KR100878420B1 - Multi lamp drive - Google Patents

Abstract

The present invention relates to a multi-lamp driving apparatus that can be applied to a multi-lamp system such as an LCD display, and more particularly, to implement a current balancing circuit using a plurality of legs included in each of a plurality of balanced transformers. By splitting the windings connecting the balanced transformers on the legs of the primary and secondary windings that deliver the driving power to the lamps, the current flowing through the multiple lamps can be balanced and the number of balanced transformers used and winding coils It relates to a multi-lamp driving device that can reduce the.

Description

Multi-lamp drive unit {MULTI-LAMP DRIVING APPARATUS}

The present invention relates to a multi-lamp driving apparatus that can be applied to a multi-lamp system such as an LCD display, and more particularly, to implement a current balancing circuit using a plurality of legs included in each of a plurality of balanced transformers. By splitting the windings connecting the balanced transformers on the legs of the primary and secondary windings that deliver the driving power to the lamps, the current flowing through the multiple lamps can be balanced and the number of balanced transformers used and winding coils It relates to a multi-lamp driving device that can reduce the.

In general, a variety of researches for reducing the manufacturing cost in the inverter field, which is one of the various components constituting the LCD display recently. 16 to 24 Cold Cathode Fluorescent Lamps (CCFLs) are used to create backlights for LCD TVs, and the same number of inverters is also required to drive them.

On the other hand, if a plurality of lamps can be driven in parallel with one inverter, significant cost reduction can be expected. By the way, it is known that CCFL is difficult in parallel driving because the lamp resistance values at the time of ignition and at the time of lighting are different from each other.

In order to solve this disadvantage, it has been known that the use of a current balancing transformer in parallel operation enables multi lamp lighting and current balancing.

Using such a current balancing transformer, one inverter can drive several lamps simultaneously. The current balancing method is called 'Jin', 'Zaulas' or 'O2 micro'. The multi lamp driving apparatus employing the 'Jin' balance method will be described with reference to FIG.

FIG. 1 is a configuration diagram of a conventional multi-lamp driving apparatus. Referring to FIG. 1, a conventional multi-lamp driving apparatus includes an AC power supply 10 for supplying driving power and a driving power supply from the AC power supply 10. A current balancing circuit 30 (1) which equalizes a plurality of lamps 20 (1) to 20 (n) to be lit and currents flowing through the plurality of lamps 20 (1) to 20 (n) uniformly with each other. 30 (n)).

Here, the current balancing circuits 30 (1) to 30 (n) are provided with a plurality of first to nth balanced transformers corresponding to each of the plurality of lamps in order to equalize currents flowing through the plurality of lamps. It includes. Since the principle of current balancing of the above-described current balancing circuit is a known matter, a description thereof will be omitted.

However, such a conventional multi-lamp drive device, since the use of the balanced transformer as the number of the plurality of lamps used as described above, the balanced transformer should be used as many as the number of lamps, because of this the current balancing circuit is complicated There is a problem that the unit price increases.

In order to solve the above problems, an object of the present invention is to provide a current balancing circuit using a plurality of legs included in each of a plurality of balance transformers in a multi lamp driving apparatus that can be applied to a multi lamp system such as an LCD display. In implementing the present invention, by splitting and winding a connection winding connecting a plurality of balanced transformers to a leg wound with primary and secondary windings for transmitting driving power to the lamp, the current flowing through the plurality of lamps can be balanced and balanced. It is to provide a multi-ramp driving device that can reduce the number of transformers and winding coils.

In order to achieve the above object, one embodiment of the multi-lamp driving apparatus of the present invention is a power supply unit for supplying a lamp driving AC power, and a plurality of first to the plurality of first to receive the lamp driving AC power from the power supply unit in parallel A lamp unit including an n-th lamp group, wherein each of the plurality of first to n-th lamp groups includes a first lamp and a second lamp to receive the lamp driving AC power in parallel; And a current balancer electrically connected to each of the first to n-th ramp groups, the current balancer including a plurality of first to n-th balance transformers to balance the current through each of the plurality of first to n-th ramp groups. Each of the plurality of first to nth balanced transformers has a magnetic core having magnetically connected first and second legs, a first winding wound on the first leg, and a second winding wound on the second leg. And a first connection winding wound on the first leg and a second connection winding wound on the second leg, wherein the first winding is the first of the lamp group of the plurality of first to nth lamp groups. One end electrically connected to the lamp, the second winding having one end electrically connected to the second lamp of the lamp group, the first connection winding connected to ground and one end connected to the second connection winding. The second connecting winding has the other end, and the second connecting winding has the other end electrically connected to each other end of the first winding and the second winding of the one balanced transformer adjacent to one end connected to the first connecting winding.

