KR20080086709A - Burial electromagnetic interference filter - Google Patents

Abstract

A burial EMI filter is provided to form a broadband filter having a bilaterally-symmetric structure based on a ferrite bead, thereby effectively blocking harmful electromagnetic waves which can be flowed from wall power or flowed from a common electronic device connected to an outlet. A wall power connecting terminal(80a,80b) is respectively connected with an active line and a neutral line of wall power. An external power connecting terminal(70a,70b) is connected with an external device. A first EMI(Electromagnetic Interference) unit(100) is connected with the wall power connecting terminal, and blocks broadband noise flowed into or flowed out of the wall power. A second EMI unit(110) is connected with the external power connecting terminal, and blocks broadband noise flowed into or flowed out of the external device. A couple of ferrite beads(90) are connected with the first and second EMI units in parallel, attenuate a magnetic field generated by electromagnetic noise, and block RF(Radio Frequency) noise.

Description

Embedded Electromagnetic Interference Filter {Burial Electromagnetic Interference Filter}

1 is a perspective view showing the appearance of the electromagnetic wave filter according to the present invention,

Figure 2 is an external perspective view showing the mounting form of the electromagnetic wave filter in accordance with the present invention,

3 is a circuit diagram showing a circuit according to the internal configuration of the electromagnetic wave blocking filter according to the present invention;

4 is a view showing the internal configuration of the electromagnetic wave filter in accordance with a preferred embodiment of the present invention;

5 is a diagram illustrating a comparison of electromagnetic radiation graphs depending on whether the electromagnetic wave filter is installed according to the present invention.

<Description of main parts of drawing>

50: electromagnetic wave filter 51: PCB

60: Ground terminal 70a, 70b: External power connection terminal

80a, 80b: wall power connector 90: ferrite bead

100: second noise blocking unit 110: first noise blocking unit

The present invention relates to an embedded electromagnetic wave blocking filter, and more particularly, is easily coupled to an embedded outlet which is embedded in a basement or a wall and supplies wall power to an electronic device, thereby effectively reducing the noise of broadband that flows in and out through the outlet. It relates to an embedded electromagnetic wave filter.

In general, in order to use an electronic device, a plug connected to the product must be connected to an outlet provided on a floor or a wall to receive power. Since the outlet is electrically coupled to a power line into which single-phase AC power or three-phase 220v AC power flows from the outdoors, the power line and the plug are electrically connected when the plug is connected to the outlet, and AC power is transmitted to the electronic device through the plug. Be sure to These outlets are classified as recessed outlets because they are buried inside the floor or wall except for the front part to which the plug is connected.

At this time, the AC power flowing into the power line is affected by the noise caused by its own noise or electronics connected to the outlet, which acts as a factor that prevents the stable operation of the electrical appliance connected to the outlet.

In general, the outlet is electrically connected to each of the neutral and constituent lines constituting the power line, and the ground line is electrically connected to the ground line of the building. At this time, a vibration current generated by the magnetic field is generated between the neutral line and the active line, and electromagnetic waves are generated accordingly to form noise.

In addition, in a powered electronic device, a magnetic field is generated by a current flowing along an internal circuit, and thus a predetermined electromagnetic wave is generated. The generated electromagnetic waves may have a detrimental effect on the human body in contact with or in proximity to the electronic device, or may cause a malfunction or failure in the electronic device. Therefore, most electronic devices are provided with an electromagnetic filter circuit for blocking harmful electromagnetic waves therein.

However, the electromagnetic filter circuit is to prevent the electromagnetic waves generated by itself from adversely affecting the human body or the internal circuits. When electromagnetic waves generated in the apparatus are transmitted to the outlet through the plug, another electronic device connected to the outlet or the Electromagnetic waves generated by electronic devices connected to another outlet electrically connected to the outlet may be transmitted. In addition, when electromagnetic waves are introduced from the connected outlets, there is a problem in that noise is introduced into the connected electronic devices because the means for blocking them is not specifically presented.

In order to solve such a problem as described above, an electromagnetic shielding filter may be installed in the recess. However, since each device connected to the outlet generates electromagnetic waves of various frequencies according to the characteristics of the device, a broadband cut filter is required to effectively block noise.

