Power supply filtering device

Abstract

The utility model relates to a power supply filtering device, which comprises a shell, a connector, a power supply filtering circuit board and a feed-through filter. An L-shaped partition plate is arranged in the shell and divides the shell into a first partition cavity and a second partition cavity, a power filter circuit board is installed in the first partition cavity, and a feed-through filter is installed in the second partition cavity. The positive and negative input ends of the power supply filter circuit are connected with the connector, the positive output end is connected with the first feed-through filter, and the negative output end is connected with the second feed-through filter. And the feed-through filter is connected with an external power supply through the threading hole. According to the device, through reasonable layout, the length of an input wire is shortened, the grounding efficiency is improved, signals before and after filtering are shielded and isolated, and the performance of the filtering device is improved. Meanwhile, due to the integrated design of the circuit, the overall assembly and maintenance of the product are facilitated, the assembly time is saved, the assembly difficulty is reduced, and the assembly efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of filtering equipment, in particular to a power supply filtering device. Background Art

[0002] Power supply filters are key devices used to suppress electromagnetic interference (EMI) and improve a system's electromagnetic compatibility (EMC). They effectively filter high-frequency noise signals from power lines, preventing EMI from affecting electronic equipment and ensuring proper operation. Traditional power supply filters are typically connected to the system via a separate filter. This type of device presents several issues. For example, long input cables can easily cause EMI to crosstalk and couple within the system, reducing the system's EMC.

[0003] In the existing technology, the most common filter is the LC filter composed of inductors and capacitors. While the LC filter filters out medium and low-frequency noise, its suppression effect on high-frequency noise is relatively weak. Furthermore, in the high-frequency field, when the grounding impedance between the filter and the casing and equipment is too large, the interference signal may not be effectively transmitted to the ground, further affecting the filtering effect and even causing electromagnetic leakage.

[0004] As the demand for miniaturization and integration increases, traditional filter devices face challenges such as complex structures, difficult assembly, and inconvenient maintenance. Existing filter components are typically discrete, with modules connected by complex cables. This increases assembly time and maintenance complexity, hindering standardization and modularization in mass production. Furthermore, power supply filters often lack effective isolation between pre- and post-filter signals, which can lead to signal coupling between pre- and post-filter circuits, weakening the filtering effect.

[0005] Therefore, how to design a power supply filter device that is compact in structure, easy to install, has high electromagnetic compatibility performance and is easy to maintain has become an urgent problem to be solved in the current technical field. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides a power supply filter device which, through reasonable structural design and circuit improvement, suppresses high-frequency noise, shields and isolates signals before and after filtering, and improves the performance of the filter device.

[0007] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0008] A power supply filter device, characterized by comprising a housing, a cover plate, a connector, a power supply filter circuit board and a feed-through filter;

[0009] The housing is detachably connected to the cover plate, a connector is fixedly connected to one side of the housing by screws, and a conductive gasket is provided between the connector and the housing;

[0010] An L-shaped partition is provided in the housing, the partition dividing the housing into a first compartment and a second compartment. A power filter circuit board is installed in the first compartment, and a feed-through filter is installed on the partition in the second compartment. The feed-through filter includes a first feed-through filter and a second feed-through filter.

[0011] The power filter circuit board is provided with a power filter circuit; the positive input terminal and the negative input terminal of the power filter circuit are respectively connected to the connector;

[0012] The positive output end of the power supply filter circuit is connected to the input end of the first feed-through filter through a wire, and the output end of the first feed-through filter is connected to the positive power output wire, which extends to the outside of the shell through a wire hole on the surface of the shell; the negative output end of the power supply filter circuit is connected to the input end of the second feed-through filter through a wire, and the output end of the second feed-through filter is connected to the negative power output wire, which extends to the outside of the shell through a wire hole on the surface of the shell.

