JP4968399B2

JP4968399B2 - LED driving device and LED lighting device

Info

Publication number: JP4968399B2
Application number: JP2011123255A
Authority: JP
Inventors: 充達吉永
Original assignee: Sanken Electric Co Ltd
Current assignee: Sanken Electric Co Ltd
Priority date: 2011-03-30
Filing date: 2011-06-01
Publication date: 2012-07-04
Anticipated expiration: 2031-06-01
Also published as: WO2012132048A1; JP2012033888A

Abstract

An LED drive device comprises: an insulating power conversion unit, further comprising a transformer having a primary coil, a secondary coil, and a tertiary coil, and a switching element which is connected to the first coil, said insulating power conversion unit supplying power to an LED load via the secondary coil; a feedback unit which is connected to the tertiary coil, said feedback unit further comprising a control information detection unit which detects control information and a voltage detection unit which detects coil voltage information of the tertiary coil; and a control unit which controls the switching element on and off. The feedback unit outputs a feedback signal wherein the control information based on the on-off control and the coil voltage information are superpositioned, and the control unit carries out the on-off control based on the feedback signal.

Description

本発明は、ＬＥＤ（発光ダイオード）を光源とするＬＥＤ駆動装置及びこれを用いたＬＥＤ照明装置に関する。 The present invention relates to an LED driving device using an LED (light emitting diode) as a light source and an LED lighting device using the same.

従来、室内外に設置される照明装置の光源として、白熱電球或いは蛍光灯等が用いられている。近年、白色ＬＥＤ（Light Emitting Diode）が開発され、ＬＥＤの高輝度化及び高効率化が進むに伴い、ＬＥＤを光源とするＬＥＤ照明装置が実用化されている。白色ＬＥＤの構成は、例えば、Ｒ（赤）、Ｇ（緑）、Ｂ（青）の３色のＬＥＤの光を混色して白色光を得る構成や、青色のような短波長ＬＥＤに蛍光体を組合せて白色光を得る構成などが知られている。 Conventionally, an incandescent bulb or a fluorescent lamp is used as a light source of a lighting device installed indoors and outdoors. In recent years, white LEDs (Light Emitting Diodes) have been developed, and LED lighting devices using LEDs as light sources have been put into practical use as LED brightness and efficiency have increased. The configuration of the white LED is, for example, a configuration in which white light is obtained by mixing the light of LEDs of three colors of R (red), G (green), and B (blue), or a phosphor in a short wavelength LED such as blue. A configuration is known in which white light is obtained by combining the above.

ＬＥＤ照明装置を構成し、ＬＥＤの駆動電流を出力するＬＥＤ駆動装置には、周知のスイッチングレギュレータからなるＤＣ−ＤＣコンバータが用いられる。なお、ＬＥＤは、非線形なＩ−Ｖ（電流−電圧）特性を有し、印加される順方向バイアスが所定のＶＦ（順方向電圧）値未満の場合、順方向電流がほとんど流れず発光しないが、順方向バイアスが所定のＶＦ値を超える場合、電圧上昇に対して急激に電流増加するようになり、電流量に応じて発光するようになる。また、ＬＥＤのＶＦ特性は一般的に±１０％程度の個体差を有し、発光（通電）時の発熱により変動することが知られ、これらの個体差や変動は、ＬＥＤ照明装置において光のちらつきの原因になってしまう。 A DC-DC converter including a well-known switching regulator is used for an LED driving device that constitutes an LED lighting device and outputs an LED driving current. The LED has a non-linear IV (current-voltage) characteristic. When the applied forward bias is less than a predetermined VF (forward voltage) value, the forward current hardly flows and does not emit light. When the forward bias exceeds a predetermined VF value, the current rapidly increases as the voltage rises, and light is emitted according to the amount of current. In addition, the VF characteristics of LEDs generally have individual differences of about ± 10%, and are known to fluctuate due to heat generation during light emission (energization). It causes flickering.

ＬＥＤ駆動装置は、上記のようにＶＦ特性の個体差及び変動に関わらずＬＥＤを所定の輝度で安定的に発光させることが求められる。例えば一般照明用の日本電球工業会規格ＪＥＬ８０１によれば、ＬＥＤ駆動装置は、ＬＥＤ電流の変動を所定値の±１０％以内に制御しなければならない。従って、ＬＥＤ駆動装置は、ＬＥＤに流れる電流を一定に制御するための定電流制御フィードバックループを備える必要がある。 As described above, the LED driving device is required to stably emit light at a predetermined luminance regardless of individual differences and fluctuations in the VF characteristics. For example, according to the Japan Light Bulb Industry Association Standard JEL801 for general illumination, the LED driving device must control the fluctuation of the LED current within ± 10% of a predetermined value. Therefore, the LED driving device needs to include a constant current control feedback loop for controlling the current flowing through the LED to be constant.

