JP2004193311A

JP2004193311A - Transformer

Info

Publication number: JP2004193311A
Application number: JP2002359062A
Authority: JP
Inventors: Tomohiro Sugimura; 智宏杉村; Yoshihiro Kuniya; 佳弘国谷; Katsumi Matsumura; 勝己松村; Sadao Morimoto; 貞雄森元
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2002-12-11
Filing date: 2002-12-11
Publication date: 2004-07-08
Anticipated expiration: 2022-12-11
Also published as: JP4062079B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transformer whoes productivity is improved without polishing the split magnetic cores to form a magnetic gap when a leakage magnetic circuit with the magnetic gap is formed. <P>SOLUTION: Collars 25 are formed at the upper-lower ends of winding shafts 24 while planes 26 are formed on the side faces of the collars 25 in two split magnetic cores 21, an input winding 27 is wound on a winding shaft 24 for one split magnetic core 21 while an output winding 28 is wound on the winding shaft 24 for the other split magnetic core 21, and the planes 26 of the two split magnetic cores 21 are abutted to form a closed magnetic circuit. The split magnetic core 21, on which the input winding 27 is wound, is constituted so that at least one thickness of the collars 25 at the upper-lower ends is made larger than that of the collar 25 of the other split magnetic core 21 while the space of the collars 25 at the upper-lower ends is made smaller than that of the collars 25 at the upper-lower ends of the other abutted split magnetic core. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、各種電子機器に用いるトランスに関するものである。
【０００２】
【従来の技術】
以下、従来のトランスについて図面を参照しながら説明する。
【０００３】
図７は従来のトランスの断面図、図８は同トランスの斜視図、図９は同トランスの分解斜視図である。
【０００４】
図７〜図９において、従来のトランスは、巻軸１の中央に貫通孔２を有するとともに上下端に鍔３を有した偏平状の二つのコイルボビン４と、一方のコイルボビン４の巻軸１の外周に巻回した入力巻線５と、他方のコイルボビン４の巻軸１の外周に巻回した出力巻線６と、コイルボビン４の下端の鍔３に植設するとともに入力巻線５および出力巻線６を接続した端子７と、二つの磁脚８の間に中脚９を有した断面Ｅ字形状の分割磁心１０と平板状の分割磁心１０と突合せて形成した閉磁路磁心１１とを備えていた。
【０００５】
そして、コイルボビン４の貫通孔２に断面Ｅ字形状の分割磁心１０の磁脚８をそれぞれ組み込むとともに平板状の分割磁心１０を突合せてトランスを構成していた。
【０００６】
また、断面Ｅ字形状の分割磁心１０の中脚９は、二つの磁脚８より高さを低くして形成しており、断面Ｅ字形状の分割磁心１０と平板状の分割磁心１０を突合せたときに、中脚９の先端と平板状の分割磁心１０との間に磁気ギャップ１２を形成していた。
【０００７】
そして、中脚９と磁気ギャップ１２は、出力巻線６に接続した負荷（図示していない）と出力巻線６に電流が流れたときに、入力巻線５の磁束が出力巻線６に鎖交しない漏れ磁束１３を通す漏れ磁路を構成していた。
【０００８】
上記従来のトランスは、負荷や出力巻線６に電流が流れていないときは、磁気ギャップ１２によって漏れ磁束１３を通さず、負荷や出力巻線６に流れる電流の増大にともない漏れ磁路に流れる漏れ磁束１３を増やして漏れリアクタンスを大きくした磁束漏洩型のトランスとして用いられていた。
【０００９】
なお、この出願の発明に関連する先行技術文献情報としては、例えば、特許文献１が知られている。
【００１０】
【特許文献１】
特開２００２−２７０４４１号公報
【００１１】
【発明が解決しようとする課題】
上記従来の構成では、漏れ磁路は平板状の分割磁心１０と中脚９の間に磁気ギャップ１２を形成しており、磁気ギャップ１２は中脚９の高さを二つの磁脚の高さより低くして形成しているので、中脚９と二つの磁脚８を研磨などして高さを合わせたあとに中脚９のみ再度研磨して高さを低くする必要があり、中脚９を二度研磨するだけでなく中脚９のみを研磨するために、作業が煩雑となり生産性が悪くなるといった問題点を有していた。
【００１２】
本発明は上記従来の問題点を解決するもので、磁気ギャップを有した漏れ磁路を形成する際に、分割磁心を研磨して磁気ギャップを形成することをなくして生産性を向上したトランスを提供することを目的としている。
【００１３】
【課題を解決するための手段】
上記目的を達成するために本発明は以下の構成を有する。
【００１４】
本発明の請求項１に記載の発明は、特に、二つの分割磁心は巻軸部の上下端に鍔を設けるとともに鍔の側面に平面部を形成しており、一方の分割磁心の巻軸部に入力巻線を巻回するとともに他方の分割磁心の巻軸部に出力巻線を巻回し、二つの分割磁心の平面部を突合せて閉磁路を形成しており、入力巻線を巻回した分割磁心は、上下端の鍔の一方の厚みを突合せた他方の分割磁心の鍔の厚みより大きくするとともに上下端の鍔の間隔を突合せた他方の分割磁心の上下端の鍔の間隔より小さくした構成である。
【００１５】
上記構成により、入力巻線を巻回した分割磁心の上下端の鍔の間隔が出力巻線を巻回した分割磁心の上下端の鍔の間隔より小さいので、出力巻線を巻回した分割磁心の上下端の鍔の間隔より漏れ磁束を通しやすくすることができ、入力巻線を巻回した分割磁心の上下端の鍔の間隔が磁気ギャップとなり、入力巻線を巻回した分割磁心の上端の鍔と磁気ギャップおよび下端の鍔とで漏れ磁路を構成することができる。
【００１６】
本発明の請求項２に記載の発明は、請求項１に記載の発明において、特に、入力巻線を巻回した分割磁心の上下端の鍔のそれぞれの厚みを突合せた他方の分割磁心の鍔の厚みより大きくした構成である。
【００１７】
上記構成により、入力巻線を巻回した分割磁心の上下端の鍔のそれぞれの厚みを突合せた他方の分割磁心の鍔の厚みより大きくしているので、入力巻線を巻回した分割磁心の間隔をより小さくして入力巻線を巻回した分割磁心の上下端の鍔の間隔の磁気ギャップがより小さくなり、出力巻線の負荷が増大したときに漏れ磁路に漏れ磁束をより通しやすくすることができる。
【００１８】
本発明の請求項３に記載の発明は、請求項１に記載の発明において、特に、出力巻線を巻回した分割磁心の巻軸部の断面積を入力巻線を巻回した分割磁心の断面積の巻軸部の断面積より小さくした構成である。
【００１９】
上記構成により、出力巻線を巻回した分割磁心の磁気抵抗を入力巻線を巻回した分割磁心の磁気抵抗を大きくして入力巻線の発生した磁束が出力巻線を通りにくくすることができ、出力巻線の負荷が増大したときに漏れ磁路に漏れ磁束をより通しやすくすることができる。
【００２０】
本発明の請求項４に記載の発明は、請求項１に記載の発明において、特に、二つの分割磁心をＭｎ系のフェライト材で形成した構成である。
【００２１】
上記構成により、Ｍｎ系のフェライト材はコアロスが小さいので、効率の良いトランスを構成できる。
【００２２】
本発明の請求項５に記載の発明は、請求項１に記載の発明において、特に、二つの分割磁心をＮｉ系のフェライト材で形成した構成である。
【００２３】
上記構成により、Ｎｉ系のフェライト材は絶縁抵抗が高いので、巻線に入力する電圧または巻線が出力する電圧が高電圧の場合でも巻線と分割磁心の絶縁性を損なうことがなく、高電圧のトランスを構成することができる。
【００２４】
本発明の請求項６に記載の発明は、請求項１に記載の発明において、特に、二つの分割磁心は、一方の分割磁心をＭｎ系のフェライト材で形成し、他方の分割磁心をＮｉ系のフェライト材で形成した構成である。
【００２５】
上記構成により、一方の分割磁心をコアロスの小さいＭｎ系のフェライトコア材で形成し、他方の分割磁心を絶縁抵抗の高いＮｉ系のフェライト材で形成しているので、Ｎｉ系のフェライト材で形成した分割磁心に高電圧の巻線を巻回すれば、高電圧に対応した効率の良いトランスを構成できる。
【００２６】
本発明の請求項７に記載の発明は、請求項６に記載の発明において、特に、入力巻線を巻回した分割磁心をＭｎ系のフェライト材で形成し、出力巻線を巻回した分割磁心をＮｉ系のフェライト材で形成した構成である。
【００２７】
上記構成により、出力巻線を巻回した分割磁心を磁気抵抗が大きいＮｉ系のフェライト材で形成し、入力巻線を巻回した分割磁心を磁気抵抗が小さいＭｎ系のフェライト材で形成しているので、入力巻線の発生した磁束が磁気抵抗の大きい出力巻線を巻回した分割磁心を通りにくくなり、漏れ磁路に漏れ磁束をより通しやすくできる。
【００２８】
本発明の請求項８に記載の発明は、請求項１に記載の発明において、特に、二つの分割磁心の少なくとも一方は、平面部を除いて絶縁樹脂で被覆した絶縁層を設けた構成である。
【００２９】
上記構成により、巻線と分割磁心との間に絶縁層があるので、巻線と分割磁心の絶縁性を向上することができる。
【００３０】
本発明の請求項９に記載の発明は、請求項１に記載の発明において、特に、二つの分割磁心の少なくとも一方は、巻軸部の断面形状を円形状とした構成である。
【００３１】
上記構成により、巻軸部に導線を巻回するときに導線にかかる応力を小さくすることができる。
【００３２】
本発明の請求項１０に記載の発明は、請求項１に記載の発明において、特に、二つの分割磁心の少なくとも一方は、巻軸部の断面形状を偏平形状とした構成である。
【００３３】
上記構成により、二つの分割磁心を突合せて閉磁路磁心を形成したときの底面積を小さくすることができる。
【００３４】
本発明の請求項１１に記載の発明は、請求項１に記載の発明において、特に、分割磁心の下端の鍔に、下端の鍔の側面から巻軸部までスリットを形成し、スリットから巻線の引き出し線を引き出した構成である。
【００３５】
上記構成により、巻線の巻軸部側の引き出し線を、分割磁心の下端の鍔に形成したスリットを通して引き出せば、巻線と引き出し線のクロスオーバーをなくすことができる。
【００３６】
本発明の請求項１２に記載の発明は、請求項１に記載の発明において、特に、二つの分割磁心の平面部と反対側の下端鍔に、下端鍔の底面を載置する載置部と、載置部と連成するとともに下端鍔の平面部と反対側の側面に巻線の引き出し線を接続する端子を有した厚肉部と、載置部および厚肉部とを連成するとともに下端鍔の側面に沿わせた固定壁とを有した端子板を設けた構成である。
【００３７】
上記構成により、端子板に載置部および厚肉部とを連成するとともに下端鍔の側面に沿わせた固定壁を有しているので、分割磁心に端子板を容易に位置決めすることができる。
【００３８】
本発明の請求項１３に記載の発明は、請求項１２に記載の発明において、特に、一方の端子板の載置部と固定壁とを一方の分割磁心の平面部より外方まで設け、一方の端子板の載置部に他方の分割磁心を載置した構成である。
【００３９】
上記構成により、一方の磁心を載置した端子板に、他方の分割磁心の下端の鍔を載置するだけで、二つの分割磁心の位置決めを容易に行うことができる。
【００４０】
【発明の実施の形態】
以下、本発明の一実施の形態におけるトランスについて図面を参照しながら説明する。
【００４１】
図１は本発明の一実施の形態におけるトランスの断面図、図２は同トランスの斜視図、図３は同トランスの分解斜視図である。
【００４２】
図１〜図３において、本発明の一実施の形態におけるトランスは、二つの分割磁心２１を突合せて閉磁路を形成した閉磁路磁心２２と、分割磁心２１に絶縁被膜付導線を巻回した巻線２３とを備えている。
【００４３】
