KR200413645Y1 - Balanced transformer having an auxiliary coil - Google Patents

Abstract

As a balanced transformer provided with an auxiliary coil, a balanced transformer having an auxiliary coil composed of a bobbin, a balanced coil portion, a detection coil, and an iron core portion is disclosed. The balanced coil portion and the detection coil are wound around the bobbin, and the iron core portion extends through the bobbin. The balanced transformer can be used for a driving circuit of a backlight module of a liquid crystal display (LCD device). The balanced coil portion is electrically connected to the cold cathode fluorescent lamps (CCFLs) of the backlight module, and the detection coil is electrically connected to the protection circuit of the backlight module. If the currents flowing through the CCFLs are not equal to each other, a voltage is induced across the detection coil to generate a protection feedback signal which is sent to the protection circuit. Therefore, the balanced transformer detects abnormal currents, thereby making it possible to more reliably protect the balanced transformer itself and the driving circuit of the backlight module.

Balanced transformer, auxiliary coil, bobbin, coil part, detection coil, iron core part, backlight module, CCFL

Description

BALANCED TRANSFORMER HAVING AN AUXILIARY COIL

1 is an exploded plan view of a conventional balanced transformer.

2 is a plan view showing the top of a bobbin of a conventional balanced transformer;

3 is an exploded plan view of a balanced transformer with an auxiliary coil of the present invention.

4 is a plan view showing the top of a bobbin of a balanced transformer with an auxiliary coil of the present invention;

5 is a front view showing a bobbin of a balanced transformer with an auxiliary coil of the present invention.

6 is a perspective view showing a bobbin of a balanced transformer with an auxiliary coil of the present invention.

7 is an exploded plan view showing another embodiment of the balanced transformer with auxiliary coil of the present invention.

* Explanation of symbols for main parts of the drawing

1: first coil 2: second coil

3: detection coil 4: iron core part

5: bobbin 50: tubular bobbin

51: first sidewall 52: second sidewall

53: first partition wall 54: second partition wall

501: first coil winding region 502: second coil winding region

503: third coil winding region

The present invention relates to a balanced transformer, and more particularly, to a balanced transformer having an auxiliary coil usable in a drive circuit of a backlight module of a liquid crystal display device (hereinafter referred to as "LCD device").

The cold cathode fluorescent lamp (hereinafter referred to as "CCFL") is a standard light source for a backlight module for an LCD device. In the case of a large LCD device, two or more CCFLs should be provided to have sufficient brightness. The currents flowing through the CCFLs must be identical to each other to ensure the uniformity of the brightness of the LCD device. Therefore, a balanced transformer is used in the driving circuit of the backlight module to ensure the sameness of the currents passing through the CCFLs. .

1 and 2, a conventional balanced transformer includes a bobbin 95, a first coil 91, a second coil 92, and an iron core 94. The first coil 91 and the second coil 92 are wound around the bobbin 95. The iron core 94 extends through the bobbin 95.

According to Lenz's law, the following equation holds.

,

,

When the voltage V1 of the first coil 91 and the voltage V2 of the second coil 92 are canceled, equilibrium with respect to the currents is achieved. In this way the currents flowing through the CCFLs connected to the balanced transformer are equal. In other words, the balance of the currents through the CCFLs is achieved.

However, the conventional balance transformer described above can balance currents but cannot detect abnormal conditions caused by sudden currents flowing through CCFLs. As a result, the balance transformer itself and the drive circuit of the backlight module may be damaged.

Accordingly, the main object of the present invention is to provide a balanced transformer having an auxiliary coil capable of detecting abnormal current.

According to the present invention, this object is achieved by a balanced transformer with an auxiliary coil. The balanced transformer is composed of a bobbin, a balanced coil portion, a detection coil, and an iron core portion. The balanced coil portion is wound around the bobbin, and the detection coil is also wound around the bobbin. The iron core extends through the bobbin.

The balance transformer may be used in a driving circuit of a backlight module of a liquid crystal display (LCD device). The balanced coil portion is electrically connected to the cold cathode fluorescent lamps (CCFLs) of the backlight module, and the detection coil is electrically connected to the protection circuit of the backlight module. If the currents flowing through the CCFLs are not equal to each other, a voltage is induced across the detection coil to generate a protection feedback signal which is sent to the protection circuit. Thus, the balanced transformer detects abnormal currents, making it possible to more reliably protect the balanced transformer itself and the drive circuit of the backlight module.