According to an embodiment of the present invention, the current balancing unit may be repeated a structure in which the other ends of the first and second windings of the one balanced transformer are electrically connected to the second connection winding of the other balanced transformer adjacent to each other. have.

According to an embodiment of the present disclosure, the magnetic core may further include a third leg that is electromagnetically connected to the first and second legs between the first leg and the second leg to form a magnetic path. .

According to an embodiment of the present invention, the coil cross-sectional area of the first winding is equal to the coil cross-sectional area of the second winding, and the coil cross-sectional area of the first connecting winding and the coil cross-sectional area of the second connecting winding are It can be twice the coil cross-sectional area.

According to one embodiment of the invention, the number of turns of the first winding is the same as the number of turns of the second winding, the number of turns of the first connection winding is 1/4 times the number of the first winding, The number of turns of the second connection winding may be one quarter times the number of turns of the second winding.

According to an embodiment of the present invention, the winding directions of the first winding and the second winding may be the same, and the winding directions of the first connection winding and the second connection winding are the winding directions of the first and second windings. May be the same as

According to an embodiment of the present invention, the power supply unit includes a driving unit for generating an AC power source having a preset voltage level, a main coil connected to the driving unit, and a sub-coil connected to an output terminal of the lamp driving AC power source, According to the winding ratio between the main coil and the sub-coil may include a transformer for boosting the AC power from the driving unit to the AC power for driving the lamp.

According to another embodiment of the multi-lamp driving apparatus of the present invention, a power supply unit for supplying a lamp driving AC power, a current balancer for maintaining a current balance of the lamp driving AC power from the power supply unit, and And a plurality of first to n-th lamp groups that receive AC power for driving lamps in parallel, and each of the first to n-th lamp groups includes first and second lamps that receive the AC power in parallel. And a lamp unit including a lamp unit, wherein the current balance unit is connected to each of a plurality of first to n-th lamp groups of the lamp unit to maintain balance of current supplied to each of the plurality of first to n-th lamp groups. A first to nth balanced transformer of which each of the plurality of first to nth balanced transformers has a magnetic core having magnetically coupled first and second legs, the first leg A first winding wound, a second winding wound on the second leg, a first connection winding wound on the first leg, and a second connection winding wound on the second leg, wherein the first winding includes: One end of the plurality of first to n-th lamp groups electrically connected to a first lamp of the lamp group, and the second winding has one end electrically connected to a second lamp of the lamp group. The first connection winding has one end connected to the second connection winding and the other end electrically connected to the output end of the power supply unit, and the second connection winding has a first winding of one balanced transformer adjacent to one end connected to the first connection winding, and And the other end electrically connected to each other end of the second winding.

According to the present invention, in a multi-lamp driving apparatus that can be applied to a multi-lamp system such as an LCD display, in implementing a current balancing circuit using a plurality of legs included in each of the plurality of balanced transformers, the plurality of balances By splitting the windings connecting the transformers to the legs of the primary and secondary windings that deliver the driving power to the lamps, the currents flowing through the multiple lamps can be balanced and the number of balanced transformers used and the winding coils can be balanced. There is an effect that can be reduced.

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

2 is a configuration diagram showing a first embodiment of a multi-lamp driving apparatus according to the present invention.

Referring to FIG. 2, the first embodiment of the multi-lamp driving apparatus of the present invention may include a power supply unit 100 for supplying AC power for driving a lamp and an output terminal OUT of the power supply unit 100 for driving the lamp. And a plurality of first to n-th lamp groups 210 to 2n0 that receive AC power in parallel, and each of the plurality of first to n-th lamp groups 210 to 2n0 includes the AC power for driving the lamp in parallel. A lamp unit 200 including a first lamp and a second lamp to be supplied, and a plurality of first to n-th lamp groups 210 to 2n0 of the lamp unit 200 and ground, respectively, A current balance unit 300 including a plurality of first to nth balanced transformers BT1 to BTn for maintaining a balance of currents I1 to I2n through the first to nth ramp groups 210 to 2n0, respectively. Include.

Referring to FIG. 2, the first lamp group 210 includes a first lamp LA11 and a second lamp LA12 that receive the lamp driving AC power in parallel. The second lamp group 220 includes a first lamp LA21 and a second lamp LA22 that receive the lamp driving AC power in parallel. In this manner, the nth lamp group 2n0 includes a first lamp LAn1 and a second lamp LAn2 that receive the lamp driving AC power in parallel.