However, the choke coil of the inductor, which is used as a conventional electromagnetic wave filter, is used by winding a copper wire around an annular core, which limits the inductance value. It cannot be blocked effectively.

In addition, when the mounting type is to be mounted in the outlet, the size of the annular core is larger than the size of the free space in the outlet, not to be mounted in the outlet, it must be mounted on the outside, there is a problem that the connection of the device is complicated.

The present invention is to solve the problems of the prior art, embedded electromagnetic shielding to effectively block the noise of the broadband frequency that can be connected to the wall-mounted outlet and inter-transmitted between the wall power source and the electronic device to meet the EMI standards The purpose is to provide a filter.

Another object of the present invention is to provide an embedded electromagnetic wave blocking filter that easily binds with a wall power line and an outlet terminal in an embedded outlet to block broadband noise.

The embedded electromagnetic wave blocking filter according to the present invention for solving the above problems is a wall power connection terminal connected to a wall power source, an external power connection terminal connected to an external device, connected to the wall power connection terminal, or introduced into the wall power source. A first noise blocker to block outflow broadband noise, a second noise blocker connected to the external power connection terminal to block broadband noise flowing in or out from the external device, and the first noise blocker and the second noise It is characterized in that it comprises a pair of ferrite beads connected in parallel between the blocking unit to cancel the magnetic field generated by the noise and block the high frequency noise.

The ferrite beads are characterized in that the magnetic permeability of 2200.

The first and second noise blocking units are connected in parallel with the ferrite beads to block low frequency noise, and are connected in parallel with the stacked capacitors, one end of which is connected to ground and the other end of the active line of the wall power source / external power source and It includes a plurality of capacitors connected to the neutral wire, respectively, to block high frequency noise.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 is an external perspective view illustrating a mounting form of an electromagnetic wave blocking filter according to the present invention.

The embedded electromagnetic wave blocking filter 50 according to the present invention is mounted on the rear of the embedded outlet so that wall power is transmitted to the outlet via the blocking filter 50. The cut filter 50 includes a housing for protecting an internal circuit configured to block electromagnetic waves. The housing is preferably formed of a flame-retardant ABS resin, flame-retardant ABS resin is excellent in tensile strength and flexural strength to make a solid product with a thin thickness, and even if the temperature range is large, there is almost no change in physical properties, requiring heat resistance There is a characteristic suitable for the product being made.

Blocking filter 50 according to the present invention is connected to the wall power connection terminal (80b) and the outlet to which the wall power wire is connected to the external power connection terminal to be electrically connected to the electronic device when the plug of the electronic device is coupled to the outlet 70a and 70b.

At this time, the wall power connection terminal 80b is formed as a hole in each side surface of the blocking filter 50, and when the electric wire is inserted into the hole, the wall power connection terminal 80b is connected to the wall power connection terminal of the internal circuit. Wall power connection terminal (80b) is formed of a hole for connecting the neutral line and the active line on both sides in accordance with each power line when the power line of the wall power is composed of a ground line, a neutral line and an active line, but this is a single-phase AC power supply This means that it is used as wall power, and in case of 3-phase AC power flow, each phase power line should be connected to wall power connection terminal.

External power connection terminal (70a, 70b) is originally intended to be connected to each hole formed in the outlet to insert the wall power line is inserted into the hole to be electrically connected to the blocking filter (50) 50 is formed with a metal rod protruding perpendicular to the. At this time, the metal rod is also formed in two because the neutral wire and the active wire should be connected between the ground terminal 60 to be connected to the ground terminal of the outlet.

Therefore, the blocking filter 50 according to the present invention may be electrically connected by inserting external power connection terminals 70a and 70b into the outlet and inserting neutral and active lines of wall power into each hole on the side. It blocks the electromagnetic noise flowing in / out between the wall power and the outlet.

Figure 2 is an external perspective view showing in more detail the mounting form of the electromagnetic wave filter in accordance with the present invention.

