KR20180055440A - Line filter and power supply comprising line filter - Google Patents

Abstract

A line filter and a power supply comprising a line filter are disclosed. The line filter includes a high-frequency choke for eliminating high-frequency noise of a predetermined second frequency or more, and a common mode (CM) choke for eliminating noise in the entire frequency band. The high-frequency choke comprises a core formed of a closed circuit and divided into two windows by a middle leg, and a first winding and a second winding wound on at least one outer leg of the core. The CM choke includes a core, a third winding wound around one side of the core, and a fourth winding wound around the outer side of the other side facing the outer side of the core around which the third winding is wound. The choke and the high-frequency choke can be miniaturized.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a power supply including a line filter and a line filter,

The present invention relates to a power supply including a line filter and a line filter, and more particularly to a power supply including a miniaturized line filter and a line filter.

With the development of broadcasting technology, the size of TV panels is increasing. Since the panel size and power consumption are proportional, a high output power supply is required to drive a large panel. However, at the same time, the power supply device is required to be downsized and slimmed in accordance with the slimness of the TV set. Of the various components of the power supply included in the TV set, the line filter circuit is bulky because it is composed of only passive elements. In addition, the passive elements increase in value as the power consumption increases, so that the volume of the passive elements also increases in proportion to the value.

On the other hand, a plurality of line filters may be used for one power supply. In general, CM (Common Mode) chokes are used to eliminate noise in the entire frequency band around the low frequency band, and high frequency chokes are separately used to effectively eliminate noise in the high frequency band.

For example, FIG. 1 is a diagram illustrating a configuration of a conventional power supply apparatus. Referring to Figure 1, the power supply includes one high frequency choke and two CM chokes. As described above, the high frequency choke eliminates the power supply noise in the high frequency band, and the two CM chokes remove the noise in the entire frequency band.

2 is a view showing a line filter. Referring to Fig. 2 (a), a high frequency choke is shown, and a CM choke is shown with reference to Fig. 2 (b). As shown in Fig. 2 (a), the size of the high-frequency choke is about 15 mm in length and 17.5 mm in length. As shown in Fig. 2 (b), the CM choke is about 31 mm in width and 27 mm in length. As described above, the line filter has a problem in that it occupies a large area in the power supply device. Therefore, a technique for miniaturizing the line filter is required.

An object of the present invention is to provide a power supply device including a line filter and a line filter capable of downsizing the CM choke and the high frequency choke.

It is also an object of the present invention to provide a power supply device including a line filter and a line filter that can simplify the production process.

In order to accomplish the above object, a line filter according to an embodiment of the present invention includes a high-frequency choke for eliminating high-frequency noise over a predetermined second frequency and a CM (Common Mode) choke for eliminating noise in the entire frequency band Wherein the high frequency choke comprises a core formed by a closed circuit and divided into two windows by a middle leg, a first winding and a second winding wound on at least one outer leg of the core, The CM choke includes a core, a third winding wound around the outer side of one side of the core, and a fourth winding wound on the outer side of the other side facing the outer side of the core around which the third winding is wound.

And wherein the first and second windings of the high frequency choke are wound on the outer circumference of a first one of the two windows of the core and wherein the third and fourth windings of the CM choke It can be wound around the outer circumference of the second window region of the windows.

The first winding is wound on the outer side of one side of the first window area adjacent to the middle, and the second winding is wound on the outer side of the other side facing the outer side of one side of the first window, You can wrap it.

Further, the first winding and the second winding may be wound side by side on one side of the outer side of the first window region facing the center of gravity.

On the other hand, the first winding and the third winding are wound side by side on the outer side of one side facing the center of gravity, and the second winding and the fourth winding are wound on the outer side of the other side facing the center, The winding may be arranged to face the first winding, and the fourth winding may be arranged to face the third winding.

The two windows of the core may have different areas.

The first winding and the second winding may have opposite winding directions and the winding directions of the third winding and the fourth winding may be opposite to each other.

The first winding and the second winding may have the same number of windings, and the third winding and the fourth winding may have the same number of windings.

The number of windings of the first winding may be smaller than the number of windings of the third winding.

