JP2004207342A

JP2004207342A - Winding type transformer and power supply apparatus using the same

Info

Publication number: JP2004207342A
Application number: JP2002372099A
Authority: JP
Inventors: Kazuo Kono; 和夫河野
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-12-24
Filing date: 2002-12-24
Publication date: 2004-07-22

Abstract

<P>PROBLEM TO BE SOLVED: To miniature a winding type transformer, and miniaturize and make effective a power supply device. <P>SOLUTION: A primary wiring 35 is mounted at the center of a bobbin 3, and opposite ends of the primary winding 35 are connected to primary input terminals 23, 33 provided on terminal mountings 19, 21 located at opposite ends of the bobbin 3 through grooves 37, 47 provided in a partition for withstand voltage. First and second secondary windings 39, 41 are mounted at the opposite sides of the primary winding 35 via the partition. A lead wire 35a of the first secondary winding 39 on the end side of the winding on the side of the same in contact with the primary winding 35, and a lead wire 41a of the second secondary winding 41 on the end side of the winding on the side of the same in contact with the primary winding 35, are led to the grooves 37, 47 in the partition in parallel to the lead wire 35a, 35a of the primary winding 35, and are connected with ground terminals 25, 31 on the terminal boards 19, 21, respectively. A self-energyzing oscillation circuit is connected with the primary side winding 35 based upon a feedback signal of primary resonance voltage. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、冷陰極型蛍光ランプなどを駆動するインバータ等に用いられる巻線型トランス及びこのトランスを用いた電源装置に関する。
【０００２】
【従来の技術】
従来、図６に示すように、冷陰極型蛍光ランプ４６を巻線型トランスの出力で駆動する場合には、巻線型トランスＴの二次側の巻線の高圧端子にコンデンサを介して蛍光ランプ４６の一方の電極を接続し、蛍光ランプ４６の他方の電極を抵抗を介してアースに接続している。また、４本の蛍光ランプを駆動する場合には、図７に示すように、蛍光ランプ４４，４６，４６，４６ごとに巻線型トランスＴ１，Ｔ２，Ｔ３，Ｔ４を用意し、２本の蛍光ランプ４６，４６を直列に接続し、この各一対の蛍光ランプの中、一方の蛍光ランプ４６，４６を対応する巻線トランスＴ１，Ｔ３の二次側高圧端子にバラストコンデンサを介して接続し、他方の蛍光ランプ４４，４４を対応する巻線トランスＴ２，Ｔ４の二次側高圧端子にバラストコンデンサを介して接続し、各巻線トランスＴ１，Ｔ２，Ｔ３，Ｔ４の二次側の他方の端子をアースに接続している。
【０００３】
【発明が解決しようとする課題】
蛍光ランプの一方の電極を巻線型トランスの二次側高圧端子に接続し、他方の電極をアースに落として蛍光ランプを駆動する方式は、蛍光ランプの両端において電位差が生じ、トランス接続側が明るく、アース側が暗くなり、輝度にムラが生じてしまうという問題点がある。２本の蛍光ランプを直列に接続し、２個の巻線型トランスで２本の蛍光ランプを駆動する方式は、２本の蛍光ランプの両端に高圧がかかり、明るさのムラの発生を解消することができるが蛍光ランプごとに巻線トランスが必要となってしまい、巻線トランスの小型化に適しないという問題点がある。
本発明は上記問題点を解決することを目的とするものである。
【０００４】
【課題を解決するための手段】
上記目的を達成するため本発明は、ボビンの中央部に一次巻線を装着し、この一次巻線の両側に第１と第２の二次巻線を装着し、前記一次巻線とその両側の第１及び第２の二次巻線との境界に絶縁耐圧用のパーティションを配設し、前記ボビンの一端に第１の端子台を設け、前記ボビンの他端に第２の端子台を設け、それぞれの端子台に二次高圧端子とこれに対して距離を存した位置に一次入力端子とグランド端子を設け、前記第１の二次巻線の一端のリード線を前記第１の端子台の二次高圧端子に接続し、前記一次巻線の一端のリード線と前記第１の二次巻線の前記一次巻線と接する側の巻線の端部のリード線とを前記パーティションに形成した溝を通して平行に前記ボビンの一端に導き、該リード線をそれぞれ前記第１の端子台の対応する一次入力端子とグランド端子に接続し、前記第２の二次巻線の一端のリード線を前記第２の端子台の二次高圧端子に接続し、前記一次巻線の他端のリード線と前記第２の二次巻線の前記一次巻線と接する側の巻線の端部のリード線とを前記パーティションに形成した溝を通して平行に前記ボビンの他端に導き、該リード線をそれぞれ前記第２の端子台の対応する一次入力端子とグランド端子に接続し、前記ボビンにコアを装備し、一次側巻線とその両側の二次巻線とで１入力２出力を構成したものである。
