JP3906708B2

JP3906708B2 - Non-contact power transmission device

Info

Publication number: JP3906708B2
Application number: JP2002048785A
Authority: JP
Inventors: 秀明安倍; 猛児島; 嘉志記桂; 幹弘山下; 智博泉
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 2002-02-25
Filing date: 2002-02-25
Publication date: 2007-04-18
Anticipated expiration: 2022-02-25
Also published as: JP2003250233A

Description

【０００１】
【発明の属する技術分野】
本発明は、非接触電力伝達装置に関するものである。
【０００２】
【従来の技術】
近年、携帯用電子機器や電気自動車、産業機器等への非接触電力伝達技術の採用が広がっている。特に電動歯ブラシや電気シェーバ等の水まわりで使う商品には、この技術が重宝される。電力供給側（給電側）と負荷側（受電側）とを着脱して用いる非接触電力伝達装置において、電力供給側から負荷側に電磁誘導により電力を供給する場合、負荷側が外されているときには電力供給側インバータ回路で用いる発振用のスイッチング素子の発振を停止、または発振強度の低減を行う必要がある。この理由は、負荷がない場合に発振を継続させると、電力供給側の電力損失によりエネルギーの無駄使いになってしまうからであり、また、正しい負荷以外の例えば金属異物が置かれれば、誘導加熱作用により、金属の異常過熱を生じ危険であるからである。さらに、負荷が２次電池等の場合、２次電池がフル充電された時点で充電制御を施す必要がある。
【０００３】
すなわち非接触電力伝達には「電力供給側が単独の場合での、省エネ制御や金属異物過熱対策のための発振停止または抑制制御」と「正しい負荷が装着された場合での連続給電制御」と「負荷側からの要求に基づく電力伝達制御」の３つの制御が必要である。
【０００４】
【発明が解決しようとする課題】
上記３つの制御を全部あるいは一部満たす従来例が、いくつか提案されている。たとえば特開平６−３１１６５８号公報で開示された技術がある。これは独立した１対の信号用コイルを、電力供給側と負荷側との１対の電力用コイルとは別途に設け、負荷が装着されると１対の電力用コイルの誘導により負荷に電力が伝達される。そして、この電力を用いて負荷側の制御回路を駆動し、１対の信号用コイルによって制御信号を負荷側から電力供給側に戻して、電力供給側はこの制御信号に基づいて発振動作を制御するものである。
【０００５】
ところが、この構成は負荷検出および発振制御のための回路が別途必要であり、さらに信号周波数を電力送受のための周波数に対して識別しやすくするために、信号周波数を高くとる必要が生じて信号発生回路が複雑になり、またそれによるノイズ対策強化等でサイズアップやコストアップをもたらすという欠点がある。
【０００６】
また、特開平１１−１７８２４９号公報は自励発振の特性を生かし、正帰還ループを電力供給側内部から、一旦負荷側へ出し、再び電力供給側へ戻して、その帰還ループを負荷情報に利用するという極めてシンプルな回路で負荷の検出を行うことができ、省電力化および金属異物過熱防止を行うことができる回路である。さらに、電力周波数と信号周波数とが同一の周波数が使えるためにシンプルな構成で非接触電力伝達を行うことができる。しかし、制御信号が電力用周波数とおなじ周波数の正帰還フイードバック信号であるため、その信号振幅の増幅制御ができず、ノイズマージンが取りにくいという欠点がある。
【０００７】
本発明は、上記事由に鑑みてなされたものであり、その目的は、給電状況を識別して電力供給制御を行うことができ、シンプルな構造を有し、低ノイズである非接触電力伝達装置を提供することにある。
【０００８】
【課題を解決するための手段】
請求項１の発明は、高周波電力を出力する高周波インバータ回路と、前記高周波インバータ回路を制御するインバータ制御回路と、前記高周波インバータ回路から高周波電力を供給され、磁気結合による給電を行う第１のコイルと、給電状況を検出するために第１のコイルの近傍に配置した第３のコイルと第４のコイルとの差動接続回路、及び前記コイルの差動接続回路の出力を増幅するために第３のコイル及び第４のコイルに接続した共振コンデンサからなる差動共振回路とを備えて、前記差動共振回路が出力する検出信号に基づいて前記インバータ制御回路が前記高周波インバータ回路を制御する非接触給電装置と、
第１のコイルに対向配置されて磁気結合による受電を行う第２のコイルと、第２のコイルの出力を所定の電気エネルギーに変換するための電力変換回路と、前記電力変換回路から電気エネルギーを供給される負荷とを有する非接触受電装置とで構成されることを特徴とする。
【０００９】
請求項２の発明は、請求項１において、第３のコイルと第４のコイルとは互いに疎結合になるように配置されていることを特徴とする。
【００１０】
請求項３の発明は、請求項１または２において、第１のコイルと、第３のコイルと第４のコイルとのうち少なくとも一方のコイルとは互いに疎結合になるように配置されていることを特徴とする。
【００１１】
請求項４の発明は、請求項１乃至３いずれかにおいて、前記差動共振回路は、第１のコイルと第２のコイルとのうち少なくとも一方のコイル電流により発生する磁束または磁場の変化を検出することで、給電状況の検出を行うことを特徴とする。
【００１２】
請求項５の発明は、請求項４において、前記非接触受電装置は、自機の状況を与える磁束信号を発生する少なくとも１つの第５のコイルを、第３のコイルと第４のコイルとの差動接続回路の近傍に備え、前記差動共振回路は、第５のコイルが発生する磁束信号を検出することで給電状況の検出を行うことを特徴とする。
【００１３】
請求項６の発明は、請求項５において、前記非接触受電装置は、第５のコイルに並列接続した共振コンデンサを備えることを特徴とする。
【００１４】
請求項７の発明は、請求項５において、前記非接触受電装置は、前記負荷の状態に応じて第５のコイルの励磁制御を行う２次側制御回路を備えることを特徴とする。
【００１５】
請求項８の発明は、請求項５乃至７いずれかにおいて、第３のコイルと第４のコイルとのうち少なくとも一方は、第１のコイルが発生する電力伝送のための磁束に対して疎結合となる配置、形状を設定され、第３のコイルと第４のコイルとの各巻数は、第３のコイルと第４のコイルとの差動接続回路の両端電圧が所定の電圧となるように設定されて、前記差動共振回路の検出信号は、前記非接触受電装置との磁気結合状況、あるいは第５のコイルが発生する磁束信号によって前記所定の電圧に対して増減し、前記インバータ制御回路は、前記検出信号に基づいて前記高周波インバータ回路の発振を制御することを特徴とする。
【００１６】
請求項９の発明は、請求項８において、前記非接触給電装置が単独である場合、前記差動共振回路の検出信号は所定の値以下になって、前記インバータ制御回路は前記検出信号に基づいて前記高周波インバータ回路の発振を間欠発振に制御し、
第１のコイルと第２のコイルとが互いに略対向配置となる場合、前記差動共振回路の検出信号は、前記非接触受電装置が有するエネルギー源または前記高周波インバータ回路の間欠発振動作による第１のコイルからの給電により、前記非接触受電装置に設けた２次側制御回路が第５のコイルを励磁して発生させた磁束信号を検出した信号であり、前記非接触給電装置が単独である場合の検出信号よりも大きい電圧値を有し、前記インバータ制御回路は前記検出信号に基づいて前記高周波インバータ回路の発振を連続発振に制御し、
前記非接触給電装置からの連続給電を停止する場合は、前記差動共振回路の検出信号は、前記２次側制御回路が第５のコイルの励磁を停止する、または励磁を弱める、または間欠励磁する、または励磁周波数を変更して発生させた磁束信号を検出した信号であり、前記高周波インバータ回路が連続発振を行っている場合の検出信号よりも小さい電圧値となり、前記インバータ制御回路は前記検出信号に基づいて前記高周波インバータ回路の発振を間欠発振に制御することを特徴とする。
【００１７】
請求項１０の発明は、請求項９において、前記インバータ制御回路は、前記高周波インバータ回路の発振を一定時間毎に開始させる定期発振開始手段と、発振を開始してから一定時間後に発振を停止させる発振強制停止手段と、前記差動共振回路の検出信号に応じて、前記発振強制停止手段の継続と解除とを制御することで、前記高周波インバータ回路の間欠発振と連続発振とを制御する手段とを備えることを特徴とする。
【００１８】
請求項１１の発明は、請求項１０において、前記発振強制停止手段は、前記第１のコイルに発生する電圧を利用して、前記定期発振開始手段により前記高周波インバータ回路の発振が立ち上がってから定常発振へと移行する過程において発振が開始したことを検知する手段を有することを特徴とする。
【００１９】
請求項１２の発明は、請求項１０または１１において、第１のコイルに発生する電圧の振幅は、前記高周波インバータ回路の発振停止時より発振開始後のほうが大きく、前記発振強制停止手段は、第１のコイルに発生する電圧によって充電される積分回路と、発振開始後に前記積分回路に充電された電圧が所定の値を超えたことを検出して前記高周波インバータ回路の発振を停止させる手段とを備えることを特徴とする。
【００２０】
請求項１３の発明は、請求項１２において、前記高周波インバータ回路の間欠発振と連続発振とを制御する手段は、前記差動共振回路の検出信号に応じて、前記積分回路を構成するコンデンサの電荷を引き抜く手段を備えて、前記積分回路に充電された電圧が所定の値を超えないようにすることで、前記発振強制停止手段の動作を阻止することを特徴とする。
【００２１】
請求項１４の発明は、請求項５乃至１３いずれかにおいて、両端に突部を設けた断面コの字型の磁性体からなる第１，第２のコアを備え、第１のコアの両突部間に巻回した第１のコイルと、第２のコアの両突部間に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３のコイルは第１のコアの両突部のうち少なくとも一方に巻回され、第４のコイルは第１のコイルの半径方向に第１のコイルに重ねて同軸に巻回され、第５のコイルは第３のコイルに対向する第２のコアの突部に巻回されることを特徴とする。
【００２２】
請求項１５の発明は、請求項５乃至１３いずれかにおいて、両端に突部を設けた断面コの字型の磁性体からなる第１，第２のコアを備え、第１のコアの両突部間に巻回した第１のコイルと、第２のコアの両突部間に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３、第４のコイルは第１のコイルを軸方向に挟んで、第１のコアの両突部間に巻回され、第５のコイルは第２のコアの両突部間に第２のコイルとは軸方向に分離して第３のコイルに対向して巻回されることを特徴とする。
【００２３】
請求項１６の発明は、請求項５乃至１３いずれかにおいて、両端に突部を設けた断面コの字型の磁性体からなる第１，第２のコアを備え、第１のコアの両突部間に巻回した第１のコイルと、第２のコアの両突部間に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３のコイルは第１のコイルとは軸方向に分離して第１のコアの両突部間に巻回され、第４のコイルは第１のコイルの半径方向に第１のコイルに重ねて同軸に巻回され、第５のコイルは第２のコアの両突部間に第２のコイルとは軸方向に分離して第３のコイルに対向して巻回されることを特徴とする。
【００２４】
請求項１７の発明は、請求項５乃至１３いずれかにおいて、両端に突部を設けた断面コの字型の磁性体からなる第１，第２のコアを備え、第１のコアの両突部に巻回した第１のコイルと、第２のコアの両突部に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３のコイルは第１のコアの両突部間の凹部に配置され、第４のコイルは第１のコアの両突部のうち少なくとも一方に巻回され、第５のコイルは第２のコアの両突部間の凹部に第３のコイルに対向して配置されることを特徴とする。
【００２５】
請求項１８の発明は、請求項５乃至１３いずれかにおいて、両端及び中央に突部を設けた断面Ｅ型の磁性体からなる第１，第２のコアを備え、第１のコアの中央の突部に巻回した第１のコイルと、第２のコアの中央の突部に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３のコイルは第１のコアの両端の突部のうち少なくとも一方に巻回され、第４のコイルは第１のコイルの半径方向に第１のコイルに重ねて同軸に巻回され、第５のコイルは第３のコイルに対向する第２のコアの突部に巻回されることを特徴とする。
【００２６】
請求項１９の発明は、請求項５乃至１３いずれかにおいて、両端及び中央に突部を設けた断面Ｅ型の磁性体からなる第１，第２のコアを備え、第１のコアの中央の突部に巻回した第１のコイルと、第２のコアの中央の突部に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３のコイルは第１のコアの両端の突部のうち一方に巻回され、第４のコイルは第１のコアの両端の突部のうち他方に巻回され、第５のコイルは第３のコイルに対向する第２のコアの突部に巻回されることを特徴とする。
【００２７】
請求項２０の発明は、請求項５乃至１３いずれかにおいて、円筒状のポット型のコアを軸方向に対して略対象に分割した一方である第１のコアと、他方である第２のコアとを備え、第１，第２のコアは軸方向の略中央の内面に突部を各々設けており、第１のコアの中央の突部に巻回した第１のコイルと、第２のコアの中央の突部に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３，第４のコイルは第１のコイルの半径方向に第１のコイルに重ねて同軸に、且つ第３のコイルは第２のコアに近くなるように第４のコイルとは軸方向に分離して巻回され、第５のコイルは第２のコイルの半径方向に第２のコイルに重ねて同軸に、第３のコイルに対向して巻回されることを特徴とする。
【００２８】
請求項２１の発明は、請求項５乃至１３いずれかにおいて、円板状または円筒状の磁性体からなる第１，第２のコアを備え、第１のコアの側面に巻回した第１のコイルと、第２のコアの側面に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３，第４のコイルは第１のコイルと同軸に、且つ第３のコイルは第２のコアに近くなるように第４のコイルとは軸方向に分離して巻回され、第５のコイルは第２のコイルと同軸に、第３のコイルに対向して巻回されることを特徴とする。
【００２９】
請求項２２の発明は、請求項５乃至１３いずれかにおいて、第１のコイルと第２のコイルとのうち少なくともいずれか一方が円板上または円筒状の磁性体からなるコアに巻回して、第１のコイルと第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３，第４のコイルは第１のコイルと同軸に、且つ第３のコイルは第２のコイルに近くなるように第４のコイルとは軸方向に分離して巻回され、第５のコイルは第２のコイルと同軸に、第３のコイルに対向して巻回されることを特徴とする。
【００３０】
請求項２３の発明は、請求項１において、前記高周波インバータ回路は自励発振を行うものであって、前記差動共振回路の検出信号は第１のコイルの電流による磁束を検出した信号であり、前記非接触給電装置が単独である場合、前記差動共振回路の検出信号は所定の電圧値より大きい信号であり、前記インバータ制御回路は前記検出信号を平滑した信号に基づいて前記高周波インバータ回路の発振を間欠発振に制御し、第１のコイルと第２のコイルとが互いに略対向配置となる場合、前記差動共振回路の検出信号は、前記非接触給電装置が単独であるときの第１のコイルが発生する磁束に対して分布、強度、方向が変化した磁束を検出した所定の電圧値より小さい信号であり、前記インバータ制御回路は前記検出信号を平滑した信号に基づいて前記高周波インバータ回路の発振を連続発振に制御することを特徴とする。
【００３１】
請求項２４の発明は、請求項２３において、前記自励発振を行う高周波インバータ回路は、発振用スイッチング素子と、発振用スイッチング素子の発振を起動させるための起動回路と、第１のコイルに磁気結合した帰還コイルと、第１のコイルまたは発振用スイッチング素子に並列接続したコンデンサと、発振用スイッチング素子の制御端をグランドレベルに接続する自励制御用スイッチング素子とを備える電圧共振型のインバータ回路であり、発振用スイッチング素子は前記帰還コイルの誘起電圧と前記起動回路の出力とによってオンし、オンしてから一定時間後に自励制御用スイッチング素子がオンして発振用スイッチング素子をオフさせることを特徴とする。
【００３２】
請求項２５の発明は、請求項２４において、前記インバータ制御回路は、前記差動共振回路の検出信号を整流、平滑する回路と、前記整流平滑回路の出力を制御端に接続し、前記自励制御用スイッチング素子に並列に接続した発振制御用スイッチング素子とを備えることを特徴とする。
【００３３】
請求項２６の発明は、請求項２４において、前記インバータ制御回路は、前記差動共振回路の検出信号を整流、平滑する回路を備え、前記整流平滑回路の出力を前記自励制御用スイッチング素子の制御端に接続したことを特徴とする。
【００３４】
請求項２７の発明は、請求項２３乃至２６いずれかにおいて、円板状または円筒状の磁性体からなるコアを備えて、第１のコイルは前記コアの側面に巻回され、第３，第４のコイルは、第１のコイルの半径方向に第１のコイルに重ねて同軸に巻回されて、第２のコイルは第１のコイルの軸方向に対向配置したことを特徴とする。
【００３５】
請求項２８の発明は、請求項２３乃至２６いずれかにおいて、円板状または円筒状の磁性体からなるコアを備えて、第１のコイルは前記コアの側面に巻回され、第３，第４のコイルは、前記コアの側面に第１のコイルとは軸方向に分離して巻回されて、第２のコイルは第１のコイルの軸方向に対向配置したことを特徴とする。
【００３６】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて説明する。
【００３７】
（実施形態１）
本実施形態の非接触電力伝達装置のブロック構成図を図１に示す。非接触電力伝達装置は、電力供給を行う非接触給電装置１と、電力を供給される負荷を含む非接触受電装置２とからなり、非接触給電装置１は、高周波電力を出力する高周波インバータ回路１１と、高周波インバータ回路１１を制御するインバータ制御回路１３と、高周波インバータ回路１１から高周波電力を供給され、磁気結合による給電を行う第１のコイルＬ１と、第１のコイルＬ１の近傍に配置され、互いに極性を反対にして直列に差動接続した第３のコイルＬ３、第４のコイルＬ４と、第３のコイルＬ３、第４のコイルＬ４の差動接続回路の出力を増幅するために差動接続回路の両端間に接続した共振コンデンサＣ４とを備え、第３のコイルＬ３、第４のコイルＬ４、及び共振コンデンサＣ４は差動共振回路１２を構成している。
【００３８】
非接触受電装置２は、負荷３０を有しており、第１のコイルＬ１に対向配置されて磁気結合による受電を行う第２のコイルＬ２と、第２のコイルＬ２の出力を負荷３０へ供給するのに適した出力に変換するための電力変換回路２１と、差動共振回路１２のコイルに対向配置された第５のコイルＬ５と、第５のコイルＬ５の両端間に接続した共振コンデンサＣ８と、共振コンデンサＣ５の両端間に接続したスイッチＳ２と、負荷３０の状態に応じてスイッチＳ２のオン・オフを制御する信号を出力する２次側制御回路２３とを備える。
【００３９】
上記のような非接触電力伝達装置は、高周波インバータ回路１１から高周波電力を供給された第１のコイルＬ１が発生する磁束によって、第２のコイルＬ２には誘起電圧を発生させ、その誘起電圧を電力変換回路２１で所定の形態に変換して負荷３０に出力している。そして、負荷３０の状態によって２次側制御回路２３は、スイッチＳ２をオン・オフさせることで第５のコイルＬ５の励磁状態を変化させている。差動共振回路１２は、コイルＬ５の励磁状態または非接触受電装置２の有無によって、給電状況を検出して検出信号を出力し、インバータ制御回路１３はこの検出信号に基づいて高周波インバータ回路１１の発振を制御している。
【００４０】
次に図２に示す具体的な回路構成を用いて、各部の構成について詳細に説明する。まず、非接触給電装置１の高周波インバータ回路１１は、自励発振回路であり、直流電源Ｅ１とスイッチＳ１との直列回路に並列接続した抵抗Ｒ２とコンデンサＣ１との直列回路と、共振コンデンサＣ２と発振用のスイッチング素子ＦＥＴ１と抵抗Ｒ１との直列回路と備えており、コンデンサＣ２には第１のコイルＬ１が並列接続している。抵抗Ｒ２とコンデンサＣ１との接続中点−スイッチング素子ＦＥＴ１のゲート間には、第１のコイルと図示の極性で密結合している帰還コイルＬ６が接続している。帰還コイルＬ６を介してコンデンサＣ１に並列に接続している自励発振制御用のスイッチング素子Ｔｒ１は、スイッチング素子ＦＥＴ１の発振を制御する素子である。また、スイッチング素子ＦＥＴ１のソース−スイッチング素子Ｔｒ１のベース間には抵抗Ｒ３が接続し、スイッチング素子Ｔｒ１のベース−エミッタ間にはコンデンサＣ３が接続している。
【００４１】
差動共振回路１２の構成は図１と同様であり、一方の出力端は、高周波インバータ回路のグランド（直流電源Ｅ１の低電圧出力側）に接続している。
【００４２】
インバータ制御回路１３は、高周波インバータ回路１１の自励発振制御用のスイッチング素子Ｔｒ１をオン・オフして、高周波インバータ回路１１の発振を連続発振と間欠発振との２通りに制御している回路で、差動共振回路１２の他方の出力端に一端を接続したダイオードＤ３とツェナダイオードＺＤ１と抵抗Ｒ７との直列回路の他端はスイッチング素子Ｔｒ２のベースに接続している。差動共振回路１２の出力端間にはダイオードＤ３を介してコンデンサＣ５が接続し、スイッチング素子Ｔｒ２のベース−エミッタ間には抵抗Ｒ８が接続している。スイッチング素子ＦＥＴ１のドレインは、抵抗Ｒ４，Ｒ５の直列回路を介してグランドレベルに接続しており、コンデンサＣ６はダイオードＤ２を介して抵抗Ｒ５に並列接続している。ダイオードＤ２とコンデンサＣ６との接続中点は、ダイオードＤ１と抵抗Ｒ３とを介して自励発振制御用のスイッチング素子Ｔｒ１のベースに接続しており、さらに抵抗Ｒ６を介してトランジスタＴｒ２のコレクタに接続している。
【００４３】
非接触受電装置２の２次側回路２１は、第２のコイルＬ２の出力端間に接続したコンデンサＣ７と、第２のコイルＬ２の一方の出力端に直列接続した整流用のダイオードＤ４とを備えて、第２のコイルＬ２の誘起電圧を半波整流した出力を負荷である２次電池２２に供給しており、２次電池２２の両端は２次側制御回路２３に接続している。
【００４４】
第５のコイルＬ５の両端間には、共振コンデンサＣ８と、ダイオードＤ５及びスイッチング素子Ｔｒ３の直列回路とを接続し、スイッチング素子Ｔｒ３のベースは２次側制御回路２３に接続している。
【００４５】
次に、スイッチＳ１がオンになった時点からの発振開始から連続発振に至る過程を、図３に示す波形図を用いて説明する。まず、スイッチＳ１がオンすると、電圧Ｖｅ１を発生する直流電源Ｅ１は抵抗Ｒ２を介してコンデンサＣ１を充電する。このとき第１のコイルＬ１と密結合している帰還コイルＬ６には、誘起電圧が発生していないため、スイッチング素子ＦＥＴ１のゲート電圧ＶｇはコンデンサＣ１の電圧Ｖｃ１に等しい。ゲート電圧Ｖｇが次第に上昇し、スイッチング素子ＦＥＴ１をオンできる電圧Ｖｇｏｎに達するとスイッチング素子ＦＥＴ１はオンになり、ドレイン電圧Ｖｄは、ほぼゼロ電位になる。この時、第１のコイルＬ１と並列接続された共振コンデンサＣ２の両端の共振電圧Ｖｃ２は直流電源Ｅ１の電源電圧Ｖｅ１でチャージされて、第１のコイルＬ１には、ほぼ単調に増加するコイル電流ＩＬ１が流れ始める。
【００４６】
コイル電流ＩＬ１が流れ始めると、第２のコイルＬ２にはトランスの作用によって誘起電圧が発生する。同様に第１のコイルＬ１と密結合している帰還コイルＬ６にも誘起電圧Ｖｆ１が発生する。すると、グランドレベルからみたゲート電圧Ｖｇは、Ｖｃ１＋Ｖｆ１となり、急速にスイッチング素子ＦＥＴ１は安定したオン状態となる。
【００４７】
またコイル電流ＩＬ１は、スイッチング素子ＦＥＴ１を通じて抵抗Ｒ１に流れるドレイン電流Ｉｄとほぼ等しく、時間とともに抵抗Ｒ１の電圧Ｖｔｒ１が増加する。電圧Ｖｔｒ１が、スイッチング素子Ｔｒ１のオンが可能な電圧に達すると、スイッチング素子Ｔｒ１はオンし始める。スイッチング素子Ｔｒ１がオンし始めると、スイッチング素子ＦＥＴ１のゲート入力容量、及び帰還コイルＬ６を介したコンデンサＣ１の容量に蓄積されていた電荷を引き抜きはじめ、電圧Ｖｃ１、ゲート電圧Ｖｇは低下し始める。ゲート電圧Ｖｇの低下が進むと、スイッチング素子ＦＥＴ１はオフ状態への移行を開始し、オン抵抗が増加してドレイン電圧Ｖｄは次第に増加していく。
【００４８】
ドレイン電圧Ｖｄの増加に応じて、共振電圧Ｖｃ２も減少し始め、そして帰還コイルＬ６の誘起電圧Ｖｆ１も減少し始めるためゲート電圧Ｖｇはさらに加速して低下する。この結果、急速にスイッチング素子ＦＥＴ１はオフ状態に移行し、電圧Ｖｔｒ１も減少してスイッチング素子Ｔｒ１は再びオフになる。
【００４９】
また共振電圧Ｖｃ２は、コンデンサＣ２と第１のコイルＬ１との共振作用により正弦波状の電圧となり、コイル電流ＩＬ１も正弦波状になる。この間、直流電源Ｅ１から抵抗Ｒ２を介してコンデンサＣ１への充電電流は常に流れており、電圧Ｖｃ１を再び増加させる。
【００５０】
共振電圧Ｖｃ２が1サイクルの終了間近になると、ドレイン電圧Ｖｄはグランドレベルに近づき、そのときの帰還コイルＬ６の起電力Ｖｆ１と電圧Ｖｃ１との和のゲート電圧Ｖｇが、再びスイッチング素子ＦＥＴ１をオンさせる。以降は、前記動作の繰り返しにより発振が縦続する。
【００５１】
しかし、非接触受電装置２が非接触給電装置１に対向配置されてない状態、すなわち非接触給電装置１が単独の場合には、省エネルギーや金属異物の過熱保護のために高周波インバータ回路１１の発振を停止または抑制する必要がある。本実施形態では高周波インバータ回路１１の発振を間欠発振とすることでこの役割を果たしている。
【００５２】
以下、図４に示す各部の波形図により間欠発振動作の制御について説明する。まず、スイッチＳ１を投入して連続発振が開始するまでは、前記図３での説明と同様である。図２のインバータ制御回路１３は、ドレイン電圧Ｖｄを抵抗Ｒ４，Ｒ５で抵抗分圧し、ダイオードＤ２を介してコンデンサＣ６に電荷を蓄積していく積分回路を有している。コンデンサＣ６の電圧はダイオードＤ１を介してトランジスタＴｒ１のベース抵抗Ｒ３に接続しており、コンデンサＣ６の電圧が、スイッチング素子Ｔｒ１をオンさせることができる入力電圧値とダイオードＤ１、抵抗Ｒ３の各電圧降下との和を超えると、スイッチング素子Ｔｒ１がオ
ン状態になる。
【００５３】
スイッチング素子Ｔｒ１がオン状態になると、スイッチング素子ＦＥＴ１のゲート入力容量、及び帰還コイルＬ６を介したコンデンサＣ１の容量に蓄積されていた電荷を引き抜く。この時スイッチング素子Ｔｒ１のオン時間が長く保持されると、電圧Ｖｃ１が、定常発振状態での電圧よりもさらに低下し、直流電源Ｅ１から抵抗Ｒ２を介してコンデンサＣ１へ流れる充電電流による電圧回復が定常状態の電圧まで達せず、スイッチング素子ＦＥＴ１はオフ状態を継続することになる。
【００５４】
したがって、直流電源Ｅ１から抵抗Ｒ２を介してコンデンサＣ１へ流れる充電電流のみによる電圧Ｖｃ１がスイッチング素子ＦＥＴ１をオンできる入力電圧に達するまで次の発振起動は行われない。すなわちこの動作の繰り返しで安定した間欠発振となる。
【００５５】
この間欠発振をさせるために重要なことは、まず、高周波インバータ回路１１を発振させてから、時間遅延をさせて停止する機能を持っていなければならないことである。理由は高周波インバータ回路１１が発振する前にスイッチング素子Ｔｒ１がオンになったとすると、永久に発振が停止した状態になるからである。図２の回路での発振停止状態は、ドレイン電圧Ｖｄの電位が電源電圧Ｖｅ１になるため、抵抗Ｒ４，Ｒ５の分圧比を、この発振停止状態ではスイッチング素子Ｔｒ１がオンしない値にしておく必要がある。そして発振が開始してからスイッチング素子Ｔｒ１がオンできるレベルに達するようにするには、発振によってドレイン電圧Ｖｄが電源電圧Ｖｅ１よりも大きくなったときの電圧を利用して、コンデンサＣ６を徐々に充電していき、適当な時間経過の後、スイッチング素子Ｔｒ１がオンできるように抵抗Ｒ４，Ｒ５の分圧比を設定しておけばよい。上記のように構成することで、図２に示す高周波インバータ回路１１とインバータ制御回路１３は、非接触給電装置１が単独の場合には、間欠発振を行うことができる。
【００５６】
ところで、非接触給電装置１に非接触受電装置２が概略、対向配置されて電力伝達を行わせる必要がある場合には、この間欠発振を確実に停止させる機能が必要となる。間欠発振を確実に停止させる、すなわち連続発振をさせる機能を果たすために非接触給電装置１のインバータ制御回路１３には本実施形態の差動共振回路１２が必要となる。また、差動共振回路１２に対向する非接触受電装置２の第５のコイルＬ５も重要な役割を持っている、以下、この動作について説明する。
【００５７】
共振コンデンサＣ４によって増幅された第４，第５のコイルの差動回路の出力は、ダイオードＤ３で整流されて、コンデンサＣ５に充電される。そして、コンデンサＣ５の充電電圧が、スイッチング素子Ｔｒ２をオンさせることができる入力電圧値とツェナダイオードＺＤ１のツェナ電圧と抵抗Ｒ７の電圧降下との和を超えると、スイッチング素子Ｔｒ２がオン状態になり、抵抗Ｒ６を介して接続しているコンデンサＣ６の電荷を引き抜く。すると、コンデンサＣ６の積分動作でトランジスタＴｒ１をオンにすることはできず、スイッチング素子ＦＥＴ１の間欠発振を停止して、連続発振にすることができる。
【００５８】
したがって、非接触給電装置１に非接触受電装置２が概略、対向配置されて電力伝達を行わせる必要がある場合には、非接触給電装置１に非接触受電装置２が概略、対向配置されたことにより発生する磁束分布等の変化状態を差動共振回路１２が検知することで得られる検出信号（差動共振出力）や、また非接触受電装置２の第５のコイルＬ５からの信号にもとづいて得られる差動共振回路１２の検出信号出力を、それまでのスイッチング素子Ｔｒ２がオフの状態を保つ電圧からオンの状態を保つ電圧にまで変化させなければならない。具体的には非接触受電装置２が配置されてない場合には、差動共振回路１２の検出信号の電圧を低くして、スイッチング素子Ｔｒ２がオンできないようにしておく。また非接触受電装置２が概略、対向配置された場合には差動共振回路１２の検出信号の電圧を大きくしてスイッチング素子Ｔｒ２がオンできるようにしておく。
【００５９】
また、図２に示すように非接触受電装置２の負荷が電池の場合ならば、過充電になる前に電力供給を停止する必要性がある。そのためには非接触給電装置１の差動共振回路１２の検出信号の電圧が、それまでのスイッチング素子Ｔｒ２がオンを保つ電圧からオフの状態を保つ電圧にまで変化できるように、第５のコイルＬ５から信号を出力すればよい。具体的には非接触受電装置２が概略、対向配置された状態において、非接触給電装置１の差動共振回路１２の出力電圧が低くなるように、非接触受電装置２の第５のコイルＬ５を励磁または励磁停止させて、スイッチング素子Ｔｒ２がオフできるようにしておけばよい。
【００６０】
次に、図５は、非接触給電装置１に非接触受電装置２が概略、対向配置された構造の側面断面図を示しており、分離着脱自在なトランス構造をなしている。この分離着脱式トランスは、磁気抵抗を小さくするために断面コの字型の磁性体からなる第１，第２のコア１４，２５を備えており、第１のコイルＬ１は第１のコア１４の両端に設けた突部１４ａ，１４ｂ間に巻回され、第３のコイルＬ３は突部１４ａに巻回され、第４のコイルＬ４は第１のコイルＬ１の半径方向に第１のコイルＬ１に重ねて同軸に巻回され、帰還コイルＬ６は突部１４ａ，１４ｂ間の第１のコイルＬ１とは軸方向に分離した突部１４ｂ側に巻回されており、第２のコイルＬ２は第２のコア２５の両端に設けた突部２５ａ，２５ｂ間に巻回され、第５のコイルＬ５は突部１４ａに対向する突部２５ａに第３のコイルＬ３に対向して巻回されている。
【００６１】
非接触給電装置１においては、第１のコイルＬ１と第４のコイルＬ４とは、磁気的に比較的密結合になっており、第１のコイルＬ１と第３のコイルＬ３、及び第３のコイルＬ３と第４のコイルＬ４とは磁気的に疎結合になっている。また、第３のコイルＬ３と第４のコイルＬ４との直列回路には並列に共振コンデンサＣ４が接続されている。そして、非接触給電装置１が単独の場合には、高周波インバータ回路１１が間欠発振の動作中の発振している期間に、第１のコイルＬ１のコイル電流ＩＬ１が作る磁束による差動共振回路１２の出力電圧が、スイッチング素子Ｔｒ２をオンさせないような小さい電圧となるように、第３，第４のコイルＬ３，Ｌ４の巻数が設定されている。
【００６２】
非接触受電装置２においては、第２のコイルＬ２と第５のコイルＬ５とは磁気的に疎結合になっており、第５のコイルＬ５に並列に共振コンデンサＣ８が接続されている。非接触給電装置１に非接触受電装置２が概略、対向配置されると、最初、高周波インバータ回路１１が間欠発振の動作中の発振している期間では、第５のコイルに第１のコイルＬ１からの磁束が錯交し、第５のコイルＬ５に誘起電圧が生じる。第５のコイルＬ５は、並列に共振コンデンサＣ８が接続されているために共振電流が流れる。また共振コンデンサＣ５がなく、第５のコイルＬ１の端子がスイッチング素子Ｔｒ３で短絡されている場合には短絡電流が流れる。
【００６３】
これら第５のコイルＬ５に流れる電流は、第５のコイルＬ５に新たな磁束を鎖交させ、第１のコイルＬ１のコイル電流ＩＬ１による磁束の変化を妨げようとし、新たに発生した磁束は第３のコイルＬ３にも影響を与える。すなわち複数のコイル間による相互誘導と自己誘導との作用により、第３のコイルＬ３にはそれまで生じていた誘起電圧に対し、振幅や波形の変化またその変化の遅れが生じ、このため、第３のコイルＬ３の誘起電圧の変化は大きくなる。
【００６４】
しかし第４のコイルＬ４の誘起電圧の変化は小さいため、第３，第４のコイルＬ３，Ｌ４の誘起電圧バランスが崩れて差動電圧が発生し、差動共振回路１２がこの周波数に共振するようにコンデンサＣ４を設定しておけば、さらに大きな信号差動共振出力、すなわち検出信号を得ることができる。したがって、図２におけるトランジスタＴｒ２をオンにするので、高周波インバータ回路１１は連続発振となる。
【００６５】
次に非接触給電装置１に非接触受電装置２が概略、対向配置された場合で、給電停止の必要性がある場合には、第５のコイルＬ５の励磁をゼロにする、または小さくすることで、第３，第４のコイルＬ３，Ｌ４の誘起電圧バランスを回復させて、差動共振回路の検出信号をゼロまたは小さくすることができ、図２におけるトランジスタＴｒ２がオフとなり高周波インバータ回路１１は間欠発振を行う。
【００６６】
第５のコイルＬ５の励磁をゼロまたは小さくする方法は、その回路を全体または部分的に短絡したり開放することで可能になる。また、このことは時間的に連続的でも周期的でもよい。図２では第５のコイルＬ５とコンデンサＣ８との共振回路全体をダイオードＤ５を介してトランジスタＴｒ３で一方向に短絡することで、差動共振回路１２の出力制御を行っている。
【００６７】
上記説明では、第５のコイルＬ５を高周波インバータ回路１１の発振周波数と同じ周波数で励磁する構成を例にとったが、その構成はいろいろ考えられ、例えば図示してない補助コイルを使って受電した電圧をそのまま使って第５のコイルＬ５に加えたりすればいい。また第２のコイルＬ２や図示してない補助コイルから得たエネルギーや非接触受電装置２が既に有しているエネルギー源を使って、電力伝送のための高周波インバータ回路１１の発振周波数とは異なるが、それに近い周波数の信号を発生させて第５のコイルＬ５に加えることもできる。
【００６８】
本発明の重要なポイントは第３のコイルＬ３と第４のコイルＬ４に発生する誘起電圧の絶対値ではなく、バランスである。すなわち、非接触給電装置１単体ではバランスが保たれ、非接触給電装置１に非接触受電装置２が概略、対向配置された状態で、給電が必要な場合にはこのバランスを崩し、さらに非接触給電装置１に非接触受電装置２が概略、対向配置された状態で、給電の停止が必要な場合にはこのバランスを取り戻すようにしておけばよい。
【００６９】
このように図２の高周波インバータ回路１１とインバータ制御回路１３との各動作は、非接触給電装置１が単独でも、非接触受電装置２が概略、対向配置された場合でも間欠発振を制御できる機能を有しており、「非接触給電装置１が単独の場合の発振停止または抑制」、「非接触給電装置１に非接触受電装置２が概略対向配置された場合の発振継続」、及び「非接触給電装置１に非接触受電装置２が概略対向配置された場合の給電制御」の３状態においても、「間欠発振の継続や停止」の制御ができる。
【００７０】
従来の方式においては、前記３つの状態を満たすために、例えば電力伝達周波数と信号伝達周波数を別々に設けたが、そのためにサイズ、及びコストの増大化を招いた。また別の方法では、電力伝達と信号伝達の周波数は同一化したが信号の変化が小さく、前記３つの状態の識別が難かしくなる等の問題点を有していた。
【００７１】
しかし本実施形態では、上記の動作説明から分かるように、電力伝達と信号伝達の周波数は同一または近い値としているものの、非接触給電装置１の入力信号部に差動共振回路１２を設けたことで、この信号の小さい変化を大きな変化として簡易に取り出せるようにり、極めてシンプルなシステムを実現することができた。
【００７２】
ところで、本実施形態の差動共振回路１２の役割は、差動接続された第３のコイルＬ３と第４のコイルＬ４の両端に生じる電圧の差を増幅する差動増幅の役割と、その差の電圧をさらに共振によって強調する共振増幅の役割との両方を組み合わせたものと考えることができる。ただし、ここでいう共振とは単独容量と自己インダクタンスとの閉回路のみで決まる単純な並列あるいは直列共振のみを対象にしているわけではない。実際のシステムにおいて、容量Ｃは独立した部品容量のみならず系内の寄生容量、配線容量を含めたものになっていると考えられ、またインダクタンスＬは自己インタクタンスの他に相互インダクタンスがあって他のコイルと相互誘導を行い、またエネルギー消費においては、負荷と各部との損失が混同していると考えられる。従って実際のシステムで利用する共振現象とは、こういう複合系での共振を利用したものである。上記差動共振の説明では、便宜上、コイルやコンデンサ等を明確に指定しているが、本実施形態の差動共振利用の意味するところは、実用において複数のインダクタンスやコンデンサや損失分などが相互的に関わる複合系において、結果的に強調された周波数成分をもつ電圧や電流の増幅効果及び強調効果を利用することである。
