JP4846420B2 - Inverter transformer and discharge lamp drive circuit - Google Patents

Description

  The present invention relates to an inverter transformer used in a DC / AC inverter circuit for discharging and lighting a cold cathode discharge lamp (CCFL) for backlights of various display panels used in, for example, notebook personal computers and liquid crystal televisions. The present invention relates to an inverter transformer and a discharge lamp driving circuit suitable for taking out a plurality of voltage outputs.

  In recent years, along with the increase in the size of various display panels, the length of CCFLs for backlights has been increased, and accordingly, the demand for higher voltage output for inverter transformers has increased.

  Conventionally, two secondary windings that are electromagnetically coupled to one primary winding are provided, and an intermediate tap is derived from each secondary winding and grounded. There is known an inverter transformer that can extract a high-voltage output that is twice as high as a normal one (see Patent Document 1 below).

JP 2005-12176 A

  By the way, the number of CCFLs to be turned on by one inverter transformer varies depending on the size of various display panels and the number of CCFLs to be arranged. Therefore, it is preferable to configure the inverter transformer so that it can flexibly cope with the difference in the required number of outputs.

  However, since the inverter transformer described in Patent Document 1 has a complicated core configuration and does not have a shape corresponding to each output, it is difficult to flexibly cope with a required difference in the number of outputs. There is.

  In addition, since the secondary windings for two windings are wound around one secondary bobbin, the winding diameter of each secondary winding becomes large, which increases the size of the secondary bobbin. There is also a problem that the mounting area of the inverter transformer on the substrate increases.

  The present invention has been made in view of such circumstances, and can flexibly cope with the required difference in the number of outputs, and can reduce the secondary bobbin size by reducing the winding diameter of each secondary winding. An object of the present invention is to provide an inverter transformer capable of reducing the mounting area on a substrate and a discharge lamp driving circuit using the inverter transformer.

In order to achieve the above object, an inverter transformer according to the present invention includes a primary bobbin around which a primary winding is wound and a secondary winding that is electromagnetically coupled to the primary winding. In an inverter transformer comprising a plurality of secondary-side bobbins,
While forming a secondary bobbin pair in which the two secondary bobbins are stacked substantially coaxially in the vertical direction,
A core that forms a closed magnetic path of magnetic flux passing through the primary winding of the primary bobbin and the two secondary windings of the secondary bobbin pair;
The core is
A first outer leg portion extending in the vertical direction inside the primary winding of the primary bobbin, and a second outer portion extending in the vertical direction inside the two secondary windings of the secondary bobbin pair. A leg portion, a middle leg portion extending vertically between the primary winding and the two secondary windings, and the first outer leg portion, the second outer leg portion and the middle leg portion. And an E-shaped core composed of a connecting part that connects each end of
An I-type core disposed on each of the other end portions of the first outer leg portion, the second outer leg portion and the middle leg portion of the E-type core;
A coil set consisting of one secondary bobbin pair and one core paired with the E-type core and the I-type core is divided into N sets (N = 2, 3, ...) Along the primary bobbin. )
It is configured to take out one or two voltage outputs from each of the coil sets.

  Two secondary windings wound on the upper and lower secondary bobbins in the secondary bobbin pair (when viewed from either one of the upper and lower directions) are clockwise and the other is It is preferable that the coil is wound counterclockwise and / or wound so that the high-pressure end side is positioned on the inner diameter side of the winding diameter.

  Moreover, the discharge lamp drive circuit according to the present invention includes the inverter transformer according to the present invention.

  According to the inverter transformer of the present invention, the secondary unit bobbin pair formed by superimposing two secondary side bobbins and the core constituting the closed magnetic circuit corresponding to each secondary side bobbin pair, Therefore, it is possible to flexibly cope with the difference in the required number of outputs by adjusting the number of the coil sets arranged in parallel.

  Further, in the coil set (secondary bobbin pair) which is a structural unit of the number of outputs, two secondary bobbins each wound with a secondary winding are arranged substantially coaxially so that 1 Compared to a configuration in which two secondary windings are wound around two secondary bobbins, the winding diameter of each secondary winding can be reduced, so that the size of each secondary bobbin can be reduced. This makes it possible to reduce the mounting area of the inverter transformer on the substrate.

