KR101032157B1 - Integrated transformer - Google Patents

Abstract

According to the present invention, a plurality of transformers may be integrated into a single transformer structure by stacking secondary windings that deliver power for driving a plurality of lamps, and in particular, eight lamps may be driven by a single transformer structure, thereby reducing volume. 1. A transformer, comprising: a bobbin portion having a bobbin body having a predetermined length and having a through hole formed in the bobbin body in a longitudinal direction, an inner core inserted into the through hole of the bobbin portion, and an outer peripheral surface of the bobbin portion; A core part having an outer core formed in the longitudinal direction and magnetically connected to the inner core to form a single path, a primary winding wound at the center of the bobbin part, and the primary winding interposed therebetween; A plurality of teeth that are laminated on both sides of the bobbin portion to form a winding ratio preset with the primary winding. Provides an integrated transformer characterized in that including a winding having a first and a second secondary winding having a winding group.

Transformers, Liquid Crystal Display (LCD), Integrated

Description

Integrated Transformers {INTEGRATED TRANSFORMER}

The present invention relates to an integrated transformer, and more particularly, to integrate a plurality of transformers into a single transformer structure by stacking secondary windings for delivering power for driving a plurality of lamps in an LCD inverter circuit. The present invention relates to an integrated transformer having a volume that can be driven by a single transformer structure.

Recently, liquid crystal display (LCD) products such as LCD TVs or LCD monitors have become larger. On the other hand, LCD products that are getting larger and larger are required to be smaller in volume.

To meet these demands, embedded circuits and components employed in LCD products are being developed in a form that can be miniaturized. The same is true of the driver circuit, which is one of the main circuits of LCD products.

LCD products, such as LCD TVs or LCD monitors, do not use liquid crystal displays (LCDs) to emit light, so backlighting is essential, and as a light source for such backlights, a cold cathode fluorescent lamp (CCFL) is used. Is mainly used. In order to use a cold cathode fluorescent lamp as a light source, a driving circuit capable of applying a high voltage is required to drive each lamp. Each lamp should have the same brightness. That is, the current flowing through each lamp should be the same. In order to satisfy such a condition, a conventional current balance circuit is used to satisfy the current balancing and simultaneous lighting conditions of a lamp while using a high voltage transformer.

However, while larger LCD products are required to be smaller in volume, a current balancing circuit for lamp current balancing and simultaneous lighting conditions is added, thereby increasing the volume of LCD products and increasing manufacturing costs. There is this.

In order to solve the above problems, an object of the present invention is to laminate a plurality of transformers in a single transformer structure by stacking secondary windings for delivering power for driving a plurality of lamps in an LCD inverter circuit, in particular eight lamps It is possible to drive a single transformer structure to provide an integrated transformer with a reduced volume.

In order to achieve the above object, one technical aspect of the present invention has a bobbin body of a certain length, the bobbin portion having a through hole formed in the longitudinal direction inside the bobbin body, and inserted into the through hole of the bobbin portion A core portion having an inner core, an outer core formed in the longitudinal direction along one of the outer circumferential surfaces of the bobbin portion and magnetically connected to the inner core to form one magnetic path, and a primary winding around the bobbin portion A winding having a winding and a first and second secondary winding group having a plurality of secondary windings laminated on both sides of the bobbin portion with the primary winding therebetween to form a predetermined winding ratio with the primary winding; It is to provide an integrated transformer, characterized in that.

According to one technical aspect of the present invention, the first secondary winding group may include a first secondary winding and a second secondary winding laminated to the first secondary winding and magnetically coupled with the first secondary winding. The second secondary winding group may include a third secondary winding and a fourth secondary winding laminated to the third secondary winding and magnetically coupled to the third secondary winding, and the first to fourth secondary windings. Each end and the other end of the winding may be electrically connected to the lamp, respectively, to transmit power for driving the lamp.

According to one technical aspect of the present invention, the first secondary winding may be wound on one side of the outer peripheral surface of the bobbin body of the bobbin portion, the third secondary winding in the longitudinal direction on one side of the outer peripheral surface of the bobbin body of the bobbin portion The second secondary winding may be laminated on the first secondary winding, the fourth secondary winding may be laminated on the third secondary winding, and the first secondary winding may be wound on the other side formed on the opposite side. An insulating part may be formed between the second secondary windings and between the third secondary winding and the fourth secondary winding to electrically insulate the secondary windings from each other.

According to one technical aspect of the present invention, the insulating portion may be at least partially open in the longitudinal direction.

According to one technical aspect of the present invention, the insulating portion may be combined with the partitions respectively formed on both sides of the outer peripheral surface of the bobbin portion.