【００７３】
さて、図５では、差動増幅と共振とによる総合効果を発揮させる分離着脱式トランスの第１の構造例を示したが、以下、図５以外の具体的構造例、仕組みを示す。
【００７４】
まず図６に側面断面図を示す第２の構造例は、分離着脱自在なトランスの非接触給電装置１側、つまりトランスの１次側を示しており、断面コの字型の磁性体からなる第１のコア１４を備えて、第１のコイルＬ１は第１のコア１４の両端に設けた突部１４ａ，１４ｂ間に巻回され、第３、第４のコイルＬ３，Ｌ４は第１のコイルＬ１を軸方向に挟んで（第１のコイルＬ１の半径方向に対称に）、突部１４ａ，１４ｂ間に巻回されている。
【００７５】
ここで、第１のコイルＬ１のコイル電流ＩＬ１による磁束の分布のイメージは磁束分布１００のようになり、第３のコイルＬ３と第４のコイルＬ４とに各々鎖交する磁束数は同じであるため差動共振回路１２の差動共振出力は略ゼロとなる。すなわち第３，第４のコイルＬ３，Ｌ４がこのような配置では、図２の回路のトランジスタＴｒ２がオフのままであるから間欠発振を継続する。
【００７６】
次に図７の側面断面図は、非接触給電装置１に非接触受電装置２が概略、対向配置した場合、すなわち図６の電力伝達用の第１のコイルＬ１に対向して第２のコイルＬ２を配置したものであり、トランスの２次側は、断面コの字型の磁性体からなる第２のコア２５を備えて、第２のコイルＬ２は第２のコア２５の両端に設けた突部２５ａ，２５ｂ間に巻回されている。
【００７７】
ここで、第１のコイルＬ１のコイル電流ＩＬ１による磁束の分布のイメージは磁束分布１０１のようになり、第３，第４のコイルＬ３，Ｌ４に錯交する磁束数は第１のコイルＬ１単独のときと同じように、磁束数は同じであり、差動共振回路１２の差動共振出力は略ゼロとなる。
【００７８】
しかし、非接触受電装置２が置かれた場合には連続発振に移行しなければならないため、図８の側面断面図に示すように、突部２５ａ，２５ｂ間の第３のコイルＬ３に対向する箇所に第２のコイルＬ２とは軸方向に分離して信号伝送用の第５のコイルＬ５を巻回し、第２のコイルＬ２からの誘起電圧や図示してない補助コイルを使った誘起電圧を励磁電源として第５のコイルＬ５に印加し、この第５のコイルＬ５の発生磁束を第３のコイルＬ３に多く鎖交するようにしておけばよい。図８には、コイル電流ＩＬ１による磁束分布１０２だけでなく、励磁電源により第５のコイルＬ５のみを励磁した場合の磁束分布１０３も示している。
【００７９】
このように第３のコイルＬ３には磁束が多く錯交するが、第４のコイルＬ４の錯交数が少ないため、電圧バランスを崩すことができる。
【００８０】
次に第３の構造例の側面断面図を図９に示す。これは図８に示す第２の構造例の第４のコイルＬ４を、第１のコイルＬ１の半径方向に第１のコイルＬ１に重ねて同軸に巻回したものである。
【００８１】
図１０に側面断面図を示す第４の構造例は、第１〜第３の構造例と同様に、両端に突部１４ａ，１４ｂを設けた断面コの字型の磁性体からなる第１のコア１４と、両端に突部２５ａ，２５ｂを設けた断面コの字型の磁性体からなる第２のコア２５とを備えて分離着脱自在なトランス構造を構成しており、第１のコイルＬ１は第１のコア１４の突部１４ａ，１４ｂに巻回され、第３のコイルＬ３は突部１４ａ，１４ｂ間の凹部に、第１のコイルＬ１の軸方向に第１のコイルＬ１に重ねて配置され、第４のコイルＬ４は突部１４ａに、第１のコイルＬ１の半径方向に第１のコイルＬ１に重ねて巻回されており、第２のコイルＬ２は第２のコア２５の突部２５ａ，２５ｂに巻回され、第５のコイルＬ５は突部２５ａ，２５ｂ間の凹部に、第２のコイルＬ２の軸方向に第２のコイルＬ２に重ねて、第３のコイルＬ３に対向して配置される。
【００８２】
図１１に側面断面図を示す第５の構造例は、断面Ｅ型の磁性体からなる第１，第２のコア１５，２６を備えて分離着脱自在なトランス構造を構成しており、第１のコア１５は両端に突部１５ａ，１５ｂを設け、中央に突部１５ｃを設けて、第２のコア２６は両端に突部２６ａ，２６ｂを設け、中央に突部２６ｃを設けている。第１のコイルＬ１は第１のコア１５の中央の突部１５ｃに巻回され、第３のコイルＬ３は突部１５ａに巻回され、第４のコイルＬ４は第１のコイルＬ１の半径方向に第１のコイルＬ１に重ねて同軸に巻回されており、第２のコイルＬ２は中央の突部２６ｃに巻回され、第５のコイルＬ５は突部１５ａに対向する突部２６ａに第３のコイルＬ３に対向して巻回される
図１２に側面断面図を示す第６の構造例は、図１１に示す第５の構造例の第４のコイルＬ４を、第１のコア１５の突部１５ｂに巻回したものである。
【００８３】
図１３に側面断面図を示す第７の構造例は、円筒状のポット型のコアを軸方向に対して略対象に分割した一方である第１のコア１６と、他方である第２のコア２７とを備え、第１のコア１６は軸方向の略中央の内面に突部１６ａを設けて、分離着脱自在なトランス構造を構成しており、第２のコア２７は軸方向の略中央の内面に突部２７ａを設けている。第１のコイルＬ１は第１のコア１６の中央の突部１６ａに巻回され、第３，第４のコイルＬ３，Ｌ４は第１のコイルＬ１の半径方向に第１のコイルＬ１に重ねて同軸に、且つ第３のコイルＬ３は第２のコア２７に近くなるように第４のコイルＬ４とは軸方向に分離して巻回され、第２のコイルＬ２は第２のコア２７の中央の突部２７ａに巻回され、第５のコイルＬ５は第２のコイルＬ２の半径方向に第２のコイルＬ２に重ねて同軸に、第３のコイルＬ３に対向して巻回される。
【００８４】
図１４に側面断面図を示す第８の構造例は、円板状または円筒状の磁性体からなる第１，第２のコア１７，２８を備えて分離着脱自在なトランス構造を構成しており、第１のコイルＬ１は第１のコア１７の側面に巻回され、第３，第４のコイルＬ３，Ｌ４は第１のコイルＬ１の半径方向に第１のコイルＬ１に重ねて同軸に、且つ第３のコイルＬ３は第１のコア１７の第２のコア２８に近い一方の端部に巻回され、第４のコイルＬ４は第１のコア１７の他方の端部に巻回されており、第２のコイルＬ２は第２のコアの側面に巻回され、第５のコイルＬ５は第２のコイルＬ２の半径方向に第２のコイルＬ２に重ねて同軸に、且つ第２のコア２８の第１のコア１７に近い一方の端部に第３のコイルＬ３に対向して巻回される。
【００８５】
図１５に側面断面図を示す第９の構造例は、図１４に示す第８の構造例の第３，第４のコイルＬ３，Ｌ４を、第１のコイルＬ１を軸方向に挟んで第１のコイルＬ１の軸方向に分離したもので、第３のコイルＬ３は第１のコア１７の第２のコア２８に近い一方の端部に巻回され、第４のコイルＬ４は第１のコア１７の他方の端部に巻回される。
【００８６】
図１６に側面断面図を示す第１０の構造例は、図１４に示す第８の構造例の第３のコイルＬ３を、第１のコア１７の第２のコア２８に近い一方の端面上に配置し、第４のコイルＬ４を、第１のコア１７の他方の端面上に配置して、第５のコイルＬ５を、第２のコア２８の第１のコア１７に近い一方の端面上に配置したものである。
【００８７】
また、本発明は、以上述べてきた分離着脱自在なトランスにおける第３，第４のコイルＬ３，Ｌ４で構成される差動接続コイルと、第５のコイルＬ５との配置は、磁性体のコアの有無によらず、異なる実施例の組み合わせも含まれる。
【００８８】
さらに、第５のコイルＬ５を必要としない場合（すなわち、「非接触給電装置１が単独の場合の発振停止または抑制」と、「非接触給電装置１に非接触受電装置２が概略対向配置された場合の発振継続」のみを対象にする場合）にも適用できる。
【００８９】
（実施形態２）
本実施形態では、「非接触給電装置１が単独の場合の発振停止または抑制」と、「非接触給電装置１に非接触受電装置２が概略対向配置された場合の発振継続」のみを対象にする場合について、ブロック構成図を図１７に示し、極めてシンプルなシステムで構成できる具体的な回路構成を図１８に示す。本実施形態は、図１，２の第５のコイルＬ５、共振コンデンサＣ８、及びその周辺素子を省略したものであり、インバータ制御回路１３を極めて簡素な回路で実現できるものである。基本的な構成は実施形態１の図１，図２と略同様であり、同様の構成には同一の符号を付して説明は省略する。
【００９０】
本実施形態のインバータ制御回路１３は、差動共振回路１２の検出信号を半波整流するダイオードＤ６と、整流出力を平滑するコンデンサＣ９と、コンデンサＣ９の並列に接続した抵抗Ｒ９と、検出信号を整流、平滑した出力をベースに接続して、自励発振制御用のトランジスタＴｒ１に並列に接続した発振制御用のトランジスタＴｒ４とから構成される。
【００９１】
高周波インバータ回路１１は実施形態１同様に、起動から連続発振を自動的に行う自励発振回路であるが、制御回路１３の発振制御用のトランジスタＴｒ４をオンにすると高周波インバータ回路１１は発振を停止して間欠発振を行い、オフにすると高周波インバータ回路１１は連続発振を行う。
【００９２】
そこで、第３と第４のコイルＬ３，Ｌ４で構成される差動共振接続コイルの出力を、非接触受電装置２がない場合に出力電圧が所定の値よりも大きく出るようにし、非接触受電装置２が概略、対向配置されると出力電圧が所定の値よりも小さくなるように調整しておけば、非接触給電装置が単独の場合は差動共振回路１２の出力電圧が大きくなって、トランジスタＴｒ４をオンして間欠発振を行い、非接触受電装置２が対向配置されると差動共振回路１２の出力電圧が小さくなって、トランジスタＴｒ４をオフして連続発振とすることができる。
【００９３】
したがって、「非接触給電装置１が単独の場合の発振停止または抑制」と、「非接触給電装置１に非接触受電装置２が概略対向配置された場合の発振継続」のみの利用においては、本実施形態を電動歯ブラシや電気シェーバ等の常時充電に適用することができる。すなわち、従来の技術では非接触受電装置２側が外された状態でも非接触給電装置１が連続発振しており、無駄なエネルギー消費となっていたが、本実施形態では極めて少ない部品の追加で非接触給電装置１が単独の場合の発振停止、抑制を行うことができ、省エネルギーに貢献することができる。
【００９４】
次に、本実施形態の分離着脱自在なトランスの非接触給電装置１側、つまりトランスの１次側の構成は、円板状または円筒状の磁性体からなる第１のコア１７を備えて、第１のコイルＬ１は第１のコア１７の側面に巻回され、第３，第４のコイルＬ３，Ｌ４は第１のコイルＬ１の半径方向に第１のコイルＬ１に重ねて同軸に、且つ第３のコイルＬ３は第１のコア１７の第２のコイルＬ２に近い一方の端部に巻回され、第４のコイルＬ４は第１のコア１７の他方の端部に巻回されており、トランスの２次側の構成は、磁性体のコアは備えす、第２のコイルＬ２が巻回されている。
【００９５】
そして、非接触受電装置２は電動歯ブラシであり、第２のコイルＬ２の出力を２次側回路２１で整流し、この整流出力で２次電池２２を充電して、本体回路２９を動作させるもので、２次電池２２と本体回路２９とで負荷回路３０を構成している。
【００９６】
また、図１９に示す回路構成では、インバータ制御回路１３を、差動共振回路１２の出力を半波整流するダイオードＤ７のみで構成しており、この整流出力を自励発振制御用のトランジスタＴｒ１のベースに接続し、トランジスタＴｒ１のオン・オフを制御して、高周波インバータ回路１１の間欠発振、連続発振を切替えている。他の構成は図１８に示す回路と同様なので説明は省略する。
【００９７】
さらに、図１８，１９に示す分離着脱式トランスの他の構造例を図２０，２１に示す。図２０のトランスの１次側の構成は、図１８，１９に示す第３のコイルを第１のコイルＬ１の半径方向に第１のコイルＬ１に重ねて同軸に巻回し、第４のコイルを第３のコイルＬ３の半径方向に第３のコイルＬ３に重ねて同軸に巻回したものであり、図２１のトランスの１次側の構成は、図１８，１９に示す第３，第４のコイルＬ３，Ｌ４を、第１のコイルＬ１を軸方向に挟んで第１のコイルＬ１の軸方向に分離したもので、第３のコイルＬ３は第１のコア１７の第２のコイルＬ２に近い一方の端部に巻回され、第４のコイルＬ４は第１のコア１７の他方の端部に巻回されたものである。
【００９８】
【発明の効果】
請求項１の発明は、高周波電力を出力する高周波インバータ回路と、前記高周波インバータ回路を制御するインバータ制御回路と、前記高周波インバータ回路から高周波電力を供給され、磁気結合による給電を行う第１のコイルと、給電状況を検出するために第１のコイルの近傍に配置した第３のコイルと第４のコイルとの差動接続回路、及び前記コイルの差動接続回路の出力を増幅するために第３のコイル及び第４のコイルに接続した共振コンデンサからなる差動共振回路とを備えて、前記差動共振回路が出力する検出信号に基づいて前記インバータ制御回路が前記高周波インバータ回路を制御する非接触給電装置と、
第１のコイルに対向配置されて磁気結合による受電を行う第２のコイルと、第２のコイルの出力を所定の電気エネルギーに変換するための電力変換回路と、前記電力変換回路から電気エネルギーを供給される負荷とを有する非接触受電装置とで構成されるので、電力と信号との周波数を同一または近い値として給電状況を識別して電力供給制御を行ってノイズ対策部品の増大を防ぎ、また回路構成やトランス構造がシンプルになって、全体のシステムのサイズの小型化とコストダウンを図ることができ、したがってシンプルな構造を有して、低ノイズである非接触電力伝達装置を提供することができるという効果がある。
【００９９】
請求項２の発明は、請求項１において、第３のコイルと第４のコイルとは互いに疎結合になるように配置されているので、コイルの差動回路を用いて給電状況を検出することができるという効果が有る。
【０１００】
請求項３の発明は、請求項１または２において、第１のコイルと、第３のコイルと第４のコイルとのうち少なくとも一方のコイルとは互いに疎結合になるように配置されているので、請求項２と同様の効果を奏する。
【０１０１】
請求項４の発明は、請求項１乃至３いずれかにおいて、前記差動共振回路は、第１のコイルと第２のコイルとのうち少なくとも一方のコイル電流により発生する磁束または磁場の変化を検出することで、給電状況の検出を行うので、請求項２と同様の効果を奏する。
【０１０２】
請求項５の発明は、請求項４において、前記非接触受電装置は、自機の状況を与える磁束信号を発生する少なくとも１つの第５のコイルを、第３のコイルと第４のコイルとの差動接続回路の近傍に備え、前記差動共振回路は、第５のコイルが発生する磁束信号を検出することで給電状況の検出を行うので、非接触給電装置に、負荷側の状況を伝達することができ、この負荷側の状況に応じた給電制御を行うことができるという効果がある。
【０１０３】
請求項６の発明は、請求項５において、前記非接触受電装置は、第５のコイルに並列接続した共振コンデンサを備えるので、第５のコイルが発生する磁束を増幅することができるという効果がある。
【０１０４】
請求項７の発明は、請求項５において、前記非接触受電装置は、前記負荷の状態に応じて第５のコイルの励磁制御を行う２次側制御回路を備えるので、第５のコイルは、負荷の状況に応じた磁束を発生することができるという効果がある。
【０１０５】
請求項８の発明は、請求項５乃至７いずれかにおいて、第３のコイルと第４のコイルとのうち少なくとも一方は、第１のコイルが発生する電力伝送のための磁束に対して疎結合となる配置、形状を設定され、第３のコイルと第４のコイルとの各巻数は、第３のコイルと第４のコイルとの差動接続回路の両端電圧が所定の電圧となるように設定されて、前記差動共振回路の検出信号は、前記非接触受電装置との磁気結合状況、あるいは第５のコイルが発生する磁束信号によって前記所定の電圧に対して増減し、前記インバータ制御回路は、前記検出信号に基づいて前記高周波インバータ回路の発振を制御するので、非接触給電装置と非接触受電装置との結合状態、及び負荷の状況に応じた給電制御を行うことができるという効果がある。
【０１０６】
請求項９の発明は、請求項８において、前記非接触給電装置が単独である場合、前記差動共振回路の検出信号は所定の値以下になって、前記インバータ制御回路は前記検出信号に基づいて前記高周波インバータ回路の発振を間欠発振に制御し、
第１のコイルと第２のコイルとが互いに略対向配置となる場合、前記差動共振回路の検出信号は、前記非接触受電装置が有するエネルギー源または前記高周波インバータ回路の間欠発振動作による第１のコイルからの給電により、前記非接触受電装置に設けた２次側制御回路が第５のコイルを励磁して発生させた磁束信号を検出した信号であり、前記非接触給電装置が単独である場合の検出信号よりも大きい電圧値を有し、前記インバータ制御回路は前記検出信号に基づいて前記高周波インバータ回路の発振を連続発振に制御し、
前記非接触給電装置からの連続給電を停止する場合は、前記差動共振回路の検出信号は、前記２次側制御回路が第５のコイルの励磁を停止する、または励磁を弱める、または間欠励磁する、または励磁周波数を変更して発生させた磁束信号を検出した信号であり、前記高周波インバータ回路が連続発振を行っている場合の検出信号よりも小さい電圧値となり、前記インバータ制御回路は前記検出信号に基づいて前記高周波インバータ回路の発振を間欠発振に制御するので、請求項８と同様の効果を奏する。
【０１０７】
請求項１０の発明は、請求項９において、前記インバータ制御回路は、前記高周波インバータ回路の発振を一定時間毎に開始させる定期発振開始手段と、発振を開始してから一定時間後に発振を停止させる発振強制停止手段と、前記差動共振回路の検出信号に応じて、前記発振強制停止手段の継続と解除とを制御することで、前記高周波インバータ回路の間欠発振と連続発振とを制御する手段とを備えるので、非接触給電装置と非接触受電装置との結合状態、及び負荷の状況に応じて間欠発振、または連続発振を行うことができるという効果がある。
【０１０８】
請求項１１の発明は、請求項１０において、前記発振強制停止手段は、前記第１のコイルに発生する電圧を利用して、前記定期発振開始手段により前記高周波インバータ回路の発振が立ち上がってから定常発振へと移行する過程において発振が開始したことを検知する手段を有するので、間欠発振を行うことができるという効果が有る。
【０１０９】
請求項１２の発明は、請求項１０または１１において、第１のコイルに発生する電圧の振幅は、前記高周波インバータ回路の発振停止時より発振開始後のほうが大きく、前記発振強制停止手段は、第１のコイルに発生する電圧によって充電される積分回路と、発振開始後に前記積分回路に充電された電圧が所定の値を超えたことを検出して前記高周波インバータ回路の発振を停止させる手段とを備えるので、発振強制停止手段の具体回路を構成することができるという効果がある。
【０１１０】
請求項１３の発明は、請求項１２において、前記高周波インバータ回路の間欠発振と連続発振とを制御する手段は、前記差動共振回路の検出信号に応じて、前記積分回路を構成するコンデンサの電荷を引き抜く手段を備えて、前記積分回路に充電された電圧が所定の値を超えないようにすることで、前記発振強制停止手段の動作を阻止するので、間欠発振と連続発振とを切換えることができるという効果がある。
【０１１１】
請求項１４の発明は、請求項５乃至１３いずれかにおいて、両端に突部を設けた断面コの字型の磁性体からなる第１，第２のコアを備え、第１のコアの両突部間に巻回した第１のコイルと、第２のコアの両突部間に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３のコイルは第１のコアの両突部のうち少なくとも一方に巻回され、第４のコイルは第１のコイルの半径方向に第１のコイルに重ねて同軸に巻回され、第５のコイルは第３のコイルに対向する第２のコアの突部に巻回されるので、断面コの字型のコアを用いて、非接触給電装置と非接触受電装置とで分離着脱自在なトランス構造を構成することができるという効果がある。
【０１１２】
請求項１５の発明は、請求項５乃至１３いずれかにおいて、両端に突部を設けた断面コの字型の磁性体からなる第１，第２のコアを備え、第１のコアの両突部間に巻回した第１のコイルと、第２のコアの両突部間に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３、第４のコイルは第１のコイルを軸方向に挟んで、第１のコアの両突部間に巻回され、第５のコイルは第２のコアの両突部間に第２のコイルとは軸方向に分離して第３のコイルに対向して巻回されるので、請求項１４と同様の効果を奏する。
【０１１３】
請求項１６の発明は、請求項５乃至１３いずれかにおいて、両端に突部を設けた断面コの字型の磁性体からなる第１，第２のコアを備え、第１のコアの両突部間に巻回した第１のコイルと、第２のコアの両突部間に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３のコイルは第１のコイルとは軸方向に分離して第１のコアの両突部間に巻回され、第４のコイルは第１のコイルの半径方向に第１のコイルに重ねて同軸に巻回され、第５のコイルは第２のコアの両突部間に第２のコイルとは軸方向に分離して第３のコイルに対向して巻回されるので、請求項１４と同様の効果を奏する。
【０１１４】
請求項１７の発明は、請求項５乃至１３いずれかにおいて、両端に突部を設けた断面コの字型の磁性体からなる第１，第２のコアを備え、第１のコアの両突部に巻回した第１のコイルと、第２のコアの両突部に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３のコイルは第１のコアの両突部間の凹部に配置され、第４のコイルは第１のコアの両突部のうち少なくとも一方に巻回され、第５のコイルは第２のコアの両突部間の凹部に第３のコイルに対向して配置されるので、請求項１４と同様の効果を奏する。
【０１１５】
請求項１８の発明は、請求項５乃至１３いずれかにおいて、両端及び中央に突部を設けた断面Ｅ型の磁性体からなる第１，第２のコアを備え、第１のコアの中央の突部に巻回した第１のコイルと、第２のコアの中央の突部に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３のコイルは第１のコアの両端の突部のうち少なくとも一方に巻回され、第４のコイルは第１のコイルの半径方向に第１のコイルに重ねて同軸に巻回され、第５のコイルは第３のコイルに対向する第２のコアの突部に巻回されるので、断面Ｅ型のコアを用いて請求項１４と同様の効果を奏する。
【０１１６】
請求項１９の発明は、請求項５乃至１３いずれかにおいて、両端及び中央に突部を設けた断面Ｅ型の磁性体からなる第１，第２のコアを備え、第１のコアの中央の突部に巻回した第１のコイルと、第２のコアの中央の突部に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３のコイルは第１のコアの両端の突部のうち一方に巻回され、第４のコイルは第１のコアの両端の突部のうち他方に巻回され、第５のコイルは第３のコイルに対向する第２のコアの突部に巻回されるので、請求項１８と同様の効果を奏する。
【０１１７】
請求項２０の発明は、請求項５乃至１３いずれかにおいて、円筒状のポット型のコアを軸方向に対して略対象に分割した一方である第１のコアと、他方である第２のコアとを備え、第１，第２のコアは軸方向の略中央の内面に突部を各々設けており、第１のコアの中央の突部に巻回した第１のコイルと、第２のコアの中央の突部に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３，第４のコイルは第１のコイルの半径方向に第１のコイルに重ねて同軸に、且つ第３のコイルは第２のコアに近くなるように第４のコイルとは軸方向に分離して巻回され、第５のコイルは第２のコイルの半径方向に第２のコイルに重ねて同軸に、第３のコイルに対向して巻回されるので、円筒状のポット型のコアを用いて請求項１４と同様の効果を奏する。
【０１１８】
請求項２１の発明は、請求項５乃至１３いずれかにおいて、円板状または円筒状の磁性体からなる第１，第２のコアを備え、第１のコアの側面に巻回した第１のコイルと、第２のコアの側面に巻回した第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３，第４のコイルは第１のコイルと同軸に、且つ第３のコイルは第２のコアに近くなるように第４のコイルとは軸方向に分離して巻回され、第５のコイルは第２のコイルと同軸に、第３のコイルに対向して巻回されるので、円板状または円筒状のコアを用いて請求項１４と同様の効果を奏する。
【０１１９】
請求項２２の発明は、請求項５乃至１３いずれかにおいて、第１のコイルと第２のコイルとのうち少なくともいずれか一方が円板上または円筒状の磁性体からなるコアに巻回して、第１のコイルと第２のコイルとは互いに分離着脱自在なトランス構造を構成しており、第３，第４のコイルは第１のコイルと同軸に、且つ第３のコイルは第２のコイルに近くなるように第４のコイルとは軸方向に分離して巻回され、第５のコイルは第２のコイルと同軸に、第３のコイルに対向して巻回されるので、第１のコイルと第２のコイルとのうち少なくともいずれか一方に円板上または円筒状のコアを用いて、請求項１４と同様の効果を奏する。
【０１２０】
請求項２３の発明は、請求項１において、前記高周波インバータ回路は自励発振を行うものであって、前記差動共振回路の検出信号は第１のコイルの電流による磁束を検出した信号であり、前記非接触給電装置が単独である場合、前記差動共振回路の検出信号は所定の電圧値より大きい信号であり、前記インバータ制御回路は前記検出信号を平滑した信号に基づいて前記高周波インバータ回路の発振を間欠発振に制御し、第１のコイルと第２のコイルとが互いに略対向配置となる場合、前記差動共振回路の検出信号は、前記非接触給電装置が単独であるときの第１のコイルが発生する磁束に対して分布、強度、方向が変化した磁束を検出した所定の電圧値より小さい信号であり、前記インバータ制御回路は前記検出信号を平滑した信号に基づいて前記高周波インバータ回路の発振を連続発振に制御するので、非接触給電装置が単独の場合の発振停止、抑制を行うことができ、省エネルギーに貢献することができるという効果がある。
【０１２１】
請求項２４の発明は、請求項２３において、前記自励発振を行う高周波インバータ回路は、発振用スイッチング素子と、発振用スイッチング素子の発振を起動させるための起動回路と、第１のコイルに磁気結合した帰還コイルと、第１のコイルまたは発振用スイッチング素子に並列接続したコンデンサと、発振用スイッチング素子の制御端をグランドレベルに接続する自励制御用スイッチング素子とを備える電圧共振型のインバータ回路であり、発振用スイッチング素子は前記帰還コイルの誘起電圧と前記起動回路の出力とによってオンし、オンしてから一定時間後に自励制御用スイッチング素子がオンして発振用スイッチング素子をオフさせるので、自励発振を行って請求項２３と同様の効果を奏する。
【０１２２】
請求項２５の発明は、請求項２４において、前記インバータ制御回路は、前記差動共振回路の検出信号を整流、平滑する回路と、前記整流平滑回路の出力を制御端に接続し、前記自励制御用スイッチング素子に並列に接続した発振制御用スイッチング素子とを備えるので、差動共振回路の検出信号で発振制御用スイッチング素子をオン・オフすることで、間欠発振と連続発振とを切換えることができ、極めて少ない部品の追加で請求項２３と同様の効果を奏する。
【０１２３】
請求項２６の発明は、請求項２４において、前記インバータ制御回路は、前記差動共振回路の検出信号を整流、平滑する回路を備え、前記整流平滑回路の出力を前記自励制御用スイッチング素子の制御端に接続したので、差動共振回路の検出信号で自励制御用スイッチング素子をオン・オフすることで、請求項２５と同様の効果を奏する。
【０１２４】
請求項２７の発明は、請求項２３乃至２６いずれかにおいて、円板状または円筒状の磁性体からなるコアを備えて、第１のコイルは前記コアの側面に巻回され、第３，第４のコイルは、第１のコイルの半径方向に第１のコイルに重ねて同軸に巻回されて、第２のコイルは第１のコイルの軸方向に対向配置したので、円板状または円筒状の磁性体からなるコアを用いて請求項１４と同様の効果を奏する。
【０１２５】
請求項２８の発明は、請求項２３乃至２６いずれかにおいて、円板状または円筒状の磁性体からなるコアを備えて、第１のコイルは前記コアの側面に巻回され、第３，第４のコイルは、前記コアの側面に第１のコイルとは軸方向に分離して巻回されて、第２のコイルは第１のコイルの軸方向に対向配置したので、請求項２７と同様の効果を奏する。
【図面の簡単な説明】
【図１】本発明の実施形態１のブロック構成を示す図である。
【図２】同上の具体的な回路構成を示す図である。
【図３】同上の発振から連続発振に至る各部の波形を示す図である。
【図４】同上の発振から間欠発振に至る各部の波形を示す図である。
【図５】同上の分離着脱式トランスの第１の構造例を示す側面断面図である。
【図６】同上の分離着脱式トランスの第２の構造例の１次側を示す側面断面図である。
【図７】同上の分離着脱式トランスの第２の構造例の１次側と２次側とを示す側面断面図である。
【図８】同上の分離着脱式トランスの第２の構造例の全体を示す側面断面図である。
【図９】同上の分離着脱式トランスの第３の構造例を示す側面断面図である。
【図１０】同上の分離着脱式トランスの第４の構造例を示す側面断面図である。
【図１１】同上の分離着脱式トランスの第５の構造例を示す側面断面図である。
【図１２】同上の分離着脱式トランスの第６の構造例を示す側面断面図である。
【図１３】同上の分離着脱式トランスの第７の構造例を示す側面断面図である。
【図１４】同上の分離着脱式トランスの第８の構造例を示す側面断面図である。
【図１５】同上の分離着脱式トランスの第９の構造例を示す側面断面図である。
【図１６】同上の分離着脱式トランスの第１０の構造例を示す側面断面図である。
【図１７】本発明の実施形態２のブロック構成を示す図である。
【図１８】同上の具体的な回路構成を示す図である。
【図１９】同上の別の回路構成を示す図である。
【図２０】同上の分離着脱式トランスの構造例を示す側面断面図である。
【図２１】同上の分離着脱式トランスの別の構造例を示す側面断面図である。
【符号の説明】
１非接触給電装置
２非接触受電装置
１１高周波インバータ回路
１２差動共振回路
１３インバータ制御回路
２１電力変換回路
２２２次電池
２３２次側制御回路
Ｌ１〜Ｌ５第１〜第５のコイル
Ｃ４，Ｃ８共振コンデンサ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a non-contact power transmission device.
[0002]
[Prior art]
In recent years, the adoption of non-contact power transmission technology for portable electronic devices, electric vehicles, industrial devices, and the like has been spreading. This technology is especially useful for products used around water, such as electric toothbrushes and electric shavers. In a non-contact power transmission device that attaches and detaches the power supply side (power supply side) and load side (power reception side), when power is supplied from the power supply side to the load side by electromagnetic induction, when the load side is removed It is necessary to stop the oscillation of the oscillation switching element used in the power supply side inverter circuit or reduce the oscillation intensity. The reason for this is that if oscillation is continued when there is no load, energy is wasted due to power loss on the power supply side, and if a metallic foreign object other than the correct load is placed, for example, induction heating is performed. This is because the action causes an abnormal overheating of the metal and is dangerous. Furthermore, when the load is a secondary battery or the like, it is necessary to perform charge control when the secondary battery is fully charged.
[0003]
In other words, for non-contact power transmission, “power saving control and oscillation stop or suppression control for measures against metal foreign matter overheating when the power supply is alone”, “continuous power supply control when a correct load is attached” and “ Three types of control, “power transmission control based on a request from the load side”, are necessary.
[0004]
[Problems to be solved by the invention]
Several conventional examples that satisfy all or part of the above three controls have been proposed. For example, there is a technique disclosed in Japanese Patent Laid-Open No. 6-311658. This is because an independent pair of signal coils is provided separately from the pair of power coils on the power supply side and the load side, and when the load is mounted, power is supplied to the load by induction of the pair of power coils. Is transmitted. Then, the control circuit on the load side is driven using this power, the control signal is returned from the load side to the power supply side by a pair of signal coils, and the power supply side controls the oscillation operation based on this control signal. To do.
[0005]
However, this configuration requires separate circuits for load detection and oscillation control, and in order to make it easier to distinguish the signal frequency from the frequency for power transmission and reception, it is necessary to increase the signal frequency. There is a drawback that the generation circuit becomes complicated, and the size and cost are increased due to enhancement of noise countermeasures.
[0006]
Japanese Patent Application Laid-Open No. 11-178249 utilizes the characteristics of self-excited oscillation, and a positive feedback loop is once taken out from the power supply side to the load side and returned to the power supply side, and the feedback loop is used for load information. In this circuit, the load can be detected with a very simple circuit that can save power and prevent overheating of the foreign metal. Furthermore, since the same power frequency and signal frequency can be used, non-contact power transmission can be performed with a simple configuration. However, since the control signal is a positive feedback feedback signal having the same frequency as the power frequency, there is a drawback in that amplification control of the signal amplitude cannot be performed and it is difficult to obtain a noise margin.