Each of the plurality of first to nth balanced transformers BT1 to BTn includes a magnetic core MC having a first leg Lg1, a second leg Lg2, and a third leg Lg3 magnetically connected to each other. , A first winding wound on the first leg Lg1 of the magnetic core MC, a second winding wound on the second leg Lg2, a first connection winding wound on the first leg Lg1, and a second leg And a second connection winding wound at Lg2. The third leg Lg3 is used for forming the magnetic path.

In FIG. 2, the first windings L11, L21, ... Ln1 are electrically connected to the first lamps LA11, LA21, ... LAn1 of the corresponding lamp group among the plurality of first to nth lamp groups, respectively. The second windings L12, L22, ... Ln2 have one end electrically connected to the second lamps LA12, LA22, ... LAn2 of the corresponding lamp group.

In addition, the first connection windings L13a, L23a, ... Ln3a have one end connected to the second connection windings L13b, L23b, ... Ln3b and the other end electrically connected to the ground GND. The connecting windings L13b, L23b, ... Ln3b have one end connected to the first connecting windings L13a, L23a, ... Ln3a and the first and second windings of one balanced transformer different from the corresponding balanced transformer. Each other end of the other end is electrically connected.

For example, the first connection windings L13a, L23a, ... Ln3a and the second connection windings L13b, L23b, ... Ln3b will be described.

In FIG. 2, the first connection winding L13a of the first balanced transformer BT1 has one end connected to the ground and the other end connected to the second connection winding L13b. The second connection winding L13b has one end connected to the first connection winding L13a and the other end electrically connected to each other end of the first winding L21 and the second winding L22 of the second balanced transformer BT2. Have

In addition, the first connection winding L23a of the second balanced transformer BT2 has one end connected to the ground and the other end connected to the second connection winding L23b, and the second connection winding L23a is the first connection winding L23a. ) And the other end electrically connected to each other end of the first and second windings of a balanced transformer (not shown) at one end and a rear end thereof.

In this way, the first and second connection windings of the balanced transformer of the front end are electrically connected to respective other ends of the first and second windings of the rear end, and the first and second connecting windings of the balanced transformer of the rear end are connected to the rear end of the balanced transformer. It is electrically connected to each other end of the first and second windings of the balanced transformer at the rear end of the balanced transformer.

Since the sum of the currents of the first and second windings flows in the first and second connection windings, the coil cross-sectional area of the first and second connection windings is twice that of the coils of the first and second windings. Preferably, the number of turns of the first and second connection windings is preferably 1/4 times the number of turns of the first winding or the second winding.

In addition, the coil cross-sectional area and the number of turns of the first winding is preferably the same as the coil cross-sectional area and the number of turns of the second winding. In addition, it is preferable that the winding direction of the first winding and the winding direction of the second winding are the same, and similarly, the winding directions of the first and second connection windings are the windings of the first and second windings to maintain current balance. It is preferable that the same direction.

Accordingly, in the current balance unit 300, a structure in which the other ends of the first and second windings of the one balanced transformer are electrically connected to the first and second connection windings of the other balanced transformer may be repeated. have.

For example, the first balanced transformer BT1 and the second balanced transformer BT2 are electrically connected to each other through the first and second connection windings L13a and L13b of the first balanced transformer BT1, and the second balanced transformer BT2 is electrically connected to each other. The second balanced transformer BT2 and the n-th balanced transformer BTn are electrically connected to each other through the first and second connection windings L23a and L23b of the balanced transformer BT2, and the first and second balanced transformers BTn are electrically connected to each other. The nth balanced transformer and the first balanced transformer BT1 may be electrically connected to each other through the second connection windings Ln3a and Ln3b.

In this way, the current balance unit 300 may be formed in a similar shape to the ring structure.

In addition, the power supply unit 100 may include a driving unit 110 generating AC power for driving a lamp having a predetermined voltage level, a main coil PC connected to the driving unit 110, and a sub-coil connected to the AC power. And a transformer 120 that boosts the AC power to the lamp driving AC power according to a winding ratio between the main coil PC and the subcoil SC. The above-described driving unit 110 may receive a commercial AC power (not shown) and convert it into DC power and then convert the lamp power into AC power for driving the lamp.