また本発明は、ボビンの中央部に一次巻線を装着し、この一次巻線の両側に第１と第２の二次巻線を装着し、前記一次巻線とその両側の第１及び第２の二次巻線との境界に絶縁耐圧用のパーティションを配設し、前記第１の二次巻線の一端のリード線を二次高圧端子に接続し、前記一次巻線の一端のリード線と前記第１の二次巻線の前記一次巻線と接する側の巻線の端部のリード線とをそれぞれ対応する一次入力端子とグランド端子に接続し、前記第２の二次巻線の一端のリード線を二次高圧端子に接続し、前記一次巻線の他端のリード線と前記第２の二次巻線の前記一次巻線と接する側の巻線の端部のリード線とをそれぞれ対応する一次入力端子とグランド端子に接続し、前記ボビンにコアを装備し、一次側巻線とその両側の二次巻線とで１入力２出力を構成し、前記一次巻線に共振コンデンサを接続して一次側共振回路を設け、前記一次巻線に、一次側共振電圧のフィードバック信号に基づいて自励発振する自励発振回路を接続し、第１の蛍光ランプの一方の電極を前記第１の二次巻線の二次高圧出力端子に接続し、第１の蛍光ランプに直列に第２の蛍光ランプを接続し、該第２の蛍光ランプを前記第２の二次巻線の二次高圧出力端子に接続したものである。
また本発明は、ボビンの中央部に一次巻線を装着し、この一次巻線の両側に第１と第２の二次巻線を装着し、前記一次巻線とその両側の第１及び第２の二次巻線との境界に絶縁耐圧用のパーティションを配設し、前記ボビンの一端に第１の端子台を設け、前記ボビンの他端に第２の端子台を設け、それぞれの端子台に二次高圧端子とこれに対して距離を存した位置に一次入力端子とグランド端子を設け、前記第１の二次巻線の一端のリード線を前記第１の端子台の二次高圧端子に接続し、前記一次巻線の一端のリード線と前記第１の二次巻線の前記一次巻線と接する側の巻線の端部のリード線とを前記パーティションに形成した溝を通して平行に前記ボビンの一端に導き、該リード線をそれぞれ前記第１の端子台の対応する一次入力端子とグランド端子に接続し、前記第２の二次巻線の一端のリード線を前記第２の端子台の二次高圧端子に接続し、前記一次巻線の他端のリード線と前記第２の二次巻線の前記一次巻線と接する側の巻線の端部のリード線とを前記パーティションに形成した溝を通して平行に前記ボビンの他端に導き、該リード線をそれぞれ前記第２の端子台の対応する一次入力端子とグランド端子に接続し、前記ボビンにコアを装備し、一次側巻線とその両側の二次巻線とで１入力２出力を構成し、前記一次巻線に共振コンデンサを接続して一次側共振回路を設け、前記一次巻線に、一次側共振電圧のフィードバック信号に基づいて自励発振する自励発振回路を接続したものである。
また本発明は、前記二次巻線のグランド端子を抵抗素子を介して接地し、この抵抗素子に発生する電圧によって出力側を流れる電流を検出するようにしたものである。
【０００５】
【発明の実施の形態】
以下に本発明の実施の形態を添付した図面を参照して詳細に説明する。
図１及び図２において、３は巻線型トランス４４のボビンであり、角筒部３ｃの両端に鍔部３ａ，３ｂが形成されている。前記ボビン３の角筒部３ｃには所定の間隔を存して四角形の絶縁耐圧用の板状のパーティション５，７，９，１１，１３，１５が複数固設され、鍔部３ａ，３ｂと角筒部３ｃとパーティション５，７，９，１１，１３，１５とで、巻線用の凹入部を形成している。前記鍔部３ａ，３ｂには端子用の端子台１９，２１が固設され、これに端子２３，２５，２７，２９，３１，３３が固着されている。
【０００６】
ボビン３の一端側の端子台１９には、その一方側に二次高圧端子２７が配置され、その他方側に、一次入力端子２３とグランド端子２５が配置されている。一次入力端子２３とグランド端子２５は、二次高圧端子２７の高電圧の影響を受けないように、できるだけ離して、端子台１９の他方側に配置されている。ボビン３の他端側の端子台２１には、その一方側に二次高圧端子２９が配置され、これからできるだけ離れた他方側に一次入力端子３３とグランド端子３１が配置されている。前記パーティション５，７，９，１１，１３，１５の外縁にはボビン３の中央部から巻線のリード線を前記一次入力端子２３とグランド端子２５及び一次入力端子３３とグランド端子３１に導く溝４７，３７が形成されている。
【０００７】
ボビン３の中央の凹入部には、一端側Ａを巻始めとして、一次巻線３５が例えば右巻きで巻回される。一次巻線３５の巻始め端側Ａのリード線３５ａはパーティション９，７，５及び鍔部３ａの外縁部に形成された溝４７を通って、ボビン３の一端側に導かれ、一次側入力端子２３に接続している。一次巻線３５の終端側のリード線３５ａは、パーティション１１，１３，１５及び鍔部３ｂの外縁部に形成された溝４７を通ってボビン３の他端側に導かれ、一次側入力端子３３に接続している。ボビン３の一次巻線３５の一方側には、ボビン３の一端側Ｂを巻始めとして、第１の二次巻線３９が右巻きで、鍔部３ａ、パーティション５間、パーティション５，７間、パーティション７，９間の各凹入部に順次巻回される。
【０００８】
二次巻線３９の中間を複数のパーティション５，７によって区画したのは、二次巻線３９の絶縁耐圧を考慮したものである。第１の二次巻線３９の巻始め端側Ｂのリード線は、鍔部３ａの溝を通って、二次高圧端子２７に接続している。第１の二次巻線３９の終端側Ｃのリード線３９ａは、３本屈折させてよじって太くし、一次巻線３５のリード線３５ａと平行してパーティション９，７，５及び鍔部３ａの溝４７を通って、ボビン３の一端側に導かれ、グランド端子２５に接続している。ボビン３の中央の一次巻線３５の他方側には、パーティション１１と接する側Ｄを巻始めとして、第２の二次巻線４１が右巻きで、パーティション１１，１３間、パーティション１３，１５間、パーティション１５、鍔部３ｂ間の各凹入部に順次巻回される。
【０００９】
一次巻線３５の左右に対称に配置された第１と第２の二次巻線３９，４１は同一の構造である。第２の二次巻線４１の巻始め端側Ｄのリード線４１ａは、３本に折り曲げられよじって太くした状態で図２に示すように、一次巻線３５のリード線３５ａと平行に、パーティション１１，１３，１５及び鍔部３ｂの溝３７を通って、ボビン３の他端側に導かれ、グランド端子３１に接続している。第２の二次巻線４１の終端側リード線は、鍔部３ｂの他端側Ｅの溝に導かれ、二次高圧端子２９に接続している。以上の巻線構造から明らかなように、パーティション９，１１間の一次側巻線３５の両端は二次巻線３９，４１の電圧の低いグランド側と接することになり、隣接する一次巻線３５の電圧と二次巻線３９，４１ｋ電圧との差が小さくなる。