That is, as shown in Figure 2, the electromagnetic wave filter according to the present invention includes a housing 15 for protecting the internal configuration of the outlet when the outlet 10 is buried in the wall or floor. The outlet 10 is exposed to the outside is coupled to the internal configuration around the front portion to which the plug is connected. Therefore, unscrewing and detaching the housing of the front part reveals the internal configuration of the outlet coupled to the back of the housing.

The inside of the outlet is provided with a ground terminal of the metal for grounding on the upper surface, the hole 11 is formed in each of the wall power line is inserted into the center. Accordingly, the blocking filter 50 according to the present invention inserts the external power connection terminals 70a and 70b of the blocking filter into each hole 11 and inserts into the wall power connection terminal 80b formed on the side of the filter 50. By inserting the wall power wires, the cutoff filter can be easily connected to the outlet.

At this time, when the external power connection terminal is inserted into the outlet, the ground terminal 60 of the cutoff filter of the present invention contacts the ground end of the outlet, and the external power connection terminals 70a and 70b of the cutoff filter are connectable to the outlet. The position can be adjusted to fit the position of (11).

Referring to the internal circuit of the electromagnetic wave filter according to the present invention configured as described above are as follows. 3 is a circuit diagram illustrating an internal configuration of an electromagnetic wave blocking filter according to the present invention.

The electromagnetic wave blocking filter according to the present invention includes wall power connection terminals 80a and 80b connected to active and neutral wires of wall power, external power connection terminals 70a and 70b connected to external devices, and the wall power connection terminal ( A first electromagnetic wave blocking unit 100 connected to 80a and 80b to block broadband noise flowing into or out of the wall power source, and connected to the external power connection terminals 70a and 70b to inflow or outflow from the external device It includes a second electromagnetic wave blocking unit 110 to block the broadband noise.

In addition, the first and second electromagnetic wave shields 100 and 110 are connected in parallel to include a pair of inductors 90 to cancel the magnetic field generated by the electromagnetic noise and to block the high frequency noise.

At this time, the inductor 90 is implemented by ferrite beads L1 and L2. The ferrite beads L1 and L2 having small high permeability are mounted to the outside of the conductor to form the active and neutral wires spaced apart from each other. Done.

At this time, the conductors forming the active line and the neutral line are formed in the form of only copper conductors without the leading edge coating, so that a dielectric does not exist between the ferrite beads so that a separate parasitic capacitor does not occur.

Accordingly, when high frequency electromagnetic waves acting as noise passes through each ferrite bead, magnetic fields in different directions are generated, and the magnetic fields existing between both ends of the active line and the neutral line cancel each other out and disappear. Therefore, the noise due to the high frequency electromagnetic wave is also canceled out.

Meanwhile, the first electromagnetic wave blocking unit 110 and the second electromagnetic wave blocking unit 100 have a symmetrical structure around the ferrite beads 90, L1, and L2. That is, each of the capacitors C1 and C4 connected in parallel between the active line and the neutral line around the ferrite bead 90, respectively, and the capacitors C1 and C4 and the respective wall power / external power connection terminals 70a and 70b, A plurality of capacitors (C2, C3, C5, C6) are connected in parallel between the 80a, 80b.

The capacitors C1 and C4 disposed around the ferrite bead 90 are connected to the active line and the neutral line to block the differential mode noise formed therebetween. In addition, it is composed of a capacitor having a larger capacitance than the plurality of capacitors (C2, C3, C5, C6) connected between the connection terminals (70a, 70b, 80a, 80b) to block low-frequency noise.

In addition, the plurality of capacitors (C2, C3, C5, C6) are connected in series between the active line and the neutral line, the center point is connected to the ground, common mode noise and differential mode flowing between the active line and ground, neutral and ground It cuts off the noise at the same time.

The electromagnetic wave blocking filter according to the present invention configured as described above operates as follows.

When a plug connected to a power line of an electric device is connected to an outlet, current flows from the wall power connection terminals 80a and 80b to the external power connection terminals 70a and 70b to transfer operating power to the connected device. At this time, when a current flows between the neutral line and the active line connecting the wall power source and the external power source, a magnetic field is formed to generate electromagnetic waves propagating to the surrounding space.

