KR101507455B1 - Line Filter With Current Sensor - Google Patents

Abstract

A technique relating to a line filter serving as a current sensor is disclosed. In one embodiment, the line filter also includes a bobbin having a through hole formed therein, a core inserted into the through hole to form a passage through which a magnetic field moves, a primary coil and a secondary coil wound around the bobbin, Wherein the primary coil is formed of a wire having a cross-sectional area larger than that of the secondary coil, and the winding of the primary coil is connected to the secondary coil Is less than the number of turns of the coil.

Description

Line Filter with Current Sensor [

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line filter, and more particularly, to a line filter technology capable of providing a current sensor function as well as noise elimination, which is a unique function of a line filter, with little structural change.

A power input terminal to which an external commercial power is input is provided with a rectifier for converting AC power to DC power, a line filter for removing noise, and a current sensor for detecting and interrupting an overcurrent.

The line filter is used to remove electromagnetic interference waves coming from a power line to which a power source is input. Generally, a coil is wound on both sides of a bobbin by a predetermined number of times and a ferrite core core is fixed to surround the bobbin. An example of such a line filter is disclosed in Korean Registered Application No. 20-0094807 'Line filter bobbin structure ".

The current transformer is a device for measuring a current by transforming a large current into a small current, and is used for detecting an overcurrent flowing in the power supply end to prevent an overcurrent flow. The current transformer has a structure similar to that of the transformer. The current ratio between the primary and secondary currents is inversely proportional to the turns ratio of the primary coil and the secondary coil so that the secondary current is reduced in comparison with the primary current.

Although the line filter and the current transformer have a generally similar structure, the line filter and the current transformer are separately used at the conventional power input terminal, which causes a rise in the unit price of the power connection terminal.

Therefore, the main object of the present invention is to provide both a line filter and a current sensor as a single device without almost any structural change by using the characteristics of a line filter and a current transformer having a structure similar to that of a transformer. From this point of view, the present line filter used in combination with the current sensor is different from the cited invention.

In one embodiment, the current sensor combined line filter is disclosed. The line filter includes a bobbin having a through hole formed therein, a core inserted into the through hole to form a passage through which a magnetic field moves, a primary coil wound around the bobbin, a secondary coil, Wherein the primary coil is formed of a wire having a cross-sectional area larger than that of the secondary coil, and the primary coil is wound less than the secondary coil .

The foregoing provides only a selective concept in a simplified form as to what is described in more detail hereinafter. The present disclosure is not intended to limit the scope of the claims or limit the scope of essential features or essential features of the claims.

1 is a perspective view of a line filter serving as a current sensor according to an embodiment of the present invention.
2 is a bottom view of a line filter serving as a current sensor according to an embodiment of the present invention.

Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the drawings. Like reference numerals in the drawings denote like elements, unless the context clearly indicates otherwise. The exemplary embodiments described above in the detailed description, the drawings, and the claims are not intended to be limiting, and other embodiments may be utilized, and other variations are possible without departing from the spirit or scope of the disclosed technology. Those skilled in the art will appreciate that the components of the present disclosure, that is, the components generally described herein and illustrated in the figures, may be arranged, arranged, combined, or arranged in a variety of different configurations, all of which are expressly contemplated, As shown in FIG. In the drawings, the width, length, thickness or shape of an element, etc. may be exaggerated in order to clearly illustrate the various layers (or films), regions and shapes.

When a component is referred to as being "connected" or " connected " with another component, the component may be directly connected to the other component, .

When a component is referred to as being " deployed "to another component, it may include the case where the component is directly disposed on the other component, as well as the case where additional components are interposed therebetween. On the other hand, other expressions that describe the relationship between components, such as " between " and " between "

It is to be understood that the singular " include " or " have " are to be construed as including the stated feature, number, step, operation, It is to be understood that the combination is intended to specify that it is present and not to preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

In each step, the identification codes (e.g., 110, 120, 130, ...) are used for convenience of explanation and the identification codes do not describe the order of the steps, Unless the specific order is described, it may occur differently from the order specified. That is, steps may occur in the same order as described, may be performed substantially concurrently, or may be performed in reverse order.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed technology belongs, unless otherwise defined. Terms defined in commonly used dictionaries should be interpreted to be consistent with meaning in the context of the relevant art and can not be construed as having ideal or overly formal meaning unless expressly defined in the present application.

