WO2009098790A1 - Multi-output high frequency step-up transformer for fluorescent tube - Google Patents

Multi-output high frequency step-up transformer for fluorescent tube Download PDF

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Publication number
WO2009098790A1
WO2009098790A1 PCT/JP2008/063098 JP2008063098W WO2009098790A1 WO 2009098790 A1 WO2009098790 A1 WO 2009098790A1 JP 2008063098 W JP2008063098 W JP 2008063098W WO 2009098790 A1 WO2009098790 A1 WO 2009098790A1
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magnetic
magnetic body
coil
transformer
magnetic flux
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PCT/JP2008/063098
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French (fr)
Japanese (ja)
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Shigetoshi Watanabe
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Shigetoshi Watanabe
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
    • H01F38/08—High-leakage transformers or inductances
    • H01F38/10—Ballasts, e.g. for discharge lamps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F3/00—Cores, Yokes, or armatures
    • H01F3/10—Composite arrangements of magnetic circuits
    • H01F3/12—Magnetic shunt paths
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F30/00—Fixed transformers not covered by group H01F19/00
    • H01F30/04—Fixed transformers not covered by group H01F19/00 having two or more secondary windings, each supplying a separate load, e.g. for radio set power supplies

Definitions

  • the present invention relates to a fluorescent tube multi-output high-frequency step-up transformer for lighting a plurality of fluorescent tubes arranged in parallel used as a backlight of a liquid crystal display panel.
  • FIG. 11 is a diagram showing a fluorescent tube driving circuit using a conventional multi-output high-frequency step-up transformer.
  • the DC input voltage 11 is applied to the inverter circuit 12, and the high-frequency voltage output from the inverter circuit 12 is applied to the primary winding 21 of the multi-output high-frequency step-up transformer 13 and boosted to a high voltage.
  • the voltages on the lines 22a to 22n are supplied to the fluorescent tubes 40a and 40n, respectively.
  • the remaining fluorescent tubes cannot start discharging, and are in the lighting state. I can't enter. That is, when the fluorescent tubes connected in parallel are lit, only the fluorescent tube having the lowest lighting voltage is lit, and the remaining fluorescent tubes cannot be lit.
  • FIG. 12 is a schematic diagram of a conventional multi-output high-frequency step-up transformer for a fluorescent tube when the number of outputs disclosed in Patent Document 1 is eight.
  • the conventional multi-output high-frequency step-up transformer 13 for a fluorescent tube shown in FIG. 12 is wound with a primary coil 21, a secondary coil 22 (22a, 22b, 22c, 22d, 22e, 22f, 22g, 22h), and a primary coil 21.
  • the primary side magnetic body 23, the secondary side magnetic body 25 (25a, 25b) around which the secondary coil 22 is wound, and a part of the secondary coil 22 are covered, and the tip thereof is joined to the secondary side magnetic body 25. It is comprised from the magnetic body 26 for shunting (26a, 26b, 26c, 26d, 26e, 26f, 26g, 26h) comprised so that it may carry out.
  • FIG. 13 shows an equivalent magnetic circuit in consideration of the equivalent magnetic resistance of the return magnetic path that circulates in the air in the multi-output high-frequency step-up transformer for a fluorescent tube of the present invention shown in FIG.
  • Vm2 (Vm2a, Vm2b, Vm2c, Vm2d, Vm2e, Vm2f, Vm2g, Vm2h) is a counter electromotive force due to the load current flowing in the secondary coil.
  • the magnetic flux ⁇ 1 generated by the magnetomotive force Vm1 generated in the primary winding 21 by the current flowing through the primary coil is shunted with the secondary side magnetic body 25a around which the secondary coil 22a is wound.
  • the magnetic flux of K1 ⁇ ⁇ 1 flows into the secondary side magnetic body, and (1-K1) ⁇ ⁇ 1 flows into the shunting magnetic body.
  • Magnetic flux K1 ⁇ ⁇ 1 flowing through the secondary side magnetic body 25a of the secondary coil 22a and magnetic flux (1-K1) ⁇ ⁇ 1 shunted to the shunt magnetic body 26a at the junction P1 are the secondary side magnetic body 25a and the shunting magnetic body. It merges again at the second junction point P2 of 26a and becomes ⁇ 1. A part of the magnetic flux ⁇ 1 flowing into the junction point P2 returns to the junction point P9 between the secondary side magnetic body 25b and the shunting magnetic body 26h through the magnetic resistance Rm of the magnetic flux return path in the air.
  • the ratio of the reflux is Ka
  • the total of the magnetic flux flowing from P2 into the secondary side magnetic body and the shunting magnetic body of the secondary coil 22b is (1 ⁇ Ka) ⁇ ⁇ 1, which is higher than the node P1 of the secondary coil 22a. -Decrease by ⁇ 1.
  • the magnetic flux interlinked by the secondary coils is as follows. Magnetic flux interlinking with secondary coil 22a K1 ⁇ ⁇ 1 Magnetic flux interlinking with the secondary coil 22b K1, (1-Ka), ⁇ 1 Magnetic flux interlinking with secondary coil 22c K1 ⁇ (1-2Ka) ⁇ ⁇ 1 Magnetic flux interlinking with secondary coil 22d K1 ⁇ (1-3Ka) ⁇ ⁇ 1
  • FIG. 14 is a diagram showing a reduction state of magnetic flux interlinked with each secondary coil when the primary coil is driven by a 40 KHz sine wave in an equivalent magnetic circuit of a multi-output high-frequency step-up transformer for fluorescent tubes according to the prior art.
  • the magnetic flux flowing through the secondary coil farthest from the primary coil is the secondary coil closest to the primary coil. It is lower than the magnetic flux flowing through The degree of the decrease is about 50% according to the simulation.
  • the relative permeability of the magnetic material is a finite value of about 3500, so that a part of the magnetic flux flowing through the closed magnetic flux magnetic circuit leaks out of the magnetic material and leaks into the air. It is inevitable to do. Furthermore, the ratio of the magnetic flux which leaks in the air increases by the counter electromotive force when the load current flows through the secondary coil. For this reason, there has been a problem that the induced voltage of the secondary coil, and hence the load current, varies greatly depending on the distance from the primary coil.
  • the magnetic resistance Rm is defined as follows: A is the magnetic path length of the magnetic circuit, S is the cross-sectional area, and ⁇ is the magnetic permeability of the magnetic material.
  • A is the magnetic path length of the magnetic circuit
  • S is the cross-sectional area
  • ⁇ is the magnetic permeability of the magnetic material.
  • the upper limit of the relative permeability is about 4000, and it is difficult to increase the relative permeability and reduce the magnetic resistance.
  • the method of increasing the cross-sectional area of the magnetic material has problems such as an increase in transformer shape and an increase in weight, and there is a limit to improvement by lowering the magnetic resistance.
  • the present invention solves this problem and realizes high current accuracy of the multi-output high-frequency step-up transformer for fluorescent tubes.
  • a multi-output high-frequency step-up transformer for a fluorescent tube includes one or more primary side magnetic bodies and a plurality of secondary side magnets arranged symmetrically with respect to the primary side magnetic body.
  • a closed magnetic flux magnetic circuit formed by the body, one or more primary coils wound on the primary magnetic body constituting the closed magnetic flux magnetic circuit, and a plurality of secondary coils wound on the secondary magnetic body,
  • the secondary coil covers a part of the secondary coil, and both ends of the secondary coil are composed of a shunt magnetic body formed so as to be joined to the secondary side magnetic body, and the plurality of secondary coils are respectively connected to the fluorescent tube and used for shunting. It is characterized by diverting the magnetic flux passing through the secondary side magnetic body by the magnetic body.
  • the second invention is characterized in that, in the first invention, the secondary side magnetic body is formed in a rod shape, and each end of the secondary side magnetic body is joined to each end of the primary side magnetic body.
  • the cross section is formed of a U-shaped magnetic body, and the magnetic body on which one of the secondary coils of the U-shaped magnetic body is wound is used as a secondary magnetic body for the coil.
  • the magnetic body on which the other secondary coil of the U-shaped magnetic body is not wound is used as a shunt magnetic body, and the primary side magnetic body and the secondary side magnetic body portion for the coil of the U-shaped magnetic body A closed magnetic flux magnetic circuit is formed, and the magnetic flux passing through the coil secondary side magnetic body portion is shunted by the other shunt magnetic body portion of the U-shaped magnetic body.
  • the cross section is formed of an E-shaped magnetic body, the branch at both ends of the E-shaped magnetic body is a secondary magnetic body for coils, and the central branch of the E-shaped magnetic body is divided.
  • a closed magnetic flux magnetic circuit is formed by the secondary side magnetic body portion of the primary side magnetic body and the E-shaped magnetic body, and the coil is formed by the branching magnetic body portion of the central branch of the E-shaped magnetic body. It is characterized by diverting the magnetic flux passing through the secondary side magnetic part.
  • the magnetic resistance for shunting is arranged at the end of the magnetic resistance of the magnetic material for shunting arranged at the intermediate portion. It is characterized by being larger than the magnetic resistance of the body.
  • the multi-output high-frequency step-up transformer for a fluorescent tube is formed of one or more primary side magnetic bodies and a plurality of secondary side magnetic bodies arranged symmetrically with respect to the primary side magnetic body.
  • a closed magnetic flux magnetic circuit, one or more primary coils wound on the primary magnetic body constituting the closed magnetic flux magnetic circuit, a plurality of secondary coils wound on the secondary magnetic body, and one of the secondary coils Since the two ends are composed of a shunt magnetic body formed so as to be joined to the secondary side magnetic body, the lighting voltage is the lowest in lighting of a plurality of fluorescent tubes connected in parallel Even after the fluorescent tubes are turned on, the remaining fluorescent tubes can be reliably turned on.
  • the problem that the output voltage of the secondary coil increases or decreases with the distance from the primary coil due to the magnetic flux leaking from the closed magnetic flux magnetic circuit and recirculating in the air is determined by arranging the secondary coil symmetrically with the primary coil. This is solved by making the magnetic flux interlinking with the secondary coil equal regardless of the position of the secondary coil.
  • the secondary side magnetic body is formed in a rod shape, and each end of the secondary side magnetic body is configured to be joined to each end of the primary side magnetic body.
  • the magnetic body having a U-shaped magnetic body whose cross section is formed and one of the secondary coils of the U-shaped magnetic body is wound is used as the secondary magnetic body for the coil.
  • the magnetic body on which the other secondary coil of the U-shaped magnetic body is not wound is used as a shunting magnetic body, and the primary side magnetic body and the secondary side magnetic body for the coil of the U-shaped magnetic body
  • a closed magnetic flux magnetic circuit is formed by the part, and the magnetic flux passing through the secondary magnetic part for the coil is shunted by the other shunting magnetic part of the U-shaped magnetic body.
  • a compact, high-efficiency, high-current multi-output high-frequency step-up transformer for fluorescent tubes can be provided.
  • the cross section is formed of an E-shaped magnetic body, the branch at both ends of the E-shaped magnetic body is the secondary magnetic body for the coil, and the central branch of the E-shaped magnetic body Is formed by a magnetic material for shunting, a closed magnetic flux magnetic circuit is formed by the primary side magnetic material, and the secondary side magnetic material portion of the E-shaped magnetic material, and by the magnetic material portion for shunting at the center branch of the E-shaped magnetic material. Since the magnetic flux passing through the secondary magnetic part for the coil is divided, it is possible to provide a multi-output high-frequency step-up transformer for a fluorescent tube with a simple structure and a small size, high efficiency, and high current accuracy.
  • the magnetic resistance of the magnetic material for shunting arranged at the intermediate portion is arranged at the end. Since it is configured to be larger than the magnetic resistance of the diverted magnetic material, the amount of magnetic flux coupling of the secondary coil can be changed linearly with respect to the distance from the primary coil, and as a result is induced in each secondary coil. The voltage can be made more even.
  • FIG. 1 is a schematic diagram of a multi-output high-frequency step-up transformer for a fluorescent tube of the present invention when the number of outputs is 8.
  • the number of outputs is not limited to eight and can be arbitrarily set.
  • the present invention as shown in FIG. 12
  • primary coils 21 (21a, 21b), The secondary coil 22 (22a, 22b, 22c, 22d, 22e, 22f, 22g, 22h), the primary side magnetic body 23 (23a, 23b) around which the primary coil 21 is wound, and the secondary coil 22 are wound around Secondary magnetic body 25 (25a, 25b) and a part of the secondary coil 22, and a shunt magnetic body 26 (26a, 26b, 26a, 26b, 26c, 26d, 26e, 26f, 26g, and 26h).
  • FIG. 2 is a diagram showing the interlinkage magnetic flux of each secondary coil by the magnetomotive force Vm1 when a current is supplied only to the first primary coil 21a.