【００１０】
そのため、一次巻線３５と二次巻線３９，４１との間の絶縁耐圧構造を簡単な構造とすることができる。一次巻線３５と、二次巻線３９，４１のグランド側は、電位差が小さいので、共通の溝３７，４７を通して、両者を平行に配置しても絶縁耐圧に問題はなく、各パーティションの限られたスペースに一次巻線のリード線と二次巻線のリード線用の溝をそれぞれ別個に設ける必要がないのでパーティションの加工及び構造を簡単にすることができ、トランスの小型化とコストダウンを図ることができる。４３はコアであり、ボビン３の外側とボビン３の筒部３ｃ内に配置されている。上記した巻線トランス４４は、図４に示すように、１入力２出力を構成し、このトランスを用いて２本の冷陰極蛍光ランプ４６，４６を明るさに明暗のムラのない状態で駆動することができる。図４において、２本のランプ４６，４６は、両端が二次巻線３９，４０の高圧側に接続されるので、ランプ４６，４６の両端に明るさの差が生じることがない。
【００１１】
上記した１入力２出力巻線トランス４４は、このトランスの一次側で直列あるいは並列共振回路を構成し、トランスの一次側に共振電圧を発生させる自励発振回路により駆動されることが望ましい。一次側に電源電圧より高い高電圧が発生することにより、二次側の巻線の量を少なくでき、結果として、従来の１入力１出力の巻線トランスと同じ大きさで２出力を実現することができる。また、１入力２出力巻線トランスは、トランスの中央部に一次コイルとコアによる発熱が集中するが、この発熱はトランスの中央部に発生するので、二次巻線との結合のバランスが良好な状態に保持され、トランスが効率的に動作する。従来の１入力１出力の巻線トランスのように、発熱がトランスの片側に集中すると、一次巻線と二次巻線との結合にアンバランスが生じ効率化の妨げとなる。
【００１２】
次にトランスの一次側に共振電圧を発生させる自励発振回路を用いた電源装置を図５を参照して説明する。
図５中、５１は位相検出回路であり、コンデンサ（Ｃ３）が接続するリード線２７を介して巻線トランス４４の一次側の一端に接続している。５２，５４，５６，５８はＦＥＴから成るスイッチング素子であり、各々のスイッチング素子のソース、ドレイン間には転流ダイオード６０，６２，６４，６６が接続されている。スイッチング素子５２，５４，５６，５８の各々のゲートにはゲート制御回路６８，７０，７２，７４が接続され、これらのうち、ゲート制御回路６８，７２はＰＷＭ制御回路７６に接続し、ゲート制御回路７０，７４はロジック回路７８に接続している。ＰＷＭ制御回路７６は、ランプ４６，４６に流れる電流を検出する整流平滑回路８０から信号を受け取り、この信号のレベルがライン８２から与えられる設定値になるように、スイッチング素子５２，５６の導通角を制御する。
【００１３】
ロジック回路７８は、リード線２７に接続する位相検出回路５１からのトランス４４の一次側直列共振位相差信号に基づいて、スイッチング素子をオンオフさせるための信号を造出し、ＰＷＭ制御回路７６を介してゲート制御回路６８，７２にオンオフ制御信号を送るとともに、ゲート制御回路７０，７４にオンオフ制御信号を送るように構成されている。また、ロジック回路７８は、調光信号が入力される調光制御回路８４の出力信号に基づいて、調光制御信号を造出し、この調光制御信号によってスイッチング素子オンオフのバースト制御とＰＷＭ制御回路７６のスイッチオンパルス幅を制御し、ランプ４６，４６の明るさを一定に保つことと、調光信号に基づき、輝度ゼロから１００％まで任意の値に設定し得るように構成されている。また、ロジック回路７８には過電流検出回路８６が接続し、ランプ４６，４６に過電流が流れたとき、ロジック回路７８は、これを検出し、過電流を阻止する信号をＰＷＭ制御回路７６に送り過電流を防止するように構成されている。
【００１４】
起動補償回路８８は、ランプ４６，４６の通電回路に接続し、抵抗４８に接続する線からランプ４６，４６の電流信号が入力されるように構成されている。起動補償回路８８は、電源オンオフ時、自励発振回路が確実に起動するように、起動補償信号を位相検出回路５１に入力する。位相検出回路５１は、この起動補償信号を受けて、ロジック回路７８に自励発振のための起動信号を出力する。起動補償回路８８は、位相検出回路５１から位相補正された信号がロジック回路７８に入ってトランス一次側に電流がロジックで決められた方向に流れても、ランプ４６，４６が放電を開始しない事がある。起動補償回路８８は、このような場合の起動補償のために設けられている。この場合、確実にランプ４６，４６を点灯させるために、起動補償回路８８は、ランプ４６，４６を流れる電流を検出してランプ４６，４６が点灯したか否か判断し、点灯していない時は、点灯するまで起動補償信号を位相検出回路５１に送り出す。位相検出回路５１はこの起動補償信号を受けてランプ４６，４６が点灯するまで起動信号ロジック回路７８に起動信号を出力する。
【００１５】
また、調光動作では、トランス４４の一次側共振周波数よりも低い周波数で、ＯＮ幅をＰＷＭ制御されたバースト信号で、全体のロジック信号をＯＮ−ＯＦＦさせ、結果的に明るさを制御している。この方法は、消灯から全点灯まで自由に調整が可能であるが、ランプ４６，４６はこの調光信号の周期でＯＮ−ＯＦＦされているため、その周期ごとに起動確認と確実な起動が必要となる。そのため、起動補償回路８８は、上記のごとく、確実な点灯を実現するために、はじめに起動補償信号を位相検出回路５１に送り出している。起動補償の動作について説明すると、始めて電源を入れる時や、ランプが点灯していない時、例えば、電流がＩ１の方向に流れる様にスイッチング素子５２と５８とを決められたパルス幅でＯＮにする。これにより直列共振回路を構成するコンデンサ（Ｃ１）とトランス４４の一次巻線３５に電流が流れ、位相検出回路５１にリード線２７を通じて信号が入り、Ｉ２，Ｉ１，Ｉ２，Ｉ１と交互に電流が流れ、検出した一次共振周波数で発振を開始する。
【００１６】
起動補償回路８８は、ロジック回路７８の初期リセット（起動時）も作っている。もしランプ４６，４６が点灯しなかった場合は、再度リセットし、始めの起動信号を位相検出回路５１を通じてロジック回路７８に対し送出する。ランプオープン・ショート検出回路９０は、巻線型トランス４４の二次側に接続し、二次側の電圧及び電流を検出する。ランプ４６，４６が点灯していないか又はランプ４６，４６が取り付けられていない状態即ちランプオープンやランプの配線等がショートした状態即ちランプショートのとき、位相検出回路５１を通じてロジック回路７８に信号を送り、ロジック回路７８、ＰＷＭ制御回路７６及びゲート制御回路６８，７０，７２，７４から成る制御回路を遮断するように構成されている。過電流検出回路８６は、ＰＷＭ制御回路７６が不良であったり、又は、ランプ４６，４６の配線がショートした時等において、ロジック回路７８に信号を送り、制御回路を遮断する。