Embodiments and examples of the present invention are illustrated in the following detailed description for a more clear understanding of the present invention. Although examples of more important features of the present invention have been summarized above in order to enhance understanding of the following detailed description and at the same time increase the contribution to the art, additional features of the present invention will be described below and attached. Will constitute the subject matter of the appended claims.

The above features and accompanying advantages of the present invention will be more clearly understood from the following detailed description, which is set forth with reference to the accompanying drawings.

3 to 6, the present invention provides a balanced transformer having an auxiliary coil. The balanced transformer of the present invention is composed of a bobbin 5, a balanced coil portion, a detection coil 3, and an iron core portion 4.

The bobbin 5 has a tubular bobbin 50, a first side wall 51, a second side wall 52, at least one first partition wall 53, and at least one second partition wall 54. ) The first side wall 51 and the second side wall 52 are respectively connected to both ends of the tubular bobbin 50. At least one first dividing wall 53 and at least one second dividing wall 54 are connected to the tubular bobbin 50 and are disposed between the first side wall 51 and the second side wall 52. It is. In the present embodiment, the bobbin 5 has a plurality of first partition walls 53 and a plurality of second partition walls 54. Spaces are provided between two adjacent first partition walls 53 and two adjacent second partition walls 54 to meet electrical safety requirements. The bobbin 5 may be formed in one piece or as a single piece by assembling a plurality of individual elements.

The bobbin 5 has a first coil winding region 501, a first coil winding region 502, and a third coil winding region 503. The first coil winding region 501 is formed between the first side wall 51 and the at least one first partition wall 53, and the second coil winding region 502 is at least one first partition wall 53. ) And at least one second dividing wall 54, and the third coil winding region 503 is formed between at least one second dividing wall 54 and the second side wall 52. In this manner, in the present embodiment, the second coil winding region 502 is disposed between the first coil winding region 501 and the third coil winding region 503.

The balanced coil portion is wound around the bobbin 5. As shown in FIG. 3, the balanced coil portion is composed of a first coil 1 and a second coil 2. The first coil 1 and the second coil 2 constitute a primary coil and a secondary coil, respectively. Alternatively, the first coil 1 may constitute a secondary coil, and the second coil 2 may constitute a primary coil. The first coil is wound on the tubular bobbin 50 of the bobbin 5 and is located in the first coil winding region 501, and the second coil is wound on the tubular bobbin 50 of the bobbin 5 It is located in the coil winding area 502.

The detection coil 3 is wound around the tubular bobbin body 50 of the bobbin 5 so as to constitute an auxiliary coil and positioned in the third coil winding region 503.

The bobbin 5 also has a plurality of terminals 55 on which respective ends of the first coil 1, the second coil 2 and the detection coil 3 are wound.

The iron core 4 extends through the bobbin 5 to form a magnetic flux path. The iron core 4 is composed of two E type iron cores, one E type iron core and one type I iron core, two U type iron cores, one U type iron core and one type I iron core, or two L type iron cores. Can be. In the case of this embodiment, the iron core part 4 is comprised from two E-type iron cores. The central part (not shown) of each E-shaped iron core extends through the tubular bobbin body 50 of the bobbin 5.

The above-described balanced transformer can be used for the driving circuit of the backlight module of the LCD device, in which case it is electrically connected to the main transformer of the driving circuit of the backlight module. The first coil 1 and the second coil 2 of the balanced coil portion are each electrically connected to two CCFLs of the backlight module. In addition, the detection coil 3 is electrically connected to the protection circuit of the backlight module.

When the currents flowing through the CCFLs become equal to each other, that is to say, when the currents flowing through the CCFLs are balanced, no voltage is induced at the two ends of the detection coil 3.

However, if the currents flowing through the CCFLs are not equal to each other, that is, if the currents flowing through the CCFLs are not balanced, then the magneticmotive force and the second coil 2 generated by the current flowing through the first coil 1 The magnetic force generated by the current flowing through) is not the same, as a result the iron core (4) generates a magnetic flux. This magnetic flux is generated by crossing the detection coil 3, and as a result, a voltage is induced between both ends of the detection coil 3 to generate a protection feedback signal, which is transmitted to the protection circuit. As described above, the balanced transformer has a function of detecting an abnormal current to protect the balanced transformer itself and the driving circuit of the backlight module.