  • Vm2 (Vm2a, Vm2b, Vm2c, Vm2d, Vm2e, Vm2f, Vm2g, Vm2h) is a counter electromotive force due to the load current flowing in the secondary coil.
  • the magnetic flux ⁇ 1 generated by the magnetomotive force Vm1 generated in the primary side magnetic body 23a by the current flowing through the primary coil when the output of the secondary coil is unloaded is the same as that of the secondary side magnetic body 25a around which the secondary coil 22a is wound.
  • the magnetic flux K1 ⁇ ⁇ 1 flows into the secondary side magnetic body 25a, and (1-K1) ⁇ ⁇ 1 flows into the diverting magnetic body 26a.
  • the magnetic flux K1 ⁇ ⁇ 1 that flows through the secondary side magnetic body of the secondary coil 22a and the magnetic flux (1-K1) ⁇ ⁇ 1 that is shunted to the shunt magnetic body at the junction point P1 are the first of the secondary side magnetic body 25a and the shunt magnetic body. 2 joins again at P2 and becomes ⁇ 1, but a part of the magnetic flux ⁇ 1 flowing into P2 is shunted with the secondary side magnetic body 25b on the opposite side through the magnetic resistance Rm of the magnetic flux return path in the air. It returns to the junction P9 of the magnetic body 26h. If the ratio of the reflux is Ka, the magnetic flux flowing from P2 to the secondary side magnetic body 25a of the secondary coil 22b becomes K1 ⁇ (1-Ka) ⁇ ⁇ 1 and is smaller than the magnetic flux interlinked with the secondary coil 22a. .
  • the magnetic fluxes linked to the secondary coils 22a to 22d are as follows. Magnetic flux interlinking with the secondary coil 22a K1 ⁇ 1 Magnetic flux interlinking with the secondary coil 22b K1, (1-Ka), ⁇ 1 Magnetic flux interlinking with secondary coil 22c K1 ⁇ (1-2Ka) ⁇ ⁇ 1 Magnetic flux interlinking with secondary coil 22d K1 ⁇ (1-3Ka) ⁇ ⁇ 1
  • FIG. 3 is a diagram showing the interlinkage magnetic flux of each secondary coil by the magnetomotive force Vm2 when a current is supplied only to the second primary coil 21b.
  • the magnetic flux ⁇ 1 generated by the magnetomotive force Vm2 generated in the primary side magnetic body 23b by the current flowing in the primary coil 21b is separated from the secondary side magnetic body 25a around which the secondary coil 22d is wound.
  • the magnetic flux K1 ⁇ ⁇ 1 flows into the secondary side magnetic body 25a, and (1-K1) ⁇ ⁇ 1 flows into the diverting magnetic body 26d.
  • FIG. 4 is a diagram showing the interlinkage magnetic flux in each secondary coil when the number of turns of the primary coil 21a and that of the primary coil 21b are made equal and currents that are equal in the direction in which the magnetic fluxes in the magnetic circuit are added simultaneously.
  • the primary coil 21a and the primary coil 21b are provided in the same magnetic path, for example, considering the secondary coil 22a, the interlinkage magnetic flux K1 ⁇ 1 when excited by the primary coil 21a and the primary coil 21b.
  • the interlinkage magnetic flux K1 ⁇ (1-3Ka) ⁇ ⁇ 1 when excited by is superposed, and the magnetic flux interlinking with the secondary coil 22a becomes K1 ⁇ (2-3Ka) ⁇ ⁇ 1.
  • the interlinkage magnetic fluxes in the secondary coils 22b, 22c, 22d, 22h, 22g, 22f, and 22e are the same, and the interlinkage magnetic fluxes in the respective secondary coils are all equal.
  • FIG. 5 is a schematic diagram of a multi-output high-frequency step-up transformer for a fluorescent tube according to the present invention when the number of outputs is 16.
  • the closed magnetic flux magnetic circuit is composed of four primary side magnetic bodies 23a, 23b, 23c, 23d and four secondary side magnetic bodies 25a, 25b, 25c, 25d.
  • a primary coil and a secondary coil are wound around each primary side magnetic body 23 and secondary side magnetic body 25, respectively.
  • the secondary coils are arranged so as to be symmetric with respect to the primary coils.
  • the voltage generated in the secondary coils can be made equal by increasing the number of primary coils.
  • FIG. 6 is a diagram showing an analysis result of the interlinkage magnetic flux of each secondary coil when both of the two primary coils 21a and 21b are driven with a sine wave voltage of 40 KHz.
  • the interlinkage magnetic flux of the secondary coil farthest from the primary coil is about 50% of the interlinkage magnetic flux of the secondary coil closest to the primary coil.
  • the interlinkage magnetic flux of any secondary coil has a value within 1%, and the present invention is a multi-output high-frequency for a fluorescent tube. It can be seen that there is a significant effect on the equalization of the output current of the step-up transformer.
  • FIG. 7 is a diagram showing the relationship between the position of the secondary coil and the output voltage. With reference to FIG. 7, it will be described that the voltage induced in the secondary coil can be made equal.
  • the magnetic resistance of the magnetic materials for shunting 26b, 26c arranged in the middle of the magnetic materials for shunting 26a, 26b, 26c, 26d is at the end.
  • the voltage induced in the secondary coil can be equalized by making it larger than the magnetic resistance of the magnetic material for shunting 26a, 26d arranged.
  • Leakage magnetic flux that circulates in the air exists not only between the opposing secondary side magnetic bodies but also between the near end and far end of one magnetic body, and is a value that cannot be ignored.
  • the degree of magnetic flux reduction due to the distance from the primary coil to the secondary coil increases as the distance increases. growing. Therefore, strictly speaking, even if the two primary coils are driven, the amount of magnetic flux received by each secondary coil is not constant. That is, the amount of magnetic flux flowing through the magnetic body is large at the near end and the far end with respect to the primary coil, and is small at the intermediate portion.
  • the output voltage when the magnetic resistance of the intermediate portions 26b and 26c of the shunting magnetic body to be covered is increased more than the magnetic resistance of the shunting magnetic bodies 26a and 26d disposed at the end, and (C) is the amount covering the secondary coil.
  • the output voltage variation of each secondary coil can be further reduced.
  • the correction magnetic resistance of the secondary secondary coil branch flow path is the leakage magnetic flux in the air with realistic parameters of permeability, output voltage, and output current. For example, as shown in FIG. 5, it is possible to make the output voltage uniform by inserting the primary coil in the middle of the secondary coil. From the examination results, if the number of secondary coils is 8, the number of secondary coils can be equalized if the number of primary coils is 2 and the number of 16 primary coils is about 4.
  • FIG. 8 is a perspective view of a multi-output high-frequency step-up transformer for a fluorescent tube when the number of outputs is four in the first embodiment of the present invention.
  • a closed magnetic flux magnetic circuit is formed by the two primary side magnetic bodies 23 (23a, 23b) and the two secondary side magnetic bodies 25 (25a, 25b).
  • primary coils 21 (21a, 21b) are wound around the primary side magnetic bodies 23 (23a, 23b), respectively, and secondary coils 25a are wound around the secondary side magnetic bodies 25a.
  • the secondary coil 22 (22a, 22b) is wound, the secondary coil 22 (22c, 22d) is wound around the secondary side magnetic body 25b, and the shunting magnetic body 26 (26a) is provided so as to cover a part of each secondary coil 22. , 26b, 26c, 26d).
  • the two primary coils are connected such that magnetic fluxes interlinking with the respective secondary coils 22 are added.
  • the diverting magnetic body 26 is formed in a U-shape, the center portion covers the secondary coil 22, and the end portion is joined to the secondary side magnetic body 25.
  • the primary coil 21 and the secondary coil 22 are respectively fitted to the primary side magnetic body 23 and the secondary side magnetic body 25 while being wound around a bobbin.
  • FIG. 9 is a schematic diagram showing the structure of a high-frequency step-up transformer according to the second embodiment of the present invention.
  • a plurality of U-shaped magnetic bodies 27 (27a, 27b, 27c, 27d) are provided between the primary side magnetic body 23a and the primary side magnetic body 23b.
  • a closed magnetic flux magnetic circuit is formed by sandwiching them.
  • a gap is provided between the magnetic bodies to facilitate understanding of the contents, but an actual transformer has no gap.
  • One branch of the U-shaped magnetic body functions as a secondary magnetic body around which the secondary coil 22 (22a, 22b, 22c, 22d) is wound, and the other branch is a magnetic flux of the secondary magnetic body. Functions as a magnetic material for diversion.
  • the magnetic body around which the secondary coil is wound can be individually manufactured, an arbitrary number of U-shaped magnetic bodies 27 can be attached according to the number of outputs.
  • each U-shaped magnetic body is small and inexpensive to manufacture, the cost of the multi-output high-frequency step-up transformer for fluorescent tubes can be reduced.
  • FIG. 10 is a schematic diagram of a multi-output high-frequency step-up transformer for a fluorescent tube when the number of outputs is eight in the third embodiment of the present invention.
  • a plurality of E-shaped magnetic bodies 28 (28a, 28b, 28c, 28d) are provided between two primary side magnetic bodies 23 (23a, 23b).
  • a closed magnetic flux magnetic circuit is formed by sandwiching them.
  • a gap is provided between the magnetic bodies to facilitate understanding of the contents, but an actual transformer has no gap.
  • the E-shaped magnetic body functions as a secondary side magnetic body on which the secondary coil is wound on the upper and lower branches, and the central branch path functions as a common shunting magnetic body for the two secondary side magnetic bodies at both ends. To do.
  • the size and weight can be reduced, and the magnetic body around which the secondary coil is wound can be individually manufactured.
  • an arbitrary number of E-shaped magnetic bodies 28 can be attached.
  • each E-shaped magnetic body is small and inexpensive to manufacture, the cost of the multi-output high-frequency step-up transformer for fluorescent tubes can be reduced.
  • the present invention can be used as a multi-output high-frequency step-up transformer for a fluorescent tube for lighting a plurality of fluorescent tubes arranged in parallel used as a backlight of a liquid crystal display panel.
  • FIG. 3 is an equivalent magnetic circuit diagram in the case where a current is passed through only a first primary coil in the multi-output high-frequency step-up transformer for a fluorescent tube according to the first embodiment of the present invention.
  • FIG. 4 is an equivalent magnetic circuit diagram when a current is supplied only to a second primary coil in the multi-output high-frequency step-up transformer for a fluorescent tube according to the first embodiment of the present invention.
  • FIG. 3 is an equivalent magnetic circuit diagram when a current is passed through both the first and second primary coils in the multi-output high-frequency step-up transformer for a fluorescent tube according to the first embodiment of the present invention.
  • the 1st Embodiment of this invention it is a schematic diagram of the multi-output high frequency step-up transformer for fluorescent tubes in case the number of outputs is 16. It is a figure which shows the relationship between the position of a secondary coil, and an output voltage. It is a figure which shows the simulation result of the output voltage of each secondary coil when driving both the 1st and 2nd primary coils with the sine wave voltage of 40 KHz.
  • the 1st Embodiment of this invention it is a perspective view of the multi-output high frequency step-up transformer for fluorescent tubes in case the number of outputs is four.
  • the 2nd Embodiment of this invention it is a schematic diagram of the multi-output high frequency step-up transformer for fluorescent tubes in case the number of outputs is four.
  • the 3rd Embodiment of this invention it is a schematic diagram of the multi-output high frequency step-up transformer for fluorescent tubes in case the number of outputs is eight.
  • This is a fluorescent tube driving circuit using a conventional multi-output high-frequency step-up transformer for fluorescent tubes.
  • FIG. 6 is an equivalent magnetic circuit diagram in the case where a current is passed through only one primary coil in a conventional multi-output high-frequency step-up transformer for a fluorescent tube. It is a figure which shows the simulation result of the interlinkage magnetic flux of each secondary coil when a primary coil is driven with the sinusoidal voltage of 40 KHz in the conventional multi-output high frequency step-up transformer for fluorescent tubes.
  • Multi-output high-frequency step-up transformer for fluorescent tube 21 Primary coil 22 Secondary coil 23 Primary side magnetic body 25 Secondary side magnetic body 26 Magnetic material for shunting 27 U-shaped magnetic body 28 E-shaped magnetic body 29 For closed magnetic circuit formation Magnetic material

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Abstract

[PROBLEMS] To provide a multi-output high frequency step-up transformer for a fluorescent tube for lighting with high current accuracy a plurality of juxtaposed fluorescent tubes to be used as a backlight of a liquid crystal display panel. [MEANS FOR SOLVING PROBLEMS] The multi-output high frequency step-up transformer for a fluorescent tube comprises a plurality of secondary coils (22) wound around a main magnetic circuit loop and shunt magnetic materials (26, 27, 28) attached to respective secondary coils (22). In the transformer, a second primary coil (21b) is wound around a magnetic material facing a first primary coil (21a) for inhibiting a decrease in an interlinking magnetic flux due to a distance between a primary coil (21) and the secondary coil (22). By providing the second primary coil (21), magnetic cross fluxes in respective secondary coils (22) are equal even if a magnetic flux leaking from the main magnetic circuit loop into the air and reflowing is present. Thus, a variation in voltages between respective outputs can be significantly reduced by a simple structure.