【００１７】
尚、図５において、位相検出回路５１及びロジック回路７８は、位相検出手段の単一の出力信号を互いに逆位相の２つの位相信号に変換し前記スイッチング素子５２，５４，５６，５８をオンオフ制御する駆動信号として出力する制御回路を構成している。また、スイッチング素子５２，５４，５６，５８及びゲート制御回路６８，７０，７２，７４は、巻線型トランスの入力側一次巻線に誘起された一次側共振電圧のフィードバック信号に基づいてスイッチング素子がオンオフしこのオンオフによって直流電源の巻線型トランスへの通電方向を正逆方向に変換して巻線型トランスの入力側一次巻線に交流信号として入力するドライブ回路を構成している。
【００１８】
上記した構成において、電源スイッチがオンとなり、ゲート制御回路６８，７４又は７２，７０のいずれかにＰＷＭ制御回路７６及びロジック回路７８からオン信号が瞬間的に供給されると、直流電源がスイッチング素子５２，５８を通じて、Ｉ１の方向に、あるいは、スイッチング素子５６，５４を通じて、Ｉ２の方向に、巻線型トランス４４の一次側巻線に電流が流れる。これにより、自励発振回路が起動し、巻線型トランス４４が共振電圧を発生する。巻線型トランス４４の一次側の共振電圧の周波数は、リード線２７により、位相検出回路５１に供給される。ロジック回路７８とＰＷＭ制御回路７６は、位相検出回路５１からの位相信号に基づいて、ゲート制御回路６８，７０，７２，７４を駆動し、スイッチング素子５２，５４，５６，５８をオンオフ制御する。スイッチング素子５２，５４，５６，５８のオンオフによって電流は、Ｉ１とＩ２の方向に交互に流れ、自励発振回路は、巻線型トランス４４の一次側共振周波数で自励発振する。尚、本発明は、一次側直列共振を利用した自励発振回路に特に限定されるものではなく、一次側に並列共振を利用したロイヤー方式の自励発振回路を使用することができる。
【００１９】
【発明の効果】
本発明は上述の如く１個のトランスで１入力２出力を実現することができ、冷陰極蛍光ランプ等の負荷を効率的に駆動することができる。
【図面の簡単な説明】
【図１】本発明の巻線トランスの説明的平面図である。
【図２】パーティションの溝を示す拡大断面図である。
【図３】本発明の巻線トランスの説明図である。
【図４】本発明の巻線トランスの回路説明図である。
【図５】電源装置の実施形態を示すブロック回路図である。
【図６】従来技術の説明図である。
【図７】従来技術の説明図である。
【符号の説明】
３ボビン
５パーティション
７パーティション
９パーティション
１１パーティション
１３パーティション
１５パーティション
１９端子台
２１端子台
２３端子
２５端子
２７端子
２９端子
３１端子
３３端子
３５一次巻線
３７溝
４７溝
３９二次巻線
４１二次巻線
４３コア
４４巻線トランス
４６冷陰極型蛍光ランプ
４８抵抗
５０誤動作防止回路
５１位相差造出回路
５２〜５８スイッチング素子
６２〜６６転流ダイオード
６８ゲート制御回路
７０ゲート制御回路
７２ゲート制御回路
７４ゲート制御回路
７６ＰＷＭ制御回路
７８ロジック回路
８０整流制御回路
８２ライン
８４調光制御回路
８６過電流検出回路
８８起動補償回路
９０ランプオープン・ショート検出回路[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a winding type transformer used for an inverter or the like for driving a cold cathode fluorescent lamp and the like, and a power supply device using the transformer.
[0002]
[Prior art]
Conventionally, as shown in FIG. 6, when the cold cathode fluorescent lamp 46 is driven by the output of a wound-type transformer, the fluorescent lamp 46 is connected to the high-voltage terminal of the secondary winding of the wound-type transformer T via a capacitor. And the other electrode of the fluorescent lamp 46 is connected to ground via a resistor. When driving four fluorescent lamps, as shown in FIG. 7, winding type transformers T1, T2, T3 and T4 are prepared for each of the fluorescent lamps 44, 46, 46 and 46, and two fluorescent lamps are provided. The lamps 46, 46 are connected in series, and one of the pair of fluorescent lamps is connected to a secondary high voltage terminal of the corresponding winding transformer T1, T3 via a ballast capacitor. The other fluorescent lamps 44, 44 are connected to the secondary high-voltage terminals of the corresponding winding transformers T2, T4 via ballast capacitors, and the other secondary terminals of the respective winding transformers T1, T2, T3, T4 are connected. Connected to earth.