[0007]
The present invention has been made in view of the above-described reasons, and an object of the present invention is to provide a non-contact power transmission device that can identify a power supply state and perform power supply control, has a simple structure, and is low noise. Is to provide.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 is a high-frequency inverter circuit that outputs high-frequency power, an inverter control circuit that controls the high-frequency inverter circuit, and a first coil that is supplied with high-frequency power from the high-frequency inverter circuit and performs power supply by magnetic coupling And a differential connection circuit between the third coil and the fourth coil arranged in the vicinity of the first coil to detect the power supply status, and a second output for amplifying the output of the differential connection circuit of the coil. And a differential resonance circuit comprising a resonance capacitor connected to the third coil and the fourth coil, and the inverter control circuit controls the high-frequency inverter circuit based on a detection signal output from the differential resonance circuit. A contact power supply device;
A second coil disposed opposite to the first coil and receiving power by magnetic coupling; a power conversion circuit for converting the output of the second coil into predetermined electrical energy; and electrical energy from the power conversion circuit And a non-contact power receiving device having a supplied load.
[0009]
The invention of claim 2 is characterized in that, in claim 1, the third coil and the fourth coil are arranged so as to be loosely coupled to each other.
[0010]
A third aspect of the present invention is the first or second aspect, wherein the first coil and at least one of the third coil and the fourth coil are arranged so as to be loosely coupled to each other. It is characterized by.
[0011]
According to a fourth aspect of the present invention, in any one of the first to third aspects, the differential resonance circuit detects a change in magnetic flux or magnetic field generated by at least one coil current of the first coil and the second coil. By doing so, the power supply status is detected.
[0012]
According to a fifth aspect of the present invention, in the fourth aspect, the non-contact power receiving device is configured such that at least one fifth coil that generates a magnetic flux signal that gives the status of the self-machine is provided between the third coil and the fourth coil. The differential resonance circuit is provided in the vicinity of a differential connection circuit, and detects a power supply state by detecting a magnetic flux signal generated by a fifth coil.
[0013]
According to a sixth aspect of the present invention, in the fifth aspect, the contactless power receiving device includes a resonant capacitor connected in parallel to the fifth coil.
[0014]
A seventh aspect of the invention is characterized in that, in the fifth aspect, the non-contact power receiving device includes a secondary side control circuit that performs excitation control of the fifth coil in accordance with the state of the load.
[0015]
The invention of claim 8 is the invention according to any one of claims 5 to 7, wherein at least one of the third coil and the fourth coil is loosely coupled to the magnetic flux for power transmission generated by the first coil. The arrangement and shape are set so that the number of turns of the third coil and the fourth coil is such that the voltage across the differential connection circuit between the third coil and the fourth coil becomes a predetermined voltage. The detection signal of the differential resonance circuit is increased or decreased with respect to the predetermined voltage according to a magnetic coupling state with the non-contact power receiving device or a magnetic flux signal generated by a fifth coil, and the inverter control circuit Controls the oscillation of the high-frequency inverter circuit based on the detection signal.
[0016]
According to a ninth aspect of the present invention, in the eighth aspect, when the non-contact power feeding device is a single device, the detection signal of the differential resonance circuit becomes a predetermined value or less, and the inverter control circuit is based on the detection signal. Control the oscillation of the high-frequency inverter circuit to intermittent oscillation,
When the first coil and the second coil are disposed substantially opposite to each other, the detection signal of the differential resonance circuit is a first signal generated by the energy source of the non-contact power receiving device or the intermittent oscillation operation of the high-frequency inverter circuit. The secondary-side control circuit provided in the non-contact power receiving device detects a magnetic flux signal generated by exciting the fifth coil by power feeding from the coil, and the non-contact power feeding device is independent. The inverter control circuit controls the oscillation of the high-frequency inverter circuit to continuous oscillation based on the detection signal,
When the continuous power supply from the non-contact power supply device is stopped, the detection signal of the differential resonance circuit indicates that the secondary control circuit stops the excitation of the fifth coil, weakens the excitation, or intermittent excitation. Or a signal obtained by detecting a magnetic flux signal generated by changing the excitation frequency, and a voltage value smaller than a detection signal when the high-frequency inverter circuit is continuously oscillating, and the inverter control circuit detects the detection The oscillation of the high-frequency inverter circuit is controlled to intermittent oscillation based on the signal.
[0017]
A tenth aspect of the present invention is that, in the ninth aspect, the inverter control circuit includes periodic oscillation start means for starting oscillation of the high-frequency inverter circuit at regular intervals, and halts oscillation after a certain period of time after starting the oscillation. Means for controlling the intermittent oscillation and the continuous oscillation of the high-frequency inverter circuit by controlling the oscillation forced stop means and the continuation and release of the oscillation forced stop means according to the detection signal of the differential resonance circuit; It is characterized by providing.
[0018]
According to an eleventh aspect of the present invention, in the tenth aspect, the forced oscillation stop means uses a voltage generated in the first coil, and the steady oscillation starts after the high-frequency inverter circuit starts oscillation by the periodic oscillation start means. It has a means for detecting that oscillation has started in the process of shifting to oscillation.
[0019]
According to a twelfth aspect of the present invention, in the tenth or eleventh aspect, the amplitude of the voltage generated in the first coil is greater after the oscillation starts than when the high-frequency inverter circuit stops oscillating. An integration circuit charged by a voltage generated in one coil, and means for detecting that the voltage charged in the integration circuit has exceeded a predetermined value after oscillation starts and stopping oscillation of the high-frequency inverter circuit It is characterized by providing.
[0020]
According to a thirteenth aspect of the present invention, in the twelfth aspect, the means for controlling the intermittent oscillation and the continuous oscillation of the high-frequency inverter circuit is a charge of a capacitor constituting the integrating circuit in accordance with a detection signal of the differential resonance circuit. Is provided, and the operation of the oscillation forced stop means is prevented by preventing the voltage charged in the integration circuit from exceeding a predetermined value.
[0021]
A fourteenth aspect of the present invention includes the first and second cores according to any one of the fifth to thirteenth aspects, comprising first and second cores made of a U-shaped magnetic body having protrusions at both ends. The first coil wound between the parts and the second coil wound between the projecting parts of the second core constitute a transformer structure that is detachable from each other, and the third coil is the first coil The first coil is wound around at least one of the projecting portions of the core, the fourth coil is coaxially wound over the first coil in the radial direction of the first coil, and the fifth coil is the third coil. It is wound around the protrusion of the second core facing the coil.
[0022]
A fifteenth aspect of the present invention includes the first and second cores according to any one of the fifth to thirteenth aspects, comprising first and second cores made of U-shaped magnetic bodies having protrusions at both ends. The first coil wound between the parts and the second coil wound between the projecting parts of the second core constitute a transformer structure that is detachable from each other. The coil is wound between both projecting portions of the first core with the first coil sandwiched in the axial direction, and the fifth coil is axially disposed between both projecting portions of the second core. And is wound so as to face the third coil.
[0023]
A sixteenth aspect of the present invention includes the first and second cores according to any one of the fifth to thirteenth aspects, comprising first and second cores made of a U-shaped magnetic body having protrusions at both ends. The first coil wound between the parts and the second coil wound between the projecting parts of the second core constitute a transformer structure that is detachable from each other, and the third coil is the first coil The first coil is axially separated and wound between both projecting portions of the first core, and the fourth coil is coaxially wound on the first coil in the radial direction of the first coil. The fifth coil is characterized in that it is wound between both protrusions of the second core so as to be separated from the second coil in the axial direction so as to face the third coil.
[0024]
A seventeenth aspect of the present invention provides the first and second cores according to any one of the fifth to thirteenth aspects, comprising first and second cores made of a U-shaped magnetic body having protrusions at both ends. The first coil wound around the part and the second coil wound around both protrusions of the second core form a transformer structure that is detachable from each other, and the third coil is the first coil The fourth coil is wound around at least one of the first core protrusions, and the fifth coil is a recess between the protrusions of the second core. It is arranged to face the third coil.
[0025]
The invention of claim 18 includes the first and second cores made of a magnetic material having an E-shaped cross section provided with protrusions at both ends and in the center according to any one of claims 5 to 13, wherein the center of the first core is provided. The first coil wound around the protrusion and the second coil wound around the center protrusion of the second core constitute a transformer structure that is detachable from each other, and the third coil is the first coil The first coil is wound around at least one of the protrusions at both ends of the core, the fourth coil is wound coaxially with the first coil in the radial direction of the first coil, and the fifth coil is the third coil. It is wound around the protrusion part of the 2nd core which opposes this coil.
[0026]
The invention of claim 19 comprises the first and second cores of the cross-section E-type magnetic body provided with protrusions at both ends and in the center according to any one of claims 5 to 13, wherein the center of the first core is provided. The first coil wound around the protrusion and the second coil wound around the center protrusion of the second core constitute a transformer structure that is detachable from each other, and the third coil is the first coil One of the protrusions at both ends of one core is wound on one side, the fourth coil is wound on the other of the protrusions at both ends of the first core, and the fifth coil faces the third coil. It is wound around the protrusion of the second core.
[0027]
A twentieth aspect of the invention relates to any one of the fifth to thirteenth aspects of the present invention, wherein the cylindrical pot-shaped core is substantially divided into the first core and the second core is the other. And the first and second cores each have a protrusion on the substantially central inner surface in the axial direction, the first coil wound around the central protrusion of the first core, and the second The second coil wound around the central projecting portion of the core forms a transformer structure that is detachable from the second coil. The third and fourth coils are formed as first coils in the radial direction of the first coil. The coil is coaxially overlapped, and the third coil is wound in the axial direction so as to be close to the second core, and the fifth coil is wound in the radial direction of the second coil. The second coil is wound around the second coil, coaxially and opposed to the third coil.
[0028]
A twenty-first aspect of the present invention provides the first or second aspect of the present invention, comprising the first or second core made of a disk-shaped or cylindrical magnetic body, and wound around the side surface of the first core. The coil and the second coil wound around the side surface of the second core constitute a transformer structure that is detachable from each other. The third and fourth coils are coaxial with the first coil and The third coil is wound separately from the fourth coil in the axial direction so as to be close to the second core, and the fifth coil is coaxial with the second coil and faces the third coil. It is characterized by being wound.
[0029]
The invention of claim 22 is any one of claims 5 to 13, wherein at least one of the first coil and the second coil is wound around a disk or a core made of a cylindrical magnetic material, The first coil and the second coil constitute a transformer structure that is detachable from each other. The third and fourth coils are coaxial with the first coil, and the third coil is the second coil. The fourth coil is wound separately from the fourth coil in the axial direction so as to be close to the second coil, and the fifth coil is wound coaxially with the second coil so as to face the third coil. To do.
[0030]
According to a twenty-third aspect of the present invention, in the first aspect, the high-frequency inverter circuit performs self-excited oscillation, and the detection signal of the differential resonance circuit is a signal obtained by detecting a magnetic flux due to the current of the first coil. When the non-contact power feeding device is single, the detection signal of the differential resonance circuit is a signal larger than a predetermined voltage value, and the inverter control circuit is configured to generate the high-frequency inverter circuit based on a signal obtained by smoothing the detection signal. When the first coil and the second coil are arranged substantially opposite to each other, the detection signal of the differential resonance circuit is obtained when the non-contact power feeding device is alone. 1 is a signal smaller than a predetermined voltage value obtained by detecting a magnetic flux whose distribution, intensity, and direction have changed with respect to the magnetic flux generated by one coil, and the inverter control circuit is based on a signal obtained by smoothing the detection signal. And controlling the continuous oscillation of the oscillation of the high frequency inverter circuit Te.
[0031]
According to a twenty-fourth aspect of the present invention, in the twenty-third aspect, the high-frequency inverter circuit that performs self-excited oscillation includes an oscillation switching element, an activation circuit for activating oscillation of the oscillation switching element, and a magnetic force applied to the first coil. A voltage resonance type inverter circuit comprising a coupled feedback coil, a capacitor connected in parallel to the first coil or the oscillation switching element, and a self-excited control switching element for connecting the control terminal of the oscillation switching element to the ground level The oscillation switching element is turned on by the induced voltage of the feedback coil and the output of the starting circuit, and the self-excitation control switching element is turned on and the oscillation switching element is turned off after a predetermined time from turning on. It is characterized by.