Description

蛍光管用多出力高周波昇圧トランスMulti-output high-frequency step-up transformer for fluorescent tubes
　この発明は液晶表示パネルのバックライトとして用いられる並列配置された複数の蛍光管を点灯させるための蛍光管用多出力高周波昇圧トランスに関する。 The present invention relates to a fluorescent tube multi-output high-frequency step-up transformer for lighting a plurality of fluorescent tubes arranged in parallel used as a backlight of a liquid crystal display panel.
　最近の大画面液晶表示パネルでは、バックライト用として多数の蛍光管がパネル背面に並列配置されている。これらの蛍光管を高周波、高電圧で点灯するための蛍光管用多出力高周波昇圧トランスも複数個必要とされ、実装面積の増加、信頼性の低下、並列配置された蛍光管の電流バラツキによる輝度ムラの発生、あるいは電流バラツキを低減するためにバランス回路などを付け加えることによる点灯回路の複雑化などの問題を抱えている。 In recent large-screen liquid crystal display panels, a large number of fluorescent tubes are arranged in parallel on the back of the panel for backlighting. In order to light these fluorescent tubes at high frequency and high voltage, a plurality of multi-output high-frequency step-up transformers for fluorescent tubes are also required, increasing the mounting area, reducing the reliability, and uneven brightness due to current variations in the fluorescent tubes arranged in parallel. Or a complicated lighting circuit due to the addition of a balance circuit in order to reduce current variation.
　図１１は、従来の多出力高周波昇圧トランスによる蛍光管駆動回路を示す図である。図１１において、直流入力電圧１１はインバータ回路１２に印加され、インバータ回路１２より出力される高周波電圧は、多出力高周波昇圧トランス１３の一次巻線２１に印加され、高圧に昇圧された２次巻線２２ａ～２２ｎの電圧はそれぞれ蛍光管４０ａおよび４０ｎに供給される。 FIG. 11 is a diagram showing a fluorescent tube driving circuit using a conventional multi-output high-frequency step-up transformer. In FIG. 11, the DC input voltage 11 is applied to the inverter circuit 12, and the high-frequency voltage output from the inverter circuit 12 is applied to the primary winding 21 of the multi-output high-frequency step-up transformer 13 and boosted to a high voltage. The voltages on the lines 22a to 22n are supplied to the fluorescent tubes 40a and 40n, respectively.
　このような駆動回路においては、液晶表示パネルのバックライト用として用いられる蛍光管を放電、点灯させるためには、通常１５００Ｖｒｍｓから３０００Ｖｒｍｓの高周波の高電圧を印加し放電状態に持ち込む必要がある。蛍光管は放電開始後、管の電圧が放電開始電圧の１／２から１／３に低下し点灯状態に入る。複数の蛍光管を並列に接続し点灯させる場合、印加電圧を徐々に上げていくと、それぞれの蛍光管の放電開始電圧にバラツキがあるため、並列接続された複数の蛍光管のうち最も放電開始電圧が低い蛍光管が放電を開始し、点灯状態に入る。そのとき、並列接続された複数の蛍光管の接続点の電圧は、すでに点灯状態にある蛍光管の点灯電圧まで低下しているために、残りの蛍光管は放電を開始できず、点灯状態に入ることができない。すなわち、並列に接続された蛍光管の点灯においては、点灯電圧が一番低い蛍光管のみが点灯し、残りの蛍光管は点灯できないという現象が生じる。 In such a drive circuit, in order to discharge and light a fluorescent tube used for a backlight of a liquid crystal display panel, it is usually necessary to apply a high frequency high voltage of 1500 Vrms to 3000 Vrms and bring it into a discharge state. After the discharge starts, the fluorescent tube voltage is reduced from 1/2 to 1/3 of the discharge start voltage and enters a lighting state. When connecting multiple fluorescent tubes in parallel and lighting them, if the applied voltage is gradually increased, the discharge start voltage of each fluorescent tube will vary, so the discharge start is the most among the multiple fluorescent tubes connected in parallel. A fluorescent tube with a low voltage starts discharging and enters a lighting state. At that time, since the voltage at the connection point of the plurality of fluorescent tubes connected in parallel has decreased to the lighting voltage of the fluorescent tube already in the lighting state, the remaining fluorescent tubes cannot start discharging, and are in the lighting state. I can't enter. That is, when the fluorescent tubes connected in parallel are lit, only the fluorescent tube having the lowest lighting voltage is lit, and the remaining fluorescent tubes cannot be lit.
　このため多数本が並列配置されたバックライト用蛍光管を従来の高結合係数形の多出力トランスで点灯するのは難しいので、図１２に示すように、複数の二次コイルの周りに分流用の磁性体を二次側磁性体に接合して二次側磁性体の磁束を分流する蛍光管用多出力高周波昇圧トランスが本出願人によって提案されている（特許文献１）。 For this reason, it is difficult to turn on a plurality of backlight fluorescent tubes arranged in parallel with a conventional high-coupling-coefficient multi-output transformer, and as shown in FIG. 12, it is used for shunting around a plurality of secondary coils. The present applicant has proposed a multi-output high-frequency step-up transformer for a fluorescent tube that joins the magnetic body to a secondary-side magnetic body to shunt the magnetic flux of the secondary-side magnetic body (Patent Document 1).
　図１２は、特許文献１に開示された出力数が８個の場合の従来技術の蛍光管用多出力高周波昇圧トランスの模式図である。図１２に示す従来の蛍光管用多出力高周波昇圧トランス１３は、一次コイル２１と、二次コイル２２（２２ａ，２２ｂ，２２ｃ，２２ｄ，２２ｅ，２２ｆ，２２ｇ，２２ｈ）と、一次コイル２１が巻かれた一次側磁性体２３と、二次コイル２２が巻かれた二次側磁性体２５（２５ａ，２５ｂ）と、二次コイル２２の一部を覆い、その先端が二次側磁性体２５に接合するように構成される分流用磁性体２６（２６ａ、２６ｂ、２６ｃ，２６ｄ，２６ｅ，２６ｆ，２６ｇ，２６ｈ）から構成される。 FIG. 12 is a schematic diagram of a conventional multi-output high-frequency step-up transformer for a fluorescent tube when the number of outputs disclosed in Patent Document 1 is eight. The conventional multi-output high-frequency step-up transformer 13 for a fluorescent tube shown in FIG. 12 is wound with a primary coil 21, a secondary coil 22 (22a, 22b, 22c, 22d, 22e, 22f, 22g, 22h), and a primary coil 21. The primary side magnetic body 23, the secondary side magnetic body 25 (25a, 25b) around which the secondary coil 22 is wound, and a part of the secondary coil 22 are covered, and the tip thereof is joined to the secondary side magnetic body 25. It is comprised from the magnetic body 26 for shunting (26a, 26b, 26c, 26d, 26e, 26f, 26g, 26h) comprised so that it may carry out.
　図１２に示す本発明の蛍光管用多出力高周波昇圧トランスにおいて、空気中を還流する還流磁路の等価磁気抵抗を考慮した等価磁気回路を図１３に示す。図１３においてＶｍ２（Ｖｍ２ａ，Ｖｍ２ｂ，Ｖｍ２ｃ，Ｖｍ２ｄ，Ｖｍ２ｅ，Ｖｍ２ｆ，Ｖｍ２ｇ，Ｖｍ２ｈ）は二次コイルに流れる負荷電流による逆起磁力である。二次コイルの出力が無負荷とすると、一次コイルに流れる電流により一次巻線２１で発生する起磁力Ｖｍ１により生じた磁束Φ１は二次コイル２２ａが巻かれた二次側磁性体２５ａと分流用磁性体２６ａの第１の接合点Ｐ１で、二次側磁性体にＫ１・Φ１の磁束が、また分流用磁性体には（１－Ｋ１）・Φ１が流れ込む。
ここで、磁束分流係数Ｋ１は、二次側磁性体の磁気抵抗Ｒｍ２、分流用磁性体磁路の磁気抵抗Ｒｍ３とすると
　　　　Ｋ１＝Ｒｍ３／（Ｒｍ２＋Ｒｍ３）
の式で表される。 FIG. 13 shows an equivalent magnetic circuit in consideration of the equivalent magnetic resistance of the return magnetic path that circulates in the air in the multi-output high-frequency step-up transformer for a fluorescent tube of the present invention shown in FIG. In FIG. 13, Vm2 (Vm2a, Vm2b, Vm2c, Vm2d, Vm2e, Vm2f, Vm2g, Vm2h) is a counter electromotive force due to the load current flowing in the secondary coil. When the output of the secondary coil is unloaded, the magnetic flux Φ1 generated by the magnetomotive force Vm1 generated in the primary winding 21 by the current flowing through the primary coil is shunted with the secondary side magnetic body 25a around which the secondary coil 22a is wound. At the first junction P1 of the magnetic body 26a, the magnetic flux of K1 · Φ1 flows into the secondary side magnetic body, and (1-K1) · Φ1 flows into the shunting magnetic body.
Here, the magnetic flux shunting coefficient K1 is K1 = Rm3 / (Rm2 + Rm3) where the magnetic resistance Rm2 of the secondary side magnetic body and the magnetic resistance Rm3 of the magnetic body magnetic path for shunting are given.
It is expressed by the following formula.
　二次コイル２２ａの二次側磁性体２５ａを流れる磁束Ｋ１・Φ１と接合点Ｐ１で分流用磁性体２６ａに分流した磁束（１－Ｋ１）・Φ１は二次側磁性体２５ａと分流用磁性体２６ａの第２の接合点Ｐ２で再び合流し、Φ１となる。接合点Ｐ２に流入した磁束Φ１のうち、その一部が空気中の磁束還流路の磁気抵抗Ｒｍを通して対辺の二次側磁性体２５ｂと分流用磁性体２６ｈの接合点Ｐ９に還流するが、この還流の割合をＫａとすればＰ２から二次コイル２２ｂの二次側磁性体、分流用磁性体に流入する磁束の合計は（１－Ｋａ）・Φ１となり二次コイル２２ａの節点Ｐ１よりもＫａ・Φ１だけ減少する。 Magnetic flux K1 · Φ1 flowing through the secondary side magnetic body 25a of the secondary coil 22a and magnetic flux (1-K1) · Φ1 shunted to the shunt magnetic body 26a at the junction P1 are the secondary side magnetic body 25a and the shunting magnetic body. It merges again at the second junction point P2 of 26a and becomes Φ1. A part of the magnetic flux Φ1 flowing into the junction point P2 returns to the junction point P9 between the secondary side magnetic body 25b and the shunting magnetic body 26h through the magnetic resistance Rm of the magnetic flux return path in the air. If the ratio of the reflux is Ka, the total of the magnetic flux flowing from P2 into the secondary side magnetic body and the shunting magnetic body of the secondary coil 22b is (1−Ka) · Φ1, which is higher than the node P1 of the secondary coil 22a. -Decrease by Φ1.
　このように、磁束は、各節点Ｐ２，Ｐ３，Ｐ４で空気中の還流路Ｒｍへ漏洩し、もう一辺の二次側磁性体２５ｂを通り一次側磁性体２３に還流する。Ｐ２，Ｐ３，Ｐ４での空気中の還流路による還流の割合を近似的に全てＫａとすると、各二次コイルが鎖交する磁束は以下のようになる。
　二次コイル２２ａと鎖交する磁束　　Ｋ１・Φ１
　二次コイル２２ｂと鎖交する磁束　　Ｋ１・（１－Ｋａ）・Φ１
二次コイル２２ｃと鎖交する磁束　　Ｋ１・（１－２Ｋａ）・Φ１
　二次コイル２２ｄと鎖交する磁束　　Ｋ１・（１－３Ｋａ）・Φ１ Thus, the magnetic flux leaks to the reflux path Rm in the air at each of the nodes P2, P3, P4, and returns to the primary side magnetic body 23 through the secondary side magnetic body 25b on the other side. Assuming that the ratio of recirculation through the air recirculation path in P2, P3, and P4 is approximately all Ka, the magnetic flux interlinked by the secondary coils is as follows.
Magnetic flux interlinking with secondary coil 22a K1 ・ Φ1
Magnetic flux interlinking with the secondary coil 22b K1, (1-Ka), Φ1
Magnetic flux interlinking with secondary coil 22c K1 ・ (1-2Ka) ・ Φ1
Magnetic flux interlinking with secondary coil 22d K1 ・ (1-3Ka) ・ Φ1
　この状況は、もう一辺の二次側磁性体２５ｂに嵌合する二次コイル２２ｅ、２２ｆ、２２ｇ、２２ｈでも同様である。
　二次コイル２２ｈと鎖交する磁束　　Ｋ１・Φ１
　二次コイル２２ｇと鎖交する磁束　　Ｋ１・（１－Ｋａ）・Φ１
　二次コイル２２ｆと鎖交する磁束　　Ｋ１・（１－２Ｋａ）・Φ１
　二次コイル２２ｅと鎖交する磁束　　Ｋ１・（１－３Ｋａ）・Φ１
したがって、鎖交磁束に比例する各二次コイルの出力電圧は一次コイルより遠くなるに従い低下する。
特許第４０２１９３１号 This situation is the same for the secondary coils 22e, 22f, 22g, and 22h fitted to the secondary side magnetic body 25b on the other side.
Magnetic flux interlinking with secondary coil 22h K1 ・ Φ1
Magnetic flux interlinking with secondary coil 22g K1 ・ (1-Ka) ・ Φ1
Magnetic flux interlinking with the secondary coil 22f K1 ・ (1-2Ka) ・ Φ1
Magnetic flux interlinking with secondary coil 22e K1 ・ (1-3Ka) ・ Φ1
Therefore, the output voltage of each secondary coil proportional to the flux linkage decreases as the distance from the primary coil increases.
Patent No. 4021931