[0013] Beneficial effects: The direct connection between the filter circuit and the connector minimizes the length of the cable from the input end to the filter component, avoiding electromagnetic compatibility problems caused by excessively long input wires; the connector is grounded through screws and conductive pads, which increases the grounding area, reduces the grounding impedance, and allows interference to be smoothly introduced into the ground through the shell, further enhancing the overall filtering effect; through the sub-cavity design of the shell, the signals of the power supply filter circuit and the feed-through filter are physically isolated, reducing the signal coupling and interference caused by the coexistence of signals before and after filtering in the same cavity, and improving the electromagnetic compatibility performance of the equipment; a feed-through filter is provided at the output end of the power supply filter circuit, which makes up for the shortcomings of the LC filter and has a stronger attenuation capability for high-frequency noise.

[0014] Preferably, the first feed-through filter and the second feed-through filter are both resin-sealed screw-mounted filters.

[0015] Furthermore, the input ends of the first feed-through filter and the second feed-through filter are both provided with a threaded section, and the threaded section passes through the partition and is screwed with a locking nut;

[0016] An insulating plate is provided between the output ends of the first feed-through filter and the second feed-through filter and the positive power output wire and the negative power output wire.

[0017] Furthermore, the positive power output wire and the negative power output wire are silver-plated copper core polytetrafluoroethylene film wrapped insulated wires;

[0018] The positive power output wire and the negative power output wire are extended to the outside of the shell and the connection with the shell is provided with a shielding net, and the shielding net is a light nickel-plated copper braided wave-proof sleeve;

[0019] Insulators are provided at the connection points between the positive power output wire and the negative power output wire and the shell.

[0020] Beneficial effect: The output wires are shielded by an external anti-wave sleeve. Compared with the existing technology, the light nickel-plated copper braided anti-wave sleeve structure is adopted to shield the output wires in all directions, reducing the interference of external electromagnetic noise on the wire transmission signal, and further improving the electromagnetic compatibility performance of the equipment.

[0021] Furthermore, the connector is a circular connector, which includes multiple custom pins for connecting to different power sources.

[0022] Furthermore, the power supply filter circuit includes a common mode inductor L1, a common mode inductor L2 and an anti-reverse connection module;

[0023] The positive input end of the common-mode inductor L1 is the positive input end of the power filter circuit, the positive output end of the common-mode inductor L1 is connected to the positive input end of the common-mode inductor L2, the negative input end of the common-mode inductor L1 is the negative input end of the power filter circuit, and the negative output end of the common-mode inductor L1 is connected to the negative input end of the common-mode inductor L2;

[0024] A capacitor CX1 is connected between the positive input terminal and the negative input terminal of the common-mode inductor L1, and a capacitor CY1 and a capacitor CY2 connected in series are connected between the positive output terminal and the negative output terminal of the common-mode inductor L1. The capacitor CY1 and the capacitor CY2 are grounded, and a capacitor CX2 is connected in parallel to the ends of the capacitor CY1 and the capacitor CY2 away from the ground.

[0025] A capacitor CY3 and a capacitor CY4 connected in series are connected between the positive output terminal and the negative output terminal of the common mode inductor L2, the capacitor CY3 and the capacitor CY4 are grounded, and a capacitor CX3 is connected in parallel to the two ends of the capacitor CY3 and the capacitor CY4 away from the ground;

[0026] The anti-reverse connection module includes an N-type MOS tube Q1, a voltage stabilizing diode D1, a first voltage dividing resistor R1 and a second voltage dividing resistor;

[0027] The positive output end of the common-mode inductor L2 serves as the positive output end of the power filter circuit and is connected to the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 connected in series. The cathode of the voltage-dividing diode D1 and the gate of the N-type MOS transistor Q1 are connected between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2. The anode of the voltage-dividing diode D1 serves as the negative output end of the power filter circuit and is connected to the source of the N-type MOS transistor Q1 and the end of the second voltage-dividing resistor R2 away from the series connection. The drain of the N-type MOS transistor Q1 is connected to the negative output end of the common-mode inductor L2.