FIG. 1 is a perspective view of a line filter serving as a current sensor according to an embodiment of the present invention, and FIG. 2 is a bottom view of a line filter serving as a current sensor according to an embodiment of the present invention.

1 and 2, the line filter 100 of the present invention includes a bobbin 110, a connection terminal 120, a core 130, a primary coil 150, a secondary coil 140 And a spacer (160). In some other embodiments, the line filter 100 may optionally further include a stationary support 170.

The bobbin 110 has a through hole (not shown) formed therein. For example, protrusions 110a and protrusions 110b may be formed at one end and the other end of the bobbin 110, respectively. The protrusions 110a and protrusions 110b may function to prevent the secondary coils 140 and the primary coils 150 from being separated from the bobbin 110, respectively. As the material of the bobbin 110, an insulator such as plastic may be used. The bobbin 110 serves as a supporting structure for the core 130, the secondary coil 140, and the primary coil 150.

The connection terminal 120 may be disposed adjacent to the protrusion 110a at one end of the bobbin 110 or may be disposed at the protrusion 110a at one end. In the drawing, a pair of connection terminals 120a and 120b as connection terminals 120 are shown as an example. As the material of the plurality of connection terminals 120, a metal, a conductive polymer, or the like may be used.

The core 130 is inserted into the through hole formed in the bobbin 110 to form a passage through which the magnetic field moves. As the material of the core 130, a magnetic material such as ferrite may be used. The core 130 serves as a magnetic path for transferring a magnetic field generated by the current flowing in the secondary coil 140 to the primary coil 150. In the primary coil 150 receiving the magnetic field, an electromotive force is generated by a Faraday electromagnetic induction law to generate a current or a voltage. The metal plate 131 may be disposed on at least a part of the surface of the core 130 exposed to the outside. The metal plate 131 may serve to guide the magnetic field so that a magnetic field generated by a current flowing through the secondary coil 140 is stably transferred to the primary coil 150. [

The secondary coil 140 is wound to wind the bobbin 110, and one end and the other end of the secondary coil 140 are electrically connected to a connection terminal selected from the connection terminals 120. For example, as shown in the figure, the one end of the secondary coil 140 may be connected to the connection terminal 120a, and the other end may be connected to the connection terminal 120b.

The primary coil 150 is wound to wind the bobbin 110, and is disposed apart from the secondary coil 140. The primary coil 150 can be directly connected to an external circuit without a separate connection terminal. In the figure, a primary coil 150 which is extended outward and can be directly connected to an external circuit without a separate connection terminal is shown as an example. The primary coil 150 may wind the bobbin 110 in a manner that passes through the bobbin 110 once, as shown in the figure. As another example, the primary coil 150 may wind the bobbin 110 in a manner that the bobbin 110 is wound several times as shown in the figure. As the material of the secondary coil 140 and the primary coil 150, a metal, a conductive polymer, or the like may be used.

The line filter 100 of the present invention is configured such that the cross-sectional area of the wire of the primary coil 150 is formed larger than the cross-sectional area of the wire of the secondary coil 140 to provide a function as a current sensor, The number of turns of the secondary coil 140 may be less than the number of turns of the secondary coil 140. 1 and 2 illustrate the case of the line filter 100 in which the winding of the primary coil 150 is 1 and the winding of the secondary coil is several tens of times.

According to the winding ratio, a very small current flows through the secondary coil 140 compared to the primary coil 150, and a resistance or an ammeter is connected to the output terminal of the secondary coil 140, It is possible to measure the magnitude of the input current flowing into the power input terminal by measuring the flowing current. Accordingly, when an overcurrent shut-off circuit is provided in the power supply connection circuit, the overcurrent shut-off operation can be performed based on the measured current value.

It is conceivable that the primary coil 150 is formed of a thin wire having a small cross sectional area. However, in this case, the primary coil 150 may be overheated and disconnected when a large current of a predetermined value or more flows, It is preferable that a wire of a thickness not breaking the wire is used even when the above-mentioned current flows.