　図１４は、従来技術による蛍光管用多出力高周波昇圧トランスの等価磁気回路において、一次コイルを４０ＫＨｚの正弦波で駆動した時の各二次コイルと鎖交する磁束の低減状況を示す図である。図１４に示すように、従来の蛍光管用多出力高周波昇圧トランスのような１つの一次コイルのみの駆動では、一次コイルから一番遠い二次コイルを流れる磁束が一次コイルから一番近い二次コイルを流れる磁束よりも低下する。その低下の度合いはシミュレーションによれば約５０％程度である。 FIG. 14 is a diagram showing a reduction state of magnetic flux interlinked with each secondary coil when the primary coil is driven by a 40 KHz sine wave in an equivalent magnetic circuit of a multi-output high-frequency step-up transformer for fluorescent tubes according to the prior art. As shown in FIG. 14, in the case of driving only one primary coil such as a conventional multi-output high-frequency step-up transformer for a fluorescent tube, the magnetic flux flowing through the secondary coil farthest from the primary coil is the secondary coil closest to the primary coil. It is lower than the magnetic flux flowing through The degree of the decrease is about 50% according to the simulation.
　すなわち、従来の蛍光管用多出力高周波昇圧トランスでは、磁性体の比透磁率が約３５００と有限な値であるため、閉磁束磁気回路を流れる磁束の一部が磁性体外に漏れ出し空気中を漏洩することは避けられない。更に、二次コイルに負荷電流が流れたときの逆起磁力により、空気中を漏洩する磁束の割合が増加する。このため、一次コイルよりの距離により、当該二次コイルの誘起電圧、ひいては負荷電流が大きく変化するという問題があった。 That is, in the conventional multi-output high-frequency step-up transformer for fluorescent tubes, the relative permeability of the magnetic material is a finite value of about 3500, so that a part of the magnetic flux flowing through the closed magnetic flux magnetic circuit leaks out of the magnetic material and leaks into the air. It is inevitable to do. Furthermore, the ratio of the magnetic flux which leaks in the air increases by the counter electromotive force when the load current flows through the secondary coil. For this reason, there has been a problem that the induced voltage of the secondary coil, and hence the load current, varies greatly depending on the distance from the primary coil.
　この遠端二次コイルの出力電圧の低下を改善するためには、空気中の磁束還流路の磁気抵抗に対して、閉磁束磁気回路の磁気抵抗を低くすることが有効である。磁気抵抗Ｒｍは磁気回路の磁路長をＡ、断面積をＳ、磁性体の透磁率をμとして
　　　磁気抵抗Ｒｍ＝Ａ／μ×Ｓ
となるが、これを低減するためには
　（ｉ）磁性体の透磁率を上げる
　（ｉｉ）一次側磁性体と二次側磁性体の磁気断面積Ｓを大きくする
　ことが必要となる。 In order to improve the decrease in the output voltage of the far-end secondary coil, it is effective to lower the magnetic resistance of the closed magnetic flux magnetic circuit with respect to the magnetic resistance of the magnetic flux return path in the air. The magnetic resistance Rm is defined as follows: A is the magnetic path length of the magnetic circuit, S is the cross-sectional area, and μ is the magnetic permeability of the magnetic material.
However, in order to reduce this, it is necessary to (i) increase the magnetic permeability of the magnetic body (ii) increase the magnetic cross-sectional area S of the primary side magnetic body and the secondary side magnetic body.
　本用途に用いられる電力用磁性体では、高い磁気飽和特性を確保する必要があるため比透磁率の上限は４０００程度であり、比透磁率を上げて磁気抵抗を低減させるのは難しい。また磁性体の断面積を増加させる方法もトランス形状が大きくなり、重量も増加するなどの問題があり、磁気抵抗を下げることによる改善には限界がある。 In the power magnetic material used in this application, it is necessary to ensure high magnetic saturation characteristics, so the upper limit of the relative permeability is about 4000, and it is difficult to increase the relative permeability and reduce the magnetic resistance. Also, the method of increasing the cross-sectional area of the magnetic material has problems such as an increase in transformer shape and an increase in weight, and there is a limit to improvement by lowering the magnetic resistance.
　本発明はこの問題を解決し、蛍光管用多出力高周波昇圧トランスの高電流精度を実現するものである。 The present invention solves this problem and realizes high current accuracy of the multi-output high-frequency step-up transformer for fluorescent tubes.
　以上の課題を解決するために、第１の発明の蛍光管用多出力高周波昇圧トランスは、１以上の一次側磁性体と前記一次側磁性体に対して対称に配置された複数の二次側磁性体とで形成された閉磁束磁気回路と、閉磁束磁気回路を構成する一次側磁性体上に巻かれた１以上の一次コイルおよび二次側磁性体上に巻かれた複数の二次コイルと、二次コイルの一部を覆い、その両端は二次側磁性体に接合するように形成される分流用磁性体とから構成され、複数の二次コイルはそれぞれ蛍光管に接続され、分流用磁性体によって二次側磁性体を通る磁束を分流することを特徴とする。 In order to solve the above problems, a multi-output high-frequency step-up transformer for a fluorescent tube according to a first aspect of the present invention includes one or more primary side magnetic bodies and a plurality of secondary side magnets arranged symmetrically with respect to the primary side magnetic body. A closed magnetic flux magnetic circuit formed by the body, one or more primary coils wound on the primary magnetic body constituting the closed magnetic flux magnetic circuit, and a plurality of secondary coils wound on the secondary magnetic body, The secondary coil covers a part of the secondary coil, and both ends of the secondary coil are composed of a shunt magnetic body formed so as to be joined to the secondary side magnetic body, and the plurality of secondary coils are respectively connected to the fluorescent tube and used for shunting. It is characterized by diverting the magnetic flux passing through the secondary side magnetic body by the magnetic body.
　第２の発明は、第１の発明において、二次側磁性体は棒状に形成され、二次側磁性体の各両端はそれぞれ一次側磁性体の各端に接合されることを特徴とする。 The second invention is characterized in that, in the first invention, the secondary side magnetic body is formed in a rod shape, and each end of the secondary side magnetic body is joined to each end of the primary side magnetic body.
　第３の発明は、断面がコの字型の磁性体で形成され、コの字型の磁性体の一方の二次コイルが巻かれた方の磁性体をコイル用二次側磁性体とし、コの字型の磁性体の他方の二次コイルが巻かれていない方の磁性体を分流用磁性体とし、一次側磁性体、コの字型磁性体のコイル用二次側磁性体部分によって閉磁束磁気回路を形成し、コの字型磁性体の他方の分流用磁性体部分によってコイル用二次側磁性体部分を通る磁束を分流することを特徴とする。 In a third aspect of the present invention, the cross section is formed of a U-shaped magnetic body, and the magnetic body on which one of the secondary coils of the U-shaped magnetic body is wound is used as a secondary magnetic body for the coil. The magnetic body on which the other secondary coil of the U-shaped magnetic body is not wound is used as a shunt magnetic body, and the primary side magnetic body and the secondary side magnetic body portion for the coil of the U-shaped magnetic body A closed magnetic flux magnetic circuit is formed, and the magnetic flux passing through the coil secondary side magnetic body portion is shunted by the other shunt magnetic body portion of the U-shaped magnetic body.
　第４の発明は、断面がＥ字型の磁性体で形成され、Ｅ字型磁性体の両端の支路をコイル用二次側磁性体とし、Ｅ字型磁性体の中央の支路を分流用磁性体とし、一次側磁性体、Ｅ字型磁性体の二次側磁性体部分によって閉磁束磁気回路を形成し、Ｅ字型磁性体の中央の支路の分流用磁性体部分によってコイル用二次側磁性体部分を通る磁束を分流することを特徴とする。 In a fourth aspect of the invention, the cross section is formed of an E-shaped magnetic body, the branch at both ends of the E-shaped magnetic body is a secondary magnetic body for coils, and the central branch of the E-shaped magnetic body is divided. A closed magnetic flux magnetic circuit is formed by the secondary side magnetic body portion of the primary side magnetic body and the E-shaped magnetic body, and the coil is formed by the branching magnetic body portion of the central branch of the E-shaped magnetic body. It is characterized by diverting the magnetic flux passing through the secondary side magnetic part.
　第５の発明は、一次コイル間に配置された複数の各二次コイルを覆う分流用磁性体において、中間部に配置される分流用磁性体の磁気抵抗が端部に配置される分流用磁性体の磁気抵抗よりも大きくなることを特徴とする。 According to a fifth aspect of the present invention, in the magnetic material for shunting that covers each of the plurality of secondary coils arranged between the primary coils, the magnetic resistance for shunting is arranged at the end of the magnetic resistance of the magnetic material for shunting arranged at the intermediate portion. It is characterized by being larger than the magnetic resistance of the body.
　第１の発明によれば、蛍光管用多出力高周波昇圧トランスは、１以上の一次側磁性体と前記一次側磁性体に対して対称に配置された複数の二次側磁性体とで形成された閉磁束磁気回路と、閉磁束磁気回路を構成する一次側磁性体上に巻かれた１以上の一次コイルおよび二次側磁性体上に巻かれた複数の二次コイルと、二次コイルの一部を覆い、その両端は二次側磁性体に接合するように形成される分流用磁性体とから構成されるので、並列に接続された複数の蛍光管の点灯において、点灯電圧が一番低い蛍光管が点灯した後でも、残りの蛍光管を確実に点灯できる。また、閉磁束磁気回路から漏れ出し空気中を還流する磁束により一次コイルからの距離で二次コイルの出力電圧が増減する問題を、二次コイルを一次コイルと対称に配置させることによって、各二次コイルと鎖交する磁束が二次コイルの位置に関係なく等しくなることにより解決される。 According to the first invention, the multi-output high-frequency step-up transformer for a fluorescent tube is formed of one or more primary side magnetic bodies and a plurality of secondary side magnetic bodies arranged symmetrically with respect to the primary side magnetic body. A closed magnetic flux magnetic circuit, one or more primary coils wound on the primary magnetic body constituting the closed magnetic flux magnetic circuit, a plurality of secondary coils wound on the secondary magnetic body, and one of the secondary coils Since the two ends are composed of a shunt magnetic body formed so as to be joined to the secondary side magnetic body, the lighting voltage is the lowest in lighting of a plurality of fluorescent tubes connected in parallel Even after the fluorescent tubes are turned on, the remaining fluorescent tubes can be reliably turned on. In addition, the problem that the output voltage of the secondary coil increases or decreases with the distance from the primary coil due to the magnetic flux leaking from the closed magnetic flux magnetic circuit and recirculating in the air is determined by arranging the secondary coil symmetrically with the primary coil. This is solved by making the magnetic flux interlinking with the secondary coil equal regardless of the position of the secondary coil.
　第２の発明によれば、二次側磁性体は棒状に形成され、二次側磁性体の各両端がそれぞれ一次側磁性体の各端に接合されるように構成されるので、簡易な構造で小型、高効率、高電流精度の蛍光管用多出力高周波昇圧トランスを提供できる。 According to the second invention, the secondary side magnetic body is formed in a rod shape, and each end of the secondary side magnetic body is configured to be joined to each end of the primary side magnetic body. Can provide a multi-output high-frequency step-up transformer for fluorescent tubes with a small size, high efficiency, and high current accuracy.