At this time, the ferrite beads (L1, L2) through which the neutral line and the active line pass, form magnetic fields different from each other as the current flows, and thus the magnetic fields are canceled between both ends, so that electromagnetic waves, in particular, high frequency electromagnetic waves Removed. In this case, since the ferrite beads L1 and L2 have no parasitic capacitor, the ferrite beads L1 and L2 may completely saturate the magnetic field generated by the flowing current, thereby obtaining an effective inductance value.

Low frequency electromagnetic waves are blocked by the capacitors C1 and C4 having a symmetrical structure around the ferrite beads L1 and L2, and the electromagnetic waves saturated in the inductor and the capacitor are transferred to the ground connected between the plurality of capacitors to the power line. Incoming / outflowing electromagnetic waves can be blocked.

4 is a diagram illustrating an internal configuration of an electromagnetic wave blocking filter according to a preferred embodiment of the present invention.

That is, the preferred embodiment of the present invention is implemented by mounting a plurality of components on the PCB substrate 51 as shown in FIG. PCB board 51 is a double-sided PCB of moisture resistant FR-4 material, it is preferable that the thickness is less than 1mm to be mounted in the outlet.

In addition, a ground line on the PCB 51 is connected to the ground terminal 60 to protrude outside the housing.

The wall power connection terminals 80a and 80b correspond to a hole formed in the housing of the cutoff filter 50, and are formed of a plurality of electrode pins such that the inserted wall power supply line is electrically connected to the cutoff filter.

The ferrite bead 90 is small in size and can carry a current of 15 A. The ferrite bead 90 is preferably a high permeability bead having an internal hole of 2.5 mm so that a conductor having a thickness of 2 mm or more can pass therethrough. The ferrite beads 90 may have a high permeability of 2000 to 2500, but it was experimentally found that the nickel-zinc ferrite having a value of about 2200 exhibits a maximum attenuation effect in the electromagnetic filter according to the present invention.

In addition, the ferrite beads 90 are connected to each of the six small ferrite beads in series to form a single ferrite bead, each of the small ferrite beads may have the same or different permeability.

Capacitors C1 and C4 arranged in parallel from the top to the bottom with a pair of ferrite beads 90 interposed therebetween are used to block low-frequency differential mode noise and take a mylar form and are implemented as stacked capacitors. It is preferable that the multilayer capacitor has a value of about 1,. If a capacitor having a larger capacity is used, the low frequency characteristics are better, but leakage current due to charge / discharge occurs, and the size thereof becomes larger, and thus, I cannot attach it.

In addition, a plurality of capacitors connected in parallel with the stacked capacitors between the external power supply terminals 70a and 70b and the stacked capacitors, and between the wall power connection terminals 80a and 80b and the stacked capacitors may have an active line, a ground, a ground and a neutral line. It can be implemented that each of the disk-shaped capacitor is connected to.

The disk-type capacitor is to block the high frequency common mode and differential mode noise at the same time, it is preferable that a ceramic capacitor having excellent high frequency characteristics is applied. At this time, the capacitor may have a value in the range of 3300 ㎊ to 10000 있으나, but since the matching with the inductor implemented with the ferrite beads is very important, it is preferable to have a value of 4700 갖는 with experimentally excellent attenuation characteristics.

In addition, to meet the electrical safety certification requirements for leakage current or withstand voltage, it is preferable that the capacitor has a breakdown voltage characteristic of about 3 kV.

On the other hand, such a large number of capacitors can be replaced by a TNR that blocks a surge, which is possible because the internal impedance of the TNR is very high before the surge component is introduced to perform a similar operation to a capacitor having a predetermined capacitance. to be.

5 is a diagram illustrating a comparison of electromagnetic radiation graphs depending on whether the electromagnetic wave filter is installed according to the present invention. Figure 5 (a) is a diagram showing the general electromagnetic radiation characteristics of the industrial cleaner, Figure 5 (b) is a diagram showing the electromagnetic radiation characteristics of the industrial cleaner when the electromagnetic wave filter is coupled to the outlet. Figure 5 (c) is a diagram showing the general electromagnetic radiation characteristics of the mixer, Figure 5 (d) is a diagram showing the electromagnetic radiation characteristics of the mixer when the electromagnetic wave filter is coupled to the outlet according to the present invention. In addition, Figure 5 (e) is a diagram showing the general electromagnetic radiation characteristics of the notebook, Figure 5 (f) is a diagram showing the electromagnetic radiation characteristics of the notebook when the electromagnetic wave blocking filter according to the present invention is coupled to the outlet.