The partition plate 160 is disposed between the secondary coil 140 and the primary coil 150. The secondary coil 140 wound around the bobbin 110 and the primary coil 150 are separated from each other, The bobbin 110 is divided. As the material of the partition plate 160, an insulator such as plastic may be used. The partition plate 160 may be formed separately from the bobbin 110 and disposed on the bobbin 110 or may be integrally formed with the bobbin 110.

The stationary supporter 170 may be disposed between the partition plate 160 and the protrusion 110b at the other end of the bobbin 110 to fix the primary coil 150 to the bobbin 110. [ Since the primary coil 150 is much thicker than the secondary coil 140 according to the present invention, the secondary coil 140 is not tightly wound around the bobbin 110 like the secondary coil 140, A fixed support means such as a stationary support 170 is needed. In this case, the fixed supporter 170 has a plurality of through holes, and the primary coil 150 passes through one of the plurality of through holes, one end of the primary coil 150 passes through one of the plurality of through holes, The other end of the through hole 150 may be fixed to the bobbin 110 by passing through any one of the plurality of through holes. For example, the fixed support portion 170 may be a plate structure having a through hole through which the primary coil 150 is inserted. In the figure, a pair of through holes 171 and 172 are illustrated as an example of the plurality of through holes. As the material of the fixed support portion 170, an insulator such as plastic may be used.

Although not shown in the drawings, an adhesive such as epoxy may be used to additionally fix the primary coil 150 to the bobbin 110 in addition to the fixed support 170. [ For example, the adhesive may be disposed between the primary coil 150 and the partition plate 160 facing the primary coil 150 to further secure the primary coil 150 to the bobbin 110. As another example, the adhesive may be disposed between the primary coil 150 and the protruding portion 110b facing the primary coil 150 to further secure the primary coil 150 to the bobbin 110. The adhesive may be disposed between the primary coil 150 and the partition plate 160 facing the primary coil 150 and the protrusion 110b facing the primary coil 150 and the primary coil 150. [ So that the primary coil 150 can be additionally fixed to the bobbin 110. As an example for the sake of understanding, the above example is not limited as to the position where the adhesive is adhered as long as the primary coil 150 is additionally fixed using the adhesive.

The operation of the line filter 100 will now be described with reference to the drawings. The primary coil 150 may be connected to a power facility (not shown), and the secondary coil 140 may be connected to an electronic device. In this case, the primary coil 150 may be directly connected to the electric power facility, and may be disposed in the electric power facility or at a predetermined interval. When the power equipment operates normally, a certain level of direct current or alternating current flows constantly through the secondary coil 140. For example, when the rated current flows through the primary coil 150, the secondary coil 140 may be preset to have an ampere or 5A. When an unexpected situation such as an electrical short-circuit occurs in the electric power facility, the current value flowing through the primary coil 150 changes. In this case, the magnetic field, that is, the magnetic flux, transmitted to the secondary coil 140 through the core 130 changes. An induced electromotive force is generated in the secondary coil 140 due to the change of the magnetic flux and the current measurement means electrically connected to the secondary coil 140 detects an overcurrent flow and performs an operation for interrupting the overcurrent flow do.

From the foregoing it will be appreciated that various embodiments of the present disclosure have been described for purposes of illustration and that there are many possible variations without departing from the scope and spirit of this disclosure. And that the various embodiments disclosed are not to be construed as limiting the scope of the disclosed subject matter, but true ideas and scope will be set forth in the following claims.

Claims (4)

A bobbin having a through hole formed therein;
A core inserted into the through hole to form a passage through which a magnetic field moves;
A primary coil and a secondary coil wound around the bobbin;
And a partition plate for allowing the primary coil and the secondary coil to be spaced apart from each other,
Wherein the primary coil is formed of a wire having a cross-sectional area larger than that of the secondary coil, and the winding of the primary coil is smaller than the winding of the secondary coil. The method according to claim 1,
Further comprising a connection terminal disposed on one side of the bobbin and electrically connected to the secondary coil,
Wherein the primary coil is connected to the external circuit directly without the connection terminal being extended to the outside. The method according to claim 1,
Further comprising a fixed support portion disposed between the partition plate and the other side of the bobbin and fixedly supporting the primary coil. The method of claim 3,
Wherein the fixed support portion is a plate structure having a through hole through which the primary coil is inserted and connected.

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