[0003]
[Problems to be solved by the invention]
The method of connecting one electrode of the fluorescent lamp to the secondary side high voltage terminal of the winding type transformer and driving the fluorescent lamp by grounding the other electrode generates a potential difference at both ends of the fluorescent lamp, and the transformer connection side is bright, There is a problem that the ground side becomes dark and the brightness becomes uneven. In a system in which two fluorescent lamps are connected in series and two fluorescent lamps are driven by two winding type transformers, a high voltage is applied to both ends of the two fluorescent lamps, thereby eliminating the occurrence of uneven brightness. However, there is a problem that a winding transformer is required for each fluorescent lamp, which is not suitable for downsizing the winding transformer.
An object of the present invention is to solve the above problems.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a method of mounting a primary winding at a center portion of a bobbin and mounting first and second secondary windings on both sides of the primary winding. A partition for withstand voltage is provided at a boundary between the first and second secondary windings, a first terminal block is provided at one end of the bobbin, and a second terminal block is provided at the other end of the bobbin. A secondary input terminal and a ground terminal provided at a distance from the secondary high voltage terminal on each terminal block, and a lead wire at one end of the first secondary winding is connected to the first terminal. And a lead wire at one end of the primary winding and a lead wire at an end of a winding of the first secondary winding that is in contact with the primary winding are connected to the partition. The lead is guided in parallel to one end of the bobbin through the formed groove, and the lead wires are respectively connected to the corresponding ones of the first terminal block. Connected to a primary input terminal and a ground terminal, a lead wire at one end of the second secondary winding is connected to a secondary high voltage terminal of the second terminal block, and a lead wire at the other end of the primary winding. A lead wire at an end of the winding of the second secondary winding that is in contact with the primary winding is guided in parallel to the other end of the bobbin through a groove formed in the partition, and the lead wires are respectively connected to the lead wire. The bobbin is provided with a core, connected to the corresponding primary input terminal and the ground terminal of the second terminal block, and the primary winding and the secondary windings on both sides thereof constitute one input and two outputs. .
The present invention also provides a primary winding mounted at the center of the bobbin, and first and second secondary windings mounted on both sides of the primary winding. A partition for insulation withstand voltage is provided at the boundary with the secondary winding of No. 2 and a lead wire at one end of the first secondary winding is connected to a secondary high voltage terminal; Connecting a wire and a lead wire at an end of the winding of the first secondary winding which is in contact with the primary winding to a corresponding primary input terminal and a ground terminal, respectively; Is connected to a secondary high-voltage terminal, and a lead wire at the other end of the primary winding and a lead wire at an end of a winding of the second secondary winding that is in contact with the primary winding. Are connected to the corresponding primary input terminal and ground terminal, and the bobbin is equipped with a core, and the primary winding and the secondary windings on both sides thereof A primary-side resonance circuit is provided by configuring an input 2 output, a resonance capacitor is connected to the primary winding, and a self-excited oscillation circuit that self-oscillates based on a feedback signal of the primary-side resonance voltage is provided in the primary winding. And connecting one electrode of the first fluorescent lamp to a secondary high-voltage output terminal of the first secondary winding, connecting a second fluorescent lamp in series with the first fluorescent lamp, 2 is connected to a secondary high-voltage output terminal of the second secondary winding.
The present invention also provides a primary winding mounted at the center of the bobbin, and first and second secondary windings mounted on both sides of the primary winding. A partition for insulation withstand voltage is provided at the boundary with the secondary winding of No. 2, a first terminal block is provided at one end of the bobbin, and a second terminal block is provided at the other end of the bobbin. A secondary high-voltage terminal and a primary input terminal and a ground terminal are provided at a position spaced apart from the secondary high-voltage terminal, and a lead wire at one end of the first secondary winding is connected to the secondary high-voltage terminal of the first terminal block. Connected to a terminal, and the lead wire at one end of the primary winding and the lead wire at the end of the winding of the first secondary winding that is in contact with the primary winding are parallelized through a groove formed in the partition. To the one end of the bobbin, and connect the lead wires to the corresponding primary input terminals of the first terminal block, respectively. And a lead wire at one end of the second secondary winding is connected to a secondary high voltage terminal of the second terminal block, and a lead wire at the other end of the primary winding is connected to the second A lead wire at an end of the secondary winding, which is in contact with the primary winding, is guided in parallel to the other end of the bobbin through a groove formed in the partition, and the lead wires are respectively connected to the second terminal. Connected to the corresponding primary input terminal and ground terminal of the table, the bobbin is equipped with a core, and a primary winding and secondary windings on both sides thereof constitute one input and two outputs. A primary-side resonance circuit is provided by connecting a capacitor, and a self-excited oscillation circuit that performs self-excited oscillation based on a feedback signal of the primary-side resonance voltage is connected to the primary winding.
Further, according to the present invention, a ground terminal of the secondary winding is grounded via a resistance element, and a current flowing on the output side is detected by a voltage generated in the resistance element.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 and 2, reference numeral 3 denotes a bobbin of the winding type transformer 44, and flange portions 3a and 3b are formed at both ends of the rectangular tube portion 3c. A plurality of rectangular plate-like partitions 5, 7, 9, 11, 13, 15 for insulation withstand voltage are fixedly provided at a predetermined interval on the square tube portion 3 c of the bobbin 3. The rectangular tube portion 3c and the partitions 5, 7, 9, 11, 13, 15 form a winding recess. Terminal blocks 19, 21 for terminals are fixed to the flanges 3a, 3b, and terminals 23, 25, 27, 29, 31, 33 are fixed to this.
[0006]
The terminal block 19 on one end of the bobbin 3 has a secondary high voltage terminal 27 disposed on one side thereof, and a primary input terminal 23 and a ground terminal 25 disposed on the other side. The primary input terminal 23 and the ground terminal 25 are arranged as far as possible on the other side of the terminal block 19 so as not to be affected by the high voltage of the secondary high voltage terminal 27. The terminal block 21 on the other end of the bobbin 3 has a secondary high voltage terminal 29 disposed on one side thereof, and a primary input terminal 33 and a ground terminal 31 disposed on the other side as far as possible from the terminal. On the outer edges of the partitions 5, 7, 9, 11, 13, 15 there are grooves for guiding the lead wires of the winding from the center of the bobbin 3 to the primary input terminal 23 and the ground terminal 25 and to the primary input terminal 33 and the ground terminal 31. 47 and 37 are formed.