そして、この二つの分割磁心２１は巻軸部２４の上下端に鍔２５を設けるとともに鍔２５の側面に平面部２６を形成しており、一方の分割磁心２１の巻軸部２４の外周に絶縁被膜付導線を数ターン程度巻回した入力巻線２７を施すとともに他方の分割磁心２１の巻軸部２４に入力巻線２７の導線よりも細い絶縁被膜付導線を千数百ターン程度巻回した出力巻線２８を施し、二つの分割磁心２１の平面部２６を突合せて閉磁路を形成している。
【００４４】
また、入力巻線２７を巻回した分割磁心２１は、上端の鍔２５の厚みを突合せた他方の分割磁心２１の鍔２５の厚みより大きくするとともに上下端の鍔２５の間隔を突合せた他方の分割磁心２１の上下端の鍔２５の間隔より小さくしている。
【００４５】
そして、出力巻線２８を巻回した分割磁心２１の巻軸部２４の断面積２９を入力巻線２７を巻回した分割磁心２１の巻軸部２４の断面積３０より小さくしている。
【００４６】
これら、二つの分割磁心２１は、入力巻線２７を巻回した分割磁心２１をＭｎ系のフェライト材で形成し、出力巻線２８を巻回した分割磁心２１をＮｉ系のフェライト材で形成しており、平面部２６を除いた表面を数十μｍの厚みの絶縁樹脂（図示していない）で被覆した絶縁層３１を設けている。
【００４７】
また、二つの分割磁心２１の巻軸部２４の断面形状を円形状にしている。
【００４８】
そして、分割磁心２１の下端の鍔２５に、下端の鍔２５の側面から巻軸部２４までスリット３２を形成し、スリット３２から巻線の引き出し線３３を引き出している。
【００４９】
さらに、二つの分割磁心２１の平面部２６と反対側の下端の鍔２５には、下端の鍔２５の底面を載置する載置部３４と、載置部３４と連成するとともに下端の鍔２５の平面部２６と反対側の側面に巻線２３の引き出し線３３を接続する端子３５を有した厚肉部３６と、載置部３４および厚肉部３６と連成するとともに下端の鍔２５の側面に沿わせた固定壁３７とを有した端子板３８を設けている。
【００５０】
また、一方の端子板３８の載置部３４と固定壁３７とを一方の分割磁心２１の平面部２６より外方まで設け、一方の端子板３８の載置部３４に他方の分割磁心２１を載置してトランスを構成したものである。
【００５１】
上記構成の本実施の形態のトランスについて以下その動作を説明する。
【００５２】
本実施の形態のトランスは、入力巻線２７を巻回した分割磁心２１の上下端の鍔２５の間隔が出力巻線２８を巻回した分割磁心２１の上下端の鍔２５の間隔より小さいので、出力巻線２８を巻回した分割磁心２１の上下端の鍔２５の間隔より漏れ磁束３９を通しやすくすることができ、入力巻線２７を巻回した分割磁心２１の上下端の鍔２５の間隔が磁気ギャップ４０となり、入力巻線２７を巻回した分割磁心２１の上端の鍔２５と磁気ギャップ４０および下端の鍔２５とで漏れ磁路を構成して漏れ磁路に漏れ磁束３９を流すことができる。
【００５３】
また、出力巻線２８を巻回した分割磁心２１の巻軸部２４の断面積２９を入力巻線２７を巻回した分割磁心２１の巻軸部２４の断面積３０より小さくしているので、出力巻線２８を巻回した分割磁心２１の磁気抵抗を入力巻線２７を巻回した分割磁心２１の磁気抵抗より大きくして入力巻線２７の発生した磁束が出力巻線２８を巻回した分割磁心２１を通りにくくすることができ、出力巻線２８に接続した負荷が増大したときに漏れ磁路に漏れ磁束３９をより通しやすくすることができる。
【００５４】
そして、入力巻線２７を巻回した分割磁心２１をコアロスの小さいＭｎ系のフェライトコア材で形成し、巻数が多く高電圧を出力する出力巻線２８を巻回した分割磁心２１を絶縁抵抗の大きいＮｉ系のフェライト材で形成しているので、高電圧に対応した効率の良いトランスを構成できる。
【００５５】
このとき、特に、出力巻線２８を巻回した分割磁心２１を形成したＮｉ系のフェライト材は、入力巻線２７を巻回した分割磁心２１を形成したＭｎ系のフェライト材に比べて磁気抵抗が大きいので、入力巻線２７の発生した磁束が磁気抵抗の高い出力巻線２８を巻回した分割磁心２１を通りにくくなり、漏れ磁路に漏れ磁束３９をより通しやすくすることができる。
【００５６】
また、二つの分割磁心２１は、平面部２６を除いた表面を絶縁樹脂で被覆した絶縁層３１を設けているので、巻線２３と分割磁心２１の絶縁性を向上することができる。
【００５７】
そして、分割磁心２１の巻軸部２４の断面形状を円形状にしているので、巻軸部２４に導線を巻回するときに導線にかかる応力を小さくすることができる。
【００５８】
さらに、分割磁心２１の下端の鍔２５に、下端の鍔２５の側面から巻軸部２４までスリット３２を形成し、スリット３２から巻線２３の引き出し線３３を引き出しているので、巻線２３と引き出し線３３のクロスオーバーをなくすことができ、出力巻線２８に高電圧を発生したときの出力巻線２８と引き出し線３３の絶縁破壊を防止できる。
【００５９】
また、端子板３８に載置部３４および厚肉部３６とを連成するとともに下端の鍔２５の側面に沿わせた固定壁３７を有しているので、分割磁心２１に端子板３８を容易に位置決めすることができる。
【００６０】
そして、一方の端子板３８の載置部３４と固定壁３７とを一方の分割磁心２１の平面部２６より外方まで設け、一方の端子板３８の載置部３４に他方の分割磁心２１を載置しているので、一方の分割磁心２１を載置した端子板３８に、他方の分割磁心２１の下端の鍔２５を載置するだけで、二つの分割磁心２１の位置決めを容易に行うことができる。
【００６１】
次に、上記本実施の形態のトランスを放電灯点灯装置に用いた使用例について図面を参照して説明する。
【００６２】
図４は本実施の形態のトランスを放電灯点灯装置に用いた使用例を示す回路図である。
【００６３】
同図において、本実施の形態のトランスは、入力巻線２７を高周波の低電圧を出力する電源部４１に接続し、出力巻線２８を放電灯４２に接続している。
【００６４】
そして、本実施の形態のトランスを電源部４１の出力を放電灯４２が点灯するために必要な高電圧に昇圧した昇圧トランスを通して用いている。
【００６５】
この放電灯点灯装置および本実施の形態のトランスの動作について説明する。
【００６６】
放電灯４２が点灯開始するまでは放電灯４２は開放状態であるので、トランスの閉磁路磁心２２には入力巻線２７が発生した磁束だけが流れ、閉磁路磁心２２の上下端の鍔２５との間には間隔が空いているので入力巻線２７が発生した磁束は全て出力巻線２８を巻回した分割磁心２１を通り、出力巻線２８に入力巻線２７と出力巻線２８の巻数比に応じた高電圧が発生し、放電灯４２に高電圧が印加されて放電灯４２が点灯する。
【００６７】
そして、放電灯４２が点灯すると、放電灯４２と出力巻線２８に電流が流れて出力巻線２８に入力巻線２７が発生した磁束を打ち消す方向に磁束が発生し、入力巻線２７が発生した磁束は出力巻線２８を巻回した分割磁心２１を通りにくくなり、入力巻線２７が発生した磁束の一部は、閉磁路磁心２２の上下端の鍔の間隔の小さい入力巻線２７を巻回した分割磁心２１の上下端の鍔２５の間隔の磁気ギャップ４０を介して上下端の鍔２５の間を通るようになり、漏れ磁束３９を通した漏れ磁路を構成する。
【００６８】
そして、放電灯４２が負性特性であるために、放電灯４２が点灯すると放電灯４２のインピーダンスが減少して放電灯４２と出力巻線２８に流れる電流が多くなり、これにともない漏れ磁路を通る漏れ磁束３９も多くなって漏れ磁束３９によるトランスの漏れリアクタンスが増大する。
【００６９】
この漏れリアクタンスは、出力巻線２８の高電圧の出力を減少させ、放電灯４２に過電流が流れることを防止したバラスト素子として機能させることができる。
【００７０】
以上のように、本実施の形態のトランスを放電灯４２装置に用いれば、放電灯４２に過電流が流れることを防止したバラスト素子の機能を備えた昇圧トランスとして用いることができる。
【００７１】
このように、本発明の一実施の形態のトランスは、入力巻線２７を巻回した分割磁心２１の上下端の鍔２５の間隔が出力巻線２８を巻回した分割磁心２１の上下端の鍔２５の間隔より小さくしているので、入力巻線２７を巻回した分割磁心２１の上下端の鍔２５の間隔を漏れ磁路の磁気ギャップ４０とすることができ、漏れ磁路の磁気ギャップ４０を分割磁心２１を研磨するなどして形成することをなくすことができ、閉磁路磁心２２の形成工程を簡素化してトランスの生産性を向上することができる。
【００７２】
また、巻軸部２４の上下端に鍔２５を有した分割磁心２１に直接巻線を巻回しているので、コイルボビンを必要とせず、さらに、漏れ磁路に従来のトランスで必要であった中脚９を必要としないので、トランスをより小型化、薄形化することができる。
【００７３】
そして、本発明の一実施の形態のトランスを放電灯点灯装置の昇圧トランスに用いれば、放電灯４２のバラスト素子の機能を備えることができ、放電灯点灯装置のバラスト素子をなくすことができる。
【００７４】
尚、本実施の形態では、入力巻線２７を巻回した分割磁心２１は上端の鍔２５の厚みを厚くしたもので説明したが、分割磁心の他の形状例を示した図５のように下端の鍔２５の厚みを大きくしてもよく、上下端の両方の鍔２５の厚みを大きくすればより漏れ磁束３９をより通しやすくすることができる。
【００７５】
また、入力巻線２７を巻回した分割磁心２１をＭｎ系のフェライト材で形成し、出力巻線２８を巻回した分割磁心２１をＮｉ系のフェライト材で形成したもので説明したが、二つの分割磁心２１をＭｎ系のフェライト材で形成すれば、Ｍｎ系のフェライト材はコアロスが小さいので、効率の良いトランスを構成できる。
【００７６】
そして、二つの分割磁心２１をＮｉ系のフェライト材で形成すれば、Ｎｉ系のフェライト材は絶縁抵抗が大きいので、巻線２３に入力する電圧または巻線２３が出力する電圧が高電圧の場合でも巻線２３と分割磁心２１の絶縁性を損なうことがなく、高電圧のトランスを構成することができる。
【００７７】
また、分割磁心２１の巻軸の断面形状を円形状のもので説明したが、図６の本発明の一実施の形態のトランスの巻軸部の他の形状例を示した平面図に示すように、巻軸部２４の断面形状を偏平形状にすれば、二つの分割磁心２１を突合せて閉磁路磁心２２を形成したときの底面積を小さくすることができ、よりトランスを小型化することができる。
【００７８】
【発明の効果】
以上のように本発明によれば、二つの分割磁心は巻軸部の上下端に鍔を設けるとともに鍔の側面に平面部を形成しており、一方の分割磁心の巻軸部に入力巻線を巻回するとともに他方の分割磁心の巻軸部に出力巻線を巻回し、二つの分割磁心の平面部を突合せて閉磁路を形成しており、入力巻線を巻回した分割磁心は、上下端の鍔の少なくとも一方の厚みを突合せた他方の分割磁心の鍔の厚みより大きくするとともに上下端の鍔の間隔を突合せた他方の分割磁心の上下端の鍔の間隔より小さくした構成である。
【００７９】
これにより、入力巻線を巻回した分割磁心の上下端の鍔の間隔で漏れ磁路の磁気ギャップを形成することができ、磁気ギャップを有した漏れ磁路を形成する際に、分割磁心を研磨して磁気ギャップを形成することをなくして生産性を向上したトランスを提供することができる。
【図面の簡単な説明】
【図１】本発明の一実施の形態におけるトランスの断面図
【図２】同トランスの斜視図
【図３】同トランスの分解斜視図
【図４】同トランスを放電灯点灯装置に用いた使用例を示す回路図
【図５】（ａ）同トランスの分割磁心の他の形状例を示す断面図
（ｂ）同トランスの分割磁心の他の形状例を示す断面図
【図６】同トランスの巻軸部の他の形状例を示した平面図
【図７】従来のトランスの断面図
【図８】同トランスの斜視図
【図９】同トランスの分解斜視図
【符号の説明】
２１分割磁心
２２閉磁路磁心
２３巻線
２４巻軸部
２５鍔
２６平面部
２７入力巻線
２８出力巻線
２９断面積
３０断面積
３１絶縁層
３２スリット
３３引き出し線
３４載置部
３５端子
３６厚肉部
３７固定壁
３８端子板
３９漏れ磁束
４０磁気ギャップ
４１電源部
４２放電灯[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transformer used for various electronic devices.
[0002]
[Prior art]
Hereinafter, a conventional transformer will be described with reference to the drawings.
[0003]
7 is a sectional view of a conventional transformer, FIG. 8 is a perspective view of the transformer, and FIG. 9 is an exploded perspective view of the transformer.
[0004]
