of the second voltage regulator, and the third interface of the third DC / DC converter are respectively connected to an output filter circuit.

8. The power supply circuit according to claim 7, wherein: The energy storage circuit includes: a first diode, a second diode, a seventh resistor, and a fourteenth capacitor; The anode of the first diode is connected to the positive input terminal of the energy storage circuit, and the cathode of the first diode is connected to the positive output terminal of the energy storage circuit; An anode of the second diode is connected to the first end of the fourteenth capacitor, and a cathode of the second diode is connected to the cathode of the first diode; The second end of the fourteenth capacitor is connected to the negative input terminal of the energy storage circuit; The seventh resistor is connected in parallel with the second diode.

9. The power supply circuit according to claim 8, wherein: The energy storage circuit further includes: an eighth resistor, a ninth resistor, and a fifteenth capacitor; The seventh resistor, the eighth resistor, the ninth resistor and the second diode are connected in parallel; A first end of the fifteenth capacitor is connected to the positive output terminal of the energy storage circuit, and a second end of the fifteenth capacitor is connected to the negative output terminal of the energy storage circuit.

10. UAV-mounted servo extension, characterized by: A filter circuit according to any one of claims 1 to 5, or a power supply circuit according to any one of claims 6 to 9.

Images