[0032]
According to a twenty-fifth aspect of the invention, in the twenty-fourth aspect, the inverter control circuit rectifies and smoothes a detection signal of the differential resonance circuit, and connects an output of the rectifying and smoothing circuit to a control terminal, so that the self-excitation And an oscillation control switching element connected in parallel to the control switching element.
[0033]
According to a twenty-sixth aspect of the present invention, in the twenty-fourth aspect, the inverter control circuit includes a circuit that rectifies and smoothes the detection signal of the differential resonance circuit, and outputs the rectifying and smoothing circuit of the switching element for self-excitation control. It is connected to the control end.
[0034]
A twenty-seventh aspect of the present invention is the method according to any one of the twenty-third to twenty-sixth aspects, further comprising a core made of a disk-shaped or cylindrical magnetic body, wherein the first coil is wound around the side surface of the core, The fourth coil is characterized in that it is wound around the first coil in the radial direction of the first coil and is coaxially wound, and the second coil is disposed opposite to the axial direction of the first coil.
[0035]
A twenty-eighth aspect of the present invention is the method according to any one of the twenty-third to twenty-sixth aspects, further comprising a core made of a disk-shaped or cylindrical magnetic body, wherein the first coil is wound around a side surface of the core, The coil No. 4 is wound around the side surface of the core so as to be separated from the first coil in the axial direction, and the second coil is disposed opposite to the axial direction of the first coil.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0037]
(Embodiment 1)
A block diagram of the non-contact power transmission apparatus of this embodiment is shown in FIG. The non-contact power transmission device includes a non-contact power feeding device 1 that supplies power and a non-contact power receiving device 2 that includes a load to which power is supplied. The non-contact power feeding device 1 outputs a high-frequency power circuit. 11, an inverter control circuit 13 that controls the high-frequency inverter circuit 11, a first coil L 1 that is supplied with high-frequency power from the high-frequency inverter circuit 11 and that supplies power by magnetic coupling, and is disposed in the vicinity of the first coil L 1. In order to amplify the outputs of the third coil L3 and the fourth coil L4 which are differentially connected in series with opposite polarities, and the differential connection circuit of the third coil L3 and the fourth coil L4. The third capacitor L3, the fourth coil L4, and the resonance capacitor C4 constitute a differential resonance circuit 12. The resonance capacitor C4 is connected between both ends of the dynamic connection circuit.
[0038]
The non-contact power receiving apparatus 2 has a load 30. The second coil L 2 is disposed opposite to the first coil L 1 and receives power by magnetic coupling, and the output of the second coil L 2 is supplied to the load 30. A power conversion circuit 21 for converting the output into a suitable output, a fifth coil L5 disposed opposite to the coil of the differential resonance circuit 12, and a resonance capacitor C8 connected between both ends of the fifth coil L5. And a switch S2 connected between both ends of the resonance capacitor C5, and a secondary control circuit 23 that outputs a signal for controlling on / off of the switch S2 according to the state of the load 30.
[0039]
The non-contact power transmission apparatus as described above generates an induced voltage in the second coil L2 by the magnetic flux generated by the first coil L1 supplied with the high frequency power from the high frequency inverter circuit 11, and the induced voltage is generated. The power conversion circuit 21 converts it into a predetermined form and outputs it to the load 30. The secondary control circuit 23 changes the excitation state of the fifth coil L5 by turning the switch S2 on and off depending on the state of the load 30. The differential resonance circuit 12 detects a power supply state and outputs a detection signal depending on the excitation state of the coil L5 or the presence or absence of the non-contact power receiving device 2, and the inverter control circuit 13 outputs a detection signal based on the detection signal. Oscillation is controlled.
[0040]
Next, the configuration of each unit will be described in detail using the specific circuit configuration shown in FIG. First, the high-frequency inverter circuit 11 of the non-contact power feeding device 1 is a self-excited oscillation circuit, a series circuit of a resistor R2 and a capacitor C1 connected in parallel to a series circuit of a DC power source E1 and a switch S1, a resonance capacitor C2, A series circuit of an oscillation switching element FET1 and a resistor R1 is provided, and a first coil L1 is connected in parallel to the capacitor C2. A feedback coil L6 that is tightly coupled with the first coil and the polarity shown in the figure is connected between the connection middle point of the resistor R2 and the capacitor C1 and the gate of the switching element FET1. A switching element Tr1 for controlling self-excited oscillation connected in parallel to the capacitor C1 via the feedback coil L6 is an element that controls oscillation of the switching element FET1. A resistor R3 is connected between the source of the switching element FET1 and the base of the switching element Tr1, and a capacitor C3 is connected between the base and emitter of the switching element Tr1.
[0041]
The configuration of the differential resonance circuit 12 is the same as that of FIG. 1, and one output terminal is connected to the ground of the high-frequency inverter circuit (the low voltage output side of the DC power supply E1).
[0042]
The inverter control circuit 13 is a circuit that controls the oscillation of the high-frequency inverter circuit 11 in two ways of continuous oscillation and intermittent oscillation by turning on and off the switching element Tr1 for controlling self-excited oscillation of the high-frequency inverter circuit 11. The other end of the series circuit of the diode D3, the Zener diode ZD1, and the resistor R7 having one end connected to the other output end of the differential resonance circuit 12 is connected to the base of the switching element Tr2. A capacitor C5 is connected between the output terminals of the differential resonance circuit 12 via a diode D3, and a resistor R8 is connected between the base and emitter of the switching element Tr2. The drain of the switching element FET1 is connected to the ground level via a series circuit of resistors R4 and R5, and the capacitor C6 is connected in parallel to the resistor R5 via a diode D2. The midpoint of connection between the diode D2 and the capacitor C6 is connected to the base of the switching element Tr1 for self-excited oscillation control via the diode D1 and the resistor R3, and further connected to the collector of the transistor Tr2 via the resistor R6. is doing.
[0043]
The secondary circuit 21 of the non-contact power receiving device 2 includes a capacitor C7 connected between the output ends of the second coil L2, and a rectifying diode D4 connected in series to one output end of the second coil L2. In addition, an output obtained by half-wave rectifying the induced voltage of the second coil L 2 is supplied to the secondary battery 22 as a load, and both ends of the secondary battery 22 are connected to the secondary-side control circuit 23.
[0044]
A resonance capacitor C8 and a series circuit of a diode D5 and a switching element Tr3 are connected between both ends of the fifth coil L5, and the base of the switching element Tr3 is connected to the secondary control circuit 23.
[0045]
Next, the process from the start of oscillation to the continuous oscillation from when the switch S1 is turned on will be described with reference to the waveform diagram shown in FIG. First, when the switch S1 is turned on, the DC power source E1 that generates the voltage Ve1 charges the capacitor C1 through the resistor R2. At this time, since no induced voltage is generated in the feedback coil L6 that is tightly coupled to the first coil L1, the gate voltage Vg of the switching element FET1 is equal to the voltage Vc1 of the capacitor C1. When the gate voltage Vg gradually increases and reaches the voltage Vgon that can turn on the switching element FET1, the switching element FET1 is turned on, and the drain voltage Vd becomes substantially zero potential. At this time, the resonance voltage Vc2 at both ends of the resonance capacitor C2 connected in parallel with the first coil L1 is charged by the power supply voltage Ve1 of the DC power supply E1, and the first coil L1 has a substantially monotonically increasing coil current. IL1 begins to flow.
[0046]
When the coil current IL1 starts to flow, an induced voltage is generated in the second coil L2 by the action of the transformer. Similarly, an induced voltage Vf1 is also generated in the feedback coil L6 that is tightly coupled to the first coil L1. Then, the gate voltage Vg viewed from the ground level becomes Vc1 + Vf1, and the switching element FET1 is rapidly turned on stably.
[0047]
The coil current IL1 is substantially equal to the drain current Id flowing through the switching element FET1 to the resistor R1, and the voltage Vtr1 of the resistor R1 increases with time. When the voltage Vtr1 reaches a voltage at which the switching element Tr1 can be turned on, the switching element Tr1 starts to turn on. When the switching element Tr1 begins to turn on, the gate input capacitance of the switching element FET1 and the charge accumulated in the capacitance of the capacitor C1 via the feedback coil L6 begin to be extracted, and the voltage Vc1 and the gate voltage Vg begin to decrease. As the gate voltage Vg decreases, the switching element FET1 starts to shift to the off state, the on resistance increases, and the drain voltage Vd gradually increases.
[0048]
As the drain voltage Vd increases, the resonance voltage Vc2 also starts decreasing, and the induced voltage Vf1 of the feedback coil L6 also starts decreasing, so the gate voltage Vg further accelerates and decreases. As a result, the switching element FET1 is rapidly turned off, the voltage Vtr1 is also decreased, and the switching element Tr1 is turned off again.
[0049]
The resonance voltage Vc2 becomes a sine wave voltage due to the resonance action of the capacitor C2 and the first coil L1, and the coil current IL1 also becomes a sine wave. During this time, the charging current from the DC power supply E1 to the capacitor C1 via the resistor R2 always flows, and the voltage Vc1 is increased again.
[0050]
When the resonance voltage Vc2 approaches the end of one cycle, the drain voltage Vd approaches the ground level, and the gate voltage Vg of the sum of the electromotive force Vf1 and the voltage Vc1 of the feedback coil L6 at that time turns on the switching element FET1 again. . Thereafter, the oscillation continues by repeating the above operation.
[0051]
However, in a state where the non-contact power receiving device 2 is not disposed opposite to the non-contact power feeding device 1, that is, when the non-contact power feeding device 1 is alone, the high-frequency inverter circuit 11 oscillates to save energy and protect metal foreign objects from overheating. Need to stop or suppress. In the present embodiment, this role is achieved by making the oscillation of the high-frequency inverter circuit 11 intermittent.
[0052]
Hereinafter, control of the intermittent oscillation operation will be described with reference to waveform diagrams of the respective parts shown in FIG. First, the process until the continuous oscillation is started after the switch S1 is turned on is the same as that described in FIG. The inverter control circuit 13 in FIG. 2 has an integration circuit that divides the drain voltage Vd by resistors R4 and R5 and accumulates charges in the capacitor C6 via the diode D2. The voltage of the capacitor C6 is connected to the base resistor R3 of the transistor Tr1 via the diode D1, and the voltage of the capacitor C6 is an input voltage value that can turn on the switching element Tr1, and each voltage drop of the diode D1 and the resistor R3. If the sum of
It becomes a state.
[0053]
When the switching element Tr1 is turned on, the charge accumulated in the gate input capacitance of the switching element FET1 and the capacitance of the capacitor C1 via the feedback coil L6 is extracted. At this time, if the ON time of the switching element Tr1 is kept long, the voltage Vc1 further decreases than the voltage in the steady oscillation state, and voltage recovery due to the charging current flowing from the DC power supply E1 to the capacitor C1 via the resistor R2 is recovered. The voltage of the steady state is not reached, and the switching element FET1 continues to be in the off state.
[0054]
Therefore, the next oscillation start-up is not performed until the voltage Vc1 due to only the charging current flowing from the DC power supply E1 to the capacitor C1 via the resistor R2 reaches the input voltage that can turn on the switching element FET1. That is, stable intermittent oscillation is obtained by repeating this operation.
[0055]
What is important for this intermittent oscillation is that the high-frequency inverter circuit 11 must first have a function of oscillating and then stopping with a time delay. The reason is that if the switching element Tr1 is turned on before the high frequency inverter circuit 11 oscillates, the oscillation is permanently stopped. In the oscillation stop state in the circuit of FIG. 2, since the potential of the drain voltage Vd becomes the power supply voltage Ve1, it is necessary to set the voltage dividing ratio of the resistors R4 and R5 to a value that does not turn on the switching element Tr1 in this oscillation stop state. is there. In order to reach a level at which the switching element Tr1 can be turned on after the oscillation starts, the capacitor C6 is gradually charged by using the voltage when the drain voltage Vd becomes higher than the power supply voltage Ve1 by the oscillation. Then, the voltage dividing ratio of the resistors R4 and R5 may be set so that the switching element Tr1 can be turned on after an appropriate time has elapsed. By configuring as described above, the high-frequency inverter circuit 11 and the inverter control circuit 13 illustrated in FIG. 2 can perform intermittent oscillation when the non-contact power feeding device 1 is alone.
[0056]
By the way, when the non-contact power receiving apparatus 2 is roughly disposed opposite to the non-contact power feeding apparatus 1 and needs to transmit power, a function for reliably stopping the intermittent oscillation is required. The differential resonance circuit 12 of this embodiment is required for the inverter control circuit 13 of the non-contact power feeding apparatus 1 in order to perform the function of reliably stopping intermittent oscillation, that is, continuous oscillation. Further, the fifth coil L5 of the non-contact power receiving device 2 facing the differential resonance circuit 12 also has an important role. Hereinafter, this operation will be described.
[0057]
The outputs of the differential circuits of the fourth and fifth coils amplified by the resonant capacitor C4 are rectified by the diode D3 and charged to the capacitor C5. When the charging voltage of the capacitor C5 exceeds the sum of the input voltage value that can turn on the switching element Tr2, the Zener voltage of the Zener diode ZD1, and the voltage drop of the resistor R7, the switching element Tr2 is turned on. The charge of the capacitor C6 connected through the resistor R6 is extracted. Then, the transistor Tr1 cannot be turned on by the integration operation of the capacitor C6, and the intermittent oscillation of the switching element FET1 can be stopped and continuous oscillation can be performed.
[0058]