7 to 9, a conventional transformer has two flat coil bobbins 4 having a through hole 2 at the center of a winding shaft 1 and flanges 3 at upper and lower ends, and a winding shaft 1 of one of the coil bobbins 4. An input winding 5 wound on the outer periphery, an output winding 6 wound on the outer periphery of the winding shaft 1 of the other coil bobbin 4, and an input winding 5 and an output winding implanted on the flange 3 at the lower end of the coil bobbin 4. A terminal 7 to which the wire 6 is connected, a divided core 10 having an E-shaped cross section having a middle leg 9 between two magnetic legs 8 and a closed magnetic circuit core 11 formed by abutting with a plate-shaped divided core 10. I was
[0005]
The transformer is constructed by incorporating the magnetic legs 8 of the divided magnetic cores 10 having an E-shaped cross section into the through holes 2 of the coil bobbin 4 and butting the plate-shaped divided magnetic cores 10 together.
[0006]
The center leg 9 of the E-shaped sectioned magnetic core 10 is formed to be lower than the two magnetic legs 8, and the divided core 10 having the E-shaped section and the divided core 10 having a flat plate shape are joined. At the time, the magnetic gap 12 was formed between the tip of the middle leg 9 and the flat core 10.
[0007]
The center leg 9 and the magnetic gap 12 allow the magnetic flux of the input winding 5 to flow to the output winding 6 when a current (not shown) connected to the output winding 6 and a current flows to the output winding 6. Thus, a leakage magnetic path through which the leakage magnetic flux 13 which does not interlink is formed.
[0008]
In the above conventional transformer, when no current flows through the load or the output winding 6, the leakage flux 13 does not pass through the magnetic gap 12 but flows through the leakage magnetic path with an increase in the current flowing through the load or the output winding 6. It has been used as a magnetic flux leakage type transformer in which the leakage magnetic flux 13 is increased to increase the leakage reactance.
[0009]
As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
[0010]
[Patent Document 1]
JP, 2002-270441, A
[Problems to be solved by the invention]
In the above-described conventional configuration, the leakage magnetic path forms a magnetic gap 12 between the plate-shaped split core 10 and the middle leg 9, and the magnetic gap 12 makes the height of the middle leg 9 higher than the height of the two magnetic legs. Since the height of the middle leg 9 and the two magnetic legs 8 are adjusted by grinding or the like, the height of the middle leg 9 needs to be reduced again by grinding the middle leg 9 again. Not only twice but also the center leg 9 only, so that the operation is complicated and the productivity is deteriorated.
[0012]
The present invention solves the above-mentioned conventional problems.When forming a leakage magnetic path having a magnetic gap, a transformer that has improved productivity by eliminating the magnetic gap by polishing the divided cores is disclosed. It is intended to provide.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration.
[0014]
In the invention according to claim 1 of the present invention, in particular, the two divided magnetic cores are provided with flanges at the upper and lower ends of a core portion and a flat portion is formed on a side surface of the flange, and the core portion of one divided magnetic core is provided. The output winding is wound around the core of the other split core while the input winding is wound, and the closed magnetic path is formed by abutting the flat portions of the two split cores, and the input winding is wound. The split core has a thickness of one of the upper and lower flanges larger than the thickness of the other split core butted, and a gap between the upper and lower flanges smaller than the gap between the upper and lower flanges of the other split core butted. Configuration.
[0015]
According to the above configuration, since the interval between the upper and lower ends of the split core wound around the input winding is smaller than the interval between the upper and lower ends of the split core wound around the output winding, the split core around which the output winding is wound. The gap between the flanges at the upper and lower ends allows the leakage magnetic flux to pass more easily, and the gap between the upper and lower flanges at the upper and lower ends of the split core wound with the input windings becomes a magnetic gap, and the upper end of the split core wound with the input windings And the magnetic gap and the lower end flange can form a leakage magnetic path.
[0016]
The invention according to claim 2 of the present invention is directed to the invention according to claim 1, wherein the flange of the other divided magnetic core is formed by abutting the thicknesses of the upper and lower ends of the divided magnetic core around which the input winding is wound. The thickness is larger than the thickness of
[0017]
According to the above configuration, the thickness of each of the upper and lower flanges of the divided core wound with the input winding is set to be larger than the thickness of the flange of the other divided core that is abutted. The magnetic gap between the flanges at the upper and lower ends of the split core with the input winding wound with a smaller spacing is smaller, making it easier for the leakage flux to pass through the leakage magnetic path when the load on the output winding increases. can do.
[0018]
According to a third aspect of the present invention, in the invention according to the first aspect, in particular, the sectional area of the core portion of the divided core wound with the output winding is adjusted to the sectional area of the divided core wound with the input winding. The cross-sectional area is smaller than the cross-sectional area of the winding shaft.
[0019]