The lamp unit 200 includes a plurality of first to n-th lamp groups 210 to 2n0, and each of the plurality of first to n-th lamp groups 210 to 2n0 parallels the lamp driving AC power. And a plurality of lamps LA11 to LAn1, LA12 to LAn2 included in the plurality of first to nth lamp groups 210 to 2n0, the first and second lamps supplied to the power supply unit 100. AC power is supplied from the

In this case, the current balance unit 300 of the present invention includes a plurality of first to n-th balanced transformers BT1 to BTn connected to the plurality of first to n-th ramp groups 210 to 2n0 of the lamp unit 200. ), And the plurality of first to n-th balanced transformers BT1 to BTn maintain the balance of current through each of the plurality of first to n-th ramp groups 210 to 2n0.

In addition, as described above, the current balance unit 300 has a structure in which the other ends of the first and second windings of the one balanced transformer are electrically connected to the second connection windings of the other balanced transformer. Thus, the balance of each current flowing to the lamp unit 200 is maintained through the first to nth balanced transformers BT1 to BTn.

The electrical principle of the current balance described above will be briefly described through a formula.

For example, assuming that the multi-lamp driving apparatus of the present invention is used for lighting six lamps, three current balancing transformers for maintaining the current balance of the lamp driving AC power delivered to the six lamps are provided. Assuming that the first and second connection windings are electrically connected, the following equation is established.

(Equation)

Where Vs is the AC voltage for driving the lamp, R1 to R6 is the equivalent resistance of the lamp, I1 to I6 is the current delivered to the first to sixth lamps, L _N is PN ² , and P is the length / (permeability * Cross-sectional area of the core), N is the number of turns)

Looking at the matrix described above, it can be seen that the Diagonal Term is constructed. That is, the same-like terms formed diagonally from the first row to the first row to the sixth to sixth columns of the matrix have the same configuration as '5', which means that the current balance applied to six lamps is maintained. The above-described determinant is obvious to those skilled in the art for maintaining a current balance, so detailed description thereof will be omitted.

3 is a configuration diagram showing a second embodiment of a multi-lamp driving apparatus according to the present invention.

Referring to FIG. 3, in the second embodiment of the multi-lamp driving apparatus of the present invention, the same power source unit 100 is employed, and the electrical connection relationship between the lamp unit 200 and the current balance unit 300 is different. That is, in the second embodiment of the multi-lamp driving apparatus of the present invention, AC power for driving the lamp from the power supply unit 100 is transferred to the current balance unit 300, and the lamp unit 200 is the current balance unit 300. It is turned on by receiving AC power for balanced lamp driving from current.

Accordingly, the first and second connection windings L13a to Ln3b of the plurality of first to nth balanced transformers BT1 to BTn are electrically connected to the first and second windings of the corresponding balanced transformer, and the power supply unit ( Is electrically connected to the output terminal of 100).

Except for the electrical connection relationship described above, the configuration of the lamp unit 200, the current balance unit and the principle of the current balance is the same, so a detailed description thereof will be omitted.

As described above, the multi-lamp driving apparatus of the present invention integrates the current balancing transformers, which were required one per lamp, into one current balancing transformer per two lamps, and the first and second connection windings are used to maintain the current balance. The use of balanced transformers and the number of winding coils can be reduced.

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 block diagram of a conventional multi-lamp driving device.

2 is a configuration diagram showing a first embodiment of the multi-lamp driving apparatus of the present invention.

3 is a configuration diagram showing a second embodiment of the multi-lamp drive device of the present invention.

<Detailed Description of Major Symbols in Drawing>

100: power supply unit 110; Driving part

120: transformer 200: lamp unit

300: current balance

210,220 ... 2n0: First to nth lamp groups

BT1, BT2 ... BTn: first to nth balanced transformers

MC: magnetic core

Lg1, Lg2, Lg3: first, second and third legs

L11, L21, ..., Ln1: first winding

L12, L22, ..., Ln2: second winding

L13a, L23a, .... Ln3a: First connection winding

L13b, L23b, .... Ln3b: second connection winding

Claims (14)