According to one technical aspect of the present invention, the integrated transformer of the present invention guides the inner core to be inserted into the through hole, and electrically connects the outer core to the first and second secondary winding groups. It may further include an insulating member for insulating.

According to one technical aspect of the present invention, an output terminal for outputting the lamp driving power from one end and the other end of the first to fourth secondary windings may be formed on one surface of the bobbin body adjacent to the outer core.

According to another technical aspect of the present invention, the first secondary winding group may include a first secondary winding and a second secondary winding magnetically coupled to the first secondary winding, and the second secondary winding The group may include a third secondary winding and a fourth secondary winding magnetically coupled to the third secondary winding, each end and the other end of the first to fourth secondary windings being electrically connected to a lamp, respectively. Lamp driving power may be transmitted, and the bobbin parts are respectively inserted into the through holes of the bobbin body, and a first auxiliary bobbin in which the first secondary winding is wound on an outer circumferential surface, and a second auxiliary winding in which the third secondary winding is wound. It is to provide an integrated transformer that may further include a bobbin.

According to another technical aspect of the present invention, the second secondary winding is wound on one side of the bobbin body of the bobbin portion, and the fourth secondary winding is formed on the other side of the bobbin body at the opposite side in the longitudinal direction. The first secondary winding wound on the first auxiliary bobbin may be wound at the same position in the length direction as the second secondary winding, and the third winding wound on the second auxiliary bobbin. The secondary winding may be wound at the same position in the longitudinal direction as the fourth secondary winding.

According to another technical aspect of the present invention, one side of the bobbin body of the bobbin portion may be formed with a slit (Slit) provided in the longitudinal direction from the inlet of the through hole, the first and second auxiliary bobbin is Each of the first and third secondary windings may have an auxiliary output terminal electrically connected to one end and the other end, and the auxiliary output terminal may extend from the inside of the bobbin body to the outside through the slit.

According to another technical aspect of the present invention, an output terminal for outputting lamp driving power from one end and the other end of the second and fourth secondary windings may be formed on one surface of the bobbin body adjacent to the outer core, The auxiliary output terminal may be formed on one surface of the auxiliary bobbin adjacent to the outer core.

According to the present invention, in the LCD inverter circuit, by stacking secondary windings that deliver electric power for driving a plurality of lamps, a plurality of transformers are integrated into one transformer structure, and in particular, eight lamps may be driven by one transformer structure. It is possible to reduce the volume of the inverter circuit for the LCD and the transformer employed therein.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic configuration diagram of a lamp driving apparatus employing a transformer of the present invention.

Referring to FIG. 1, the AC power from the inverter is converted to a voltage level of the lamp driving power by the transformer T and transferred to each lamp.

In this case, the impedance of each lamp may be different from each other, and in a strike mode operation in which a voltage higher than the voltage level of the lamp driving power is applied at the initial stage of lamp lighting, only a specific lamp is lit and other lamps are not lit. You may not.

Accordingly, leakage inductance by the winding of the transformer T is formed.

That is, in the transformer, the flux generated by the windings Np, Ns1 to Ns4 flows along the magnetic path by the core, and at this time, a part of the flux does not flow along the magnetic path and leaks between the winding and the core, thereby causing leakage inductance Lk1 to Lk8) can be formed.

The leakage inductance Lk1 to Lk8 may set the leakage inductance to be larger than the impedance of each lamp in order to keep the driving of the lamp constant, thereby solving the partial unlighting of the lamp caused by the impedance of the lamp. . That is, in the transformer, the leakage inductance is greater than the impedance of the lamp so that the impedance of the lamp can be ignored, and the leakage inductance should be formed uniformly in consideration of the partial unlighting of the lamp and the current balance in the lamp.

In consideration of such leakage inductance setting, as shown in FIG. 2, a transformer for driving a plurality of lamps may be integrated into a single transformer structure.

2 (a) and 2 (b) are schematic diagrams of an integrated transformer of the present invention.

Referring to Figures 1 and 2 (a), the integrated transformer of the present invention is a bobbin having a bobbin body (B) having a through-hole (Bi) formed in the longitudinal direction therein, and is wound around the bobbin Winding part having a primary winding (Np) and a plurality of secondary windings, and magnetically coupled to the inner core (Coi1, Coi2) and the inner core (Coi1, Coi2) inserted into the through hole (Bi) of the bobbin one It may include a core portion having an outer core (Coo1, Coo2) to form a chair path.

