阅读说明：本技术 开关电源输入端抗辐射干扰滤波器 (Anti-radiation interference filter for input end of switching power supply ) 是由 陈雪峰 杨宇帆 于 2021-05-08 设计创作，主要内容包括：本发明公开了开关电源输入端抗辐射干扰滤波器,包括LC滤波电路与第二级LC滤波电路,第一级LC滤波电路与第二级LC滤波电路处于同一轴线处,第一级LC滤波电路包括C1环形管状电容、C2环形管状电容、C3差模电容、C4差模电容与第一线圈。通过环形管状电容和差模电容,采用以上设计的开关电源输入端抗辐射干扰滤波器,可直接更换普通EMI电源滤波器,使用开关电源输入端抗辐射干扰滤波器后,辐射发射(RE)测试结果良好,完全符合电磁兼容中辐射发射相关标准要求,有效的解决了开关电源输入端传导发射干扰和辐射发射干扰,并符合相关电磁兼容标准,可以广泛应用在有开关电源要求的民用、工业、军用电子设备产品上。(The invention discloses a radiation interference resistant filter at an input end of a switching power supply, which comprises an LC filter circuit and a second-stage LC filter circuit, wherein the first-stage LC filter circuit and the second-stage LC filter circuit are positioned at the same axis, and the first-stage LC filter circuit comprises a C1 annular tubular capacitor, a C2 annular tubular capacitor, a C3 differential mode capacitor, a C4 differential mode capacitor and a first coil. Through the annular tubular capacitor and the differential mode capacitor, the anti-radiation interference filter of the switching power supply input end is adopted, the common EMI power supply filter can be directly replaced, after the anti-radiation interference filter of the switching power supply input end is used, the Radiation Emission (RE) test result is good, the relevant standard requirements of radiation emission in electromagnetic compatibility are completely met, the conducted emission interference and the radiation emission interference of the switching power supply input end are effectively solved, the relevant electromagnetic compatibility standard is met, and the anti-radiation interference filter can be widely applied to civil, industrial and military electronic equipment products with the switching power supply requirements.)

1. Switching power supply input anti-radiation interference filter, including LC filter circuit and second grade LC filter circuit, first grade LC filter circuit is in same axis department with second grade LC filter circuit, its characterized in that:

the first-stage LC filter circuit comprises a C1 annular tubular capacitor (1), a C2 annular tubular capacitor (2), a C3 differential mode capacitor (3), a C4 differential mode capacitor (4) and a first coil (11), wherein a switching power supply anode (13) and a switching power supply cathode (14) are respectively embedded in the inner walls of the C1 annular tubular capacitor (1) and the C2 annular tubular capacitor (2), the electrode ends of the switching power supply anode (13) and the switching power supply cathode (14) are respectively and electrically connected with two electrode ends of the C3 differential mode capacitor (3) through leads, the number of the first coil (11) is two, and the electrode end of each first coil (11) is respectively and electrically connected with the two electrode ends of the C3 differential mode capacitor (3) through leads;

the second-stage LC filter circuit comprises a C9 annular tubular capacitor (9), a C1 annular tubular capacitor (10), a C8 differential mode capacitor (8), a C4 differential mode capacitor (4), a C5 annular tubular capacitor (5), a C6 annular tubular capacitor (6) and a second coil (12), the inner walls of the C9 annular tubular capacitor (9) and the C1 annular tubular capacitor (10) are respectively embedded at one end of the anode (13) and the cathode (14) of the switching power supply, the number of the second coils (12) is two, the electrode end of each second coil (12) is respectively and electrically connected with the two electrode ends of the C8 differential mode capacitor (8) through leads, one end of the first coil (11) close to one end of the second coil (12) is electrically connected with one end of the second coil (12) close to one another through a C5 annular tubular capacitor (5), and the other end of the first coil (11) close to one end of the second coil (12) is electrically connected with one another through a C6 annular tubular capacitor (6).

2. The input terminal anti-radiation interference filter of the switching power supply as claimed in claim 1, wherein: the electrode ends of the C1 annular tubular capacitor (1) and the C9 annular tubular capacitor (9) are electrically connected with the anode (13) of the switching power supply through a lead.