According to an aspect of the present invention, there is provided a power supply device including a power supply for receiving power from the outside and a line filter for removing noise included in the power supply, And a CM (Common Mode) choke for eliminating high-frequency chokes and a noise in the entire frequency band, wherein the high-frequency choke is formed as a closed circuit and is formed by two windows A first winding wound around at least one outer leg of the core, and a second winding, the CM choke comprising a core, a third winding wound on one outer side of the core, And a fourth winding wound on the outer side of the other side facing the outer side of the core wound with the winding.

As described above, according to the various embodiments of the present invention, the power supply device including the line filter and the line filter can miniaturize the CM choke and the high-frequency choke in one.

In addition, since the power supply device including the line filter and the line filter can be manufactured in one, the production process can be simplified and the production cost can be reduced.

1 is a view for explaining a configuration of a conventional power supply apparatus.
2 is a view showing an existing line filter.
3 is a view showing a line filter according to a first embodiment of the present invention.
4 is a view showing a line filter according to a second embodiment of the present invention.
5 is a view showing a line filter according to a third embodiment of the present invention.
6 is a diagram illustrating a power supply according to an embodiment of the present invention.
7 is a diagram illustrating a power supply apparatus according to another embodiment of the present invention.
Fig. 8 is a diagram showing the results of testing for the presence and absence of middle ear.

Various embodiments will now be described in detail with reference to the accompanying drawings. The embodiments described herein can be variously modified. Specific embodiments are described in the drawings and may be described in detail in the detailed description. It should be understood, however, that the specific embodiments disclosed in the accompanying drawings are intended only to facilitate understanding of various embodiments. Accordingly, it is to be understood that the technical idea is not limited by the specific embodiments disclosed in the accompanying drawings, but includes all equivalents or alternatives falling within the spirit and scope of the invention.

 Terms including ordinals, such as first, second, etc., may be used to describe various elements, but such elements are not limited to the above terms. The above terms are used only for the purpose of distinguishing one component from another.

In this specification, the terms "comprises" or "having ", and the like, are intended to specify the presence of stated features, integers, steps, operations, elements, parts, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

In addition, in the description of the present invention, when it is judged that the detailed description of known functions or constructions related thereto may unnecessarily obscure the gist of the present invention, the detailed description thereof will be abbreviated or omitted.

3 is a view showing a line filter according to a first embodiment of the present invention.

The line filter 100 according to an embodiment of the present invention includes a high frequency choke and a CM (Common Mode) choke. The high-frequency choke is the part that removes the high-frequency noise contained in the circuit line, and the CM choke is the part which removes the noise of the whole frequency band.

In general, most of the noise included in the circuit line may be several hundreds of KHz to tens of MHz. Therefore, the CM choke can remove the noise in the entire frequency band around the noise in the low frequency region. However, even if there are not many components of noise in the high-frequency region, it is necessary to reliably remove the noise component in the high-frequency region because the influence on the electronic apparatus is large. Therefore, as described above, a line filter for high frequency elimination that can eliminate high frequency noise is separately included.

However, the line filter 100 according to an embodiment of the present invention includes the high frequency choke and the CM choke together. That is, the line filter 100 according to an embodiment of the present invention may be implemented with a filter for removing noise in the high frequency region and a filter for removing noise in the entire frequency band. The line filter 100 may be implemented with some passive elements for impedance matching, including high frequency chokes, CM chokes. Therefore, in this specification, the portion including the high frequency choke and the CM choke will be referred to as a line filter.

The line filter 100 includes a core 10 including a middle leg, a first winding 21 and a second winding 22 for implementing a high frequency choke, a third winding 31 for implementing a CM choke, And a four-winding 32. The core can be divided into two regions by the central region. The sizes of the two windows may be the same, but they may be different.

In one embodiment, a relatively small window area may be implemented with a high frequency choke, and a relatively large window area may be implemented with a CM choke. That is, the first winding 21 and the second winding 22 are wound on the outer leg of the relatively small window region of the core 10 so that they can be realized with a high frequency choke. The third winding 31 and the fourth winding 32 are wound on the outer circumference of the relatively large window region of the core 10 so that the CM choke can be realized.