Therefore, when the non-contact power receiving device 2 is generally arranged so as to face the non-contact power receiving device 2 and to transmit power, the non-contact power feeding device 1 is roughly arranged to face the non-contact power receiving device 2. Based on a detection signal (differential resonance output) obtained by the differential resonance circuit 12 detecting a change state of the magnetic flux distribution and the like generated by this, and a signal from the fifth coil L5 of the non-contact power receiving device 2 The detection signal output of the differential resonance circuit 12 obtained in this way must be changed from the voltage at which the switching element Tr2 is kept off to the voltage at which the switching element Tr2 is kept on. Specifically, when the non-contact power receiving device 2 is not disposed, the voltage of the detection signal of the differential resonance circuit 12 is lowered so that the switching element Tr2 cannot be turned on. In addition, when the non-contact power receiving device 2 is generally arranged opposite to the other, the voltage of the detection signal of the differential resonance circuit 12 is increased so that the switching element Tr2 can be turned on.
[0059]
Also, as shown in FIG. 2, if the load of the non-contact power receiving device 2 is a battery, it is necessary to stop the power supply before overcharging. For this purpose, the fifth coil is arranged so that the voltage of the detection signal of the differential resonance circuit 12 of the non-contact power feeding device 1 can be changed from the voltage at which the switching element Tr2 is kept on to the voltage at which the switching element Tr2 is kept off. What is necessary is just to output a signal from L5. Specifically, the fifth coil L5 of the non-contact power receiving device 2 is set so that the output voltage of the differential resonance circuit 12 of the non-contact power feeding device 1 becomes lower in a state where the non-contact power receiving device 2 is generally disposed opposite to the non-contact power receiving device 2. May be excited or stopped so that the switching element Tr2 can be turned off.
[0060]
Next, FIG. 5 shows a side cross-sectional view of a structure in which the non-contact power receiving device 2 is roughly disposed opposite to the non-contact power feeding device 1 and forms a transformer structure that can be separated and attached. The separate detachable transformer includes first and second cores 14 and 25 made of a U-shaped magnetic body in order to reduce the magnetic resistance, and the first coil L1 is the first core 14. The third coil L3 is wound around the protrusion 14a, and the fourth coil L4 is wound in the radial direction of the first coil L1. The feedback coil L6 is wound on the protrusion 14b side separated in the axial direction from the first coil L1 between the protrusions 14a and 14b, and the second coil L2 is the second coil L2. The fifth coil L5 is wound around the projecting portion 25a facing the projecting portion 14a so as to face the third coil L3. .
[0061]
In the non-contact power feeding device 1, the first coil L1 and the fourth coil L4 are magnetically relatively tightly coupled, and the first coil L1, the third coil L3, and the third coil The coil L3 and the fourth coil L4 are magnetically loosely coupled. A resonance capacitor C4 is connected in parallel to the series circuit of the third coil L3 and the fourth coil L4. When the non-contact power feeding device 1 is alone, the differential resonance circuit 12 using the magnetic flux generated by the coil current IL1 of the first coil L1 during the period in which the high-frequency inverter circuit 11 is oscillating during the intermittent oscillation operation. The number of turns of the third and fourth coils L3 and L4 is set so that the output voltage becomes a small voltage that does not turn on the switching element Tr2.
[0062]
In the non-contact power receiving device 2, the second coil L2 and the fifth coil L5 are magnetically loosely coupled, and a resonance capacitor C8 is connected in parallel to the fifth coil L5. When the non-contact power receiving device 2 is roughly disposed opposite to the non-contact power feeding device 1, first, in the period in which the high-frequency inverter circuit 11 is oscillating during the intermittent oscillation operation, the first coil L1 is used as the fifth coil. Are mixed with each other, and an induced voltage is generated in the fifth coil L5. A resonance current flows through the fifth coil L5 because the resonance capacitor C8 is connected in parallel. When there is no resonant capacitor C5 and the terminal of the fifth coil L1 is short-circuited by the switching element Tr3, a short-circuit current flows.
[0063]
The current flowing through the fifth coil L5 causes a new magnetic flux to be linked to the fifth coil L5 so as to prevent the change of the magnetic flux due to the coil current IL1 of the first coil L1, and the newly generated magnetic flux The third coil L3 is also affected. That is, due to the effects of mutual induction and self-induction between the plurality of coils, the third coil L3 has a change in amplitude or waveform or a delay in the change relative to the induced voltage that has been generated so far. The change in the induced voltage of the third coil L3 increases.
[0064]
However, since the change in the induced voltage of the fourth coil L4 is small, the induced voltage balance of the third and fourth coils L3 and L4 is broken to generate a differential voltage, and the differential resonance circuit 12 resonates at this frequency. If the capacitor C4 is set in this manner, a larger signal differential resonance output, that is, a detection signal can be obtained. Accordingly, since the transistor Tr2 in FIG. 2 is turned on, the high-frequency inverter circuit 11 is continuously oscillated.
[0065]
Next, in the case where the non-contact power receiving device 2 is roughly disposed opposite to the non-contact power feeding device 1 and there is a need to stop power feeding, the excitation of the fifth coil L5 is made zero or small. Thus, the induced voltage balance of the third and fourth coils L3 and L4 can be restored, and the detection signal of the differential resonance circuit can be made zero or small, and the transistor Tr2 in FIG. Perform intermittent oscillation.
[0066]
The method of making the excitation of the fifth coil L5 zero or small becomes possible by short-circuiting or opening the circuit entirely or partially. This can also be continuous in time or periodic. In FIG. 2, the entire resonant circuit of the fifth coil L5 and the capacitor C8 is short-circuited in one direction by the transistor Tr3 via the diode D5, thereby controlling the output of the differential resonant circuit 12.
[0067]
In the above description, the configuration in which the fifth coil L5 is excited at the same frequency as the oscillation frequency of the high-frequency inverter circuit 11 is taken as an example, but various configurations are conceivable. For example, power is received using an auxiliary coil (not shown). What is necessary is just to apply a voltage to the 5th coil L5 as it is. Further, the energy obtained from the second coil L2 or an auxiliary coil (not shown) or the energy source already possessed by the non-contact power receiving device 2 is different from the oscillation frequency of the high-frequency inverter circuit 11 for power transmission. However, a signal having a frequency close to that can be generated and applied to the fifth coil L5.
[0068]
An important point of the present invention is not the absolute value of the induced voltage generated in the third coil L3 and the fourth coil L4 but the balance. In other words, the balance is maintained with the contactless power supply device 1 alone, and when the contactless power receiving device 2 is roughly opposed to the contactless power supply device 1 and power supply is required, this balance is lost and further contactless. In the state where the non-contact power receiving device 2 is generally disposed opposite to the power feeding device 1, this balance may be restored when it is necessary to stop power feeding.
[0069]
As described above, the operations of the high-frequency inverter circuit 11 and the inverter control circuit 13 in FIG. 2 are functions that can control intermittent oscillation even when the non-contact power feeding device 1 is independent or the non-contact power receiving device 2 is roughly arranged oppositely. "Oscillation stop or suppression when the non-contact power feeding device 1 is alone", "Oscillation continuation when the non-contact power receiving device 2 is disposed substantially opposite to the non-contact power feeding device 1", and "Non-contact power feeding device 1" Even in the three states of “power supply control when the non-contact power receiving device 2 is disposed substantially opposite to the contact power supply device 1”, “continuation or stop of intermittent oscillation” can be controlled.
[0070]
In the conventional method, in order to satisfy the above three states, for example, a power transmission frequency and a signal transmission frequency are provided separately, but this leads to an increase in size and cost. In another method, the power transmission frequency and the signal transmission frequency are the same, but the change in the signal is small, and it is difficult to identify the three states.
[0071]
However, in this embodiment, as can be seen from the above description of the operation, although the frequency of power transmission and signal transmission is the same or close to each other, the differential resonance circuit 12 is provided in the input signal portion of the non-contact power feeding device 1. Thus, it was possible to easily extract a small change in this signal as a large change, and an extremely simple system could be realized.
[0072]
By the way, the role of the differential resonance circuit 12 of the present embodiment is the role of differential amplification for amplifying the difference between the voltages generated at both ends of the third coil L3 and the fourth coil L4 that are differentially connected, and the difference between them. It can be considered that both of the roles of resonance amplification that further emphasizes the voltage of the current by resonance are combined. However, the resonance here does not mean only a simple parallel or series resonance determined only by a closed circuit of a single capacitance and a self-inductance. In an actual system, it is considered that the capacitance C includes not only the independent component capacitance but also the parasitic capacitance and wiring capacitance in the system, and the inductance L has mutual inductance in addition to self-inductance. Mutual induction is performed with other coils, and it is considered that the load and the loss of each part are confused in energy consumption. Therefore, the resonance phenomenon used in an actual system is one utilizing such resonance in a complex system. In the above description of differential resonance, coils, capacitors, etc. are clearly designated for convenience. However, the meaning of using differential resonance in this embodiment is that a plurality of inductances, capacitors, losses, etc. are mutually used in practice. In the complex system concerned, it is to utilize the amplification effect and the enhancement effect of the voltage and current having the frequency component emphasized as a result.
[0073]
FIG. 5 shows a first structure example of a separation / detachment type transformer that exhibits the overall effect of differential amplification and resonance. Hereinafter, a specific structure example and mechanism other than FIG. 5 will be shown.
[0074]
First, the second structural example shown in the side sectional view in FIG. 6 shows the non-contact power feeding device 1 side of the detachable transformer, that is, the primary side of the transformer, and is made of a U-shaped magnetic body. The first coil L1 is provided between the protrusions 14a and 14b provided at both ends of the first core 14, and the third and fourth coils L3 and L4 are provided with the first core 14. The coil L1 is wound between the protrusions 14a and 14b with the coil L1 sandwiched in the axial direction (symmetrically in the radial direction of the first coil L1).
[0075]
Here, the image of the distribution of the magnetic flux by the coil current IL1 of the first coil L1 becomes a magnetic flux distribution 100, and the number of magnetic fluxes linked to the third coil L3 and the fourth coil L4 is the same. Therefore, the differential resonance output of the differential resonance circuit 12 is substantially zero. That is, when the third and fourth coils L3 and L4 are arranged in this way, the transistor Tr2 in the circuit of FIG.
[0076]
Next, the side cross-sectional view of FIG. 7 shows that the non-contact power receiving device 2 is roughly opposed to the non-contact power feeding device 1, that is, the second coil facing the first coil L1 for power transmission in FIG. L2 is arranged, and the secondary side of the transformer includes a second core 25 made of a U-shaped magnetic body, and the second coil L2 is provided at both ends of the second core 25. It is wound between the protrusions 25a and 25b.
[0077]
Here, the image of the distribution of the magnetic flux by the coil current IL1 of the first coil L1 is as shown in the magnetic flux distribution 101, and the number of magnetic fluxes intermingled with the third and fourth coils L3 and L4 is the first coil L1 alone. As in the case of the above, the number of magnetic fluxes is the same, and the differential resonance output of the differential resonance circuit 12 is substantially zero.
[0078]
However, when the non-contact power receiving device 2 is placed, it is necessary to shift to continuous oscillation, so that the third coil L3 between the protrusions 25a and 25b faces the third coil L3 as shown in the side sectional view of FIG. A fifth coil L5 for signal transmission is wound around the second coil L2 in the axial direction, and an induced voltage from the second coil L2 or an induced voltage using an auxiliary coil (not shown) is applied. What is necessary is just to apply to the 5th coil L5 as an exciting power supply, and to interlink with the 3rd coil L3 much the magnetic flux generated by this 5th coil L5. FIG. 8 shows not only the magnetic flux distribution 102 due to the coil current IL1, but also the magnetic flux distribution 103 when only the fifth coil L5 is excited by the excitation power source.
[0079]
As described above, the third coil L3 has a lot of magnetic flux, but the voltage balance can be lost because the number of the fourth coil L4 is small.
[0080]
Next, FIG. 9 shows a side sectional view of the third structural example. This is obtained by winding the fourth coil L4 of the second structural example shown in FIG. 8 on the first coil L1 in the radial direction of the first coil L1 and coaxially winding it.
[0081]
As in the first to third structure examples, the fourth structure example shown in the side sectional view in FIG. 10 is a first U-shaped magnetic body having protrusions 14a and 14b provided at both ends. The first coil L1 includes a core 14 and a second core 25 made of a U-shaped magnetic body having protrusions 25a and 25b provided at both ends, and a separable and detachable transformer structure. Is wound around the protrusions 14a and 14b of the first core 14, and the third coil L3 is overlapped with the first coil L1 in the axial direction of the first coil L1 in the recess between the protrusions 14a and 14b. The fourth coil L4 is wound around the projection 14a so as to overlap the first coil L1 in the radial direction of the first coil L1, and the second coil L2 is projected from the second core 25. The fifth coil L5 is wound around the recess 25b between the protrusions 25a and 25b. In the axial direction of L2 superimposed on the second coil L2, is disposed opposite to the third coil L3.
[0082]
The fifth structural example shown in the side cross-sectional view in FIG. 11 includes a first and second cores 15 and 26 made of a magnetic material having an E-shaped cross section, and constitutes a detachable transformer structure. The core 15 has protrusions 15a and 15b at both ends, a protrusion 15c at the center, and the second core 26 has protrusions 26a and 26b at both ends and a protrusion 26c at the center. The first coil L1 is wound around the central protrusion 15c of the first core 15, the third coil L3 is wound around the protrusion 15a, and the fourth coil L4 is in the radial direction of the first coil L1. The second coil L2 is wound around the central protrusion 26c, and the fifth coil L5 is wound around the protrusion 26a facing the protrusion 15a. 3 is wound opposite to the coil L3
In the sixth structure example shown in the side sectional view in FIG. 12, the fourth coil L4 of the fifth structure example shown in FIG. 11 is wound around the protrusion 15b of the first core 15.
[0083]