7 shows another embodiment of a balanced transformer with an auxiliary coil of the present invention. Compared with the above embodiment, the present embodiment differs in the arrangement of the first coil winding region 501, the second coil winding region 502, and the third coil winding region 503 of the bobbin 5. In the present embodiment, the first coil winding region 501 is formed between the first side wall 51 and the at least one first partition wall 53, and the second coil winding region 502 is formed on the second side wall ( 52 and between the at least one second dividing wall 54 and the third coil winding region 503 between the at least one first dividing wall 53 and the at least one second dividing wall 54. It is formed in. In this manner, in the present embodiment, the third coil winding region 503 is disposed between the first coil winding region 501 and the second coil winding region 502. Thus, referring to FIGS. 3 and 7 it can be seen that the detection coil 3 can be wound at any suitable position of the bobbin 5.

In addition, the first coil 1, the second coil 2, and the detection coil 3 are respectively wound by changing the shape of the iron core 4 and using the closed magnetic flux path theory of the iron core 4. It is also possible to balance multiple CCFLs by integrating a plurality of bobbins 5. Therefore, the balance transformer described above can be extended in accordance with the requirements of the LCD device.

As can be seen from the above description, a balanced transformer having an auxiliary coil of the present invention has the following advantages.

1. If the currents flowing through the CCFLs are not equal to each other, a voltage is induced that generates a protective feedback signal sent to the protection circuit across the detection coil. Therefore, the balanced transformer of the present invention detects an abnormal current and more reliably protects the balanced transformer itself and the driving circuit of the backlight module.

2. It is also possible to balance the multiple CCFLs by integrating a plurality of bobbins in which the first coil, the second coil, and the detection coil are respectively wound by using the closed core magnetic flux path theory of the iron core.

Those skilled in the art should recognize that the above description is made merely for the purpose of illustrating specific embodiments and embodiments of the present invention, and as such is intended to be construed as limited by the utility model registration claims below. Various changes and modifications may be made to the structure and operation of the present invention described herein within the scope of the present disclosure.

Claims (10)

In a balanced transformer with an auxiliary coil, Bobbin, A balanced coil unit wound around the bobbin, A detection coil wound around the bobbin, Balanced transformer with an auxiliary coil, characterized in that it comprises an iron core extending through the bobbin. The bobbin of claim 1, wherein the bobbin has a first coil winding region, a second coil winding region, and a third coil winding region, and the balanced coil portion has a first coil and a second coil, and the first coil. Is wound on the bobbin and positioned in the first coil winding region, the second coil is wound on the bobbin and positioned in the second coil winding region, and the detection coil is wound on the bobbin and wound on the third coil winding. Balanced transformer with auxiliary coil, characterized in that located in the region. 3. The balanced transformer as claimed in claim 2, wherein the second coil winding region is disposed between the first coil winding region and the third coil winding region. 4. The balanced transformer of claim 3, wherein the first coil is a primary coil and the second coil is a secondary coil. 4. The balanced transformer of claim 3, wherein the first coil is a secondary coil and the second coil is a primary coil. The balanced transformer as claimed in claim 2, wherein the third coil winding region is disposed between the first coil winding region and the second coil winding region. 3. The bobbin of claim 2, wherein the bobbin has a tubular bobbin, a first side wall, a second side wall, at least one first partition wall, and at least one second partition wall. Respectively connected to both ends of the tubular bobbin, wherein the at least one first partition wall and the at least one second partition wall are connected between the tubular bobbin and at the same time located between the first side wall and the second side wall. And the first coil winding region is formed between the first side wall and the at least one first partition wall, and the second coil winding region is the at least one first partition wall and the at least one second portion. And a third coil winding region formed between the at least one second dividing wall and the second side wall. The balanced transformer having an auxiliary coil, wherein the third coil winding region is formed between the dividing walls. 8. The balanced transformer of claim 7, wherein the first coil is a primary coil and the second coil is a secondary coil. 8. The balanced transformer of claim 7, wherein the first coil is a secondary coil and the second coil is a primary coil. 3. The bobbin of claim 2, wherein the bobbin has a tubular bobbin, a first side wall, a second side wall, at least one first partition wall, and at least one second partition wall. Respectively connected to both ends of the tubular bobbin, wherein the at least one first partition wall and the at least one second partition wall are connected between the tubular bobbin and at the same time located between the first side wall and the second side wall. And the first coil winding region is formed between the first side wall and the at least one first partition wall, and the second coil winding region is formed between the second side wall and the at least one second partition wall. And said third coil winding region is formed between said at least one first dividing wall and said at least one second dividing wall.

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