The bobbin portion may form a winding region in which the winding portion may be wound on the outer circumferential surface of the bobbin body B, and the primary winding Np of the winding portion may be wound in the winding region provided in the center of the outer circumferential surface of the bobbin body B. And a plurality of secondary windings including first to fourth secondary windings Ns1 to Ns4 may be wound in winding regions provided at both sides of the outer circumferential surface of the bobbin body B in the length direction.

In addition, the primary winding Np receives the input power, and each of the secondary windings Ns1 to Ns4 outputs a lamp driving power whose voltage level is converted according to the winding ratio with the primary winding Np. One end and the other end of Np are electrically connected to the input terminal, and one end and the other end of each of the secondary windings Ns1 to Ns4 are electrically connected to the output terminal Io. In consideration of the current balance of the lamp driving power delivered to the lamp, the output terminal Io is preferably formed adjacent to the outer cores Coo1 and Coo2.

That is, the output terminal Io and the outer cores Coo1 and Coo2 may be formed on the outer circumferential surface of the same bobbin body B. The output terminal (Io) and the outer core (Coo1, Coo2) is formed on the outer peripheral surface of the same bobbin body (B) by the electromagnetic action between the input and output terminals, the core portion and the winding portion as shown in Table 1 below Experiments show that the variation in current can be reduced.

<Table 1>

Referring to Table 1, the output terminal Io and the outer cores Co1 and Co2 have a 0.3 mA tube current deviation in the case of being formed on the outer circumferential surface of the same bobbin body B, whereas the output terminal Io and the outer core Coo1 and Co2 are 0.3 mA. It can be seen that the tube current deviation of the lamp when the cores Co1 and Co2 are formed on the outer circumferential surface of the bobbin portion B opposite to each other is 1.8 mA. (The 1, 3, 5, 7 lamp current and the 2, 4, 6, 8 lamp current may be opposite signs of the current value, but the absolute value is assumed to be the same.)

In general, considering that the deviation of the output current required by the user is 0.5 mA when the rated output current (lamp tube current) is 8 mA, the output terminal Io and the external cores Coo1 and Coo2 have the same bobbin body B. It is preferable that it is formed in the outer peripheral surface.

FIG. 2B is a cross-sectional view of the integrated transformer shown in FIG. 2A in the aa ′ direction. Referring to FIG. 2B, first to fourth secondary windings Ns1 to Ns4 may be stacked on both sides of the bobbin body B. Referring to FIG. That is, the first secondary winding (Ns1) is wound on one side of the bobbin body (B), the second secondary winding (Ns2) may be laminated and wound on the first secondary winding (Ns1), and the bobbin body (B) The third secondary winding Ns3 may be wound on the other side opposite to the length direction of one side, and the fourth secondary winding Ns4 may be laminated and wound on the third secondary winding Ns3. There may be various embodiments of the integrated transformer of the present invention according to the form in which the first to fourth secondary windings Ns1 to Ns4 are wound, which will be described in detail with reference to FIGS. 4 and 5.

3 is a magnetic equivalent circuit diagram of the integrated transformer of the present invention.

1 to 3, in the integrated transformer of the present invention, a first secondary winding Ns1 and a second secondary winding Ns2 are formed on one side of the bobbin body B in the length direction, and The third secondary winding Ns3 and the fourth secondary winding Ns4 are formed on the other side of the bobbin body B in the same length direction.

Accordingly, the leakage inductances Lk1 to Lk4 by the first secondary winding Ns1 and the second secondary winding Ns2 may be the same, and may be equal to the third secondary winding Ns3 and the fourth secondary winding Ns4. Leakage inductors Lk5 to Lk8 may also be the same.

More specifically, when the integrated transformer of the present invention is viewed as a magnetic equivalent circuit, the reluctance (magnetic resistance) of the outer cores Coo1 and Coo2 may be shown as Ro in FIG. 3, and the inner core Coi1. The reluctance of Coi2) can be shown as Rc. Similarly, the connection of the outer cores Co1, Co2 and the inner cores Co1, Co2 can be shown as Roc, and the reluctance of the lamp can be shown as Rs and the leakage inductance as Rlk. The current flowing in the primary winding Np may be shown as I1, and the current flowing in each of the secondary windings Ns1 to Ns4 may be shown as I2. The depicted reluctance can be calculated using the cross-sectional area, length and permeability of the corresponding part of the transformer. The leakage inductance Rlk is a model of the leakage path in which the magnetic flux from the primary side of the transformer is not transmitted to the secondary side. It can vary depending on factors such as the shape of the and the spacing between the primary winding.

That is, in the integrated transformer of the present invention, since the shape of the transformer and the distance between the primary windings and the like are symmetrical, the leakage magnetic flux paths on the left and right sides are the same, so that the leakage inductance Rlk values on the left and right sides are the same. The value of the leakage inductance of the secondary winding is also the same.