[0028] The positive output end of the power supply filter circuit is connected to the input end of the first feed-through filter CY5, and the negative output end of the power supply filter circuit is connected to the input end of the second feed-through filter CY6. The first feed-through filter CY5 and the second feed-through filter CY6 are grounded.

[0029] Furthermore, the capacitors are all multilayer ceramic chip capacitors.

[0030] Furthermore, polytetrafluoroethylene films are provided between the common-mode inductor L1, the common-mode inductor L2 and the power filter circuit board, and between the power filter circuit board and the connector.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] Beneficial effects: The filter module and the anti-reverse connection module are integrated on one circuit board, which facilitates the overall assembly and disassembly and maintenance of the product, saves assembly time and improves assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is an assembly diagram of an embodiment of a power supply filter device of the utility model.

[0034] Figure 2 This is a schematic diagram of the shell structure of an embodiment of a power supply filter device of the present utility model.

[0035] Figure 3 This is a circuit diagram of an embodiment of a power supply filter device of the utility model.

[0036] In the above drawings:

[0037] 1. Housing; 2. Connector; 3. Power filter circuit board; 4. Feed-through filter; 5. Cover; 6. Conductive gasket; 7. Screws; 8. First compartment; 9. Second compartment; 10. Positive power output wire; 11. Negative power output wire; 12. Wire hole; 13. Insulation board; 14. Shielding net; 15. Insulator. DETAILED DESCRIPTION

[0038] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The example embodiments can be implemented in various forms and should not be understood as being limited to the examples set forth herein. On the contrary, these embodiments are provided so that the invention will be more comprehensive and complete, and the concepts of the example embodiments will be fully conveyed to those skilled in the art. In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] like Figure 1 、 Figure 2 As shown, the present invention provides a power supply filtering device comprising a housing 1, a connector 2, a power supply filter circuit board 3, and a feed-through filter 4. A cover plate 5 is provided on top of the housing 1 to seal the inner cavity. The connector 2 is a circular connector with multiple custom pins for connecting to different power sources. A conductive gasket 6 is provided between the connector 2 and the housing 1. The connector 2 is grounded and connected to the housing 1 via screws 7. This installation method provides a large grounding area and low grounding impedance, allowing interference to pass smoothly through the housing to the ground, thereby enhancing the overall filtering effect.

[0040] An L-shaped partition is provided in the shell 1, which divides the shell 1 into a first compartment 8 and a second compartment 9. A power filter circuit board 3 is installed in the first compartment 8, and a first feed-through filter 4a and a second feed-through filter 4b are installed on the partition in the second compartment 9. This cavity design shields and isolates the signals before and after filtering, reduces signal coupling and interference caused by the coexistence of the signals before and after filtering in the same cavity, and improves the electromagnetic compatibility performance of the equipment.

[0041] A power filter circuit is provided on the power filter circuit board 3; the positive input terminal and the negative input terminal of the power filter circuit are respectively connected to the connector 2; the positive output terminal of the power filter circuit 3 is connected to the input terminal of the first feed-through filter 4a via a wire, and the input terminal of the first feed-through filter 4a is connected to the positive power output wire 10 and extends to the outside of the housing 1 through the wire hole 12; the input terminal of the second feed-through filter 4b is connected to the input terminal of the second feed-through filter 4b via a wire, and the output terminal of the second feed-through filter 4b is connected to the negative power output wire 11 and extends to the outside of the housing 1 through the wire hole 12.

[0042] In this embodiment, the first feed-through filter 4a and the second feed-through filter 4b are both resin-sealed screw-mounted filters; the input terminals of the first feed-through filter 4a and the second feed-through filter 4b are both provided with threaded sections, and the threaded sections are screwed with locking nuts through the partition.