[0007]
The primary winding 35 is wound, for example, clockwise around the center recessed portion of the bobbin 3, starting from one end A. The lead wire 35a on the winding start end side A of the primary winding 35 is guided to one end side of the bobbin 3 through a groove 47 formed on the outer edge of the partitions 9, 7, 5 and the flange 3a, and the primary side input is provided. Connected to terminal 23. The lead wire 35a on the terminal side of the primary winding 35 is guided to the other end of the bobbin 3 through a groove 47 formed on the outer edge of the partitions 11, 13, 15 and the flange 3b. Connected to On one side of the primary winding 35 of the bobbin 3, the first secondary winding 39 is wound rightward, starting from one end B of the bobbin 3, between the flange 3 a, between the partitions 5, and between the partitions 5 and 7. , Are sequentially wound around the recessed portions between the partitions 7 and 9.
[0008]
The reason why the middle of the secondary winding 39 is divided by the plurality of partitions 5 and 7 is in consideration of the dielectric strength of the secondary winding 39. The lead wire on the winding start end side B of the first secondary winding 39 is connected to the secondary high voltage terminal 27 through the groove of the flange 3a. The lead wire 39a on the terminal side C of the first secondary winding 39 is bent three times by bending it, and parallel to the lead wire 35a of the primary winding 35, the partitions 9, 7, 5 and the flange 3a. , And is guided to one end of the bobbin 3 and connected to the ground terminal 25. On the other side of the center primary winding 35 of the bobbin 3, the second secondary winding 41 is wound rightward, starting from the side D in contact with the partition 11, between the partitions 11 and 13, and between the partitions 13 and 15. , The partition 15 and the flange 3b.
[0009]
The first and second secondary windings 39 and 41 symmetrically arranged on the left and right of the primary winding 35 have the same structure. As shown in FIG. 2, the lead wire 41 a on the winding start end side D of the second secondary winding 41 is bent and bent to three pieces, and is parallel to the lead wire 35 a of the primary winding 35, as shown in FIG. It is guided to the other end side of the bobbin 3 through the partitions 11, 13, 15 and the groove 37 of the flange 3b, and is connected to the ground terminal 31. The terminal wire on the end side of the second secondary winding 41 is guided to the groove on the other end E of the flange 3 b and is connected to the secondary high voltage terminal 29. As is apparent from the above winding structure, both ends of the primary winding 35 between the partitions 9 and 11 come into contact with the low voltage ground side of the secondary windings 39 and 41, and the adjacent primary winding 35 , And the voltage between the secondary windings 39 and 41k becomes smaller.
[0010]
Therefore, the withstand voltage structure between the primary winding 35 and the secondary windings 39 and 41 can be simplified. Since the potential difference between the primary winding 35 and the ground side of the secondary windings 39 and 41 is small, there is no problem in the withstand voltage even if both are arranged in parallel through the common grooves 37 and 47. It is not necessary to provide separate grooves for the primary winding lead wire and the secondary winding lead wire in the space provided, so the processing and structure of the partition can be simplified, miniaturization of the transformer and cost reduction Can be achieved. Reference numeral 43 denotes a core, which is arranged outside the bobbin 3 and inside the cylindrical portion 3c of the bobbin 3. As shown in FIG. 4, the above-mentioned winding transformer 44 has one input and two outputs, and drives the two cold cathode fluorescent lamps 46, 46 using this transformer without unevenness in brightness. can do. 4, both ends of the two lamps 46, 46 are connected to the high voltage side of the secondary windings 39, 40, so that there is no difference in brightness between both ends of the lamps 46, 46.
[0011]
It is desirable that the one-input two-output winding transformer 44 constitutes a series or parallel resonance circuit on the primary side of the transformer, and is driven by a self-excited oscillation circuit that generates a resonance voltage on the primary side of the transformer. By generating a high voltage higher than the power supply voltage on the primary side, the amount of winding on the secondary side can be reduced, and as a result, two outputs with the same size as the conventional one-input one-output winding transformer are realized. be able to. In the 1-input, 2-output winding transformer, heat generated by the primary coil and the core is concentrated at the center of the transformer. However, since this heat is generated at the center of the transformer, the coupling with the secondary winding is well balanced. And the transformer operates efficiently. When heat is concentrated on one side of the transformer, as in a conventional one-input one-output winding transformer, an unbalance occurs in the coupling between the primary winding and the secondary winding, which hinders efficiency.
[0012]
Next, a power supply device using a self-excited oscillation circuit for generating a resonance voltage on the primary side of a transformer will be described with reference to FIG.
In FIG. 5, reference numeral 51 denotes a phase detection circuit, which is connected to one end on the primary side of the winding transformer 44 via the lead wire 27 to which the capacitor (C3) is connected. Reference numerals 52, 54, 56 and 58 denote switching elements composed of FETs, and commutation diodes 60, 62, 64 and 66 are connected between the source and drain of each switching element. Gate control circuits 68, 70, 72, 74 are connected to the gates of the switching elements 52, 54, 56, 58, respectively. Of these, the gate control circuits 68, 72 are connected to the PWM control circuit 76, The circuits 70 and 74 are connected to a logic circuit 78. The PWM control circuit 76 receives a signal from the rectifying / smoothing circuit 80 which detects the current flowing through the lamps 46, 46, and sets the conduction angle of the switching elements 52, 56 so that the level of the signal becomes a set value given from the line 82. Control.