With the above configuration, it is possible to increase the magnetic resistance of the split core wound with the input winding by increasing the magnetic resistance of the split core wound with the output winding, thereby making it difficult for the magnetic flux generated by the input winding to pass through the output winding. Thus, when the load on the output winding increases, the leakage magnetic flux can more easily pass through the leakage magnetic path.
[0020]
According to a fourth aspect of the present invention, in the first aspect of the present invention, particularly, the two divided cores are formed of a Mn-based ferrite material.
[0021]
According to the above configuration, since the Mn-based ferrite material has a small core loss, an efficient transformer can be formed.
[0022]
According to a fifth aspect of the present invention, in the first aspect, the two divided cores are formed of a Ni-based ferrite material.
[0023]
According to the above configuration, the Ni-based ferrite material has a high insulation resistance. Therefore, even when the voltage input to the winding or the voltage output from the winding is high, the insulation between the winding and the split core is not impaired. A voltage transformer can be configured.
[0024]
According to a sixth aspect of the present invention, in the invention according to the first aspect, in particular, in the two divided cores, one divided core is formed of a Mn-based ferrite material, and the other divided core is formed of a Ni-based ferrite material. This is a configuration formed of a ferrite material.
[0025]
According to the above configuration, one of the divided cores is formed of a Mn-based ferrite core material having a small core loss, and the other divided core is formed of a Ni-based ferrite material having a high insulation resistance. By winding a high voltage winding around the divided magnetic core, an efficient transformer corresponding to the high voltage can be constructed.
[0026]
The invention according to claim 7 of the present invention is the invention according to claim 6, in which the split core in which the input winding is wound is formed of a Mn-based ferrite material and the output winding is wound. The magnetic core is made of a Ni-based ferrite material.
[0027]
According to the above configuration, the split core wound with the output winding is formed of a Ni-based ferrite material having a large magnetic resistance, and the split core wound with the input winding is formed of a Mn-based ferrite material having a small magnetic resistance. As a result, the magnetic flux generated by the input winding is less likely to pass through the split core wound around the output winding having a high magnetic resistance, and the leakage magnetic flux can be more easily passed through the leakage magnetic path.
[0028]
According to an eighth aspect of the present invention, in the first aspect, at least one of the two divided magnetic cores is provided with an insulating layer covered with an insulating resin except for a plane portion. .
[0029]
According to the above configuration, since the insulating layer is provided between the winding and the split core, the insulation between the winding and the split core can be improved.
[0030]
According to a ninth aspect of the present invention, in the first aspect, at least one of the two divided magnetic cores has a configuration in which the cross-sectional shape of the winding shaft portion is circular.
[0031]
According to the above configuration, it is possible to reduce stress applied to the conductor when the conductor is wound around the winding shaft portion.
[0032]
According to a tenth aspect of the present invention, in the first aspect, at least one of the two divided magnetic cores has a configuration in which the cross-sectional shape of the winding shaft portion is flat.
[0033]
According to the above configuration, the bottom area when the closed magnetic circuit core is formed by abutting the two divided magnetic cores can be reduced.
[0034]
According to an eleventh aspect of the present invention, in the invention according to the first aspect, in particular, a slit is formed on a lower end flange of the divided magnetic core from a side surface of the lower end flange to a winding shaft portion, and a winding is formed from the slit. Are drawn out.
[0035]
With the above configuration, if the lead wire on the winding shaft side of the winding is drawn out through the slit formed in the flange at the lower end of the divided magnetic core, crossover between the winding and the drawing wire can be eliminated.
[0036]
The invention according to claim 12 of the present invention is directed to the invention according to claim 1, wherein, in particular, a mounting portion for mounting the bottom surface of the lower end flange on the lower end flange opposite to the plane portion of the two split magnetic cores. A thick portion having a terminal coupled to the mounting portion and having a terminal for connecting a lead wire of a winding on a side surface opposite to the flat portion of the lower end flange, and a mounting portion and a thick portion are coupled. This is a configuration in which a terminal plate having a fixed wall along the side surface of the lower end flange is provided.
[0037]
According to the above configuration, since the mounting portion and the thick portion are coupled to the terminal plate and the fixed plate is provided along the side surface of the lower end flange, the terminal plate can be easily positioned on the divided magnetic core. .
[0038]
According to a thirteenth aspect of the present invention, in the invention of the twelfth aspect, in particular, the mounting portion and the fixed wall of one of the terminal boards are provided from a plane portion of one of the divided magnetic cores to an outer side. And the other divided magnetic core is mounted on the mounting portion of the terminal plate.
[0039]