  In addition, according to the discharge lamp driving circuit of the present invention, by mounting the inverter transformer of the present invention, it is possible to flexibly cope with the difference in the number of required discharge lamps and to make the circuit board compact. Can be achieved.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an inverter transformer according to the present invention will be described in detail with reference to the accompanying drawings. 1 to 12 show an embodiment of an inverter transformer according to the present invention. In the following description, the direction of the X axis of the three-dimensional orthogonal coordinate system shown in FIG. 1 is the left and right (the direction of the arrow is right), the direction of the Y axis is the front and rear (the direction of the arrow is behind), The direction is referred to as up and down (the direction of the arrow line is up). In addition, the three-dimensional orthogonal coordinate system in the other figures is shown so that the direction coincides with that in FIG.

  <Overall Configuration> First, the overall configuration of an inverter transformer according to an embodiment of the present invention will be schematically described with reference to FIGS. FIG. 1 is a perspective view from the front side showing the overall configuration of an inverter transformer according to an embodiment of the present invention, and FIG. 2 is a right side view thereof.

  As shown in FIG. 1, the inverter transformer 1 according to the present embodiment has one primary bobbin 2 around which a primary winding 8 is wound, and symmetrically along the longitudinal direction of the primary bobbin 2. It consists of two coil sets 3 arranged side by side, and each coil set 3 has first and second secondary bobbins 6 and 7 around which secondary windings 9A and 9B are wound, respectively. Closed magnetic circuit of the magnetic flux passing through the secondary bobbin pair 4, the primary winding 8 of the primary bobbin 2, and the upper and lower secondary windings 9 A and 9 B of each secondary bobbin pair 4. It is comprised with the core 5 which comprises. As will be described in detail later, the core 5 includes an E-type core 51 and an I-type core 52 (partially indicated by broken lines) as shown in FIG.

  <Primary Bobbin> Next, the configuration of the primary bobbin 2 will be described in more detail with reference to FIGS. 3 is a perspective view from the back side of the primary bobbin shown in FIG. 1, and FIG. 4 is a front view thereof (shown in a state where no windings and terminals are mounted).

  As shown in FIG. 3, the primary bobbin 2 includes a terminal block 21 that holds a plurality (eight in this embodiment) of primary terminals 11, a flange 22 that is formed in a rectangular plate shape, As shown in FIG. 4, it is composed of two winding shaft portions 23 having a rectangular tube shape extending in the vertical direction between the terminal block 21 and the flange portion 22, so as to bridge between the two winding shaft portions 23. The next winding 8 is wound.

Inside of the two winding shaft portion 23, a core insertion hole 24 penetrating in a vertical direction along the respective axes C ₁ are (see FIG. 3) is formed, also on the upper surface of the flange portion 22 The two U-shaped wall portions 25 surrounding the space where the one end portion of the I-shaped core 52 is installed are formed corresponding to the respective forming positions of the two winding shaft portions 23.

  Further, as shown in FIG. 4, the left and right ends of the terminal block 21 are arranged on the back surface of the second secondary bobbin 7 when the primary bobbin 2 is combined with the secondary bobbin pair 4. Positioning protrusions 26 that are engaged with the formed recesses (not shown) are formed.

  <First Secondary Bobbin> Next, the configuration of the first secondary bobbin 6 will be described in more detail with reference to FIGS. 5 is a perspective view from the front side of the first secondary bobbin shown in FIG. 1, FIG. 6 is a front view thereof (shown with no windings and terminals attached), and FIG. 7 is a bottom view thereof. FIG.

  As shown in FIG. 5, the first secondary bobbin 6 is formed in a rectangular plate shape with a terminal block 61 that holds a plurality of (two in this embodiment) long secondary terminals 12. As shown in FIG. 6, a substantially circular lower collar 63 formed on the upper surface of the terminal base 61, and a cylinder extending in the vertical direction between the upper collar 62 and the lower collar 63. The secondary winding 9 </ b> A is wound around the outer periphery of the winding shaft portion 64. As shown in FIG. 6, a disk portion 62 a is formed on the lower surface of the upper collar portion 62 corresponding to the winding region of the secondary winding 9 </ b> A. A taper portion 63a is formed corresponding to the winding region of the next winding 9A.

A core insertion hole 65 (see FIG. 5) penetrating in the vertical direction along the axis C ₂ is formed inside the winding shaft portion 64, and the I-type is formed on the upper surface of the upper collar portion 62. A U-shaped wall portion 66 surrounding the space where the other end portion of the core 52 is installed is formed corresponding to the position where the winding shaft portion 64 is formed.