A power supply unit supplying AC power for driving the lamp; And a plurality of first to n-th lamp groups that receive the lamp driving AC power in parallel from the power supply unit, wherein each of the plurality of first to n-th lamp groups receives the lamp driving AC power in parallel. A lamp unit including a first lamp and a second lamp; And A current electrically connected to each of the plurality of first to n-th lamp groups of the lamp unit and having a plurality of first to n-th balanced transformers to maintain a balance of current through each of the plurality of first to n-th lamp groups Includes an equilibrium, Each of the plurality of first to nth balanced transformers includes a magnetic core having magnetically connected first and second legs, a first winding wound on the first leg, a second winding wound on the second leg, and A first connection winding wound on a first leg and a second connection winding wound on the second leg, the first winding being connected to a first lamp of a corresponding lamp group among the plurality of first to nth lamp groups; Has one end electrically connected, the second winding has one end electrically connected to a second lamp of the lamp group, and the first connection winding has one end connected to the second connection winding and the other end connected to ground. The second connection winding has a multi-lamp drive field, characterized in that the other end is electrically connected to each other end of the first winding and the second winding of one balanced transformer adjacent to one end connected to the first connection winding. Chi. The method of claim 1, wherein the current balance unit, And a structure in which the other ends of the first and second windings of the one balanced transformer are electrically connected to the second connection windings of the other balanced transformer adjacent to each other. The method of claim 2, And the magnetic core further comprises a third leg electromagnetically connected between the first and second legs to form a magnetic path between the first leg and the second leg. The method of claim 3, The coil cross-sectional area of the first winding is equal to the coil cross-sectional area of the second winding, The coil cross-sectional area of the first connecting winding and the coil cross-sectional area of the second connecting winding are twice as large as the coil cross-sectional area of the first winding. The method of claim 4, wherein The number of turns of the first winding is equal to the number of turns of the second winding, The number of turns of the first connection winding is 1/4 times the number of the first winding, and the number of turns of the second connection winding is a multi-lamp drive device, characterized in that 1/4 of the number of turns of the second winding. The method of claim 5, The winding direction of the first winding and the second winding is the same, and the winding direction of the first connection winding and the second connection winding is the same as the winding direction of the first and second windings. The method of claim 1, wherein the power supply unit A driver for generating an AC power source having a preset voltage level; And A main coil connected to the driving unit and a sub-coil connected to the output terminal of the lamp driving AC power, AC power from the driving unit according to the winding ratio of the main coil and the sub-coil boosts the AC power for driving the lamp Transformer Multi-lamp driving apparatus comprising a. A power supply unit supplying AC power for driving the lamp; A current balance unit for maintaining a current balance of the lamp driving AC power source from the power source unit; And And a plurality of first to n-th lamp groups that receive the lamp driving AC power in parallel from the current balancer, wherein each of the plurality of first to n-th lamp groups receives the AC power in parallel. Including a lamp unit including a first lamp and a second lamp, The current balancing unit is connected to each of the plurality of first to n-th lamp groups of the lamp unit, and maintains the balance of the current supplied to each of the plurality of first to n-th lamp groups. Equipped with Each of the plurality of first to nth balanced transformers includes a magnetic core having magnetically connected first and second legs, a first winding wound on the first leg, a second winding wound on the second leg, and A first connection winding wound on a first leg and a second connection winding wound on the second leg, the first winding being connected to a first lamp of a corresponding lamp group among the plurality of first to nth lamp groups; The second winding has one end electrically connected, the second winding has one end electrically connected to the second lamp of the lamp group, and the first connection winding is electrically connected to one end connected to the second connection winding and the output terminal of the power supply unit. And the other end of the second connection winding having a second end electrically connected to each other end of the first winding and the second winding of one balanced transformer adjacent to one end connected to the first connection winding. Multi-lamp driving apparatus as. The method of claim 8, wherein the current balance unit, And a structure in which the other ends of the first and second windings of the one balanced transformer are electrically connected to the second connection windings of the other balanced transformer adjacent to each other. The method of claim 9, And the magnetic core further comprises a third leg electromagnetically connected between the first and second legs to form a magnetic path between the first leg and the second leg. The method of claim 10, The coil cross-sectional area of the first winding is equal to the coil cross-sectional area of the second winding, The coil cross-sectional area of the first connecting winding and the coil cross-sectional area of the second connecting winding are twice as large as the coil cross-sectional area of the first winding. The method of claim 11, The number of turns of the first winding is equal to the number of turns of the second winding, The number of turns of the first connection winding is 1/4 times the number of the first winding, the number of turns of the second connection winding is a multi-lamp drive device, characterized in that the number of turns of the second winding. The method of claim 12, The winding direction of the first winding and the second winding is the same, and the winding direction of the first connection winding and the second connection winding is the same as the winding direction of the first and second windings. The method of claim 8, wherein the power supply unit A driver for generating an AC power source having a preset voltage level; And A main coil connected to the driving unit and a sub-coil connected to the output terminal of the lamp driving AC power, AC power from the driving unit according to the winding ratio of the main coil and the sub-coil boosts the AC power for driving the lamp Transformer Multi-lamp driving apparatus comprising a.

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