The seventh structural example shown in the side sectional view in FIG. 13 includes a first core 16 that is a cylindrical pot-shaped core that is substantially divided in the axial direction, and a second core that is the other. 27, the first core 16 is provided with a protrusion 16a on the substantially central inner surface in the axial direction to form a separable and detachable transformer structure, and the second core 27 is substantially central in the axial direction. A protrusion 27a is provided on the inner surface. The first coil L1 is wound around the central protrusion 16a of the first core 16, and the third and fourth coils L3 and L4 are overlapped with the first coil L1 in the radial direction of the first coil L1. The third coil L3 is wound around the fourth coil L4 in the axial direction so that the third coil L3 is close to the second core 27, and the second coil L2 is the center of the second core 27. The fifth coil L5 is wound coaxially with the second coil L2 in the radial direction of the second coil L2 and coaxially with the third coil L3.
[0084]
The eighth structural example shown in the side cross-sectional view in FIG. 14 includes a first and second cores 17 and 28 made of a disk-shaped or cylindrical magnetic body, and constitutes a detachable transformer structure. The first coil L1 is wound around the side surface of the first core 17, and the third and fourth coils L3 and L4 are coaxially overlapped with the first coil L1 in the radial direction of the first coil L1, The third coil L3 is wound around one end of the first core 17 near the second core 28, and the fourth coil L4 is wound around the other end of the first core 17. The second coil L2 is wound around the side surface of the second core, the fifth coil L5 is coaxially overlapped with the second coil L2 in the radial direction of the second coil L2, and the second core 28 is wound around one end close to the first core 17 so as to face the third coil L3.
[0085]
15 is a first structural example in which the third and fourth coils L3 and L4 of the eighth structural example shown in FIG. 14 are sandwiched between the first coil L1 in the axial direction. The third coil L3 is wound around one end of the first core 17 close to the second core 28, and the fourth coil L4 is the first core. 17 is wound around the other end of 17.
[0086]
The tenth structure example shown in the side sectional view of FIG. 16 has the third coil L3 of the eighth structure example shown in FIG. 14 on one end face of the first core 17 close to the second core 28. The fourth coil L4 is disposed on the other end surface of the first core 17, and the fifth coil L5 is disposed on the one end surface of the second core 28 close to the first core 17. It is arranged.
[0087]
Further, according to the present invention, the arrangement of the differential connection coil composed of the third and fourth coils L3 and L4 and the fifth coil L5 in the above-described transformer that can be detached and attached is a magnetic core. A combination of different embodiments is also included regardless of the presence or absence.
[0088]
Further, when the fifth coil L5 is not required (that is, “oscillation stop or suppression when the non-contact power feeding device 1 is alone”) and “the non-contact power receiving device 2 is disposed substantially opposite to the non-contact power feeding device 1”. This is also applicable to the case of “only oscillation continuation in the case of”.
[0089]
(Embodiment 2)
In the present embodiment, only “oscillation stop or suppression when the non-contact power feeding device 1 is alone” and “continuation of oscillation when the non-contact power receiving device 2 is disposed substantially opposite to the non-contact power feeding device 1” are targeted. In this case, a block diagram is shown in FIG. 17, and a specific circuit configuration that can be configured with a very simple system is shown in FIG. In this embodiment, the fifth coil L5, the resonance capacitor C8, and its peripheral elements in FIGS. 1 and 2 are omitted, and the inverter control circuit 13 can be realized with a very simple circuit. The basic configuration is substantially the same as that in FIG. 1 and FIG. 2 of the first embodiment, and the same components are denoted by the same reference numerals and description thereof is omitted.
[0090]
The inverter control circuit 13 of the present embodiment includes a diode D6 that half-wave rectifies the detection signal of the differential resonance circuit 12, a capacitor C9 that smoothes the rectified output, a resistor R9 that is connected in parallel with the capacitor C9, and a detection signal. The rectified and smoothed output is connected to the base, and the oscillation control transistor Tr4 is connected in parallel to the self-excited oscillation control transistor Tr1.
[0091]
The high-frequency inverter circuit 11 is a self-excited oscillation circuit that automatically performs continuous oscillation from startup as in the first embodiment. However, when the transistor Tr4 for oscillation control of the control circuit 13 is turned on, the high-frequency inverter circuit 11 stops oscillation. Then, intermittent oscillation is performed, and when turned off, the high-frequency inverter circuit 11 performs continuous oscillation.
[0092]
Therefore, the output of the differential resonance connection coil constituted by the third and fourth coils L3 and L4 is set so that the output voltage is larger than a predetermined value when the non-contact power receiving device 2 is not provided. If the device 2 is roughly adjusted so that the output voltage becomes smaller than a predetermined value when opposed to each other, the output voltage of the differential resonance circuit 12 increases when the non-contact power feeding device is single, When the transistor Tr4 is turned on to perform intermittent oscillation and the non-contact power receiving device 2 is disposed oppositely, the output voltage of the differential resonance circuit 12 is reduced, and the transistor Tr4 can be turned off to perform continuous oscillation.
[0093]
Therefore, in the use of only “the oscillation stop or suppression when the non-contact power feeding device 1 is alone” and “the oscillation continuation when the non-contact power receiving device 2 is arranged substantially opposite to the non-contact power feeding device 1” The embodiment can be applied to continuous charging such as an electric toothbrush or an electric shaver. That is, in the conventional technique, the non-contact power feeding device 1 continuously oscillates even when the non-contact power receiving device 2 side is removed, which results in wasteful energy consumption. Oscillation can be stopped and suppressed when the contact power supply device 1 is used alone, which can contribute to energy saving.
[0094]
Next, the configuration of the non-contact power feeding apparatus 1 side of the detachable transformer of this embodiment, that is, the primary side of the transformer includes a first core 17 made of a disk-shaped or cylindrical magnetic body, The first coil L1 is wound around the side surface of the first core 17, and the third and fourth coils L3 and L4 are coaxially overlapped with the first coil L1 in the radial direction of the first coil L1, and The third coil L3 is wound around one end of the first core 17 close to the second coil L2, and the fourth coil L4 is wound around the other end of the first core 17. The structure of the secondary side of the transformer is provided with a magnetic core, and a second coil L2 is wound thereon.
[0095]
The non-contact power receiving device 2 is an electric toothbrush that rectifies the output of the second coil L2 by the secondary side circuit 21, charges the secondary battery 22 with this rectified output, and operates the main body circuit 29. Thus, the secondary battery 22 and the main body circuit 29 constitute a load circuit 30.
[0096]
In the circuit configuration shown in FIG. 19, the inverter control circuit 13 is configured only by a diode D7 that half-wave rectifies the output of the differential resonant circuit 12, and this rectified output is supplied to the transistor Tr1 for self-oscillation control. The high frequency inverter circuit 11 is switched between intermittent oscillation and continuous oscillation by connecting to the base and controlling on / off of the transistor Tr1. Since other structures are the same as those of the circuit shown in FIG.
[0097]
Further, other structural examples of the separation / detachable transformer shown in FIGS. 18 and 19 are shown in FIGS. The configuration of the primary side of the transformer of FIG. 20 is such that the third coil shown in FIGS. 18 and 19 is overlapped with the first coil L1 in the radial direction of the first coil L1 and wound coaxially. The configuration of the primary side of the transformer of FIG. 21 is the third and fourth configurations shown in FIGS. 18 and 19, which are wound around the third coil L 3 in the radial direction in the radial direction of the third coil L 3. The coils L3 and L4 are separated in the axial direction of the first coil L1 with the first coil L1 sandwiched in the axial direction, and the third coil L3 is close to the second coil L2 of the first core 17 It is wound around one end, and the fourth coil L4 is wound around the other end of the first core 17.
[0098]
【The invention's effect】
The invention according to claim 1 is a high-frequency inverter circuit that outputs high-frequency power, an inverter control circuit that controls the high-frequency inverter circuit, and a first coil that is supplied with high-frequency power from the high-frequency inverter circuit and performs power supply by magnetic coupling And a differential connection circuit between the third coil and the fourth coil arranged in the vicinity of the first coil to detect the power supply status, and a second output for amplifying the output of the differential connection circuit of the coil. And a differential resonance circuit comprising a resonance capacitor connected to the third coil and the fourth coil, and the inverter control circuit controls the high-frequency inverter circuit based on a detection signal output from the differential resonance circuit. A contact power supply device;
A second coil disposed opposite to the first coil and receiving power by magnetic coupling; a power conversion circuit for converting the output of the second coil into predetermined electrical energy; and electrical energy from the power conversion circuit Since it is configured with a non-contact power receiving device having a load to be supplied, power supply control is performed by identifying the power supply status with the frequency of the power and the signal being the same or close to each other to prevent an increase in noise countermeasure components, Further, the circuit configuration and the transformer structure are simplified, and the overall system size can be reduced and the cost can be reduced. Therefore, a non-contact power transmission device having a simple structure and low noise is provided. There is an effect that can be.
[0099]
According to a second aspect of the present invention, in the first aspect, since the third coil and the fourth coil are arranged so as to be loosely coupled to each other, the power supply status is detected using a differential circuit of the coil. There is an effect that can be.
[0100]
The invention of claim 3 is that in claim 1 or 2, the first coil and at least one of the third coil and the fourth coil are arranged so as to be loosely coupled to each other. The effect similar to that of claim 2 is achieved.
[0101]
According to a fourth aspect of the present invention, in any one of the first to third aspects, the differential resonance circuit detects a change in magnetic flux or magnetic field generated by at least one coil current of the first coil and the second coil. By doing so, the power feeding status is detected, and the same effect as in claim 2 is obtained.
[0102]
According to a fifth aspect of the present invention, in the fourth aspect, the non-contact power receiving device is configured such that at least one fifth coil that generates a magnetic flux signal that gives the status of the self-machine is provided between the third coil and the fourth coil. In the vicinity of the differential connection circuit, the differential resonance circuit detects the power supply status by detecting the magnetic flux signal generated by the fifth coil, so that the load-side status is transmitted to the non-contact power supply device. There is an effect that it is possible to perform power supply control according to the situation on the load side.
[0103]
According to a sixth aspect of the present invention, in the fifth aspect, the non-contact power receiving device includes a resonance capacitor connected in parallel to the fifth coil, so that the magnetic flux generated by the fifth coil can be amplified. is there.
[0104]
The invention according to claim 7 is the invention according to claim 5, wherein the non-contact power receiving device includes a secondary side control circuit that performs excitation control of the fifth coil in accordance with the state of the load. There is an effect that the magnetic flux according to the load condition can be generated.
[0105]
The invention of claim 8 is the invention according to any one of claims 5 to 7, wherein at least one of the third coil and the fourth coil is loosely coupled to the magnetic flux for power transmission generated by the first coil. The arrangement and shape are set so that the number of turns of the third coil and the fourth coil is such that the voltage across the differential connection circuit between the third coil and the fourth coil becomes a predetermined voltage. The detection signal of the differential resonance circuit is increased or decreased with respect to the predetermined voltage according to a magnetic coupling state with the non-contact power receiving device or a magnetic flux signal generated by a fifth coil, and the inverter control circuit Controls the oscillation of the high-frequency inverter circuit based on the detection signal, so that it is possible to perform power feeding control according to the coupling state between the non-contact power feeding device and the non-contact power receiving device and the load status. is there.
[0106]
According to a ninth aspect of the present invention, in the eighth aspect, when the non-contact power feeding device is a single device, the detection signal of the differential resonance circuit becomes a predetermined value or less, and the inverter control circuit is based on the detection signal. Control the oscillation of the high-frequency inverter circuit to intermittent oscillation,
When the first coil and the second coil are disposed substantially opposite to each other, the detection signal of the differential resonance circuit is a first signal generated by the energy source of the non-contact power receiving device or the intermittent oscillation operation of the high-frequency inverter circuit. The secondary-side control circuit provided in the non-contact power receiving device detects a magnetic flux signal generated by exciting the fifth coil by power feeding from the coil, and the non-contact power feeding device is independent. The inverter control circuit controls the oscillation of the high-frequency inverter circuit to continuous oscillation based on the detection signal,
When the continuous power supply from the non-contact power supply device is stopped, the detection signal of the differential resonance circuit indicates that the secondary control circuit stops the excitation of the fifth coil, weakens the excitation, or intermittent excitation. Or a signal obtained by detecting a magnetic flux signal generated by changing the excitation frequency, and a voltage value smaller than a detection signal when the high-frequency inverter circuit is continuously oscillating, and the inverter control circuit detects the detection Since the oscillation of the high-frequency inverter circuit is controlled to intermittent oscillation based on the signal, the same effect as in the eighth aspect can be obtained.
[0107]
A tenth aspect of the present invention is that, in the ninth aspect, the inverter control circuit includes periodic oscillation start means for starting oscillation of the high-frequency inverter circuit at regular intervals, and halts oscillation after a certain period of time after starting the oscillation. Means for controlling the intermittent oscillation and the continuous oscillation of the high-frequency inverter circuit by controlling the oscillation forced stop means and the continuation and release of the oscillation forced stop means according to the detection signal of the differential resonance circuit; Therefore, there is an effect that intermittent oscillation or continuous oscillation can be performed according to a coupling state between the non-contact power feeding device and the non-contact power receiving device and a load state.