  Further, a notch 67 reaching the winding shaft 64 is formed in the front center of the terminal block 61 and the lower collar 63, and as shown in FIG. From the bottom surface side, the secondary winding 9A wound around the winding shaft portion 64 can be seen through the notch 67.

Further, as shown in FIG. 7, on the bottom surface side of the terminal block 61, a pair of grooves Q ₁ and Q ₂ extending in the vertical direction (direction perpendicular to the paper surface of FIG. 7) on the left and right side surfaces of the notch 67. A pair of pin portions P ₁ and P ₂ projecting downward (from the front side of FIG. 7) to the left and right sides of the notch 67 on the end side are provided. These groove portions Q ₁ and Q ₂ and pin portions P ₁ and P ₂ function as latching portions when the secondary winding 9A is wound around the winding shaft portion 64. In the present embodiment, As shown in FIG. 7, the secondary winding 9 </ b> A having the start end portion entangled with the secondary terminal 12 (the entangled portion) on the right side is hooked on the pin portion P < _b > ₂ , and the above-described through the notch portion 67. after introduction to the winding shaft portion 64 side, deriving began turning winding shaft portion 64 wound clockwise when viewed from the bottom side, the secondary winding 9A after the end winding on the bottom side while engaging in the groove Q ₁ And the terminal part is comprised so that it may entangle with the left side secondary terminal 12 (entanglement part). Incidentally, on the contrary, while hooking the secondary winding 9A of beginning has been tied to the left side of the secondary terminal 12 (tied part of) the pin portion P _1, through the cutouts 67 after introduction to the winding shaft portion 64 side, as viewed from the bottom side began turning winding shaft portion 64 wound counterclockwise, while hooked after the end winding to the secondary winding 9A to the groove Q ₂ bottom side It is also possible to connect the terminal portion to the secondary terminal 12 (the binding portion) on the right side.

  Further, as shown in FIG. 5, the right side front end of the terminal block 61 is formed on the left side front end of the first secondary bobbin 6 when the first secondary bobbins 6 are combined with each other. A positioning projection 68 is formed to be engaged with the recessed portion (not shown) formed, and the first secondary bobbin 6 is formed at the corner of the bottom surface of the terminal block 61 as shown in FIG. Is combined with the second secondary bobbin 7, a positioning recess 69 that is engaged with a positioning protrusion 76 (see FIG. 8) formed on the upper portion of the second secondary bobbin 7. Is formed.

  <Second Secondary Bobbin> Next, the configuration of the second secondary bobbin 7 will be described in more detail with reference to FIGS. 8 is a perspective view from the front side of the second secondary bobbin shown in FIG. 1, FIG. 9 is a front view thereof (shown with no windings and terminals attached), and FIG. 10 is a bottom view thereof. FIG.

  As shown in FIG. 8, the second secondary bobbin 7 is formed in a rectangular plate shape and a terminal block 71 that holds a plurality of (two in this embodiment) short-type secondary terminals 13. The upper collar 72, a substantially circular lower collar 73 formed on the upper surface of the terminal block 71, and a cylindrical shape extending vertically between the upper collar 72 and the lower collar 73 as shown in FIG. The secondary winding 9 </ b> B is wound around the outer peripheral portion of the winding shaft portion 74. As shown in FIG. 9, a taper portion 72a is formed on the lower surface of the upper collar portion 72 corresponding to the winding region of the secondary winding 9B.

A core insertion hole 75 (see FIG. 8) penetrating in the vertical direction along the axis C ₃ is formed inside the winding shaft portion 74. When the second secondary bobbin 7 is combined with the first secondary bobbin 6, the second secondary bobbin 7 is engaged with the recess 69 (see FIG. 7) formed in the lower part of the first secondary bobbin 6. A positioning projection 76 is formed.

  Further, a notch 77 that reaches the winding shaft 74 is formed in the front center of the terminal block 71 and the lower collar 73, and as shown in FIG. From the bottom surface side, the secondary winding 9 </ b> B wound around the winding shaft portion 74 can be seen through the cutout portion 77.