According to the above configuration, the positioning of the two divided cores can be easily performed only by placing the flange at the lower end of the other divided core on the terminal plate on which one of the cores is mounted.
[0040]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a transformer according to an embodiment of the present invention will be described with reference to the drawings.
[0041]
FIG. 1 is a sectional view of a transformer according to an embodiment of the present invention, FIG. 2 is a perspective view of the transformer, and FIG. 3 is an exploded perspective view of the transformer.
[0042]
1 to 3, a transformer according to an embodiment of the present invention includes a closed magnetic path core 22 in which two divided magnetic cores 21 are joined to form a closed magnetic path, and a winding in which a conductive wire with an insulating coating is wound around the divided magnetic core 21. And a line 23.
[0043]
The two split magnetic cores 21 are provided with flanges 25 at the upper and lower ends of the winding shaft portion 24 and form a flat portion 26 on the side surface of the flange 25, and the outer circumference of the winding shaft portion 24 of one of the split magnetic cores 21 is insulated. An input winding 27 in which a coated conductor is wound for several turns is applied, and a conductor with an insulating coating, which is thinner than the input winding 27, is wound around the winding shaft portion 24 of the other divided magnetic core 21 for about one thousand and several hundred turns. An output winding 28 is applied, and the flat portions 26 of the two split magnetic cores 21 abut to form a closed magnetic path.
[0044]
The split magnetic core 21 around which the input winding 27 is wound has the thickness of the flange 25 at the upper end which is larger than the thickness of the flange 25 of the other split magnetic core 21 and the other of the split ends of the upper and lower flanges 25 at which the gap between the upper and lower flanges 25 is aligned. The distance between the flanges 25 at the upper and lower ends of the divided magnetic core 21 is made smaller.
[0045]
The sectional area 29 of the core portion 24 of the divided magnetic core 21 around which the output winding 28 is wound is smaller than the sectional area 30 of the core portion 24 of the divided magnetic core 21 around which the input winding 27 is wound.
[0046]
These two divided cores 21 are formed by forming the divided core 21 around the input winding 27 with a Mn-based ferrite material, and forming the divided core 21 around the output winding 28 with a Ni-based ferrite material. An insulating layer 31 is provided in which the surface excluding the flat part 26 is covered with an insulating resin (not shown) having a thickness of several tens of μm.
[0047]
Further, the cross-sectional shape of the winding shaft portion 24 of the two divided magnetic cores 21 is circular.
[0048]
A slit 32 is formed in the flange 25 at the lower end of the divided magnetic core 21 from the side surface of the flange 25 at the lower end to the winding shaft portion 24, and a lead wire 33 of the winding is drawn out of the slit 32.
[0049]
Further, the lower flange 25 at the lower end opposite to the plane portion 26 of the two split magnetic cores 21 has a mounting portion 34 on which the bottom surface of the lower flange 25 is mounted, and a lower end flange coupled with the mounting portion 34. A thick portion 36 having a terminal 35 for connecting a lead wire 33 of the winding 23 to a side surface opposite to the flat portion 26 of the winding portion 25, and a flange 25 at the lower end which is coupled to the mounting portion 34 and the thick portion 36. A terminal plate 38 having a fixed wall 37 along the side surface of is provided.
[0050]
Also, the mounting portion 34 of one terminal plate 38 and the fixed wall 37 are provided outside the flat portion 26 of the one divided magnetic core 21, and the other divided magnetic core 21 is mounted on the mounting portion 34 of the one terminal plate 38. The transformer is mounted on the transformer.
[0051]
The operation of the transformer of the present embodiment having the above configuration will be described below.
[0052]
In the transformer of the present embodiment, the interval between the upper and lower flanges 25 of the divided core 21 around which the input winding 27 is wound is smaller than the interval between the upper and lower flanges 25 of the divided core 21 around which the output winding 28 is wound. The leakage magnetic flux 39 can be easily passed through the gap between the upper and lower flanges 25 of the divided magnetic core 21 around which the output winding 28 is wound, and the upper and lower flanges 25 of the divided magnetic core 21 around which the input winding 27 is wound can be formed. The interval is the magnetic gap 40, and the upper end flange 25 of the divided magnetic core 21 around which the input winding 27 is wound, the magnetic gap 40 and the lower end flange 25 form a leakage magnetic path, and the leakage magnetic flux 39 flows through the leakage magnetic path. be able to.
[0053]
Further, since the cross-sectional area 29 of the core portion 24 of the divided magnetic core 21 around which the output winding 28 is wound is smaller than the cross-sectional area 30 of the core portion 24 of the divided magnetic core 21 around which the input winding 27 is wound, The magnetic resistance of the divided core 21 around which the output winding 28 is wound is larger than the magnetic resistance of the divided core 21 around which the input winding 27 is wound, and the magnetic flux generated by the input winding 27 winds the output winding 28. It is possible to make it difficult to pass through the split magnetic core 21 and to make it easier for the leakage magnetic flux 39 to pass through the leakage magnetic path when the load connected to the output winding 28 increases.