[0108]
According to an eleventh aspect of the present invention, in the tenth aspect, the forced oscillation stop means uses a voltage generated in the first coil, and the steady oscillation starts after the high-frequency inverter circuit starts oscillation by the periodic oscillation start means. Since there is means for detecting that oscillation has started in the process of shifting to oscillation, there is an effect that intermittent oscillation can be performed.
[0109]
According to a twelfth aspect of the present invention, in the tenth or eleventh aspect, the amplitude of the voltage generated in the first coil is greater after the oscillation starts than when the high-frequency inverter circuit stops oscillating. An integration circuit charged by a voltage generated in one coil, and means for detecting that the voltage charged in the integration circuit has exceeded a predetermined value after oscillation starts and stopping oscillation of the high-frequency inverter circuit Thus, there is an effect that a specific circuit of the forced oscillation stop means can be configured.
[0110]
According to a thirteenth aspect of the present invention, in the twelfth aspect, the means for controlling the intermittent oscillation and the continuous oscillation of the high-frequency inverter circuit is a charge of a capacitor constituting the integrating circuit in accordance with a detection signal of the differential resonance circuit. The means for forcibly stopping the oscillation is prevented by preventing the oscillation of the voltage charged in the integrating circuit from exceeding a predetermined value, thereby switching between intermittent oscillation and continuous oscillation. There is an effect that can be done.
[0111]
A fourteenth aspect of the present invention includes the first and second cores according to any one of the fifth to thirteenth aspects, comprising first and second cores made of a U-shaped magnetic body having protrusions at both ends. The first coil wound between the parts and the second coil wound between the projecting parts of the second core constitute a transformer structure that is detachable from each other, and the third coil is the first coil The first coil is wound around at least one of the projecting portions of the core, the fourth coil is coaxially wound over the first coil in the radial direction of the first coil, and the fifth coil is the third coil. Since it is wound around the protrusion of the second core facing the coil, a non-contact power feeding device and a non-contact power receiving device constitute a transformer structure that is detachable and removable using a U-shaped core. There is an effect that can be.
[0112]
A fifteenth aspect of the present invention includes the first and second cores according to any one of the fifth to thirteenth aspects, comprising first and second cores made of U-shaped magnetic bodies having protrusions at both ends. The first coil wound between the parts and the second coil wound between the projecting parts of the second core constitute a transformer structure that is detachable from each other. The coil is wound between both projecting portions of the first core with the first coil sandwiched in the axial direction, and the fifth coil is axially disposed between both projecting portions of the second core. Thus, the same effect as in the fourteenth aspect can be obtained.
[0113]
A sixteenth aspect of the present invention includes the first and second cores according to any one of the fifth to thirteenth aspects, comprising first and second cores made of a U-shaped magnetic body having protrusions at both ends. The first coil wound between the parts and the second coil wound between the projecting parts of the second core constitute a transformer structure that is detachable from each other, and the third coil is the first coil The first coil is axially separated and wound between both projecting portions of the first core, and the fourth coil is coaxially wound on the first coil in the radial direction of the first coil. Since the fifth coil is wound between the protrusions of the second core and separated from the second coil in the axial direction so as to face the third coil, the same effect as in the fourteenth aspect can be obtained. Play.
[0114]
A seventeenth aspect of the present invention provides the first and second cores according to any one of the fifth to thirteenth aspects, comprising first and second cores made of a U-shaped magnetic body having protrusions at both ends. The first coil wound around the part and the second coil wound around both protrusions of the second core form a transformer structure that is detachable from each other, and the third coil is the first coil The fourth coil is wound around at least one of the first core protrusions, and the fifth coil is a recess between the protrusions of the second core. Thus, the same effect as in the fourteenth aspect can be achieved.
[0115]
The invention of claim 18 includes the first and second cores made of a magnetic material having an E-shaped cross section provided with protrusions at both ends and in the center according to any one of claims 5 to 13, wherein the center of the first core is provided. The first coil wound around the protrusion and the second coil wound around the center protrusion of the second core constitute a transformer structure that is detachable from each other, and the third coil is the first coil The first coil is wound around at least one of the protrusions at both ends of the core, the fourth coil is wound coaxially with the first coil in the radial direction of the first coil, and the fifth coil is the third coil. Since it is wound around the protrusion of the second core facing the other coil, the same effect as in the fourteenth aspect can be achieved by using the core having an E-shaped cross section.
[0116]
The invention of claim 19 comprises the first and second cores of the cross-section E-type magnetic body provided with protrusions at both ends and in the center according to any one of claims 5 to 13, wherein the center of the first core is provided. The first coil wound around the protrusion and the second coil wound around the center protrusion of the second core constitute a transformer structure that is detachable from each other, and the third coil is the first coil One of the protrusions at both ends of one core is wound on one side, the fourth coil is wound on the other of the protrusions at both ends of the first core, and the fifth coil faces the third coil. Since it is wound around the protrusion of the second core, the same effect as that of the 18th aspect can be achieved.
[0117]
A twentieth aspect of the invention relates to any one of the fifth to thirteenth aspects of the present invention, wherein the cylindrical pot-shaped core is substantially divided into the first core and the second core is the other. And the first and second cores each have a protrusion on the substantially central inner surface in the axial direction, the first coil wound around the central protrusion of the first core, and the second The second coil wound around the central projecting portion of the core forms a transformer structure that is detachable from the second coil. The third and fourth coils are formed as first coils in the radial direction of the first coil. The coil is coaxially overlapped, and the third coil is wound in the axial direction so as to be close to the second core, and the fifth coil is wound in the radial direction of the second coil. Since the second coil is wound coaxially with the second coil and opposed to the third coil, a cylindrical pot-shaped core is used. 4 provides the same effect as.
[0118]
A twenty-first aspect of the present invention provides the first or second aspect of the present invention, comprising the first or second core made of a disk-shaped or cylindrical magnetic body, and wound around the side surface of the first core. The coil and the second coil wound around the side surface of the second core constitute a transformer structure that is detachable from each other. The third and fourth coils are coaxial with the first coil and The third coil is wound separately from the fourth coil in the axial direction so as to be close to the second core, and the fifth coil is coaxial with the second coil and faces the third coil. Since it is wound, the same effect as that of claim 14 can be obtained by using a disk-shaped or cylindrical core.
[0119]
The invention of claim 22 is any one of claims 5 to 13, wherein at least one of the first coil and the second coil is wound around a disk or a core made of a cylindrical magnetic material, The first coil and the second coil constitute a transformer structure that is detachable from each other. The third and fourth coils are coaxial with the first coil, and the third coil is the second coil. The fourth coil is wound separately from the fourth coil in the axial direction so as to be close to the first coil, and the fifth coil is wound coaxially with the second coil so as to face the third coil. The same effects as those of the fourteenth aspect can be achieved by using a disk-shaped or cylindrical core for at least one of the second coil and the second coil.
[0120]
According to a twenty-third aspect of the present invention, in the first aspect, the high-frequency inverter circuit performs self-excited oscillation, and the detection signal of the differential resonance circuit is a signal obtained by detecting a magnetic flux due to the current of the first coil. When the non-contact power feeding device is single, the detection signal of the differential resonance circuit is a signal larger than a predetermined voltage value, and the inverter control circuit is configured to generate the high-frequency inverter circuit based on a signal obtained by smoothing the detection signal. When the first coil and the second coil are arranged substantially opposite to each other, the detection signal of the differential resonance circuit is obtained when the non-contact power feeding device is alone. 1 is a signal smaller than a predetermined voltage value obtained by detecting a magnetic flux whose distribution, intensity, and direction have changed with respect to the magnetic flux generated by one coil, and the inverter control circuit is based on a signal obtained by smoothing the detection signal. And controls the continuous oscillation of the oscillation of the high frequency inverter circuit Te, oscillation stop when the non-contact power feeding device alone can perform suppression, there is an effect that can contribute to energy saving.
[0121]
According to a twenty-fourth aspect of the present invention, in the twenty-third aspect, the high-frequency inverter circuit that performs self-excited oscillation includes an oscillation switching element, an activation circuit for activating oscillation of the oscillation switching element, and a magnetic force applied to the first coil. A voltage resonance type inverter circuit comprising a coupled feedback coil, a capacitor connected in parallel to the first coil or the oscillation switching element, and a self-excited control switching element for connecting the control terminal of the oscillation switching element to the ground level The oscillation switching element is turned on by the induced voltage of the feedback coil and the output of the starter circuit, and the self-excitation control switching element is turned on and the oscillation switching element is turned off after a predetermined time from turning on. The self-excited oscillation is performed, and the same effect as in the 23rd aspect is obtained.
[0122]
According to a twenty-fifth aspect of the invention, in the twenty-fourth aspect, the inverter control circuit rectifies and smoothes a detection signal of the differential resonance circuit, and connects an output of the rectifying and smoothing circuit to a control terminal, so that the self-excitation The switching element for oscillation control connected in parallel to the switching element for control can be switched between intermittent oscillation and continuous oscillation by turning on and off the oscillation control switching element by the detection signal of the differential resonance circuit. The effect similar to that of the twenty-third aspect can be obtained by adding very few parts.
[0123]
According to a twenty-sixth aspect of the present invention, in the twenty-fourth aspect, the inverter control circuit includes a circuit that rectifies and smoothes the detection signal of the differential resonance circuit, and outputs the rectifying and smoothing circuit of the switching element for self-excitation control. Since it is connected to the control terminal, the same effect as in the 25th aspect can be obtained by turning on / off the self-excited control switching element by the detection signal of the differential resonance circuit.
[0124]
A twenty-seventh aspect of the present invention is the method according to any one of the twenty-third to twenty-sixth aspects, further comprising a core made of a disk-shaped or cylindrical magnetic body, wherein the first coil is wound around the side surface of the core, The fourth coil is coaxially wound on the first coil in the radial direction of the first coil, and the second coil is disposed so as to face the first coil in the axial direction. The same effects as in the fourteenth aspect can be obtained by using a core made of a magnetic material.
[0125]
A twenty-eighth aspect of the present invention is the method according to any one of the twenty-third to twenty-sixth aspects, further comprising a core made of a disk-shaped or cylindrical magnetic body, wherein the first coil is wound around a side surface of the core, The coil No. 4 is wound around the side surface of the core in the axial direction separately from the first coil, and the second coil is disposed opposite to the axial direction of the first coil. The effect of.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a block configuration according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a specific circuit configuration of the above.
FIG. 3 is a diagram showing waveforms at various parts from the above oscillation to the continuous oscillation.
FIG. 4 is a diagram showing waveforms at various parts from the same oscillation to intermittent oscillation.
FIG. 5 is a side sectional view showing a first structure example of the above-described separation / detachment type transformer.
FIG. 6 is a side sectional view showing a primary side of a second structural example of the above-described separation / detachment type transformer.
FIG. 7 is a side sectional view showing a primary side and a secondary side of a second structural example of the above-described separation / detachment type transformer.
FIG. 8 is a side sectional view showing the entire second structural example of the above-described separation / detachment type transformer.
FIG. 9 is a side sectional view showing a third structural example of the above-described separation / detachment type transformer.
FIG. 10 is a side sectional view showing a fourth structural example of the above-described separation / detachment type transformer.
FIG. 11 is a side sectional view showing a fifth structural example of the above-described separation / detachment type transformer.
FIG. 12 is a side sectional view showing a sixth structural example of the above-described separation / detachment type transformer.
FIG. 13 is a side sectional view showing a seventh structure example of the separation / detachment type transformer.
FIG. 14 is a side sectional view showing an eighth structure example of the above-described separation / detachment type transformer.
FIG. 15 is a side sectional view showing a ninth structural example of the above-described separation / detachment type transformer.
FIG. 16 is a side sectional view showing a tenth structural example of the above-described separation / detachment type transformer.
FIG. 17 is a diagram showing a block configuration according to the second embodiment of the present invention.
FIG. 18 is a diagram showing a specific circuit configuration of the above.
FIG. 19 is a diagram showing another circuit configuration of the above.
FIG. 20 is a side sectional view showing an example of the structure of the above-described separation / detachment type transformer.
FIG. 21 is a side sectional view showing another structural example of the above-described separation / detachment type transformer.
[Explanation of symbols]
1 Contactless power supply
2 Non-contact power receiving device
11 High frequency inverter circuit
12 Differential resonance circuit
13 Inverter control circuit
21 Power conversion circuit
22 Secondary battery
23 Secondary side control circuit
L1 to L5 1st to 5th coils
C4, C8 resonant capacitor