Further, as shown in FIG. 10, on the bottom surface side of the terminal block 71, a pair of grooves Q ₃ and Q ₄ extending in the vertical direction (direction perpendicular to the paper surface of FIG. 10) on the left and right side surfaces of the notch 77. A pair of pin portions P ₃ and P ₄ projecting downward (from the front side of FIG. 10) to the left and right sides of the terminal portion of the notch 77 are provided. These groove portions Q ₃ , Q ₄ and pin portions P ₃ , P ₄ function as latching portions when the secondary winding 9B is wound around the winding shaft portion 74. In this embodiment, As shown in FIG. 10, the secondary winding 9 </ b> B having its start end entangled with the left secondary terminal 13 (entangled portion) is hooked on the pin portion P <b> ₃ , and the above described through the notch 77. after introduction to the winding shaft portion 74 side, as seen from the bottom side began turning winding shaft portion 74 wound counterclockwise, the secondary winding 9B on the bottom side while engaging in the groove Q ₄ after completion of the winding The terminal portion is led out to the right side secondary terminal 13 (the binding portion). Incidentally, on the contrary, while hooking the secondary winding 9B of beginning has been tied to the right side of the secondary side terminals 13 (tied part of) the pin portion P _4, through the notch 77 after introduction to the winding shaft portion 74 side, began turning the winding shaft portion 74 wound clockwise when viewed from the bottom side, the bottom side of the secondary winding 9B after the end winding while hooked to the groove Q ₃ It is also possible to connect the terminal portion to the secondary terminal 13 (the binding portion) on the left side.

  Further, as shown in FIG. 8, the right and left end portions of the terminal block 71 are formed at both left and right end portions of the second secondary bobbin 7 when the second secondary bobbins 7 are combined with each other. A positioning projection 78 is formed to be engaged with the recessed portion (not shown), and the secondary end extending downward from the first secondary bobbin 6 is formed at the front end of the terminal block 71. The insertion holes 79 of the side terminal 12 are formed at two corresponding positions, respectively.

The first and second secondary bobbins 6 and 7 described above are stacked one above the other with the first secondary bobbin 6 facing upward as shown in FIG. Further, the coil set 3 is configured by combining with the core 5. Note that the axes C ₂ and C ₃ of the first and second secondary bobbins 6 and 7 described above are configured to overlap each other when they are overlapped.

  <Core> Next, the configuration of the core 5 will be described in more detail with reference to FIGS. 11 is a perspective view from the front side of the E-type core shown in FIG. 2, and FIG. 12 is a perspective view from the front side of the I-type core shown in FIG.

  As shown in FIG. 11, the E-shaped core 51 includes a prismatic first outer leg portion 53 that extends in the vertical direction, a columnar second outer leg portion 54 that extends in the vertical direction, and the first and second portions. A prismatic middle leg portion 55 extending in the vertical direction between the outer leg portions 53, 54, and one end of each of the first outer leg portion 53, the second outer leg portion 54, and the middle leg portion 55 (see FIG. It consists of the connection part 56 which connects middle lower end part).

  The first outer leg 53 is inserted into the core insertion hole 24 of the primary bobbin 2 so as to extend in the vertical direction inside the primary winding 8 of the primary bobbin 2, Two outer leg portions 54 of the first and second secondary bobbins 6 and 7 extend in the vertical direction inside the two secondary windings 9A and 9B of the secondary bobbin pair 4. The cores are inserted into the core insertion holes 65 and 75. Further, the middle leg portion 55 includes the primary side bobbin 2 and the secondary side bobbin pair 4 so as to extend vertically between the primary winding 8 and the two secondary windings 9A and 9B. (See FIG. 2).

  On the other hand, as shown in FIG. 12, the I-type core 52 is formed in a prismatic shape. As shown in FIG. 1, the inside of the wall portion 25 of the primary bobbin 2 and the first secondary side are formed. It arrange | positions so that it may span between the said wall part 66 of the bobbin 6. FIG. That is, as shown in FIG. 2, the I-type core 52 includes the first outer leg portion 53, the second outer leg portion 54, and the middle leg portion 55 of the E-type core 51. ) And the core 5 together with the E-type core 51.

The core 5 is disposed in a plane including the axis C ₁ of the primary bobbin 2 and the axes C ₂ and C _{3 of} the first and second secondary bobbins 6 and 7. The first outer leg portion 53, the second outer leg portion 54 and the connecting portion 56 of the core 51, and the I-type core 52 penetrate the primary winding 8 and the upper and lower secondary windings 9A and 9B. A closed-shaped magnetic path through which magnetic flux passes is formed. As shown in FIG. 2, a gap is provided between the middle leg portion 55 of the E-type core 51 and the I-type core 52 so as to adjust the leakage inductance. That is, the inverter transformer 1 of this embodiment is configured as a magnetic leakage type leakage transformer.