[0054]
The divided magnetic core 21 around which the input winding 27 is wound is formed of a Mn-based ferrite core material having a small core loss, and the divided magnetic core 21 around which the output winding 28 which has a large number of turns and outputs a high voltage is insulated is used. Since it is made of a large Ni-based ferrite material, an efficient transformer corresponding to a high voltage can be constructed.
[0055]
At this time, in particular, the Ni-based ferrite material in which the split magnetic core 21 wound with the output winding 28 is formed has a higher magnetic resistance than the Mn-based ferrite material in which the split magnetic core 21 with the input winding 27 wound is formed. Is large, it is difficult for the magnetic flux generated by the input winding 27 to pass through the divided magnetic core 21 around the output winding 28 having a high magnetic resistance, and the leakage magnetic flux 39 can be more easily passed through the leakage magnetic path.
[0056]
In addition, since the two divided cores 21 are provided with the insulating layer 31 whose surface excluding the flat portion 26 is covered with the insulating resin, the insulation between the winding 23 and the divided cores 21 can be improved.
[0057]
Since the cross-sectional shape of the winding shaft portion 24 of the divided magnetic core 21 is circular, the stress applied to the conductive wire when winding the conductive wire around the winding shaft portion 24 can be reduced.
[0058]
Further, a slit 32 is formed in the flange 25 at the lower end of the divided magnetic core 21 from the side surface of the flange 25 at the lower end to the winding shaft portion 24, and the lead wire 33 of the winding 23 is drawn out from the slit 32. Crossover of the lead wire 33 can be eliminated, and dielectric breakdown between the output winding 28 and the lead wire 33 when a high voltage is generated in the output winding 28 can be prevented.
[0059]
Further, since the mounting portion 34 and the thick portion 36 are coupled to the terminal plate 38 and the fixing plate 37 is provided along the side surface of the lower flange 25 at the lower end, the terminal plate 38 can be easily attached to the divided magnetic core 21. Can be positioned.
[0060]
Then, the mounting portion 34 of one terminal plate 38 and the fixed wall 37 are provided outside the flat portion 26 of one divided magnetic core 21, and the other divided magnetic core 21 is mounted on the mounting portion 34 of one terminal plate 38. The two cores 21 can be easily positioned simply by mounting the flange 25 at the lower end of the other core 21 on the terminal plate 38 on which the one core 21 is mounted. Can be.
[0061]
Next, an example of use of the transformer of the present embodiment in a discharge lamp lighting device will be described with reference to the drawings.
[0062]
FIG. 4 is a circuit diagram showing a usage example in which the transformer of the present embodiment is used in a discharge lamp lighting device.
[0063]
In the figure, in the transformer of the present embodiment, the input winding 27 is connected to a power supply unit 41 that outputs a high-frequency low voltage, and the output winding 28 is connected to a discharge lamp 42.
[0064]
The transformer of the present embodiment is used through a boosting transformer that boosts the output of the power supply unit 41 to a high voltage required for the discharge lamp 42 to light.
[0065]
The operation of the discharge lamp lighting device and the transformer of the present embodiment will be described.
[0066]
Since the discharge lamp 42 is open until the discharge lamp 42 starts lighting, only the magnetic flux generated by the input winding 27 flows through the closed magnetic circuit core 22 of the transformer, and the flanges 25 at the upper and lower ends of the closed magnetic circuit core 22 , All of the magnetic flux generated by the input winding 27 passes through the divided core 21 wound around the output winding 28, and the output winding 28 has the number of turns of the input winding 27 and the output winding 28. A high voltage corresponding to the ratio is generated, the high voltage is applied to the discharge lamp 42, and the discharge lamp 42 is turned on.
[0067]
When the discharge lamp 42 is turned on, a current flows through the discharge lamp 42 and the output winding 28, and a magnetic flux is generated in the output winding 28 in a direction to cancel the magnetic flux generated by the input winding 27, and the input winding 27 is generated. It is difficult for the generated magnetic flux to pass through the divided magnetic core 21 around which the output winding 28 is wound, and a part of the magnetic flux generated by the input winding 27 is transmitted through the input winding 27 having a small gap between the upper and lower flanges of the closed magnetic core 22. It passes between the flanges 25 at the upper and lower ends via the magnetic gap 40 at the interval between the flanges 25 at the upper and lower ends of the wound core 21 and forms a leakage magnetic path through which the leakage magnetic flux 39 passes.
[0068]
Since the discharge lamp 42 has a negative characteristic, when the discharge lamp 42 is turned on, the impedance of the discharge lamp 42 decreases, and the current flowing through the discharge lamp 42 and the output winding 28 increases. , The leakage reactance of the transformer due to the leakage magnetic flux 39 increases.
[0069]
This leakage reactance reduces the output of the high voltage of the output winding 28, and can function as a ballast element that prevents an overcurrent from flowing through the discharge lamp 42.
[0070]