3. The input terminal anti-radiation interference filter of the switching power supply as claimed in claim 2, wherein: the electrode ends of the C2 annular tubular capacitor (2) and the C1 annular tubular capacitor (10) are electrically connected with a switch power supply cathode (14) through a lead.

4. The input terminal anti-radiation interference filter of the switching power supply as claimed in claim 3, wherein: magnetic cores are embedded in the centers of the inner walls of the first coil (11) and the second coil (12).

5. The input terminal anti-radiation interference filter of the switching power supply as claimed in claim 4, wherein: and a metal shell (15) is embedded in the outer walls of the C1 annular tubular capacitor (1), the C2 annular tubular capacitor (2), the C9 annular tubular capacitor (9) and the C1 annular tubular capacitor (10).

6. The input terminal anti-radiation interference filter of the switching power supply as claimed in claim 5, wherein: the C5 annular tubular capacitor (5) and the C6 annular tubular capacitor (6) are embedded at two sides of the center of the inner wall of the metal shell (15).

7. The input terminal anti-radiation interference filter of the switching power supply as claimed in claim 6, wherein: the C3 differential mode capacitor (3), the C4 differential mode capacitor (4), the C7 differential mode capacitor (7) and the C8 differential mode capacitor (8) are composed of one or more capacitors, and the material, capacity and withstand voltage of the capacitors can be flexibly selected according to actual use.

8. The input terminal anti-radiation interference filter of the switching power supply as claimed in claim 7, wherein: the conducting wire is selected to be a conducting wire with a proper diameter according to actual power.

9. The input terminal anti-radiation interference filter of the switching power supply as claimed in claim 8, wherein: the metal outer walls of the C1 annular tubular capacitor (1), the C2 annular tubular capacitor (2), the C5 annular tubular capacitor (5), the C6 annular tubular capacitor (6), the C9 annular tubular capacitor (9) and the C1 annular tubular capacitor (10) are electrically connected with the metal shell (15).

10. The input terminal anti-radiation interference filter of the switching power supply as claimed in claim 9, wherein: the inner walls of the C1 annular tubular capacitor (1), the C2 annular tubular capacitor (2), the C5 annular tubular capacitor (5), the C6 annular tubular capacitor (6), the C9 annular tubular capacitor (9) and the C1 annular tubular capacitor (10) are respectively embedded with rubber rings in a sliding manner.

Technical Field

The invention belongs to the technical field of power supplies, and particularly relates to an anti-radiation interference filter for an input end of a switching power supply.

Background

The power module is a power supply device that can be directly mounted on a printed circuit board, and is characterized in that the power module can provide power for an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a microprocessor, a memory, a Field Programmable Gate Array (FPGA) and other digital or analog loads, generally, such a module is called a point-of-load (POL) power supply system or a point-of-use power supply system (PUPS), and because of the great advantages of a modular structure, the module power is widely used in the communication fields of switching devices, access devices, mobile communication, microwave communication, optical transmission, routers and the like, and in automotive electronics, aerospace and the like.

The switching power supply has the advantages of low power consumption, high efficiency, high power density, small volume, light weight, wide voltage stabilizing range and the like, the switching power supply has the defect of generating stronger electromagnetic interference (EMI), an EMI signal not only has a very wide frequency range but also has a certain amplitude, the electromagnetic environment is polluted by conduction emission and radiation emission, and interference is caused to communication equipment and electronic products, so that the electronic equipment does not meet the requirements of relevant electromagnetic compatibility standards, the main way of the switching power supply interference is the input end of the power supply, and the interference mainly comprises conduction emission interference and radiation emission interference.

Disclosure of Invention

The invention aims to: through the annular tubular capacitor and the differential mode capacitor, the anti-radiation interference filter of the switching power supply input end is adopted, the common EMI power supply filter can be directly replaced, after the anti-radiation interference filter of the switching power supply input end is used, the Radiation Emission (RE) test result is good, the relevant standard requirements of radiation emission in electromagnetic compatibility are completely met, the conducted emission interference and the radiation emission interference of the switching power supply input end are effectively solved, the normal and good work of electronic products is ensured, the relevant electromagnetic compatibility standards are met, and the anti-radiation interference filter can be widely applied to civil, industrial and military electronic equipment products with the requirements of the switching power supply.