Claims

A high-frequency inverter circuit that outputs high-frequency power, an inverter control circuit that controls the high-frequency inverter circuit, a first coil that is supplied with high-frequency power from the high-frequency inverter circuit and that supplies power by magnetic coupling, and detects a power supply state In order to amplify the differential connection circuit between the third coil and the fourth coil arranged in the vicinity of the first coil and the differential connection circuit of the coil, the third coil and the fourth coil A non-contact power feeding device including a differential resonance circuit including a resonance capacitor connected to a coil, wherein the inverter control circuit controls the high-frequency inverter circuit based on a detection signal output from the differential resonance circuit;
A second coil disposed opposite to the first coil and receiving power by magnetic coupling; a power conversion circuit for converting the output of the second coil into predetermined electrical energy; and electrical energy from the power conversion circuit A non-contact power transmission device comprising a non-contact power receiving device having a load to be supplied.

The non-contact power transmission device according to claim 1, wherein the third coil and the fourth coil are disposed so as to be loosely coupled to each other.

3. The non-contact power according to claim 1, wherein at least one of the first coil, the third coil, and the fourth coil is disposed so as to be loosely coupled to each other. Transmission device.

The differential resonance circuit detects a power supply state by detecting a change in a magnetic flux or a magnetic field generated by at least one coil current of the first coil and the second coil. Item 4. The non-contact power transmission device according to any one of Items 1 to 3.

The non-contact power receiving device includes at least one fifth coil that generates a magnetic flux signal that gives a situation of the own device in the vicinity of a differential connection circuit of a third coil and a fourth coil, and the differential The contactless power transmission device according to claim 4, wherein the resonance circuit detects a power supply state by detecting a magnetic flux signal generated by the fifth coil.

The contactless power transmission device according to claim 5, wherein the contactless power receiving device includes a resonant capacitor connected in parallel to a fifth coil.

6. The non-contact power transmission apparatus according to claim 5, wherein the non-contact power receiving apparatus includes a secondary side control circuit that performs excitation control of the fifth coil in accordance with the state of the load.

At least one of the third coil and the fourth coil is set to be loosely coupled to the magnetic flux for power transmission generated by the first coil, and the third coil and the fourth coil are set. The number of turns of each coil is set so that the voltage across the differential connection circuit between the third coil and the fourth coil is a predetermined voltage, and the detection signal of the differential resonance circuit The inverter control circuit controls oscillation of the high-frequency inverter circuit based on the detection signal based on the magnetic coupling status with the contact power receiving device or the magnetic flux signal generated by the fifth coil. The non-contact power transmission device according to claim 5, wherein:

When the non-contact power feeding device is single, the detection signal of the differential resonance circuit becomes a predetermined value or less, and the inverter control circuit controls the oscillation of the high-frequency inverter circuit to intermittent oscillation based on the detection signal. And
When the first coil and the second coil are disposed substantially opposite to each other, the detection signal of the differential resonance circuit is a first signal generated by the energy source of the non-contact power receiving device or the intermittent oscillation operation of the high-frequency inverter circuit. The secondary-side control circuit provided in the non-contact power receiving device detects a magnetic flux signal generated by exciting the fifth coil by power feeding from the coil, and the non-contact power feeding device is independent. The inverter control circuit controls the oscillation of the high-frequency inverter circuit to continuous oscillation based on the detection signal,
When the continuous power supply from the non-contact power supply device is stopped, the detection signal of the differential resonance circuit indicates that the secondary control circuit stops the excitation of the fifth coil, weakens the excitation, or intermittent excitation. Or a signal obtained by detecting a magnetic flux signal generated by changing the excitation frequency, and a voltage value smaller than a detection signal when the high-frequency inverter circuit is continuously oscillating, and the inverter control circuit detects the detection 9. The non-contact power transmission device according to claim 8, wherein oscillation of the high-frequency inverter circuit is controlled to intermittent oscillation based on a signal.

The inverter control circuit includes periodic oscillation start means for starting oscillation of the high-frequency inverter circuit at regular intervals, oscillation forced stop means for stopping oscillation after a fixed time from the start of oscillation, and the differential resonance circuit 10. The apparatus according to claim 9, further comprising means for controlling intermittent oscillation and continuous oscillation of the high-frequency inverter circuit by controlling continuation and cancellation of the oscillation forced stop means according to a detection signal. Non-contact power transmission device.

The oscillation forced stop means uses the voltage generated in the first coil, and oscillation has started in the process of transitioning to steady oscillation after the oscillation of the high-frequency inverter circuit is started by the periodic oscillation start means. The non-contact power transmission device according to claim 10, further comprising means for detecting

The amplitude of the voltage generated in the first coil is greater after the start of oscillation than when the high-frequency inverter circuit stops oscillating, and the oscillation forced stop means includes an integrating circuit charged by the voltage generated in the first coil; And a means for stopping the oscillation of the high-frequency inverter circuit by detecting that the voltage charged in the integrating circuit exceeds a predetermined value after the start of oscillation. Contact power transfer device.

The means for controlling intermittent oscillation and continuous oscillation of the high-frequency inverter circuit comprises means for extracting a charge of a capacitor constituting the integration circuit in accordance with a detection signal of the differential resonance circuit, and charging the integration circuit The contactless power transmission device according to claim 12, wherein the operation of the forced oscillation stop means is prevented by preventing the generated voltage from exceeding a predetermined value.

A first coil comprising first and second cores made of a U-shaped magnetic body having protrusions at both ends, and wound between both protrusions of the first core; and a second core The second coil wound between the two protrusions constitutes a transformer structure that is detachable from the second coil, and the third coil is wound around at least one of the two protrusions of the first core, The fourth coil is wound coaxially on the first coil in the radial direction of the first coil, and the fifth coil is wound on the protrusion of the second core facing the third coil. The non-contact power transmission device according to claim 5, wherein

A first coil comprising first and second cores made of a U-shaped magnetic body having protrusions at both ends, and wound between both protrusions of the first core; and a second core The second coil wound between the two protrusions constitutes a transformer structure that is detachable from the second coil. The third and fourth coils sandwich the first coil in the axial direction, The fifth coil is wound between the projecting portions of the core, and the fifth coil is wound between the projecting portions of the second core so as to be separated from the second coil in the axial direction so as to face the third coil. The non-contact power transmission device according to claim 5, wherein

A first coil comprising first and second cores made of a U-shaped magnetic body having protrusions at both ends, and wound between both protrusions of the first core; and a second core The second coil wound between the two protrusions forms a transformer structure that can be separated from and attached to the second coil. The third coil is separated from the first coil in the axial direction and separated from the first core. The fourth coil is wound around the first coil in the radial direction of the first coil, is coaxially wound around the first coil, and the fifth coil is wound between the two cores. The contactless power transmission device according to any one of claims 5 to 13, wherein the second coil is wound in an axial direction so as to face the third coil.

First and second cores made of a U-shaped magnetic body having protrusions at both ends, a first coil wound around both protrusions of the first core, and a second core The second coil wound around both protrusions constitutes a transformer structure that is detachable from each other, and the third coil is disposed in a recess between both protrusions of the first core, and the fourth coil Is wound around at least one of both protrusions of the first core, and the fifth coil is disposed in a recess between both protrusions of the second core so as to face the third coil. The non-contact power transmission device according to claim 5.

A first coil having first and second cores made of a magnetic material having an E-shaped cross section with protrusions at both ends and in the center, and wound around the central protrusion of the first core; and a second core The second coil wound around the central protrusion of the first and second coils forms a transformer structure that can be separated from and attached to the second coil. The third coil is wound around at least one of the protrusions at both ends of the first core. The fourth coil is coaxially wound on the first coil in the radial direction of the first coil, and the fifth coil is wound around the protrusion of the second core facing the third coil. The non-contact power transmission device according to claim 5, wherein the non-contact power transmission device is a non-contact power transmission device.

A first coil having first and second cores made of a magnetic material having an E-shaped cross section with protrusions at both ends and in the center, and wound around the central protrusion of the first core; and a second core The second coil wound around the central protrusion of the first and second coils constitutes a detachable and detachable transformer structure, and the third coil is wound around one of the protrusions at both ends of the first core, The fourth coil is wound around the other of the protrusions at both ends of the first core, and the fifth coil is wound around the protrusion of the second core facing the third coil. The non-contact power transmission device according to claim 5.

A cylindrical pot-shaped core is provided with a first core that is substantially divided in the axial direction and a second core that is the other, and the first and second cores are substantially in the axial direction. The first coil wound around the central protrusion of the first core and the second coil wound around the central protrusion of the second core are provided with protrusions on the central inner surface, respectively. The transformer structure is detachable from each other. The third and fourth coils are coaxially overlapped with the first coil in the radial direction of the first coil, and the third coil is the second core. The fourth coil is wound separately from the fourth coil in the axial direction so as to be close to each other, and the fifth coil is coaxially overlapped with the second coil in the radial direction of the second coil and opposed to the third coil. The non-contact power transmission device according to claim 5, wherein the non-contact power transmission device is wound.

A first coil wound around the side surface of the first core, and a second coil wound around the side surface of the second core. The coil has a transformer structure that is detachable from the coil. The third and fourth coils are coaxial with the first coil, and the third coil is close to the second core. The coil is wound separately in the axial direction, and the fifth coil is wound coaxially with the second coil and facing the third coil. The non-contact power transmission device described.

At least one of the first coil and the second coil is wound on a disk or a core made of a cylindrical magnetic body, and the first coil and the second coil are detachable from each other. It constitutes a transformer structure, and the third and fourth coils are separated from the fourth coil in the axial direction so that it is coaxial with the first coil and the third coil is close to the second coil. The non-contact power transmission device according to claim 5, wherein the fifth coil is wound coaxially with the second coil so as to face the third coil.

The high-frequency inverter circuit performs self-excited oscillation, and the detection signal of the differential resonance circuit is a signal obtained by detecting a magnetic flux due to the current of the first coil, and when the non-contact power feeding device is alone, The detection signal of the differential resonance circuit is a signal larger than a predetermined voltage value, and the inverter control circuit controls the oscillation of the high-frequency inverter circuit to intermittent oscillation based on a signal obtained by smoothing the detection signal. When the coil and the second coil are disposed substantially opposite to each other, the detection signal of the differential resonance circuit is distributed with respect to the magnetic flux generated by the first coil when the non-contact power feeding device is alone, The inverter control circuit continuously links the oscillation of the high frequency inverter circuit based on a signal obtained by smoothing the detection signal. A contactless power transmission system according to claim 1, wherein the controller controls the oscillation.

The high-frequency inverter circuit that performs self-excited oscillation includes an oscillation switching element, an activation circuit for activating oscillation of the oscillation switching element, a feedback coil magnetically coupled to the first coil, and the first coil or oscillation A voltage resonance type inverter circuit including a capacitor connected in parallel to the switching element for oscillation and a switching element for self-excitation control that connects the control terminal of the oscillation switching element to the ground level, and the oscillation switching element is connected to the feedback coil. 24. The non-contact power according to claim 23, wherein the non-contact power is turned on by an induced voltage and an output of the starting circuit, and the self-excitation control switching element is turned on and the oscillation switching element is turned off after a predetermined time from the turning on. Transmission device.

The inverter control circuit is a circuit for rectifying and smoothing a detection signal of the differential resonance circuit, an output of the rectifying and smoothing circuit connected to a control terminal, and connected to the self-excited control switching element in parallel. The non-contact power transmission device according to claim 24, further comprising a switching element.

The inverter control circuit includes a circuit for rectifying and smoothing a detection signal of the differential resonance circuit, and an output of the rectifying and smoothing circuit is connected to a control terminal of the switching element for self-excitation control. The non-contact power transmission device according to 24.

A core made of a disk-like or cylindrical magnetic body is provided, the first coil is wound around the side surface of the core, and the third and fourth coils are first in the radial direction of the first coil. 27. The non-contact power transmission device according to any one of claims 23 to 26, wherein the second coil is disposed coaxially with the coil so as to be opposed to the first coil in the axial direction.

The first coil is wound around the side surface of the core, and the third and fourth coils are the first coil on the side surface of the core. 27. The non-contact power transmission device according to claim 23, wherein the second coil is wound separately in the axial direction, and the second coil is disposed opposite to the first coil in the axial direction.