A line filter is a filter that removes noise that is common to circuit lines. Therefore, the first winding 21 and the second winding 22 must be wound in opposite directions to each other. The third winding 31 and the fourth winding 32 are also wound in opposite directions. The first winding 21 and the third winding 31 are input side lines, and the second winding 22 and the third winding 32 are output side lines. That is, the current input to the first winding 21 is output to the second winding 22 via the various elements, and the current input to the third winding 31 is output to the fourth winding 32 do.

A magnetic field in the counterclockwise direction is formed in the core 10 by the current inputted from the upper line of the first winding 21 and the third winding 31. The input current flows from the upper line to the lower line of the second winding 22 and the fourth winding 32 through the various elements of the circuit. The magnetic field of the core is also formed counterclockwise by the current flowing through the third winding 22 and the fourth winding 32, and therefore the magnetic field of the core becomes stronger. The common noise can be eliminated because the energized magnetic field is canceled for the differential current and acts as a resistor for the common noise. The specific noise removal process will be described later.

On the other hand, when the inductance is low or the number of turns of the winding is small, the resonance point rises. In other words, since the number of turns of the first winding 21 and the second winding 22 is relatively small, parasitic capacitance is low and a large impedance can be formed at a relatively high frequency. Therefore, the first winding 21 and the second winding 22 can remove noise in the high frequency band. Since the third winding 31 and the fourth winding 32 have a relatively large number of turns, the parasitic capacitance is high and a large impedance can be formed at a relatively low frequency. Thus, the third winding 31 and the fourth winding 32 can remove noise over the entire frequency band at a relatively low frequency center.

Therefore, the number of turns of the first winding 21 and the second winding 22 included in the high frequency choke is smaller than the number of turns of the third winding 31 and the fourth winding 32 included in the CM choke. Since the first winding 21 and the second winding 22 form a high frequency choke, the number of turns of the first winding 21 and the number of turns of the second winding 22 may be the same. Further, since the third winding 31 and the fourth winding 32 form the CM choke, the number of turns of the third winding 31 and the number of turns of the fourth winding 32 can be the same. The number of turns of each winding can be variously determined based on the frequency band to be removed or the like.

3, the high frequency choke is formed of a closed circuit and includes a core 10 divided into two windows by a middle leg, at least one outer winding 21 of the core 10, And a second winding (22). The CM choke includes the same core 10, the third winding 31 and the fourth winding 32 as the core included in the high frequency choke. The core 10 is commonly used for high-frequency chokes and CM chokes. In one embodiment, the first winding 21 and the second winding 22 may be respectively wound on the confronting outer surface of a relatively small window area. As described above, the first winding 21 and the second winding 22 are wound in opposite directions to each other. The first winding 21 and the second winding 22 can be wound the same number of times. The third winding 31 and the fourth winding 32 can be respectively wound on the facing outer circumference of a relatively large window area. The third winding 31 and the fourth winding 32 are wound in opposite directions to each other. The third winding 31 and the fourth winding 32 can be wound by the same number of times. The third winding 31 is wound a greater number of times than the first winding 21 and the fourth winding 32 is wound more times than the second winding 22. Further, the third winding 31 and the first winding 21 are wound in the same direction, and the fourth winding 32 and the second winding 22 are wound in the same direction.

One line filter 100 including a high-frequency choke and a CM choke using one core can be realized, so that the volume and area of the line filter can be reduced. Thus, the miniaturized line filter 100 can make the circuit board smaller and slimmer, contributing to miniaturization and slimming of the electronic device. In addition, the miniaturized line filter 100 can simplify the production process of the line filter and reduce the production cost.

On the other hand, the windings can be arranged at various positions.

4 is a view showing a line filter according to a second embodiment of the present invention.

Referring to Fig. 4, a line filter 100a in which the position of a winding is changed is shown. As described above, the line filter 100a includes high-frequency chokes and CM chokes. The CM choke includes a third winding 31 and a fourth winding 32 wound respectively on opposite cores of one core. The high frequency choke includes a first winding (21) and a second winding (22). The first winding 21 and the second winding 22 may be arranged side by side. In other words, the first winding 21 and the second winding 22 can be arranged in a mutually facing outer zone. As described above, the first winding 21 and the second winding 22 are wound in opposite directions to each other, and the number of windings can be the same.