The technical scheme adopted by the invention is as follows: the anti-radiation interference filter at the input end of the switching power supply comprises an LC filter circuit and a second-stage LC filter circuit, wherein the first-stage LC filter circuit and the second-stage LC filter circuit are positioned at the same axis, the first-stage LC filter circuit comprises a C1 annular tubular capacitor, a C2 annular tubular capacitor, a C3 differential mode capacitor, a C4 differential mode capacitor and a first coil, the inner walls of the C1 annular tubular capacitor and the C2 annular tubular capacitor are respectively embedded with a positive electrode and a negative electrode of the switching power supply, the electrode ends of the positive electrode and the negative electrode of the switching power supply are respectively and electrically connected with the two electrode ends of the C3 differential mode capacitor through wires, the number of the first coils is two, and the electrode end of each first coil is respectively and electrically connected with the two electrode ends of the C3 differential mode capacitor through wires;

the second-stage LC filter circuit comprises a C9 annular tubular capacitor, a C1 annular tubular capacitor, a C8 differential mode capacitor, a C4 differential mode capacitor, a C5 annular tubular capacitor, a C6 annular tubular capacitor and a second coil, wherein the inner walls of the C9 annular tubular capacitor and the C1 annular tubular capacitor are respectively embedded at one end of the anode of the switching power supply and one end of the cathode of the switching power supply, the number of the second coil is two, the electrode end of each second coil is respectively and electrically connected with the two electrode ends of the C8 differential mode capacitor through leads, one end, close to each other, of the first coil and the second coil is electrically connected with each other through the C5 annular tubular capacitor, and the other end, close to each other, of the remaining one first coil and the second coil is electrically connected with each other through the C6 annular tubular capacitor.

Furthermore, the electrode ends of the C1 annular tubular capacitor and the C9 annular tubular capacitor are electrically connected with the anode of the switching power supply through a lead.

Further, the electrode ends of the C2 annular tubular capacitor and the C1 annular tubular capacitor are electrically connected with the negative electrode of the switching power supply through a lead.

Furthermore, magnetic cores are embedded in the centers of the inner walls of the first coil and the second coil.

Furthermore, metal shells are embedded in the outer walls of the C1 annular tubular capacitor, the C2 annular tubular capacitor, the C9 annular tubular capacitor and the C1 annular tubular capacitor.

Further, the C5 annular tubular capacitor and the C6 annular tubular capacitor are embedded at two sides of the center of the inner wall of the metal shell.

Furthermore, the C3 differential mode capacitor, the C4 differential mode capacitor, the C7 differential mode capacitor and the C8 differential mode capacitor are composed of one or more capacitors, and the material, the capacity and the withstand voltage of the capacitors can be flexibly selected according to actual use.

Further, the conducting wire is a conducting wire with a proper diameter according to actual power.

Furthermore, the metal outer walls of the C1 annular tubular capacitor, the C2 annular tubular capacitor, the C5 annular tubular capacitor, the C6 annular tubular capacitor, the C9 annular tubular capacitor and the C1 annular tubular capacitor are electrically connected with the metal shell.

Further, rubber rings are slidably embedded in the inner walls of the C1 annular tubular capacitor, the C2 annular tubular capacitor, the C5 annular tubular capacitor, the C6 annular tubular capacitor, the C9 annular tubular capacitor and the C1 annular tubular capacitor.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

according to the invention, through the annular tubular capacitor and the differential mode capacitor, the anti-radiation interference filter at the input end of the switching power supply is adopted, the common EMI power supply filter can be directly replaced, after the anti-radiation interference filter at the input end of the switching power supply is used, the Radiation Emission (RE) test result is good, the relevant standard requirements of radiation emission in electromagnetic compatibility are completely met, the conducted emission interference and the radiation emission interference at the input end of the switching power supply are effectively solved, the normal and good work of electronic products is ensured, the relevant electromagnetic compatibility standard is met, and the anti-radiation interference filter can be widely applied to civil, industrial and military electronic equipment products with the requirements of the switching power supply.