[0013]
The logic circuit 78 generates a signal for turning on and off the switching element based on the primary side series resonance phase difference signal of the transformer 44 from the phase detection circuit 51 connected to the lead wire 27, and outputs the signal through the PWM control circuit 76. In addition, an on / off control signal is sent to the gate control circuits 68 and 72, and an on / off control signal is sent to the gate control circuits 70 and 74. Further, the logic circuit 78 generates a dimming control signal based on the output signal of the dimming control circuit 84 to which the dimming signal is input, and uses the dimming control signal to perform burst control of switching on / off of the switching element and PWM control. The switch-on pulse width of the circuit 76 is controlled to keep the brightness of the lamps 46 and 46 constant, and the brightness can be set to any value from zero to 100% based on the dimming signal. . An overcurrent detection circuit 86 is connected to the logic circuit 78. When an overcurrent flows through the lamps 46 and 46, the logic circuit 78 detects the overcurrent and sends a signal for preventing the overcurrent to the PWM control circuit 76. It is configured to prevent feed overcurrent.
[0014]
The start-up compensation circuit 88 is connected to the energizing circuit of the lamps 46, 46, and is configured such that current signals of the lamps 46, 46 are inputted from a line connected to the resistor 48. The start-up compensation circuit 88 inputs a start-up compensation signal to the phase detection circuit 51 so that the self-excited oscillation circuit is started up reliably when the power is turned on and off. The phase detection circuit 51 receives the start-up compensation signal and outputs a start-up signal for self-excited oscillation to the logic circuit 78. The start-up compensation circuit 88 prevents the lamps 46, 46 from starting discharging even if the phase-corrected signal from the phase detection circuit 51 enters the logic circuit 78 and the current flows in the primary side of the transformer in the direction determined by the logic. There is. The starting compensation circuit 88 is provided for starting compensation in such a case. In this case, in order to surely turn on the lamps 46, 46, the starting compensation circuit 88 detects the current flowing through the lamps 46, 46 to determine whether or not the lamps 46, 46 have been turned on. Sends a start-up compensation signal to the phase detection circuit 51 until it is turned on. The phase detection circuit 51 receives the start-up compensation signal and outputs a start-up signal to the start-up signal logic circuit 78 until the lamps 46, 46 are turned on.
[0015]
In the dimming operation, the entire logic signal is turned on and off by a burst signal whose ON width is PWM-controlled at a frequency lower than the primary resonance frequency of the transformer 44, and as a result, the brightness is controlled. I have. In this method, the adjustment can be freely performed from the extinguishing to the full lighting. However, since the lamps 46 and 46 are turned on and off at the cycle of the dimming signal, it is necessary to confirm the start and to surely start at each cycle. It becomes. Therefore, the start-up compensation circuit 88 first sends out a start-up compensation signal to the phase detection circuit 51 in order to realize reliable lighting as described above. The start-up compensation operation will be described. When the power is turned on for the first time or when the lamp is not lit, for example, the switching elements 52 and 58 are turned on with a predetermined pulse width so that a current flows in the direction of I1. . As a result, a current flows through the capacitor (C1) constituting the series resonance circuit and the primary winding 35 of the transformer 44, a signal enters the phase detection circuit 51 through the lead wire 27, and the current alternately flows with I2, I1, I2, and I1. The flow starts to oscillate at the detected primary resonance frequency.
[0016]
The startup compensation circuit 88 also makes an initial reset (at startup) of the logic circuit 78. If the lamps 46, 46 do not light up, they are reset again, and the first start signal is sent to the logic circuit 78 through the phase detection circuit 51. The lamp open / short detection circuit 90 is connected to the secondary side of the winding type transformer 44 and detects the voltage and current on the secondary side. When the lamps 46, 46 are not turned on or the lamps 46, 46 are not mounted, that is, when the lamps are opened or the wiring of the lamps are short-circuited, that is, when the lamp is short-circuited, a signal is sent to the logic circuit 78 through the phase detection circuit 51. It is configured to cut off the control circuit composed of the logic circuit 78, the PWM control circuit 76, and the gate control circuits 68, 70, 72, 74. The overcurrent detection circuit 86 sends a signal to the logic circuit 78 and shuts off the control circuit when the PWM control circuit 76 is defective or when the wiring of the lamps 46 is short-circuited.
[0017]
In FIG. 5, a phase detection circuit 51 and a logic circuit 78 convert a single output signal of the phase detection means into two phase signals having phases opposite to each other, and turn on / off the switching elements 52, 54, 56, 58. And a control circuit that outputs the drive signal as a drive signal. Further, the switching elements 52, 54, 56, 58 and the gate control circuits 68, 70, 72, 74 each have a switching element based on a feedback signal of a primary side resonance voltage induced in the input side primary winding of the wound type transformer. The drive circuit is turned on and off, and the direction of current supply to the wound transformer of the DC power supply is changed in the forward and reverse directions by the on / off, and is input to the input-side primary winding of the wound transformer as an AC signal.
[0018]
In the above configuration, when the power switch is turned on and an ON signal is momentarily supplied from the PWM control circuit 76 and the logic circuit 78 to any of the gate control circuits 68, 74 or 72, 70, the DC power supply is switched to the switching element. A current flows through the primary winding of the wound transformer 44 in the direction of I1 through 52 and 58 or in the direction of I2 through the switching elements 56 and 54. As a result, the self-excited oscillation circuit is activated, and the winding type transformer 44 generates a resonance voltage. The frequency of the resonance voltage on the primary side of the winding type transformer 44 is supplied to the phase detection circuit 51 via the lead wire 27. The logic circuit 78 and the PWM control circuit 76 drive the gate control circuits 68, 70, 72, 74 based on the phase signal from the phase detection circuit 51, and control the switching elements 52, 54, 56, 58 on and off. When the switching elements 52, 54, 56, 58 are turned on and off, current flows alternately in the directions of I1 and I2, and the self-excited oscillation circuit self-oscillates at the primary-side resonance frequency of the wound transformer 44. Note that the present invention is not particularly limited to the self-excited oscillation circuit using the primary-side series resonance, and a Royer-type self-excited oscillation circuit using the parallel resonance on the primary side can be used.
[0019]
【The invention's effect】
As described above, the present invention can realize one input and two outputs with one transformer, and can efficiently drive loads such as a cold cathode fluorescent lamp.
[Brief description of the drawings]
FIG. 1 is an explanatory plan view of a winding transformer of the present invention.
FIG. 2 is an enlarged sectional view showing a groove of a partition.