　第３の発明によれば、断面がコの字型の磁性体で形成され、コの字型の磁性体の一方の二次コイルが巻かれた方の磁性体をコイル用二次側磁性体とし、コの字型の磁性体の他方の二次コイルが巻かれていない方の磁性体を分流用磁性体とし、一次側磁性体、コの字型磁性体のコイル用二次側磁性体部分によって閉磁束磁気回路を形成し、コの字型磁性体の他方の分流用磁性体部分によってコイル用二次側磁性体部分を通る磁束を分流するように構成されるので、簡易な構造で小型、高効率、高電流精度の蛍光管用多出力高周波昇圧トランスを提供できる。 According to the third aspect of the present invention, the magnetic body having a U-shaped magnetic body whose cross section is formed and one of the secondary coils of the U-shaped magnetic body is wound is used as the secondary magnetic body for the coil. The magnetic body on which the other secondary coil of the U-shaped magnetic body is not wound is used as a shunting magnetic body, and the primary side magnetic body and the secondary side magnetic body for the coil of the U-shaped magnetic body A closed magnetic flux magnetic circuit is formed by the part, and the magnetic flux passing through the secondary magnetic part for the coil is shunted by the other shunting magnetic part of the U-shaped magnetic body. A compact, high-efficiency, high-current multi-output high-frequency step-up transformer for fluorescent tubes can be provided.
　第４の発明によれば、断面がＥ字型の磁性体で形成され、Ｅ字型磁性体の両端の支路をコイル用二次側磁性体とし、Ｅ字型磁性体の中央の支路を分流用磁性体とし、一次側磁性体、Ｅ字型磁性体の二次側磁性体部分によって閉磁束磁気回路を形成し、Ｅ字型磁性体の中央の支路の分流用磁性体部分によってコイル用二次側磁性体部分を通る磁束を分流するように構成されるので、簡易な構造で小型、高効率、高電流精度の蛍光管用多出力高周波昇圧トランスを提供できる。 According to the fourth invention, the cross section is formed of an E-shaped magnetic body, the branch at both ends of the E-shaped magnetic body is the secondary magnetic body for the coil, and the central branch of the E-shaped magnetic body Is formed by a magnetic material for shunting, a closed magnetic flux magnetic circuit is formed by the primary side magnetic material, and the secondary side magnetic material portion of the E-shaped magnetic material, and by the magnetic material portion for shunting at the center branch of the E-shaped magnetic material. Since the magnetic flux passing through the secondary magnetic part for the coil is divided, it is possible to provide a multi-output high-frequency step-up transformer for a fluorescent tube with a simple structure and a small size, high efficiency, and high current accuracy.
　第５の発明によれば、一次コイル間に配置された複数の各二次コイルを覆う分流用磁性体において、中間部に配置される分流用磁性体の磁気抵抗が端部に配置される分流用磁性体の磁気抵抗よりも大きくなるように構成されるので、二次コイルの磁束結合量を一次コイルからの距離に対し線形に変化させることができ、その結果各二次コイルに誘起される電圧をさらに均等にすることができる。 According to the fifth invention, in the magnetic material for shunting that covers the plurality of secondary coils arranged between the primary coils, the magnetic resistance of the magnetic material for shunting arranged at the intermediate portion is arranged at the end. Since it is configured to be larger than the magnetic resistance of the diverted magnetic material, the amount of magnetic flux coupling of the secondary coil can be changed linearly with respect to the distance from the primary coil, and as a result is induced in each secondary coil. The voltage can be made more even.
第１の実施形態．
　図１は、出力数が８個の場合の本発明の蛍光管用多出力高周波昇圧トランスの模式図である。なお、本発明においては、出力数は８個だけでなく、任意に設定することができる。本発明は、図１２に示す従来の蛍光管用多出力高周波昇圧トランスの特徴を活かしながら各出力の電流精度を改善するために、図１に示すように、一次コイル２１（２１ａ、２１ｂ）と、二次コイル２２（２２ａ，２２ｂ，２２ｃ，２２ｄ，２２ｅ，２２ｆ，２２ｇ，２２ｈ）と、一次コイル２１が巻かれた一次側磁性体２３（２３ａ，２３ｂ）と、二次コイル２２が巻かれた二次側磁性体２５（２５ａ，２５ｂ）と、二次コイル２２の一部を覆い、その先端が二次側磁性体２５に接合するように構成される分流用磁性体２６（２６ａ、２６ｂ、２６ｃ，２６ｄ，２６ｅ，２６ｆ，２６ｇ，２６ｈ）から構成される。 First embodiment.
FIG. 1 is a schematic diagram of a multi-output high-frequency step-up transformer for a fluorescent tube of the present invention when the number of outputs is 8. In the present invention, the number of outputs is not limited to eight and can be arbitrarily set. In order to improve the current accuracy of each output while utilizing the characteristics of the conventional multi-output high-frequency step-up transformer for fluorescent tubes shown in FIG. 12, the present invention, as shown in FIG. 1, primary coils 21 (21a, 21b), The secondary coil 22 (22a, 22b, 22c, 22d, 22e, 22f, 22g, 22h), the primary side magnetic body 23 (23a, 23b) around which the primary coil 21 is wound, and the secondary coil 22 are wound around Secondary magnetic body 25 (25a, 25b) and a part of the secondary coil 22, and a shunt magnetic body 26 (26a, 26b, 26a, 26b, 26c, 26d, 26e, 26f, 26g, and 26h).
　図１に示す本発明の蛍光管用多出力高周波昇圧トランスにおいて、空気中を還流する磁束還流磁路の等価磁気抵抗を考慮した等価磁気回路を図２～図４に示す。図２は、第１の一次コイル２１ａのみに電流を流した場合、その起磁力Ｖｍ１による各二次コイルの鎖交磁束を示す図である。図２において、Ｖｍ２（Ｖｍ２ａ，Ｖｍ２ｂ，Ｖｍ２ｃ，Ｖｍ２ｄ，Ｖｍ２ｅ，Ｖｍ２ｆ，Ｖｍ２ｇ，Ｖｍ２ｈ）は二次コイルに流れる負荷電流による逆起磁力である。二次コイルの出力が無負荷のときに一次コイルに流れる電流により一次側磁性体２３ａに発生する起磁力Ｖｍ１により生じた磁束Φ１は、二次コイル２２ａが巻かれた二次側磁性体２５ａと分流用磁性体２６ａの第１の接合点Ｐ１で、二次側磁性体２５ａにＫ１・Φ１の磁束が流れ込み、また分流用磁性体２６ａには（１－Ｋ１）・Φ１が流れ込む。
ここで、磁束分流係数Ｋ１は、当該区間の二次側磁性体の磁気抵抗Ｒｍ２分流用磁性体磁路の磁気抵抗Ｒｍ３とすると
　　　　Ｋ１＝Ｒｍ３／（Ｒｍ２＋Ｒｍ３）
の式で表される。 In the multi-output high-frequency step-up transformer for a fluorescent tube of the present invention shown in FIG. 1, equivalent magnetic circuits taking into account the equivalent magnetic resistance of the magnetic flux return magnetic path that circulates in the air are shown in FIGS. FIG. 2 is a diagram showing the interlinkage magnetic flux of each secondary coil by the magnetomotive force Vm1 when a current is supplied only to the first primary coil 21a. In FIG. 2, Vm2 (Vm2a, Vm2b, Vm2c, Vm2d, Vm2e, Vm2f, Vm2g, Vm2h) is a counter electromotive force due to the load current flowing in the secondary coil. The magnetic flux Φ1 generated by the magnetomotive force Vm1 generated in the primary side magnetic body 23a by the current flowing through the primary coil when the output of the secondary coil is unloaded is the same as that of the secondary side magnetic body 25a around which the secondary coil 22a is wound. At the first junction P1 of the diverting magnetic body 26a, the magnetic flux K1 · Φ1 flows into the secondary side magnetic body 25a, and (1-K1) · Φ1 flows into the diverting magnetic body 26a.
Here, the magnetic flux shunting coefficient K1 is defined as K1 = Rm3 / (Rm2 + Rm3) where the magnetic resistance Rm2 of the secondary side magnetic material in the section is the magnetic resistance Rm3 of the magnetic material magnetic path for shunting.
It is expressed by the following formula.
　二次コイル２２ａの二次側磁性体を流れる磁束Ｋ１・Φ１と接合点Ｐ１で分流用磁性体に分流した磁束（１－Ｋ１）・Φ１は二次側磁性体２５ａと分流用磁性体の第２の接合点Ｐ２で再び合流し、Φ１となるが、Ｐ２に流入した磁束Φ１のうち、その一部が空気中の磁束還流路の磁気抵抗Ｒｍを通して対辺の二次側磁性体２５ｂと分流用磁性体２６ｈの接合点Ｐ９に還流する。この還流の割合をＫａとすればＰ２から二次コイル２２ｂの二次側磁性体２５ａに流入する磁束はＫ１・（１－Ｋａ）・Φ１となり二次コイル２２ａと鎖交する磁束よりも減少する。 The magnetic flux K1 · Φ1 that flows through the secondary side magnetic body of the secondary coil 22a and the magnetic flux (1-K1) · Φ1 that is shunted to the shunt magnetic body at the junction point P1 are the first of the secondary side magnetic body 25a and the shunt magnetic body. 2 joins again at P2 and becomes Φ1, but a part of the magnetic flux Φ1 flowing into P2 is shunted with the secondary side magnetic body 25b on the opposite side through the magnetic resistance Rm of the magnetic flux return path in the air. It returns to the junction P9 of the magnetic body 26h. If the ratio of the reflux is Ka, the magnetic flux flowing from P2 to the secondary side magnetic body 25a of the secondary coil 22b becomes K1 · (1-Ka) · Φ1 and is smaller than the magnetic flux interlinked with the secondary coil 22a. .
　同様にして、Ｐ３，Ｐ４で空気中の各磁束還流路Ｒｍへの漏れ出しを繰り返し、もう一辺の二次側磁性体２５ｂを通り一次側磁性体２３ａに還流する。Ｐ３，Ｐ４での空気中の磁束還流路による還流の割合を近似的に全てＫａとすると、各二次コイル２２ａ～２２ｄと鎖交する磁束は以下のようになる。
　二次コイル２２ａと鎖交する磁束　　Ｋ１Φ１
　二次コイル２２ｂと鎖交する磁束　　Ｋ１・（１－Ｋａ）・Φ１
二次コイル２２ｃと鎖交する磁束　　Ｋ１・（１－２Ｋａ）・Φ１
　二次コイル２２ｄと鎖交する磁束　　Ｋ１・（１－３Ｋａ）・Φ１ Similarly, the leakage to the magnetic flux return paths Rm in the air is repeated at P3 and P4, and then returns to the primary side magnetic body 23a through the secondary side magnetic body 25b on the other side. Assuming that the ratio of recirculation through the magnetic flux recirculation path in air at P3 and P4 is approximately all Ka, the magnetic fluxes linked to the secondary coils 22a to 22d are as follows.
Magnetic flux interlinking with the secondary coil 22a K1Φ1
Magnetic flux interlinking with the secondary coil 22b K1, (1-Ka), Φ1
Magnetic flux interlinking with secondary coil 22c K1 ・ (1-2Ka) ・ Φ1
Magnetic flux interlinking with secondary coil 22d K1 ・ (1-3Ka) ・ Φ1
　この状況はもう一辺の二次側磁性体２５ｂに巻かれた二次コイル２２ｅ、２２ｆ、２２ｇ、２２ｈでも以下のように同じようになる。
二次コイル２２ｈと鎖交する磁束　　Ｋ１Φ１
　二次コイル２２ｇと鎖交する磁束　　Ｋ１・（１－Ｋａ）・Φ１
二次コイル２２ｆと鎖交する磁束　　Ｋ１・（１－２Ｋａ）・Φ１
　二次コイル２２ｅと鎖交する磁束　　Ｋ１・（１－３Ｋａ）・Φ１ This situation also applies to the secondary coils 22e, 22f, 22g, and 22h wound around the secondary side magnetic body 25b on the other side as follows.
Magnetic flux interlinking with secondary coil 22h K1Φ1
Magnetic flux interlinking with secondary coil 22g K1 ・ (1-Ka) ・ Φ1
Magnetic flux interlinking with the secondary coil 22f K1 ・ (1-2Ka) ・ Φ1
Magnetic flux interlinking with secondary coil 22e K1 ・ (1-3Ka) ・ Φ1
　図３は、第２の一次コイル２１ｂのみに電流を流した場合、この起磁力Ｖｍ２による各二次コイルの鎖交磁束を示す図である。図３において、図２と同様に、一次コイル２１ｂに流れる電流により一次側磁性体２３ｂに発生する起磁力Ｖｍ２により生じた磁束Φ１は二次コイル２２ｄが巻かれた二次側磁性体２５ａと分流用磁性体２６ｄの第５の接合点Ｐ５で、二次側磁性体２５ａにＫ１・Φ１の磁束が、また分流用磁性体２６ｄには（１－Ｋ１）・Φ１が流れ込む。以下、この起磁力Ｖｍ２による各二次コイルの鎖交磁束は、上記と同様にして、
　二次コイル２２ｄと鎖交する磁束　　Ｋ１Φ１
　二次コイル２２ｃと鎖交する磁束　　Ｋ１・（１－Ｋａ）・Φ１
　二次コイル２２ｂと鎖交する磁束　　Ｋ１・（１－２Ｋａ）・Φ１
　二次コイル２２ａと鎖交する磁束　　Ｋ１・（１－３Ｋａ）・Φ１ FIG. 3 is a diagram showing the interlinkage magnetic flux of each secondary coil by the magnetomotive force Vm2 when a current is supplied only to the second primary coil 21b. In FIG. 3, as in FIG. 2, the magnetic flux Φ1 generated by the magnetomotive force Vm2 generated in the primary side magnetic body 23b by the current flowing in the primary coil 21b is separated from the secondary side magnetic body 25a around which the secondary coil 22d is wound. At the fifth junction point P5 of the diverting magnetic body 26d, the magnetic flux K1 · Φ1 flows into the secondary side magnetic body 25a, and (1-K1) · Φ1 flows into the diverting magnetic body 26d. Hereinafter, the interlinkage magnetic flux of each secondary coil by the magnetomotive force Vm2 is the same as described above,