Drawings

FIG. 1 is a schematic circuit diagram of the present invention;

FIG. 2 is a graphical representation of the conducted emission (CE 102) test results of the present invention;

FIG. 3 is a schematic diagram of a Radiated Emission (RE) test without using an anti-EMI filter at the input of the switching power supply according to the present invention;

fig. 4 is a schematic diagram of the Radiation Emission (RE) test of the invention using the input terminal of the switching power supply with the anti-radiation interference filter.

The labels in the figure are: 1. c1 toroidal tube capacitor; 2. c2 toroidal tube capacitor; 3. c3 differential mode capacitance; 4. c4 differential mode capacitance; 5. c5 toroidal tube capacitor; 6. c6 toroidal tube capacitor; 7. c7 differential mode capacitance; 8. c8 differential mode capacitance; 9. c9 toroidal tube capacitor; 10. c10 toroidal tube capacitor; 11. a first coil; 12. a second coil; 13. a switching power supply anode; 14. switching power supply cathode; 15. a metal housing.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to fig. 1-4 and the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The anti-radiation interference filter at the input end of the switching power supply comprises an LC filter circuit and a second-stage LC filter circuit, wherein the first-stage LC filter circuit and the second-stage LC filter circuit are positioned at the same axis, the first-stage LC filter circuit comprises a C1 annular tubular capacitor 1, a C2 annular tubular capacitor 2, a C3 differential mode capacitor 3, a C4 differential mode capacitor 4 and a first coil 11, a switching power supply anode 13 and a switching power supply cathode 14 are respectively embedded in the inner walls of the C1 annular tubular capacitor 1 and the C2 annular tubular capacitor 2, the electrode ends of the switching power supply anode 13 and the switching power supply cathode 14 are respectively and electrically connected with two electrode ends of the C3 differential mode capacitor 3 through leads, the number of the first coils 11 is two, and the electrode end of each first coil 11 is respectively and electrically connected with two electrode ends of the C3 differential mode capacitor 3 through leads;

the second-stage LC filter circuit comprises a C9 annular tubular capacitor 9, a C1 annular tubular capacitor 1, a C8 differential mode capacitor 8, a C4 differential mode capacitor 4, a C5 annular tubular capacitor 5, a C6 annular tubular capacitor 6 and a second coil 12, wherein the inner walls of the C9 annular tubular capacitor 9 and the C1 annular tubular capacitor 1 are respectively embedded at one end of a switching power supply anode 13 and one end of a switching power supply cathode 14, the number of the second coils 12 is two, the electrode end of each second coil 12 is respectively and electrically connected with the two electrode ends of the C8 differential mode capacitor 8 through conducting wires, one end, close to each other, of the first coil 11 and the second coil 12 is electrically connected with each other through the C5 annular tubular capacitor 5, the other end, close to each other, of the remaining first coil 11 and the second coil 12 is electrically connected with each other through the C6 annular tubular capacitor 6, and the annular tubular capacitor is directly installed on a metal panel, therefore, the grounding inductance of the capacitor is smaller, the influence of lead inductance is hardly caused, in addition, the input and output ends of the capacitor are isolated by the metal plate, the high-frequency coupling is eliminated, the two characteristics determine that the annular tubular capacitor has the filtering effect close to the ideal capacitor, the self inductance of the annular tubular capacitor is much smaller than that of the common capacitor, so the self-resonant frequency is very high, meanwhile, the straight-through design also effectively prevents the high-frequency signal from being directly coupled to the output end from the input end, the combination of the low-pass high-resistance provides excellent inhibition effect in the frequency range of 10Kz to 10GHz, and the environmental adaptability is good: the annular tubular capacitor is highly moisture-proof, corrosion-resistant and capable of preventing the influence of other severe environments which may be encountered in military application, and the product still requires high-reliability filtering in the severe environments, and is the best choice; meanwhile, the selectable series of the high-voltage-resistant DC power supply has the voltage resistance of more than 2.5KVac, the DC power supply is allowed to be used in 20Vac AC and various DC switching power supplies, the appearance of an annular tubular capacitor is adopted, an anti-radiation interference filter is arranged at the input end of the switching power supply, a multi-stage LC high-frequency, low-frequency common-mode and differential-mode filter combination is adopted, the high-frequency radiation interference fed back to the input end by the switching power supply is well inhibited by adopting a metal shell 15 integrated design, a two-cavity combination is adopted, a first-stage LC filter circuit comprising a C3 differential-mode capacitor, a first coil 11, a C4 differential-mode capacitor and the like is filtered, the high-frequency radiation interference fed back to the input end by the switching power supply is filtered, a C3 differential-mode capacitor, a C7 differential-mode capacitor, a second coil 12 and C8 differential-mode capacitor are adopted, and a second-stage LC filter circuit is used for filtering the medium-frequency and low-frequency radiation interference fed back to the input end by the switching power supply.