5 is a view showing a line filter according to a third embodiment of the present invention.

Referring to Fig. 5, a line filter 100b in which the position of the winding is changed is shown. In Fig. 3 and Fig. 4, a line filter in which two windows in the core are different in size, and high-frequency chokes and CM chokes are distinguished in respective window regions has been described. However, the size of the two windows in the core may be the same. Further, the first winding 21 and the third winding 31 may be disposed in the same outer group around the center of gravity, and the second winding 22 and the fourth winding 32 may be disposed in the same outer group. As described above, the first winding 21 and the second winding 22 are included in the high frequency choke, and the third winding 32 and the fourth winding 33 are included in the CM choke.

According to Fig. 5, the line filter 100b includes a high frequency choke and a CM choke. The high frequency choke includes a core 10, a primary winding 21 and a secondary winding 22, and the CM choke includes the same core 10, a third winding 31 and a fourth winding 32 . The first winding 21 and the third winding 31 can be wound side by side on the outer side of one side facing the middle. The second winding 22 and the fourth winding 32 can be wound around the outer periphery of the other outer side of the first winding 21 and the third winding 31. That is, the first winding 21 and the third winding 31 are wound around the same outer circumference at one side, and the second winding 22 and the fourth winding 32 can be wound around the same outer side of the other side. The second winding 22 may be arranged to face the first winding 21 and the fourth winding 32 may be arranged to face the third winding 31. [ The first winding 21 is wound in the opposite direction to the second winding 22 and wound in the same direction as the third winding 31. [ The fourth winding 32 is wound in the opposite direction to the third winding 31 and wound in the same direction as the second winding 22. [ The first winding 21 may be wound the same number of times as the second winding 22 and wound a few times less than the third winding 31. [ The fourth winding 32 may be wound the same number of times as the third winding 31 and may be wound more times than the second winding 22. [ The number of windings can be variously determined based on the inductance, frequency band to be removed, and the like.

6 is a diagram illustrating a power supply according to an embodiment of the present invention.

Referring to FIG. 6, an embodiment of a power supply 1000a including a line filter 100 is shown. The power supply 1000a may include a line filter 100 and may include an X-capacitor X-cap and a Y-capacitor Y-cap around the line filter 100. FIG. The X capacitor is a capacitor connected to both ends of the AC line, and the Y capacitor is a capacitor connected between the AC line and the ground. The X capacitor serves to reduce the low frequency noise, and the Y capacitor can reduce the high frequency noise.

The power supply 100 may receive AC and transmit it to an equipment under test (EUT) through a line filter 100 and various capacitors. The EUT may be a device to be tested by supplying power using the power supply 100 and may be a device for testing the power supply 100. [ In the case of a general electronic device, a body or a regulator of an electronic device to supply power may be connected instead of the EUT.

In one embodiment, the first and second windings of the line filter 100 may be coupled to the AC line, and the third and fourth windings may be coupled to the EUT. In other words, the high frequency choke part can be connected to the AC terminal, and the CM choke part can be connected to the EUT terminal.

Briefly describing the operation of the line filter, a current within a certain time can be input from an AC power source and transmitted to the first winding, the third winding, the EUT, and output to the fourth winding and the second winding. That is, in the case of normal current, it is the opposite direction when flowing the first winding and flowing the second winding. Since the normal current is in the differential mode, it may not be affected by the line filter. However, the power supply noise may occur in the first winding and the second winding at the same time, and thus may be a common mode. As described above, since the magnetic field generated in the core of the line filter hinders the flow of the power supply noise in the common mode, the line filter can eliminate the power supply noise.

7 is a diagram illustrating a power supply apparatus according to another embodiment of the present invention.

Referring to FIG. 7, an embodiment of a power supply 1000b including a line filter 100 is shown. The power supply 1000b may include a line filter 100 and may include an X-capacitor X-cap and a Y-capacitor Y-cap around the line filter 100. [

As described above, the power supply apparatus 100 can receive AC and transmit it to the equipment under test (EUT) through the line filter 100 and various capacitors. In one embodiment, the third and fourth windings of the line filter 100 may be connected to the AC line, and the first and second windings may be coupled to the EUT. That is, the CM choke portion can be connected to the AC terminal, and the high frequency choke portion can be connected to the EUT terminal.