As described above, if the transformer of the present embodiment is used in the discharge lamp 42 device, it can be used as a boosting transformer having the function of a ballast element that prevents an overcurrent from flowing through the discharge lamp 42.
[0071]
As described above, in the transformer according to the embodiment of the present invention, the distance between the flanges 25 at the upper and lower ends of the divided magnetic core 21 around which the input winding 27 is wound is equal to the distance between the upper and lower ends of the divided magnetic core 21 around which the output winding 28 is wound. Since the distance between the flanges 25 is smaller than the distance between the flanges 25, the distance between the flanges 25 at the upper and lower ends of the divided magnetic core 21 around which the input winding 27 is wound can be set as the magnetic gap 40 of the leakage magnetic path. The step of forming the closed magnetic core 22 can be simplified by improving the productivity of the transformer by eliminating the formation of the split core 21 by polishing the divided magnetic core 21 or the like.
[0072]
In addition, since the winding is wound directly on the divided magnetic core 21 having the flanges 25 at the upper and lower ends of the winding shaft portion 24, no coil bobbin is required. Since the legs 9 are not required, the transformer can be made smaller and thinner.
[0073]
When the transformer according to the embodiment of the present invention is used for a boosting transformer of a discharge lamp lighting device, the function of the ballast element of the discharge lamp 42 can be provided, and the ballast element of the discharge lamp lighting device can be eliminated.
[0074]
In the present embodiment, the split magnetic core 21 around which the input winding 27 is wound has been described as having a thicker flange 25 at the upper end, but as shown in FIG. 5 showing another example of the shape of the split magnetic core. The thickness of the flange 25 at the lower end may be increased, and if the thickness of both the flanges 25 at the upper and lower ends is increased, the leakage magnetic flux 39 can be more easily passed.
[0075]
Also, the split core 21 wound with the input winding 27 is formed of a Mn-based ferrite material, and the split core 21 wound with the output winding 28 is formed of a Ni-based ferrite material. If the two split magnetic cores 21 are formed of a Mn-based ferrite material, the Mn-based ferrite material has a small core loss, so that an efficient transformer can be formed.
[0076]
If the two divided cores 21 are formed of a Ni-based ferrite material, the Ni-based ferrite material has a large insulation resistance, so that the voltage input to the winding 23 or the voltage output from the winding 23 is high. However, a high-voltage transformer can be configured without impairing the insulation between the winding 23 and the split magnetic core 21.
[0077]
Although the sectional shape of the winding shaft of the divided magnetic core 21 is described as a circular shape, as shown in a plan view of FIG. 6 showing another example of the shape of the winding shaft portion of the transformer according to the embodiment of the present invention. In addition, if the cross-sectional shape of the winding shaft portion 24 is made flat, the bottom area when the closed magnetic circuit core 22 is formed by abutting the two divided magnetic cores 21 can be reduced, and the transformer can be further downsized. it can.
[0078]
【The invention's effect】
As described above, according to the present invention, the two divided magnetic cores are provided with flanges at the upper and lower ends of the winding shaft portion and form flat portions on the side surfaces of the flange, and the input winding is formed on the winding shaft portion of one of the divided magnetic cores. And the output winding is wound around the winding shaft portion of the other split core, and a closed magnetic path is formed by abutting the flat portions of the two split cores.The split core wound with the input winding is: The thickness of at least one of the upper and lower flanges is set to be larger than the thickness of the other divided magnetic core butted, and the interval between the upper and lower flanges is made smaller than the upper and lower flange of the other divided magnetic core butted. .
[0079]
Thereby, the magnetic gap of the leakage magnetic path can be formed at the interval between the flanges at the upper and lower ends of the divided magnetic core around which the input winding is wound, and when forming the leakage magnetic path having the magnetic gap, the divided magnetic core is formed. It is possible to provide a transformer with improved productivity without polishing to form a magnetic gap.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a transformer according to an embodiment of the present invention. FIG. 2 is a perspective view of the transformer. FIG. 3 is an exploded perspective view of the transformer. FIG. FIG. 5A is a cross-sectional view showing another example of the shape of the split core of the transformer. FIG. 5B is a cross-sectional view showing another example of the shape of the split core of the transformer. FIG. 7 is a plan view showing another example of the shape of the winding shaft portion. FIG. 7 is a sectional view of a conventional transformer. FIG. 8 is a perspective view of the transformer. FIG. 9 is an exploded perspective view of the transformer.
DESCRIPTION OF SYMBOLS 21 Split magnetic core 22 Closed magnetic path magnetic core 23 Winding 24 Winding shaft part 25 Flange 26 Flat part 27 Input winding 28 Output winding 29 Cross-sectional area 30 Cross-sectional area 31 Insulating layer 32 Slit 33 Leader wire 34 Mounting part 35 Terminal 36 Thick Part 37 fixed wall 38 terminal plate 39 leakage magnetic flux 40 magnetic gap 41 power supply part 42 discharge lamp