Specifically, the electrode terminals of the C1 annular tubular capacitor 1 and the C9 annular tubular capacitor 9 are electrically connected to the positive electrode 13 of the switching power supply through a lead.

Specifically, the electrode ends of the C2 annular tubular capacitor 2 and the C1 annular tubular capacitor 1 are electrically connected with the negative electrode 14 of the switching power supply through a lead.

Specifically, magnetic cores are embedded in the centers of the inner walls of the two first coils 11 and the second coil 12.

Specifically, the metal casing 15 is embedded in the outer walls of the C1 annular tubular capacitor 1, the C2 annular tubular capacitor 2, the C9 annular tubular capacitor 9 and the C1 annular tubular capacitor 1.

Specifically, the C5 annular tubular capacitor 5 and the C6 annular tubular capacitor 6 are embedded at two sides of the center of the inner wall of the metal shell 15.

Specifically, the C3 differential mode capacitor 3, the C4 differential mode capacitor 4, the C7 differential mode capacitor 7 and the C8 differential mode capacitor 8 are composed of one or more capacitors, and the capacitor material, capacity and withstand voltage can be flexibly selected according to actual use.

Specifically, the wire is selected to have a suitable diameter according to the actual power.

Specifically, the metal outer walls of the C1 annular tubular capacitor 1, the C2 annular tubular capacitor 2, the C5 annular tubular capacitor 5, the C6 annular tubular capacitor 6, the C9 annular tubular capacitor 9 and the C1 annular tubular capacitor 1 are electrically connected to the metal housing 15.

Specifically, rubber rings are slidably embedded in the inner walls of the C1 annular tubular capacitor 1, the C2 annular tubular capacitor 2, the C5 annular tubular capacitor 5, the C6 annular tubular capacitor 6, the C9 annular tubular capacitor 9 and the C1 annular tubular capacitor 1.

When in use: the C1 ring-shaped tubular capacitor is directly mounted on the metal panel of the metal shell, so the grounding inductance is smaller, and the influence of lead inductance is almost eliminated, in addition, the input and output ends of the capacitor are isolated by the metal plate, high-frequency coupling is eliminated, the two characteristics determine that the ring-shaped tubular capacitor has the filtering effect close to the ideal capacitance, the self-inductance of the ring-shaped tubular capacitor is much smaller than that of the common capacitor, so the self-resonance frequency is very high, meanwhile, the straight-through design also effectively prevents the high-frequency signal from being directly coupled from the input end to the output end, the combination of low-pass and high-resistance provides excellent inhibition effect in the frequency range of 10Kz to 10GHz, and the environmental adaptability is good: the annular tubular capacitor is highly moisture-proof, corrosion-resistant and capable of preventing the influence of other severe environments which may be encountered in military application, and the product still requires high-reliability filtering in the severe environments, and is the best choice; meanwhile, the series of the voltage-resistant switch can be selected to be more than 2.5KVac, so that the switch can be used in 20Vac alternating current and various direct current switch power supplies.

The present invention is not limited to the preferred embodiments, and any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.