Magnetic flux interlinking with the secondary coil 22d K1Φ1
Magnetic flux interlinking with secondary coil 22c K1 ・ (1-Ka) ・ Φ1
Magnetic flux interlinking with the secondary coil 22b K1 ・ (1-2Ka) ・ Φ1
Magnetic flux interlinking with secondary coil 22a K1 ・ (1-3Ka) ・ Φ1
　この状況はもう一辺の二次側磁性体２５ｂに嵌合する二次コイル２２ｅ、２２ｆ、２２ｇ、２２ｈでも上記と同様になる。したがって、
二次コイル２２ｅと鎖交する磁束　　Ｋ１Φ１
　二次コイル２２ｆと鎖交する磁束　　Ｋ１・（１－Ｋａ）・Φ１
二次コイル２２ｇと鎖交する磁束　　Ｋ１・（１－２Ｋａ）・Φ１
　二次コイル２２ｈと鎖交する磁束　　Ｋ１・（１－３Ｋａ）・Φ１ This situation is the same as described above for the secondary coils 22e, 22f, 22g, and 22h fitted to the secondary side magnetic body 25b on the other side. Therefore,
Magnetic flux interlinking with secondary coil 22e K1Φ1
Magnetic flux interlinking with secondary coil 22f K1, (1-Ka), Φ1
Magnetic flux interlinking with secondary coil 22g K1 ・ (1-2Ka) ・ Φ1
Magnetic flux interlinking with secondary coil 22h K1 ・ (1-3Ka) ・ Φ1
　図４は、一次コイル２１ａと、一次コイル２１ｂの巻数を等しくし、磁気回路中の磁束が加算される方向に等しい電流を同時に流した場合の各二次コイルにおける鎖交磁束を示す図である。図４のように、一次コイル２１ａと、一次コイル２１ｂを同じ磁路中に設けると、例えば、二次コイル２２ａで考えると、一次コイル２１ａで励磁したときの鎖交磁束Ｋ１Φ１と、一次コイル２１ｂで励磁したときの鎖交磁束Ｋ１・（１－３Ｋａ）・Φ１とが重畳され、二次コイル２２ａと鎖交する磁束はＫ１・（２－３Ｋａ）・Φ１となる。
二次コイル２２ｂ、２２ｃ、２２ｄ、２２ｈ、２２ｇ、２２ｆ、２２ｅにおける鎖交磁束も同様になり、各二次コイルにおける鎖交磁束は全て等しくなる。
二次コイル２２ａと鎖交する磁束　　Ｋ１・（２－３Ｋａ）・Φ１
　二次コイル２２ｂと鎖交する磁束　　Ｋ１・（２－３Ｋａ）・Φ１
二次コイル２２ｃと鎖交する磁束　　Ｋ１・（２－３Ｋａ）・Φ１
　二次コイル２２ｄと鎖交する磁束　　Ｋ１・（２－３Ｋａ）・Φ１
　二次コイル２２ｅと鎖交する磁束　　Ｋ１・（２－３Ｋａ）・Φ１
　二次コイル２２ｆと鎖交する磁束　　Ｋ１・（２－３Ｋａ）・Φ１
　二次コイル２２ｇと鎖交する磁束　　Ｋ１・（２－３Ｋａ）・Φ１
　二次コイル２２ｈと鎖交する磁束　　Ｋ１・（２－３Ｋａ）・Φ１
このように、一次コイル２１ａと、一次コイル２１ｂを同じ閉磁束磁気回路中に設けた場合には、鎖交磁束が等しくなるので、全ての二次コイルにおいて出力電圧も全く等しいものとなる。 FIG. 4 is a diagram showing the interlinkage magnetic flux in each secondary coil when the number of turns of the primary coil 21a and that of the primary coil 21b are made equal and currents that are equal in the direction in which the magnetic fluxes in the magnetic circuit are added simultaneously. . As shown in FIG. 4, when the primary coil 21a and the primary coil 21b are provided in the same magnetic path, for example, considering the secondary coil 22a, the interlinkage magnetic flux K1Φ1 when excited by the primary coil 21a and the primary coil 21b. And the interlinkage magnetic flux K1 · (1-3Ka) · Φ1 when excited by is superposed, and the magnetic flux interlinking with the secondary coil 22a becomes K1 · (2-3Ka) · Φ1.
The interlinkage magnetic fluxes in the secondary coils 22b, 22c, 22d, 22h, 22g, 22f, and 22e are the same, and the interlinkage magnetic fluxes in the respective secondary coils are all equal.
Magnetic flux interlinking with the secondary coil 22a K1 ・ (2-3Ka) ・ Φ1
Magnetic flux interlinking with secondary coil 22b K1 ・ (2-3Ka) ・ Φ1
Magnetic flux interlinking with secondary coil 22c K1 ・ (2-3Ka) ・ Φ1
Magnetic flux interlinking with the secondary coil 22d K1 ・ (2-3Ka) ・ Φ1
Magnetic flux interlinking with the secondary coil 22e K1 ・ (2-3Ka) ・ Φ1
Magnetic flux interlinking with the secondary coil 22f K1 ・ (2-3Ka) ・ Φ1
Magnetic flux interlinking with secondary coil 22g K1 ・ (2-3Ka) ・ Φ1
Magnetic flux interlinking with secondary coil 22h K1 ・ (2-3Ka) ・ Φ1
As described above, when the primary coil 21a and the primary coil 21b are provided in the same closed magnetic flux magnetic circuit, the interlinkage magnetic flux becomes equal, and therefore, the output voltages are all equal in all the secondary coils.
　図５は、出力数が１６個の場合の本発明の蛍光管用多出力高周波昇圧トランスの模式図である。図５において、閉磁束磁気回路は、４つの一次側磁性体２３ａ、２３ｂ、２３ｃ、２３ｄおよび４つの二次側磁性体２５ａ、２５ｂ、２５ｃ、２５ｄから構成されている。各一次側磁性体２３および二次側磁性体２５にはそれぞれ一次コイルおよび二次コイルが巻かれている。また、二次コイルは一次コイルに対称になるように配列されている。このように、二次コイルの数が多くなるに従い、一次コイルの数を増加させることによって、二次コイルに発生する電圧を均等にすることができる。 FIG. 5 is a schematic diagram of a multi-output high-frequency step-up transformer for a fluorescent tube according to the present invention when the number of outputs is 16. In FIG. 5, the closed magnetic flux magnetic circuit is composed of four primary side magnetic bodies 23a, 23b, 23c, 23d and four secondary side magnetic bodies 25a, 25b, 25c, 25d. A primary coil and a secondary coil are wound around each primary side magnetic body 23 and secondary side magnetic body 25, respectively. The secondary coils are arranged so as to be symmetric with respect to the primary coils. Thus, as the number of secondary coils increases, the voltage generated in the secondary coils can be made equal by increasing the number of primary coils.
　図６は、２つの一次コイル２１ａ，２１ｂの双方を４０ＫＨｚの正弦波電圧で駆動した時の各二次コイルの鎖交磁束の解析結果を示す図である。図１４に示したように、１つの一次コイルのみの従来の駆動では一次コイルから一番遠い二次コイルの鎖交磁束が一次コイルから一番近い二次コイルの鎖交磁束の約５０％程度にまで低下しているのに対し、本発明による図６のシミュレーション結果では、いずれの二次コイルの鎖交磁束も誤差が１％以内の値となっており、本発明が蛍光管用多出力高周波昇圧トランスの出力電流の均一化に対して顕著な効果のあることが分かる。 FIG. 6 is a diagram showing an analysis result of the interlinkage magnetic flux of each secondary coil when both of the two primary coils 21a and 21b are driven with a sine wave voltage of 40 KHz. As shown in FIG. 14, in the conventional driving with only one primary coil, the interlinkage magnetic flux of the secondary coil farthest from the primary coil is about 50% of the interlinkage magnetic flux of the secondary coil closest to the primary coil. On the other hand, in the simulation result of FIG. 6 according to the present invention, the interlinkage magnetic flux of any secondary coil has a value within 1%, and the present invention is a multi-output high-frequency for a fluorescent tube. It can be seen that there is a significant effect on the equalization of the output current of the step-up transformer.
　図７は、二次コイルの位置と出力電圧との関係を示す図である。図７を用いて、二次コイルに誘起される電圧を均等にすることができることを説明する。図１や図６に示される分流用磁性体において、例えば、分流用磁性体２６ａ、２６ｂ、２６ｃ、２６ｄのうち、中間部に配置される分流用磁性体２６ｂ、２６ｃの磁気抵抗が端部に配置される分流用磁性体２６ａ、２６ｄの磁気抵抗よりも大きくなるようにすることによって、二次コイルに誘起される電圧を均等にすることができる FIG. 7 is a diagram showing the relationship between the position of the secondary coil and the output voltage. With reference to FIG. 7, it will be described that the voltage induced in the secondary coil can be made equal. In the magnetic material for shunting shown in FIGS. 1 and 6, for example, the magnetic resistance of the magnetic materials for shunting 26b, 26c arranged in the middle of the magnetic materials for shunting 26a, 26b, 26c, 26d is at the end. The voltage induced in the secondary coil can be equalized by making it larger than the magnetic resistance of the magnetic material for shunting 26a, 26d arranged.
　空中を還流する漏れ磁束は対向する二次側磁性体間だけでなく、当然１つの磁性体の近端と遠端の間にも存在し、無視できない値となる。１つの二次側磁性体の中の漏れ磁束、２つの二次側磁性体間の漏れ磁束を考慮すると、一次コイルからの二次コイルまでの距離による磁束減少の度合いはその距離が大きくなるに従い大きくなる。このため２つの一次コイルを駆動しても厳密にはそれぞれの二次コイルが受け取る磁束量は一定にならない。すなわち、磁性体を流れる磁束量は一次コイルに対し近端及び遠端が大きく、中間部は小さい。１つの磁性体のなかの磁束結合量を距離に対し線形にするためには中間部の二次コイルの磁束結合量を増やすことが必要であり、これを実現させるには中間部の分流用磁性体の磁気抵抗を増加させることで実現できる。 Leakage magnetic flux that circulates in the air exists not only between the opposing secondary side magnetic bodies but also between the near end and far end of one magnetic body, and is a value that cannot be ignored. Considering the leakage flux in one secondary side magnetic body and the leakage flux between the two secondary side magnetic bodies, the degree of magnetic flux reduction due to the distance from the primary coil to the secondary coil increases as the distance increases. growing. Therefore, strictly speaking, even if the two primary coils are driven, the amount of magnetic flux received by each secondary coil is not constant. That is, the amount of magnetic flux flowing through the magnetic body is large at the near end and the far end with respect to the primary coil, and is small at the intermediate portion. In order to make the magnetic flux coupling amount in one magnetic body linear with respect to the distance, it is necessary to increase the magnetic flux coupling amount of the intermediate secondary coil. This can be achieved by increasing the body's magnetic resistance.
　図７において、（Ａ）は二次コイルを覆う分流用磁性体の磁気抵抗を何ら補正しないときの各二次コイル（二次コイル数＝４）の出力電圧、（Ｂ）は二次コイルを覆う分流用磁性体の中間部２６ｂ、２６ｃの磁気抵抗を端部に配置される分流用磁性体２６ａ、２６ｄの磁気抵抗よりも増やしたときの出力電圧、（Ｃ）は二次コイルを覆う分流用磁性体の中間部２６ｂ、２６ｃの磁気抵抗を端部に配置される分流用磁性体２６ａ、２６ｄの磁気抵抗よりも増やすと共に一次コイルを２つに分割して駆動した時の各二次コイルの出力電圧を示す。 In FIG. 7, (A) shows the output voltage of each secondary coil (number of secondary coils = 4) when no correction is made for the magnetic resistance of the shunting magnetic material covering the secondary coil, and (B) shows the secondary coil. The output voltage when the magnetic resistance of the intermediate portions 26b and 26c of the shunting magnetic body to be covered is increased more than the magnetic resistance of the shunting magnetic bodies 26a and 26d disposed at the end, and (C) is the amount covering the secondary coil. Each secondary coil when the magnetic resistance of the diverting magnetic bodies 26b and 26c is increased more than the magnetic resistance of the diverting magnetic bodies 26a and 26d arranged at the end and the primary coil is divided into two and driven. Indicates the output voltage.
　このように二次側磁性体の分流路磁気抵抗を調整した上で、一次コイルを２つにすることにより、各二次コイルの出力電圧バラツキをさらに少なくすることができる。二次コイルが１つの二次側磁性体に対し８個以上になると、透磁率、出力電圧、出力電流の現実的なパラメータで中間部の二次コイル分流路の補正磁気抵抗が空中の漏洩磁束の等価磁気抵抗のオーダーに近づくため、例えば、図５に示すように、二次コイルの中間に一次コイルを挿入することにより出力電圧を均一にすることが可能となる。検討結果より、二次コイルが８個の場合は一次コイルが２個、１６個の場合は一次コイルが４個程度あれば、二次電圧を均等にできる。 As described above, by adjusting the shunt magnetic resistance of the secondary side magnetic material and using two primary coils, the output voltage variation of each secondary coil can be further reduced. When the number of secondary coils is 8 or more for one secondary side magnetic body, the correction magnetic resistance of the secondary secondary coil branch flow path is the leakage magnetic flux in the air with realistic parameters of permeability, output voltage, and output current. For example, as shown in FIG. 5, it is possible to make the output voltage uniform by inserting the primary coil in the middle of the secondary coil. From the examination results, if the number of secondary coils is 8, the number of secondary coils can be equalized if the number of primary coils is 2 and the number of 16 primary coils is about 4.