FIG. 3 is an explanatory diagram of a winding transformer of the present invention.
FIG. 4 is a circuit diagram of a winding transformer according to the present invention.
FIG. 5 is a block circuit diagram showing an embodiment of a power supply device.
FIG. 6 is an explanatory diagram of a conventional technique.
FIG. 7 is an explanatory diagram of a conventional technique.
[Explanation of symbols]
3 Bobbin 5 Partition 7 Partition 9 Partition 11 Partition 13 Partition 15 Partition 19 Terminal block 21 Terminal block 23 Terminal 25 Terminal 27 Terminal 29 Terminal 31 Terminal 33 Terminal 35 Primary winding 37 Groove 47 Groove 39 Secondary winding 41 Secondary winding 43 Core 44 Winding transformer 46 Cold cathode fluorescent lamp 48 Resistance 50 Malfunction prevention circuit 51 Phase difference creation circuit 52 to 58 Switching element 62 to 66 Commutation diode 68 Gate control circuit 70 Gate control circuit 72 Gate control circuit 74 Gate control Circuit 76 PWM control circuit 78 Logic circuit 80 Rectification control circuit 82 Line 84 Dimming control circuit 86 Overcurrent detection circuit 88 Startup compensation circuit 90 Lamp open / short detection circuit

Claims

A primary winding is mounted at the center of the bobbin, first and second secondary windings are mounted on both sides of the primary winding, and the primary winding and first and second secondary windings on both sides thereof are mounted. A partition for withstand voltage is provided at the boundary with the wire, a first terminal block is provided at one end of the bobbin, and a second terminal block is provided at the other end of the bobbin. A terminal and a primary input terminal and a ground terminal are provided at a position apart from the terminal, a lead wire at one end of the first secondary winding is connected to a secondary high voltage terminal of the first terminal block, A lead wire at one end of the primary winding and a lead wire at an end of the winding of the first secondary winding which is in contact with the primary winding are passed through one end of the bobbin in parallel through a groove formed in the partition. And connect the lead wires to corresponding primary input terminals and ground terminals of the first terminal block, respectively. Then, a lead wire at one end of the second secondary winding is connected to a secondary high voltage terminal of the second terminal block, and a lead wire at the other end of the primary winding is connected to the second secondary winding. And the lead wire at the end of the winding on the side in contact with the primary winding is guided in parallel to the other end of the bobbin through the groove formed in the partition, and the lead wires respectively correspond to the second terminal block. A winding transformer which is connected to a primary input terminal and a ground terminal, is provided with a core on the bobbin, and has one input and two outputs composed of a primary winding and secondary windings on both sides thereof.

A primary winding is mounted at the center of the bobbin, first and second secondary windings are mounted on both sides of the primary winding, and the primary winding and first and second secondary windings on both sides thereof are mounted. A partition for withstand voltage is disposed at a boundary with the wire, a lead wire at one end of the first secondary winding is connected to a secondary high voltage terminal, and a lead wire at one end of the primary winding is connected to the first high voltage terminal. And the lead wires at the ends of the windings on the side in contact with the primary winding of the secondary winding are connected to the corresponding primary input terminals and ground terminals, respectively, and the lead wire at one end of the second secondary winding is connected. Is connected to a secondary high-voltage terminal, and the lead wire at the other end of the primary winding corresponds to the lead wire at the end of the winding of the second secondary winding that is in contact with the primary winding, respectively. Connected to the primary input terminal and the ground terminal, the bobbin is equipped with a core, and the primary winding and the secondary winding on both sides provide one input and two outputs. A primary-side resonance circuit is provided by connecting a resonance capacitor to the primary winding, and a self-excited oscillation circuit that self-oscillates based on a feedback signal of the primary-side resonance voltage is connected to the primary winding, One electrode of the first fluorescent lamp is connected to a secondary high-voltage output terminal of the first secondary winding, and a second fluorescent lamp is connected in series with the first fluorescent lamp; Is connected to a secondary high voltage output terminal of the second secondary winding.

A primary winding is mounted at the center of the bobbin, first and second secondary windings are mounted on both sides of the primary winding, and the primary winding and first and second secondary windings on both sides thereof are mounted. A partition for withstand voltage is provided at the boundary with the wire, a first terminal block is provided at one end of the bobbin, and a second terminal block is provided at the other end of the bobbin. A terminal and a primary input terminal and a ground terminal are provided at a position apart from the terminal, a lead wire at one end of the first secondary winding is connected to a secondary high voltage terminal of the first terminal block, A lead wire at one end of the primary winding and a lead wire at an end of the winding of the first secondary winding which is in contact with the primary winding are passed through one end of the bobbin in parallel through a groove formed in the partition. And connect the lead wires to corresponding primary input terminals and ground terminals of the first terminal block, respectively. Then, a lead wire at one end of the second secondary winding is connected to a secondary high voltage terminal of the second terminal block, and a lead wire at the other end of the primary winding is connected to the second secondary winding. And the lead wire at the end of the winding on the side in contact with the primary winding is guided in parallel to the other end of the bobbin through the groove formed in the partition, and the lead wires respectively correspond to the second terminal block. Connected to the primary input terminal and the ground terminal, the bobbin is equipped with a core, a primary winding and secondary windings on both sides constitute one input and two outputs, and a resonance capacitor is connected to the primary winding. A power supply device, wherein a primary resonance circuit is provided, and a self-excited oscillation circuit that self-oscillates based on a feedback signal of the primary resonance voltage is connected to the primary winding.

The ground terminal of the secondary winding is grounded via a resistance element, and a current flowing on the output side is detected by a voltage generated in the resistance element. 3. The power supply device according to item 3.

One electrode of the first fluorescent lamp is connected to a secondary high voltage output terminal of the first secondary winding, and a second fluorescent lamp is connected in series with the first fluorescent lamp, and the second fluorescent lamp is connected to the second fluorescent lamp. The power supply device according to claim 3, wherein a lamp is connected to a secondary high-voltage output terminal of the second secondary winding.