As described above, the first secondary winding Ns1 and the second secondary winding Ns2 are formed at the same position, and the third secondary winding Ns3 and the fourth secondary winding Ns4 are formed at the same position. A plurality of transformers that deliver lamp driving power to eight lamps can be integrated into a single transformer structure, and the lamp non-lighting problem can be solved by maintaining the same leakage inductance.

There may be the following embodiments with respect to the formation of the same position of the first to fourth secondary windings Ns1 to Ns4.

4 (a) and 4 (b) are diagrams illustrating an embodiment of the integrated transformer of the present invention.

Figure 4 (a) is an exploded perspective view of one embodiment of the integrated transformer of the present invention.

2 to 4 (a), since the integrated transformer of the present invention has a symmetrical shape, only the right side of the transformer is illustrated.

As shown in (a) of FIG. 2 and FIG. 4, the third and fourth secondary windings Ns3 and Ns4 are wound on one side of the bobbin body B, and the third secondary winding Ns3 is wound thereon. The fourth secondary winding Ns4 is laminated and wound. In this case, an insulation portion In may be formed between the third secondary winding Ns3 and the fourth secondary winding Ns4, and the insulation portion In may be the third secondary winding Ns3 and the fourth secondary winding Ns4. Insulate the liver electrically.

The insulation part In may cover the entire winding area in which the third secondary winding Ns3 is wound, and at least a part of the insulating part In may be opened in the length direction as shown, and the bobbin body B may be divided into a plurality of pieces. It may be coupled to one side of).

In addition, the integrated transformer of the present invention may further include an insulating member Inb. The insulating member Inb guides the insertion of the through hole Bi of the inner core Coi2 and electrically insulates the third and fourth secondary windings Ns3 and Ns4 from the outer core Coo2.

4B illustrates a configuration in which the integrated transformer illustrated in FIG. 4A is combined.

As shown in (b) of Figure 4, the insulating portion (In) is composed of four pieces are coupled to one side of the bobbin body (B), wherein the insulating portion (In) is on one side of the bobbin body (B) The third secondary winding N3 may be formed to be coupled to the partition wall dividing the number of turns to be fixed to one side of the bobbin body B.

One embodiment of the integrated transformer of the present invention described above shows only the right side of the integrated transformer, but considering the lateral symmetry of the integrated transformer of the present invention, the above-described insulating portion and the insulating member are formed on the left side of the transformer. It is natural.

5 is a block diagram showing another embodiment of the integrated transformer of the present invention.

2 and 5, in another embodiment of the integrated transformer of the present invention, the first and second auxiliary bobbins B1 and B2 are inserted into the through holes Bi of the bobbin body B.

The first secondary winding Ns1 is wound around the outer circumferential surface of the first auxiliary bobbin B1, and the third secondary winding Ns3 is wound around the outer circumferential surface of the second auxiliary bobbin B2. Second and fourth secondary windings Ns2 and Ns4 are wound in winding regions on both sides of the bobbin body B, respectively.

The winding region in which the first secondary winding Ns1 is wound on the first auxiliary bobbin B1 is located in the longitudinal direction with the winding region in which the second secondary winding Ns2 is wound on one side of the bobbin body B. The winding region in which the third secondary winding Ns3 is wound on the second auxiliary bobbin B2 is located in the longitudinal direction of the winding region in which the fourth secondary winding Ns4 is wound on the other side of the bobbin body B.

Accordingly, another embodiment of the integrated transformer of the present invention may have the same electrical characteristics as that in which the second secondary winding Ns2 is laminated on the first secondary winding Ns1, and the third secondary winding ( The fourth secondary winding Ns4 on the Ns3 may have the same electrical characteristics as that of the laminated winding.

One end and the other end of the second secondary winding Ns2 and the fourth secondary winding Ns4 may be electrically connected to the output terminals Po1 to Po4, respectively, and the first secondary winding Ns1 and the third secondary winding Ns3. One end and the other end of may be electrically connected to the auxiliary output terminals Pos1 to Pos4, respectively.

The output terminals Po1 to Po4 and the auxiliary output terminals Pos1 to Pos4 are preferably formed on the same outer circumferential surface of the outer cores Coo1 and Coo2 and the bobbin body B, and the bobbin body B Slit (Sl) is formed on one surface of the) so that the auxiliary output terminals Pos1 to Pos4 may extend outwardly from the through-holes Bi that are inside the bobbin body B.