[0043] In this embodiment, an insulating plate 13 is provided between the output terminals of the first feedthrough filter 4a and the second feedthrough filter 4b and the positive power output conductor 10 and the negative power output conductor 11. The positive power output conductor 10 and the negative power output conductor 11 are silver-plated copper-core insulated conductors wrapped with polytetrafluoroethylene film. A shielding mesh 14 is provided at the connection between the positive power output conductor 10 and the negative power output conductor 11 extending outside the housing 1. The shielding mesh 14 used in this embodiment is a lightweight nickel-plated copper braided surge shield. Insulators 15 are provided at the connection between the positive power output conductor and the negative power output conductor and the housing 1. A polytetrafluoroethylene film is provided between the power filter circuit board and the connector. In this embodiment, the output conductors are connected to the feedthrough filter, with an insulating plate 13 interposed between them and a surge shield. This effectively prevents external interference from being coupled to the output cable through space and affecting the filtering effect.

[0044] like Figure 3 The figure shows the principle diagram of the power filter circuit of this embodiment, which includes a common-mode inductor L1, a common-mode inductor L2 and an anti-reverse connection module;

[0045] The positive input end of the common-mode inductor L1 is the positive input end (A, B) of the power supply filter circuit, the positive output end of the common-mode inductor L1 is connected to the positive input end of the common-mode inductor L2, the negative input end of the common-mode inductor L1 is the negative input end of the power supply filter circuit, and the negative output end of the common-mode inductor L1 is connected to the negative input end of the common-mode inductor L2; a capacitor CX1 is connected between the positive input end and the negative input end of the common-mode inductor L1, and a capacitor CY1 and a capacitor CY2 connected in series are connected between the positive output end and the negative output end of the common-mode inductor L1, the capacitor CY1 and the capacitor CY2 are grounded, and the two ends of the capacitor CY1 and the capacitor CY2 away from the ground are connected in parallel with a capacitor CX2; a capacitor CY3 and a capacitor CY4 are connected in series between the positive output end and the negative output end of the common-mode inductor L2, the capacitor CY3 and the capacitor CY4 are grounded, and the two ends of the capacitor CY3 and the capacitor CY4 away from the ground are connected in parallel with a capacitor CX3.

[0046] In this embodiment, Figure 3As shown, the anti-reverse connection module includes an N-type MOS transistor Q1, a voltage-dividing diode D1, a first voltage-dividing resistor R1, and a second voltage-dividing resistor; the positive output end (C, D) of the common-mode inductor L2 serves as the positive output end of the power filter circuit and is connected to the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 connected in series. The cathode of the voltage-dividing diode D1 and the gate of the N-type MOS transistor Q1 are connected between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2. The anode of the voltage-dividing diode D1 serves as the negative output end of the power filter circuit and is connected to the source of the N-type MOS transistor Q1 and the end of the second voltage-dividing resistor R2 away from the series connection. The drain of the N-type MOS transistor Q1 is connected to the negative output end of the common-mode inductor L2.

[0047] The positive output terminal (P') of the power filter circuit is connected to the input terminal of the first feed-through filter CY5, and the negative output terminal (N') of the power filter circuit is connected to the input terminal of the second feed-through filter CY6. The first feed-through filter CY5 and the second feed-through filter CY6 are connected to ground. In this embodiment, the capacitors are all multilayer ceramic chip capacitors; a polytetrafluoroethylene film is installed between the common-mode inductors L1 and L2 and the power filter circuit board. The integrated design of the filter circuit in this embodiment facilitates overall product assembly and maintenance, saving assembly time, reducing assembly difficulty, and improving assembly efficiency.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A power supply filter device, characterized in that: It includes a housing, a cover, a connector, a power filter circuit board and a feed-through filter; The housing is detachably connected to the cover plate, a connector is fixedly connected to one side of the housing by screws, and a conductive gasket is provided between the connector and the housing; An L-shaped partition is provided in the housing, the partition dividing the housing into a first compartment and a second compartment. A power filter circuit board is installed in the first compartment, and a feed-through filter is installed on the partition in the second compartment. The feed-through filter includes a first feed-through filter and a second feed-through filter. The power filter circuit board is provided with a power filter circuit; the positive input terminal and the negative input terminal of the power filter circuit are respectively connected to the connector; The positive output end of the power filter circuit is connected to the input end of the first feed-through filter through a wire, and the output end of the first feed-through filter is connected to a positive power output wire, which extends to the outside of the housing through a wire hole on the surface of the housing; The negative output end of the power supply filter circuit is connected to the input end of the second feed-through filter through a wire. The output end of the second feed-through filter is connected to a negative power output wire. The negative power output wire extends to the outside of the shell through a wire hole on the surface of the shell.