  The E-type core 51 and the I-type core 52 are made of a soft magnetic material such as ferrite (for example, permalloy, sendust, iron carbonyl, etc., or a dust core obtained by compression molding these fine powders. Can also be formed.

  <Circuit Configuration> Next, an embodiment of a discharge lamp driving circuit according to the present invention will be described. FIG. 13 shows a configuration of a discharge lamp driving circuit according to an embodiment of the present invention. The discharge lamp driving circuit shown in FIG. 13 includes the inverter transformer 1 described above. The configuration of the inverter transformer 1 shown in FIG. 13 corresponds to the configuration of the inverter transformer 1 shown in FIG. 1, but the first and second secondary bobbins 6, 7 ( The two secondary windings 9A and 9B) are shown side by side for convenience. Further, the arrangement of the secondary terminal 12 provided on the first secondary bobbin 6 and the secondary terminal 13 provided on the second secondary bobbin 7 corresponds to that shown in FIG. For this reason, the circuits of the secondary windings 9A and 9B are shown as partially intersecting.

  In the example shown in FIG. 13, in each of the secondary bobbin pairs 4 arranged side by side, the start end of the secondary winding 9 </ b> A of the first secondary bobbin 6 disposed on the upper side is two secondary bobbins. The side terminal 12 is connected to the secondary side terminal 12 located on the right side, and the terminal portion is connected to the secondary side terminal 12 located on the left side. In each secondary bobbin pair 4, the starting end of the secondary winding 9 </ b> B of the second secondary bobbin 7 disposed on the lower side is located on the left side of the two secondary terminals 13. The terminal is connected to the secondary terminal 13 located on the right side. The secondary terminal 12 located on the left side of the two secondary terminals 12 and the secondary terminal 13 located on the right side of the two secondary terminals 13 are both grounded. ing. The two secondary windings 9A and 9B in each secondary bobbin pair 4 are configured to be electromagnetically coupled to the primary winding 8 with the same degree of coupling.

  Further, as described above, in the present embodiment, the secondary winding 9A of the first secondary bobbin 6 has a start end portion entangled with the secondary terminal 12 on the right side and is then watched from the bottom side. The terminal portion is wound around the secondary terminal 12 on the left side. On the other hand, the secondary winding 9B of the second secondary bobbin 7 is wound in the counterclockwise direction as viewed from the bottom side after the start end portion is entangled with the secondary terminal 13 on the left side. The portion is entangled with the secondary terminal 13 on the right side.

  Thereby, in this embodiment, although depending on the winding direction of the primary winding 8, one of the secondary terminal 12 on the right side and the secondary terminal 13 on the left side is the positive high voltage (H) side, and the other is the negative. The secondary side terminal 12 on the left side and the secondary side terminal 13 on the right side are on the ground (G) side, and the secondary side terminals on the H and -H sides. Each end of a U-shaped CCFL (U-shaped pipe; straight-line CCFL (straight pipe) connected in series) 15 is connected to the 12 and secondary side terminals 13 respectively. Thus, a high voltage output can be supplied to the U-shaped CCFL 15.

  In the present embodiment, the upper and lower secondary windings 9A and 9B are wound as described above, thereby connecting the two secondary terminals 12 and 13 alternately arranged in the left-right direction to H, G, G , -H in this order. Such an arrangement facilitates the routing of the circuit to the H and -H sides and the circuit to the G side on a substrate (not shown), and is particularly suitable for connecting U-shaped CCFLs. . It is also possible to connect two linear CCFLs to one secondary bobbin pair 4 instead of one U-shaped CCFL. That is, the inverter transformer 1 of the present embodiment can extract one output having a relatively high voltage and one output having two relatively low voltages from one coil set.

  In the present embodiment, the start ends of the upper and lower secondary windings 9A and 9B are both connected to the H (or -H) side, and the start ends are each winding of the secondary windings 9A and 9B. It is configured to be located on the inner diameter side of the diameter. For this reason, the high voltage end sides of the two secondary windings 9A and 9B can be separated from the surrounding electric / electronic components and the like.

In the example described above, the two coil sets 3 are arranged side by side in the left-right direction. However, in the inverter transformer 1 of the present embodiment, N sets (N = 2, 3, ...) Of coil sets 3 are arranged in the left-right direction. It is comprised so that it can arrange in parallel. When changing the number of coil sets 3 arranged side by side, a primary bobbin (not shown) formed in a size corresponding to the number of coil sets 3 is installed instead of the primary bobbin 2 described above. A necessary number of coil sets 3 may be arranged in parallel along the primary bobbin.