As described above, the integrated transformer of the present invention integrates a plurality of transformers into a single transformer structure by stacking secondary windings that deliver electric power for driving a plurality of lamps to both winding regions of the bobbin, and in particular, eight lamps. It can be driven by a single transformer structure can reduce the volume of the inverter circuit for LCD and the transformer employed therein.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, but is defined by the claims below, and the configuration of the present invention may be modified in various ways without departing from the technical spirit of the present invention. It will be apparent to those skilled in the art that the present invention may be changed and modified.

1 is a schematic configuration diagram of a lamp driving device employing a transformer of the present invention.

2 (a) and 2 (b) are schematic diagrams of an integrated transformer of the present invention.

3 is a magnetic equivalent circuit diagram of an integrated transformer of the present invention.

4 (a) and 4 (b) are diagrams illustrating one embodiment of the integrated transformer of the present invention.

5 is a block diagram showing another embodiment of the integrated transformer of the present invention.

<Detailed Description of Major Symbols in Drawing>

B ... bobbin body Bi ... through hole

B1 ... First Auxiliary Bobbin B2 ... Secondary Auxiliary Bobbin

Np ... primary windings Ns1 to Ns4 ... 1st to 4th secondary windings

Io, Po1 to Po4 ... output terminals Pos1 to Po4 ... auxiliary output terminals

Coo1, Coo2 ... Outer Core Coi1, Coi2 ... Inner Core

In ... insulation Inb ... insulation member

Sl ... Slit

Claims (11)

delete delete A bobbin having a bobbin body having a predetermined length and having a through hole formed in the longitudinal direction of the bobbin body; A core part having an inner core inserted into the through-hole of the bobbin part and an outer core formed along one surface of the outer circumferential surface of the bobbin part in the longitudinal direction and magnetically connected to the inner core to form a magnetic path; And First and second secondary having a primary winding wound in the center of the bobbin portion and a plurality of secondary windings laminated on both sides of the bobbin portion with the primary winding therebetween to form a predetermined winding ratio with the primary winding. A winding having a winding group, The first secondary winding group includes a first secondary winding and a second secondary winding laminated to the first secondary winding and magnetically coupled to the first secondary winding, The second secondary winding group includes a third secondary winding and a fourth secondary winding laminated to the third secondary winding and magnetically coupled to the third secondary winding, Each one end and the other end of the first to fourth secondary windings are electrically connected to the lamp, respectively, to transfer power for driving the lamp, The first secondary winding is wound on one side of the outer peripheral surface of the bobbin body of the bobbin portion, The third secondary winding is wound on the other side formed on the opposite side in the longitudinal direction on one side of the outer peripheral surface of the bobbin body of the bobbin portion, The second secondary winding is laminated winding on the first secondary winding, the fourth secondary winding is laminated winding on the third secondary winding, And an insulation portion electrically insulating each secondary winding between the first secondary winding and the second secondary winding and between the third secondary winding and the fourth secondary winding. delete The method of claim 3, The insulation unit is coupled to the barrier ribs formed on both sides of the outer peripheral surface of the bobbin portion integrated transformer. The method of claim 5, And an insulating member for guiding the inner core to be inserted into the through hole and accommodating the outer core to electrically insulate the outer core from the first or second secondary winding group. Type transformer. The method of claim 6, An output transformer configured to output lamp driving power from one end and the other end of the first to fourth secondary windings to one surface of the bobbin body adjacent to the outer core; The method of claim 3, The bobbin portion is inserted into the through-holes of the bobbin body, respectively, the outer peripheral surface further comprises a first auxiliary bobbin winding the first secondary winding and the second auxiliary bobbin winding the third secondary winding, characterized in that Integrated transformer. The method of claim 8, The second secondary winding is wound on one side of the bobbin body of the bobbin portion, and the fourth secondary winding is wound on the other side formed on the opposite side in the longitudinal direction on one side of the outer peripheral surface of the bobbin body. The first secondary winding wound on the first auxiliary bobbin is wound at the same position in the longitudinal direction as the second secondary winding, And the third secondary winding wound on the second auxiliary bobbin is wound at the same position in the longitudinal direction as the fourth secondary winding. 10. The method of claim 9, On the bobbin body one surface of the bobbin portion is formed a slit (Slit) provided in the longitudinal direction from the inlet of the through hole, The first and second auxiliary bobbins each have an auxiliary output terminal electrically connected to one end and the other end of the first or third secondary winding, And the auxiliary output terminal extends from the inside of the bobbin body to the outside through the slit. The method of claim 10, Output terminals for outputting the lamp driving power from one end and the other end of the second and fourth secondary windings are formed on one surface of the bobbin body adjacent to the outer core, And the auxiliary output terminal is formed on one surface of the auxiliary bobbin adjacent to the outer core.

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