CN213402957U

CN213402957U - EMI filter with slow start function

Info

Publication number: CN213402957U
Application number: CN202022439238.8U
Authority: CN
Inventors: 卞卡
Original assignee: AERODEV ELECTROMAGNETIC TECH Inc
Current assignee: AERODEV ELECTROMAGNETIC TECH Inc
Priority date: 2020-10-28
Filing date: 2020-10-28
Publication date: 2021-06-08
Anticipated expiration: 2030-10-28

Abstract

The utility model relates to an EMI wave filter that possesses slow start function belongs to electromagnetic compatibility technical field. A MOS tube driving circuit board and an EMI filtering module are arranged in the metal shell; the EMI filtering module is provided with a leading-out wire leading to the outer side of the metal shell. The utility model discloses designed the slow starting circuit based on N type MOS pipe before EMI filter circuit, slow starting circuit and EMI filter circuit encapsulation are in same casing, make EMI wave filter possess the function of slowly starting, effectively slow down the power-on time, reduce transient state rush current. The utility model provides a filter circuit with slow start function, when the equipment is electrified, the impact current produced at the moment of electrification is greatly reduced, the problem of transient impact current existing in the traditional EMI filter is solved, and the electromagnetic compatibility of the equipment can be improved; meanwhile, the slow starting circuit and the EMI filter circuit are packaged in the same shell, so that the whole size is reduced, and the design is simple.

Description

EMI filter with slow start function

Technical Field

The utility model relates to an EMI wave filter that possesses slow start function belongs to electromagnetic compatibility technical field.

Background

At present, the functions of precision instruments and equipment are more and more, and the integration level is higher and more, so the electromagnetic compatibility requirement on instrument and equipment systems is stricter and stricter; an electromagnetic interference filter (EMI filter), which is one of effective devices for solving electromagnetic compatibility, is usually designed at the frontmost end of a circuit, and when filtering protection is performed, a differential mode capacitor inside the filter circuit generates an impulse current when equipment is powered on, and the transmission of the impulse current on a power line can generate certain interference on other functional modules in the circuit; therefore, the problem of the inrush current generated by the conventional EMI filter is more and more noticed, and there is a need in the art to provide an EMI filter with a slow start function.

Disclosure of Invention

The utility model aims at solving the technical problem of the produced impulse current of traditional EMI wave filter.

In order to solve the above problems, the present invention provides an EMI filter with a slow start function; a MOS tube driving circuit board and an EMI filtering module are arranged in the metal shell; the EMI filtering module is provided with a leading-out wire leading to the outer side of the metal shell.

Preferably, an EMI filter circuit is disposed in the EMI filter module.

Preferably, a slow start circuit is arranged on the MOS tube driving circuit board.

Preferably, the EMI filter circuit is connected to a soft start circuit.

Preferably, an N-type MOS transistor is disposed in the slow start circuit.

Preferably, the MOS tube is arranged adjacent to the metal shell.

Compared with the prior art, the utility model discloses following beneficial effect has:

the utility model aims at providing a DC EMI wave filter that possesses slow start function, at the inside start circuit that delays of increase based on N type MOS pipe of EMI wave filter encapsulation, delay filter circuit's last electric time, and then reduce the impulse current that electric time capacity device caused.

The utility model adds N type MOS tube at the front end of EMI filter circuit, delays the power-on time of the filter circuit by adjusting the conduction time of the MOS tube, and further reduces the current impact caused by capacitive devices in the back end circuit; a slow starting circuit and an EMI filter circuit are packaged in the same shell, and a small EMI filter with a slow starting function is designed.

The utility model has the advantages that:

1. the filter circuit with the slow start function greatly reduces the impact current generated at the power-on moment when the equipment is powered on, solves the problem of transient impact current existing in the traditional EMI filter, and can improve the electromagnetic compatibility of the equipment;

2. the slow starting circuit and the EMI filter circuit are packaged in the same shell, the size is small, and the design is simple.

Drawings

Fig. 1 is a circuit logic block diagram of the EMI filter of the present invention.

Fig. 2 is a schematic diagram of an EMI filter having a slow start function according to the present invention.

Fig. 3 is the utility model relates to a possesses EMI wave filter internal structure schematic diagram of slowly starting function.

Reference numerals: an MOS tube driving circuit board; an N-type MOS tube; 3, an EMI filtering module; 4. a metal housing; 5. an outgoing line; 6. a slow start circuit; an EMI filter circuit.

Detailed Description

In order to make the present invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings:

as shown in fig. 1-3, the present invention provides an EMI filter with a slow start function; a MOS tube driving circuit board 1 and an EMI filtering module 3 are arranged in the metal shell 4; the EMI filter module 3 is provided with a lead-out line 5 leading to the outside of the metal case 4. An EMI filter circuit 7 is arranged in the EMI filter module 3. The MOS tube driving circuit board 1 is provided with a slow starting circuit 6. The EMI filter circuit 7 is connected to the soft start circuit 6. An N-type MOS tube 2 is arranged in the slow starting circuit 6. The MOS transistor is disposed adjacent to the metal case 4.

As shown in fig. 2 and fig. 3, the structure of the filter of the present invention includes: the circuit comprises an MOS tube driving circuit board 1, an N-type MOS tube 2, an EMI filtering module 3, a metal shell 4 and a lead-out wire 5, wherein the MOS tube driving circuit board is specially used for pasting a tube shell of the MOS tube to the bottom of the metal shell 4 of a packaging shell of the filter in consideration of the heat dissipation problem of the MOS tube, and the whole circuit adopts a PCB integrated circuit process.

The utility model discloses a theory of operation: as shown in FIG. 1, the utility model discloses EMI wave filter's circuit structure has designed the slow start-up circuit based on N type MOS pipe at EMI filter circuit front end, and this circuit is charged to the condenser by resistance in the twinkling of an eye at last electricity, and Vgs slowly rises this moment, and when Vc voltage reached Vgs turn-on voltage, the MOS pipe switched on the back-end circuit, adjusted MOS pipe turn-on time through adjusting the electric capacity size, and then played the slow start-up effect.

The foregoing is merely a preferred embodiment of the present invention, and is not intended to limit the present invention in any way and in any way, and it should be understood that modifications and additions may be made by those skilled in the art without departing from the scope of the present invention. Those skilled in the art can make various changes, modifications and evolutions equivalent to those made by the above-disclosed technical content without departing from the spirit and scope of the present invention, and all such changes, modifications and evolutions are equivalent embodiments of the present invention; meanwhile, any changes, modifications and evolutions of equivalent changes to the above embodiments according to the actual technology of the present invention are also within the scope of the technical solution of the present invention.

Claims

1. The utility model provides a possesses EMI wave filter of slowly starting function which characterized in that: a MOS tube driving circuit board and an EMI filtering module are arranged in the metal shell; the EMI filtering module is provided with a leading-out wire leading to the outer side of the metal shell; a slow starting circuit is arranged on the MOS tube driving circuit board; an N-type MOS tube is arranged in the slow starting circuit; the EMI filtering module is connected with the slow starting circuit.

2. The EMI filter with soft start of claim 1, wherein: and an EMI filter circuit is arranged in the EMI filter module.

3. The EMI filter with soft start of claim 2, wherein: the EMI filter circuit is connected with the slow starting circuit.

4. The EMI filter with soft start functionality of claim 3, wherein: the MOS tube is arranged adjacent to the metal shell.