Since only the connection terminal of the line filter is changed in the power supply apparatus 1000b of FIG. 7, a further description will be omitted.

Fig. 8 is a diagram showing the results of testing for the presence and absence of middle ear.

Referring to FIG. 8, there is shown a result of a test in which first to fourth windings are connected to a core having no core and a core having no core. The new core is the core described herein, including the core, and the existing core is a core that does not contain the common core. L1 denotes a first winding, L2 denotes a second winding, L3 denotes a third winding, and L4 denotes a fourth winding. The first and second windings are included in the high frequency choke, and the third and fourth windings are included in the CM choke.

Referring to Fig. 8, in the case of using a core including a core, the degree of coupling between the first winding and the second winding and the degree of coupling between the third winding and the fourth winding are high. That is, the coupling coefficient (K ₁₂ ) between the first winding and the second winding is close to unity. On the other hand, the coupling between high-frequency choke windings and CM choke windings is low. That is, the coupling coefficient (K ₁₃ ) between the first winding and the third winding is close to zero. That is, the windings of the high frequency choke and the CM choke are operated without affecting each other. On the other hand, when a core not containing a core is used, the coupling between the high-frequency choke winding and the CM choke winding is also high. That is, the coupling coefficient (K ₁₃ ) between the first winding and the third winding is close to unity. That is, the high-frequency choke winding and the CM choke winding are ineffective because they affect each other. Therefore, the line filter including the high-frequency choke and the CM choke integrally formed by winding the winding around the core including the core can be miniaturized and exhibits superior performance.

100: Line filter 10: Core
21: 1st winding 22: 2nd winding
31: Third winding 32: Fourth winding

Claims (10)

A high-frequency choke for eliminating high-frequency noise over a predetermined second frequency; And
And a CM (Common Mode) choke for eliminating noise in the entire frequency band,
The high-
A core formed of a closed circuit and separated by two windows by a middle leg, a first winding wound around at least one outer leg of the core and a second winding,
Wherein the CM choke comprises:
And a fourth winding wound around the core, a third winding wound on one outer side of the core, and a fourth winding wound on the other side facing the outer circumference of the core on which the third winding is wound. The method according to claim 1,
Wherein the first winding and the second winding of the high frequency choke are wound around the outer circumference of the first one of the two windows of the core,
Wherein the third winding and the fourth winding of the CM choke are wound to the outer circumference of a second one of the two windows of the core. 3. The method of claim 2,
Wherein the first winding is wound on the outer side of one side of the first window region adjacent to the middle, and the second winding is wound on the outer side of the other side facing the outer side of one side of the first window, , Line filter. 3. The method of claim 2,
Wherein the first winding and the second winding are wound on one side of the outer side of the first window region facing the center of gravity of the first window region. The method according to claim 1,
Wherein the first winding and the third winding are wound on one side of the outer side facing the center of gravity, and the second winding and the fourth winding are wound on the outer side of the other side facing the center,
The second winding being arranged to face the first winding, and the fourth winding being arranged to face the third winding. The method according to claim 1,
Wherein the two windows of the core are different in area. The method according to claim 1,
Wherein the first winding and the second winding have opposite winding directions and the winding directions of the third winding and the fourth winding are opposite to each other. The method according to claim 1,
Wherein the first winding and the second winding have the same number of windings and the third winding and the fourth winding have the same number of windings. 9. The method of claim 8,
Wherein the number of windings of the first winding is less than the number of windings of the third winding. A power supply for receiving power from the outside; And
And a line filter for removing noise included in the input power source,
The line filter includes:
A high-frequency choke that eliminates high-frequency noise above a predetermined second frequency, and
And CM (Common Mode) chokes for eliminating noise in the entire frequency band,
Wherein the high frequency choke comprises a core formed by a closed circuit and separated by two windows by a middle leg, a first winding and a second winding wound around at least one outer leg of the core,
Wherein the CM choke comprises a core, a third winding wound around the outer side of one side of the core, and a fourth winding wound on the other side facing the outer side of the core around which the third winding is wound.

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