　図８は、本発明の第１の実施形態において、出力数が４個の場合の蛍光管用多出力高周波昇圧トランスの斜視図である。この第１の実施形態においては、２つの一次側磁性体２３（２３ａ，２３ｂ）と２つの二次側磁性体２５（２５ａ，２５ｂ）によって閉磁束磁気回路が形成される。この第１の実施形態の蛍光管用多出力高周波昇圧トランスでは、一次側磁性体２３（２３ａ，２３ｂ）にそれぞれ一次コイル２１（２１ａ，２１ｂ）が巻かれ、二次側磁性体２５ａに二次コイル２２（２２ａ、２２ｂ）が巻かれ、二次側磁性体２５ｂに二次コイル２２（２２ｃ、２２ｄ）が巻かれ、各二次コイル２２の一部を覆うようにそれぞれ分流用磁性体２６（２６ａ、２６ｂ、２６ｃ、２６ｄ）が取りつけられる。２つの一次コイルは、それぞれの二次コイル２２と鎖交する磁束が加算されるように接続される。また、分流用磁性体２６はコの字形状に形成され、中央部は二次コイル２２を覆い、端部は二次側磁性体２５に接合される。一般に、一次コイル２１および二次コイル２２はそれぞれボビンに巻かれた状態でそれぞれ一次側磁性体２３および二次側磁性体２５に嵌合される。 FIG. 8 is a perspective view of a multi-output high-frequency step-up transformer for a fluorescent tube when the number of outputs is four in the first embodiment of the present invention. In the first embodiment, a closed magnetic flux magnetic circuit is formed by the two primary side magnetic bodies 23 (23a, 23b) and the two secondary side magnetic bodies 25 (25a, 25b). In the multi-output high-frequency step-up transformer for a fluorescent tube of the first embodiment, primary coils 21 (21a, 21b) are wound around the primary side magnetic bodies 23 (23a, 23b), respectively, and secondary coils 25a are wound around the secondary side magnetic bodies 25a. 22 (22a, 22b) is wound, the secondary coil 22 (22c, 22d) is wound around the secondary side magnetic body 25b, and the shunting magnetic body 26 (26a) is provided so as to cover a part of each secondary coil 22. , 26b, 26c, 26d). The two primary coils are connected such that magnetic fluxes interlinking with the respective secondary coils 22 are added. Further, the diverting magnetic body 26 is formed in a U-shape, the center portion covers the secondary coil 22, and the end portion is joined to the secondary side magnetic body 25. In general, the primary coil 21 and the secondary coil 22 are respectively fitted to the primary side magnetic body 23 and the secondary side magnetic body 25 while being wound around a bobbin.
第２の実施形態。
　図９は本発明の第２の実施形態の高周波昇圧トランスの構造を示す模式図である。この第２の実施形態においては、図９に示すように、一次側磁性体２３ａと一次側磁性体２３ｂの間に複数のコの字型の磁性体２７（２７ａ、２７ｂ、２７ｃ、２７ｄ）を挟んで閉磁束磁気回路を形成する。各磁性体間は内容の理解を容易にするために間隙を設けてあるが、実際のトランスでは間隙は無いものである。コの字型磁性体の一方の支路はそれぞれ二次コイル２２（２２ａ，２２ｂ，２２ｃ，２２ｄ）が巻かれる二次側磁性体として機能し、他方の支路は二次側磁性体の磁束を分流する分流用磁性体として機能する。第２の実施形態では、二次コイルが巻かれる磁性体を個別に製造できるため、出力数に応じてコの字型の磁性体２７を任意の個数取りつけることができる。また、各コの字型磁性体は小型のため製造価格が安価であるので、蛍光管用多出力高周波昇圧トランスのコスト低減を実現することができる。 Second embodiment.
FIG. 9 is a schematic diagram showing the structure of a high-frequency step-up transformer according to the second embodiment of the present invention. In the second embodiment, as shown in FIG. 9, a plurality of U-shaped magnetic bodies 27 (27a, 27b, 27c, 27d) are provided between the primary side magnetic body 23a and the primary side magnetic body 23b. A closed magnetic flux magnetic circuit is formed by sandwiching them. A gap is provided between the magnetic bodies to facilitate understanding of the contents, but an actual transformer has no gap. One branch of the U-shaped magnetic body functions as a secondary magnetic body around which the secondary coil 22 (22a, 22b, 22c, 22d) is wound, and the other branch is a magnetic flux of the secondary magnetic body. Functions as a magnetic material for diversion. In the second embodiment, since the magnetic body around which the secondary coil is wound can be individually manufactured, an arbitrary number of U-shaped magnetic bodies 27 can be attached according to the number of outputs. In addition, since each U-shaped magnetic body is small and inexpensive to manufacture, the cost of the multi-output high-frequency step-up transformer for fluorescent tubes can be reduced.
第３の実施形態．
　図１０は、本発明の第３の実施形態において、出力数が８個の場合の蛍光管用多出力高周波昇圧トランスの模式図である。この第３の実施形態においては、図１０に示すように、２つの一次側磁性体２３（２３ａ，２３ｂ）の間に複数のＥ字型の磁性体２８（２８ａ、２８ｂ、２８ｃ、２８ｄ）を挟んで閉磁束磁気回路を形成する。各磁性体間は内容の理解を容易にするために間隙を設けてあるが、実際のトランスでは間隙は無いものである。Ｅ字型の磁性体は、上下の支路は二次コイルが巻かれる二次側磁性体として、また中央の支路は両端のふたつの二次側磁性体の共通の分流用磁性体として機能する。第３の実施形態では、２つの二次コイルが１つの分流用磁性体を共用するため小型・軽量化が図れるとともに、二次コイルが巻かれる磁性体を個別に製造できるため、出力数に応じてＥ字型の磁性体２８を任意の個数に取りつけることができる。また、各Ｅ字型磁性体は小型のため製造価格が安価であるので、蛍光管用多出力高周波昇圧トランスのコスト低減を実現することができる。 Third embodiment.
FIG. 10 is a schematic diagram of a multi-output high-frequency step-up transformer for a fluorescent tube when the number of outputs is eight in the third embodiment of the present invention. In the third embodiment, as shown in FIG. 10, a plurality of E-shaped magnetic bodies 28 (28a, 28b, 28c, 28d) are provided between two primary side magnetic bodies 23 (23a, 23b). A closed magnetic flux magnetic circuit is formed by sandwiching them. A gap is provided between the magnetic bodies to facilitate understanding of the contents, but an actual transformer has no gap. The E-shaped magnetic body functions as a secondary side magnetic body on which the secondary coil is wound on the upper and lower branches, and the central branch path functions as a common shunting magnetic body for the two secondary side magnetic bodies at both ends. To do. In the third embodiment, since the two secondary coils share one shunting magnetic body, the size and weight can be reduced, and the magnetic body around which the secondary coil is wound can be individually manufactured. Thus, an arbitrary number of E-shaped magnetic bodies 28 can be attached. Further, since each E-shaped magnetic body is small and inexpensive to manufacture, the cost of the multi-output high-frequency step-up transformer for fluorescent tubes can be reduced.
　本発明は、液晶表示パネルのバックライトとして用いられる並列配置された複数の蛍光管を点灯させるための蛍光管用多出力高周波昇圧トランスとして利用することができる。 The present invention can be used as a multi-output high-frequency step-up transformer for a fluorescent tube for lighting a plurality of fluorescent tubes arranged in parallel used as a backlight of a liquid crystal display panel.
本発明の第１の実施形態において、出力数が８個の場合の蛍光管用多出力高周波昇圧トランスの模式図である。In the 1st Embodiment of this invention, it is a schematic diagram of the multi-output high frequency step-up transformer for fluorescent tubes in case the number of outputs is eight. 本発明の第１の実施形態における蛍光管用多出力高周波昇圧トランスにおいて、第１の一次コイルのみに電流を流した場合の等価磁気回路図である。FIG. 3 is an equivalent magnetic circuit diagram in the case where a current is passed through only a first primary coil in the multi-output high-frequency step-up transformer for a fluorescent tube according to the first embodiment of the present invention. 本発明の第１の実施形態における蛍光管用多出力高周波昇圧トランスにおいて、第２の一次コイルのみに電流を流した場合の等価磁気回路図である。FIG. 4 is an equivalent magnetic circuit diagram when a current is supplied only to a second primary coil in the multi-output high-frequency step-up transformer for a fluorescent tube according to the first embodiment of the present invention. 本発明の第１の実施形態における蛍光管用多出力高周波昇圧トランスにおいて、第１および第２の一次コイルの双方に電流を流した場合の等価磁気回路図である。FIG. 3 is an equivalent magnetic circuit diagram when a current is passed through both the first and second primary coils in the multi-output high-frequency step-up transformer for a fluorescent tube according to the first embodiment of the present invention. 本発明の第１の実施形態において、出力数が１６個の場合の蛍光管用多出力高周波昇圧トランスの模式図である。In the 1st Embodiment of this invention, it is a schematic diagram of the multi-output high frequency step-up transformer for fluorescent tubes in case the number of outputs is 16. 二次コイルの位置と出力電圧との関係を示す図である。It is a figure which shows the relationship between the position of a secondary coil, and an output voltage. 第１および第２の一次コイルの双方を４０ＫＨｚの正弦波電圧で駆動した時の各二次コイルの出力電圧のシミュレーション結果を示す図である。It is a figure which shows the simulation result of the output voltage of each secondary coil when driving both the 1st and 2nd primary coils with the sine wave voltage of 40 KHz. 本発明の第１の実施形態において、出力数が４個の場合の蛍光管用多出力高周波昇圧トランスの斜視図である。In the 1st Embodiment of this invention, it is a perspective view of the multi-output high frequency step-up transformer for fluorescent tubes in case the number of outputs is four. 本発明の第２の実施形態において、出力数が４個の場合の蛍光管用多出力高周波昇圧トランスの模式図である。In the 2nd Embodiment of this invention, it is a schematic diagram of the multi-output high frequency step-up transformer for fluorescent tubes in case the number of outputs is four. 本発明の第３の実施形態において、出力数が８個の場合の蛍光管用多出力高周波昇圧トランスの模式図である。In the 3rd Embodiment of this invention, it is a schematic diagram of the multi-output high frequency step-up transformer for fluorescent tubes in case the number of outputs is eight. 従来の蛍光管用多出力高周波昇圧トランスによる蛍光管駆動回路である。This is a fluorescent tube driving circuit using a conventional multi-output high-frequency step-up transformer for fluorescent tubes. 従来の蛍光管用多出力高周波昇圧トランスにおいて、出力数が８個の場合の蛍光管用多出力高周波昇圧トランスの模式図である。In the conventional multi-output high-frequency boost transformer for fluorescent tubes, it is a schematic diagram of the multi-output high-frequency boost transformer for fluorescent tubes when the number of outputs is eight. 従来の蛍光管用多出力高周波昇圧トランスにおいて、１つの一次コイルのみに電流を流した場合の等価磁気回路図である。FIG. 6 is an equivalent magnetic circuit diagram in the case where a current is passed through only one primary coil in a conventional multi-output high-frequency step-up transformer for a fluorescent tube. 従来の蛍光管用多出力高周波昇圧トランスにおいて、一次コイルを４０ＫＨｚの正弦波電圧で駆動した時の各二次コイルの鎖交磁束のシミュレーション結果を示す図である。It is a figure which shows the simulation result of the interlinkage magnetic flux of each secondary coil when a primary coil is driven with the sinusoidal voltage of 40 KHz in the conventional multi-output high frequency step-up transformer for fluorescent tubes.
符号の説明Explanation of symbols
　　１３　蛍光管用多出力高周波昇圧トランス
　　２１　一次コイル
　　２２　二次コイル
　　２３　一次側磁性体
　　２５　二次側磁性体
　　２６　分流用磁性体
　　２７　コの字型磁性体
　　２８　Ｅの字型磁性体
　　２９　閉磁路形成用磁性体
 