  As described above, according to the inverter transformer 1 of the present embodiment, the secondary side bobbin pair 4 formed by overlapping the two secondary side bobbins 6 and 7 and the closed magnetic circuit corresponding to each secondary side bobbin pair 4 are configured. The core 5 constitutes a coil set 3 that is a structural unit of the number of outputs, and by adjusting the number of the coil sets 3 arranged in parallel, it is possible to flexibly cope with the difference in the required number of outputs. It has become.

  As described above, the embodiments of the inverter transformer and the discharge lamp driving circuit according to the present invention have been described. However, the inverter transformer and the discharge lamp driving circuit according to the present invention are not limited to the above-described embodiments, and variously. It is possible to change the aspect.

For example, with the cross-sectional shape of the core, or a circular said second outer leg 54 in a rectangular, square of the first outer leg 53 and the center leg 55 or circular, or other shapes It is possible to make various changes such as.

The perspective view from the front side of the inverter transformer which concerns on one Embodiment The right side view of the inverter transformer concerning one embodiment Front view of the primary bobbin shown in Fig. 1 (windings are not installed) The perspective view from the back side of the primary side bobbin shown in FIG. The perspective view from the front side of the 1st secondary bobbin shown in FIG. Front view of the first secondary bobbin shown in FIG. Bottom view of the first secondary bobbin shown in FIG. The perspective view from the front side of the 2nd secondary bobbin shown in FIG. Front view of the second secondary bobbin shown in FIG. 1 (windings are not mounted) Bottom view of the second secondary bobbin shown in FIG. The perspective view from the front side of the E type core shown in FIG. The perspective view from the front side of the I-type core shown in FIG. The figure which shows the structure of the discharge lamp drive circuit which concerns on one Embodiment .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inverter transformer 2 Primary side bobbin 3 Coil set 4 Secondary side bobbin pair 5,5A Core 6 1st secondary side bobbin 7 2nd secondary side bobbin 8 Primary winding 9A, 9B Secondary winding 11 Primary side terminal 12 (Long type) Secondary side terminal 13 (Short type) Secondary side terminal 15 U-shaped CCFL
21, 61, 71 Terminal block 22 Hook 23, 64, 74 Winding shaft 24, 65, 75 Core insertion hole 25, 66 Wall 26, 68, 76, 77 Protrusion 51, 51A E-type core 52 I-type core 53 1st outer leg part 54 2nd outer leg part 55 Middle leg part 56 Connection part 62,72 Upper collar part 62a Disk part 63,73 Lower collar part 63a, 72a Tapered part 67,77 Notch part 69 Concave part C _{1 to} C ₃ axis P _{1 to} P ₄ pin part Q _{1 to} Q ₄ groove part

Claims (4)

An inverter transformer comprising one primary bobbin wound with a primary winding and a plurality of secondary bobbins each wound with a secondary winding electromagnetically coupled to the primary winding. In
While forming a secondary bobbin pair in which the two secondary bobbins are stacked substantially coaxially in the vertical direction,
A core that forms a closed magnetic path of magnetic flux passing through the primary winding of the primary bobbin and the two secondary windings of the secondary bobbin pair;
The core is
A first outer leg portion extending in the vertical direction inside the primary winding of the primary bobbin, and a second outer portion extending in the vertical direction inside the two secondary windings of the secondary bobbin pair. A leg portion, a middle leg portion extending vertically between the primary winding and the two secondary windings, and the first outer leg portion, the second outer leg portion and the middle leg portion. And an E-shaped core composed of a connecting part that connects each end of
An I-type core disposed on each of the other end portions of the first outer leg portion, the second outer leg portion and the middle leg portion of the E-type core;
A coil set consisting of one secondary bobbin pair and one core paired with the E-type core and the I-type core is divided into N sets (N = 2, 3, ...) Along the primary bobbin. )
An inverter transformer configured to extract one or two voltage outputs from each of the coil sets.   2. The two secondary windings wound around the upper and lower secondary bobbins in the secondary bobbin pair are set such that one is clockwise and the other is counterclockwise. The inverter transformer described.   The two secondary windings wound around the upper and lower secondary bobbins in the pair of secondary bobbins are respectively wound so that the high voltage end side is located on the inner diameter side of the winding diameter. The inverter transformer according to claim 1 or 2. A discharge lamp driving circuit comprising the inverter transformer according to any one of claims 1 to 3 .

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