Claims

A closed magnetic circuit core formed by joining two divided magnetic cores to form a closed magnetic circuit core, and a winding in which an insulating film conductor is wound around the divided magnetic core, and the two divided magnetic cores have flanges at upper and lower ends of a winding shaft portion. A flat portion is formed on the side surface of the flange, and an input winding is wound around a winding shaft portion of one of the divided magnetic cores, and an output winding is wound around a winding shaft portion of the other divided magnetic core. A flat magnetic path is formed by abutting the flat portions of the two split cores, and the split core wound with the input winding is formed of a flange of the other split core having the thickness of one of the upper and lower flanges butted. A transformer having a thickness larger than the thickness and smaller than the gap between the upper and lower flanges at the upper and lower ends of the other split magnetic core where the gap between the upper and lower flanges is abutted.

2. The transformer according to claim 1, wherein the thickness of each of the upper and lower flanges of the divided core around which the input winding is wound is greater than the thickness of the flange of the other divided core.

2. The transformer according to claim 1, wherein a cross-sectional area of a core portion of the divided core wound with the output winding is smaller than a cross-sectional area of the core portion of the divided core wound with the input winding.

2. The transformer according to claim 1, wherein the two split cores are formed of a Mn-based ferrite material.

2. The transformer according to claim 1, wherein the two split cores are formed of a Ni-based ferrite material.

2. The transformer according to claim 1, wherein the two split cores are formed by using one of the split cores with a Mn-based ferrite material and the other split core with a Ni-based ferrite material. 3.

7. The transformer according to claim 6, wherein the split core wound with the input winding is formed of a Mn-based ferrite material, and the split core wound with the output winding is formed of a Ni-based ferrite material.

2. The transformer according to claim 1, wherein at least one of the two divided magnetic cores is provided with an insulating layer covered with an insulating resin except for a plane portion.

2. The transformer according to claim 1, wherein at least one of the two divided magnetic cores has a cross-sectional shape of a winding shaft portion formed in a circular shape.

2. The transformer according to claim 1, wherein at least one of the two divided magnetic cores has a flat cross-sectional shape of a winding shaft portion.

2. The transformer according to claim 1, wherein a slit is formed in a flange at a lower end of the divided magnetic core from a side surface of the flange at the lower end to a winding shaft portion, and a lead wire of a winding is drawn from the slit.

A mounting portion for mounting the bottom surface of the lower flange on the lower end flange opposite to the flat portion of the two divided magnetic cores, and a mounting portion coupled to the mounting portion and wound on a side surface opposite to the flat portion of the lower end flange. A terminal plate having a thick portion having a terminal for connecting a lead line of the wire, and a fixed wall coupled to the placing portion and the thick portion and along a side surface of the lower end flange is provided. The transformer according to claim 1.

The mounting part of one terminal board and the fixed wall are provided from the plane part of one of the divided cores to the outside, and the other divided core is mounted on the mounting part of one of the terminal boards. Transformer.