That is, as shown in FIG. 5, the electromagnetic wave blocking filter according to the present invention combines the electromagnetic wave blocking filter of the present invention with an outlet, and then connects a plug to the outlet to operate the electronic device. It can be seen that is largely blocked in the main band, and the value is greatly reduced.

In particular, as shown in Figure 5 (a), (c), (e) when using the electronic appliances in various fields other than home appliances such as industrial cleaners, mixers, laptops, even if the frequency band of the electromagnetic wave emitted a lot different from each other Nevertheless, as shown in Figure 5 (b), (d), (f) it can be seen that it is excellent in electromagnetic shielding characteristics in various frequency bands can be easily used in general.

As described above, the embedded electromagnetic wave blocking filter according to the present invention has been described with reference to the illustrated drawings, but the present invention is not limited to the embodiments and drawings disclosed herein, and the ferrite beads and the beads blocking high frequency electromagnetic waves. The technical concept of the present invention includes a plurality of capacitors which are symmetrically configured to block high and low frequencies so that the electromagnetic wave noise of the broadband can be effectively reduced and easily coupled to an embedded outlet within the scope of protection. It can be easily applied by those skilled in the art.

Built-in electromagnetic wave filter according to the present invention configured as described above is a harmful filter that can be introduced from a general-purpose electronic device that is introduced from the wall power source or connected to the outlet by forming a broadband filter having a symmetrical structure around the ferrite beads There is an effect that can effectively block the electromagnetic waves.

In addition, it is possible to guarantee durability and safety as it can be protected by housing, inserting power line of wall power, and connecting terminal into outlet except for wiring structure with wall power and outlet. It is easy to apply.

Claims (7)

A wall power connection terminal connected to the active wire and the neutral wire of the wall power; An external power connection terminal connected to an external device; A first electromagnetic wave blocking unit connected to the wall power connection terminal to block broadband noise flowing into or out of the wall power; A second electromagnetic wave blocking unit connected to the external power connection terminal to block broadband noise flowing in or out of the external device; And A pair of ferrite beads connected in parallel with the first and second electromagnetic wave shields to cancel the magnetic field generated by the electromagnetic noises and block high frequency noises. Embedded electromagnetic wave blocking filter, characterized in that configured to include. The method of claim 1, The ferrite beads are embedded electromagnetic shielding filter, characterized in that the nickel-zinc ferrite having a permeability of 2200. The method of claim 2, The ferrite beads are six embedded electromagnetic cut filter, characterized in that each arranged side by side along the lead. The method of claim 1, The first noise blocking unit is connected in parallel to the active line and the neutral line of the wall power connection terminal, and the second noise blocking unit is an embedded electromagnetic wave blocking filter, characterized in that connected in parallel to the active line and the neutral line of the external power connection terminal. . The method of claim 4, wherein The first noise blocking unit is connected to the ferrite bead in parallel stacked capacitors to block low-frequency noise; And A plurality of capacitors connected in parallel with the stacked capacitor, one end of which is connected to ground and the other end of which is connected to an active line and a neutral line of the wall power source to block high frequency noise Embedded electromagnetic wave blocking filter, characterized in that configured to include. The method of claim 4, wherein The second noise blocking unit is connected to the ferrite bead in parallel stacked capacitors to block low-frequency noise; And A plurality of capacitors connected in parallel with the stacked capacitor, one end of which is connected to ground, and the other end of which is connected to an active line and a neutral line of the external power source to block high frequency noise Embedded electromagnetic wave blocking filter, characterized in that configured to include. The method of claim 1, Embedded electromagnetic shielding filter, characterized in that the outside of the cut filter is surrounded by a material of flame-retardant ABS resin.

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