2. A power supply filter device according to claim 1, characterized in that: The first feed-through filter and the second feed-through filter are both resin-sealed screw-mounted filters.

3. A power supply filter device according to claim 2, characterized in that: The input ends of the first feed-through filter and the second feed-through filter are both provided with a threaded section, and the threaded section passes through the partition and is screwed with a locking nut; An insulating plate is provided between the output ends of the first feed-through filter and the second feed-through filter and the positive power output wire and the negative power output wire.

4. A power supply filter device according to claim 3, characterized in that: The positive power output wire and the negative power output wire are silver-plated copper core polytetrafluoroethylene film wrapped insulated wires; The positive power output wire and the negative power output wire are extended to the outside of the shell and the connection with the shell is provided with a shielding net, and the shielding net is a light nickel-plated copper braided wave-proof sleeve; Insulators are provided at the connection points between the positive power output wire and the negative power output wire and the shell.

5. A power supply filter device according to claim 1, characterized in that: The connector is a circular connector, which includes multiple custom pins for connecting different power sources.

6. A power supply filter device according to claim 1, characterized in that: The power supply filter circuit includes a common mode inductor L1, a common mode inductor L2 and an anti-reverse connection module; The positive input end of the common-mode inductor L1 is the positive input end of the power filter circuit, the positive output end of the common-mode inductor L1 is connected to the positive input end of the common-mode inductor L2, the negative input end of the common-mode inductor L1 is the negative input end of the power filter circuit, and the negative output end of the common-mode inductor L1 is connected to the negative input end of the common-mode inductor L2; A capacitor CX1 is connected between the positive input terminal and the negative input terminal of the common-mode inductor L1, and a capacitor CY1 and a capacitor CY2 connected in series are connected between the positive output terminal and the negative output terminal of the common-mode inductor L1. The capacitor CY1 and the capacitor CY2 are grounded, and a capacitor CX2 is connected in parallel to the ends of the capacitor CY1 and the capacitor CY2 away from the ground. A capacitor CY3 and a capacitor CY4 connected in series are connected between the positive output terminal and the negative output terminal of the common mode inductor L2, the capacitor CY3 and the capacitor CY4 are grounded, and a capacitor CX3 is connected in parallel to the two ends of the capacitor CY3 and the capacitor CY4 away from the ground; The anti-reverse connection module includes an N-type MOS tube Q1, a voltage stabilizing diode D1, a first voltage dividing resistor R1 and a second voltage dividing resistor; The positive output end of the common-mode inductor L2 serves as the positive output end of the power filter circuit and is connected to the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 connected in series. The cathode of the voltage-dividing diode D1 and the gate of the N-type MOS transistor Q1 are connected between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2. The anode of the voltage-dividing diode D1 serves as the negative output end of the power filter circuit and is connected to the source of the N-type MOS transistor Q1 and the end of the second voltage-dividing resistor R2 away from the series connection. The drain of the N-type MOS transistor Q1 is connected to the negative output end of the common-mode inductor L2. The positive output end of the power supply filter circuit is connected to the input end of the first feed-through filter CY5, and the negative output end of the power supply filter circuit is connected to the input end of the second feed-through filter CY6. The first feed-through filter CY5 and the second feed-through filter CY6 are grounded.

7. A power supply filter device according to claim 6, characterized in that: The capacitors are all multilayer ceramic chip capacitors.

8. The power supply filter device according to claim 6, characterized in that: Polytetrafluoroethylene films are provided between the common-mode inductor L1, the common-mode inductor L2 and the power filter circuit board, and between the power filter circuit board and the connector.

Images