  13 Multi-output high-frequency step-up transformer for fluorescent tube 21 Primary coil 22 Secondary coil 23 Primary side magnetic body 25 Secondary side magnetic body 26 Magnetic material for shunting 27 U-shaped magnetic body 28 E-shaped magnetic body 29 For closed magnetic circuit formation Magnetic material

Claims (5)

  1. 　１以上の一次側磁性体と前記一次側磁性体に対して対称に配置された複数の二次側磁性体とで形成された閉磁束磁気回路と、
    　前記閉磁束磁気回路を構成する一次側磁性体上に巻かれた１以上の一次コイルおよび二次側磁性体上に巻かれた複数の二次コイルと、
    　前記二次コイルの一部を覆い、その両端は前記二次側磁性体に接合するように形成される分流用磁性体とから構成され、
    　前記複数の二次コイルはそれぞれ蛍光管に接続され、
    　前記分流用磁性体によって前記二次側磁性体を通る磁束を分流することを特徴とする蛍光管用高周波昇圧トランス。     A closed magnetic flux magnetic circuit formed of one or more primary magnetic bodies and a plurality of secondary magnetic bodies arranged symmetrically with respect to the primary magnetic bodies;
    One or more primary coils wound on the primary side magnetic body constituting the closed magnetic flux magnetic circuit and a plurality of secondary coils wound on the secondary side magnetic body;
    Covering a part of the secondary coil, both ends thereof are composed of a magnetic material for shunting formed so as to be joined to the secondary side magnetic material,
    The plurality of secondary coils are each connected to a fluorescent tube,
    A high-frequency step-up transformer for a fluorescent tube, wherein a magnetic flux passing through the secondary side magnetic body is shunted by the shunting magnetic body.
  2. 　前記二次側磁性体は棒状に形成され、前記二次側磁性体の各両端はそれぞれ前記一次側磁性体の各端に接合されることを特徴とする請求項１に記載の蛍光管用多出力高周波昇圧トランス。 2. The multi-output for a fluorescent tube according to claim 1, wherein the secondary side magnetic body is formed in a rod shape, and each end of the secondary side magnetic body is joined to each end of the primary side magnetic body. High frequency step-up transformer.
  3. 　断面がコの字型の磁性体で形成され、前記コの字型の磁性体の一方の二次コイルが巻かれた方の磁性体をコイル用二次側磁性体とし、前記コの字型の磁性体の他方の二次コイルが巻かれていない方の磁性体を分流用磁性体とし、前記一次側磁性体、前記コの字型磁性体の前記コイル用二次側磁性体部分によって閉磁束磁気回路を形成し、前記コの字型磁性体の他方の分流用磁性体部分によって前記コイル用二次側磁性体部分を通る磁束を分流することを特徴とする請求項２に記載の蛍光管用多出力高周波昇圧トランス。 The U-shaped magnetic body having a cross-section formed of a U-shaped magnetic body and one of the U-shaped magnetic bodies on which the secondary coil is wound is used as a secondary magnetic body for the coil, and the U-shaped The other magnetic body on which the other secondary coil is not wound is used as a shunting magnetic body, and is closed by the primary side magnetic body and the secondary side magnetic body portion for the coil of the U-shaped magnetic body. 3. The fluorescence according to claim 2, wherein a magnetic flux magnetic circuit is formed, and the magnetic flux passing through the coil secondary side magnetic body portion is shunted by the other shunt magnetic body portion of the U-shaped magnetic body. Multi-output high-frequency step-up transformer for tubes.
  4. 　断面がＥ字型の磁性体で形成され、前記Ｅ字型磁性体の両端の支路をコイル用二次側磁性体とし、前記Ｅ字型磁性体の中央の支路を分流用磁性体とし、前記一次側磁性体、前記Ｅ字型磁性体の前記二次側磁性体部分によって閉磁束磁気回路を形成し、前記Ｅ字型磁性体の中央の支路の分流用磁性体部分によって前記コイル用二次側磁性体部分を通る磁束を分流することを特徴とする請求項２に記載の蛍光管用多出力高周波昇圧トランス。 The cross section is formed of an E-shaped magnetic body, the branch at both ends of the E-shaped magnetic body is a secondary magnetic body for a coil, and the branch at the center of the E-shaped magnetic body is a branching magnetic body. A closed magnetic flux magnetic circuit is formed by the primary side magnetic body and the secondary side magnetic body portion of the E-shaped magnetic body, and the coil is formed by the shunt magnetic body portion of the central branch of the E-shaped magnetic body. 3. The multi-output high-frequency step-up transformer for a fluorescent tube according to claim 2, wherein a magnetic flux passing through the secondary side magnetic body portion is shunted.
  5. 　前記一次コイル間に配置された複数の各二次コイルを覆う分流用磁性体において、中間部に配置される分流用磁性体の磁気抵抗が端部に配置される分流用磁性体の磁気抵抗よりも大きくなることを特徴とする請求項２に記載の蛍光管用多出力高周波昇圧トランス。
     
          In the magnetic material for shunting that covers each of the plurality of secondary coils arranged between the primary coils, the magnetic resistance of the magnetic material for shunting arranged at the intermediate portion is larger than the magnetic resistance of the magnetic material for shunting arranged at the end portion. The multi-output high-frequency step-up transformer for a fluorescent tube according to claim 2, wherein

PCT/JP2008/063098 2008-02-06 2008-07-22 Multi-output high frequency step-up transformer for fluorescent tube WO2009098790A1 (en)

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JP2008026962A JP4124806B1 (en) 2008-02-06 2008-02-06 Multi-output high-frequency step-up transformer for fluorescent tubes
JP2008-026962 2008-02-06

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2544201A3 (en) * 2011-07-06 2017-08-09 Rockwell Automation Technologies, Inc. Power converter and integrated DC choke therefor

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5820498U (en) * 1981-07-31 1983-02-08 松下電工株式会社 discharge lamp lighting device
JPH10208949A (en) * 1997-01-24 1998-08-07 Toko Inc Inverter transformer
JP4021931B1 (en) * 2007-04-10 2007-12-12 薫明 渡辺 High frequency step-up transformer for fluorescent tubes

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5820498U (en) * 1981-07-31 1983-02-08 松下電工株式会社 discharge lamp lighting device
JPH10208949A (en) * 1997-01-24 1998-08-07 Toko Inc Inverter transformer
JP4021931B1 (en) * 2007-04-10 2007-12-12 薫明 渡辺 High frequency step-up transformer for fluorescent tubes

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2544201A3 (en) * 2011-07-06 2017-08-09 Rockwell Automation Technologies, Inc. Power converter and integrated DC choke therefor

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JP4124806B1 (en) 2008-07-23
TW200935974A (en) 2009-08-16

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