また、一般的に人が比較的容易に手を触れることができる民生品においては、感電防止等の安全性を備えることが要求されるため、ＬＥＤ駆動装置は、商用電源と負荷との間を電気的に絶縁するトランスを含んで構成される必要がある。 In general, consumer products that can be easily touched by humans are required to have safety such as prevention of electric shock. It is necessary to include an electrically insulating transformer.

図１０に示すように、特許文献１に記載される従来のＬＥＤ駆動装置の構成は、一般にフライバックコンバータと呼ばれ、絶縁型スイッチング電源として知られている。従来のＬＥＤ照明装置３００は、ＬＥＤ駆動装置２０１とＬＥＤ負荷２０２とを有する。ＬＥＤ駆動装置２０１は、入力コンデンサ２１１と、トランス２１２と、ＭＯＳＦＥＴ２１３と、制御部２１９とを有する。また、ＬＥＤ駆動装置２０１は、誤差増幅器２１５と、ダイオード２１６と、フォトカプラ２１７とを有する。 As shown in FIG. 10, the configuration of the conventional LED driving device described in Patent Document 1 is generally called a flyback converter, and is known as an isolated switching power supply. The conventional LED lighting device 300 includes an LED driving device 201 and an LED load 202. The LED driving device 201 includes an input capacitor 211, a transformer 212, a MOSFET 213, and a control unit 219. Further, the LED driving device 201 includes an error amplifier 215, a diode 216, and a photocoupler 217.

従来のＬＥＤ照明装置の誤差増幅器２１５は、電流検出抵抗２１８に発生する電圧と基準電圧源の電圧値とに基づいて演算を行い、フォトカプラ２１７を介して制御部２１９に演算結果をフィードバックすることで、ＬＥＤ駆動装置２０１がＬＥＤ負荷２０２に流れる電流を一定に制御する。 The error amplifier 215 of the conventional LED lighting device performs calculation based on the voltage generated in the current detection resistor 218 and the voltage value of the reference voltage source, and feeds back the calculation result to the control unit 219 via the photocoupler 217. Thus, the LED driving device 201 controls the current flowing through the LED load 202 to be constant.

特開２０１０−０９２９９７号公報JP 2010-092997 A

従来のＬＥＤ駆動装置３００は、ＬＥＤ負荷２０２に流れる電流に応じてＭＯＳＦＥＴ２１３を制御するために、トランス２１２の二次側で検出されたＬＥＤ電流に基づく信号をトランス２１２の一次側に設けられた制御部２１９に伝達するフォトカプラ２１７を用いる必要があった。また、フォトカプラ２１７の駆動回路として誤差増幅器２１５及びその電源回路等の周辺部品が必要であり、ＬＥＤ駆動装置及びＬＥＤ照明装置の小型化、低コスト化を妨げてしまう。 In the conventional LED driving device 300, a signal based on the LED current detected on the secondary side of the transformer 212 is provided on the primary side of the transformer 212 in order to control the MOSFET 213 according to the current flowing through the LED load 202. It is necessary to use a photocoupler 217 that transmits to the unit 219. Moreover, peripheral components such as the error amplifier 215 and its power supply circuit are required as a driving circuit for the photocoupler 217, which hinders downsizing and cost reduction of the LED driving device and the LED lighting device.

本発明は、小型且つ低コストに構成され、ＬＥＤ負荷の定電流制御を行うＬＥＤ駆動装置及びＬＥＤ照明装置を提供することを目的とする。 An object of the present invention is to provide an LED driving device and an LED lighting device that are configured in a small size and at low cost and perform constant current control of an LED load.

本発明の一態様によれば、一次巻線、二次巻線及び三次巻線を有するトランスと該一次巻線に接続されるスイッチング素子とを有し、前記二次巻線を介してＬＥＤ負荷に電力を供給する絶縁型の電力変換部と、前記三次巻線に接続され、制御情報を検出する制御情報検出部と前記三次巻線の巻線電圧情報を検出する電圧検出部とを有するフィードバック部と、前記スイッチング素子をオンオフ制御する制御部と、を備え、前記フィードバック部は、前記オンオフ制御に基づく前記制御情報と前記巻線電圧情報とが重畳されたフィードバック信号を出力し、前記制御部は、前記フィードバック信号に基づき前記オンオフ制御を行うとともに前記制御情報と前記巻線電圧情報とに基づき前記電力を制御することを特徴とするＬＥＤ駆動装置が提供される。 According to one aspect of the present invention, a transformer having a primary winding, a secondary winding, and a tertiary winding, and a switching element connected to the primary winding, the LED load via the secondary winding. A feedback having an insulation type power converter for supplying power to the power source, a control information detector connected to the tertiary winding for detecting control information, and a voltage detector for detecting winding voltage information of the tertiary winding And a control unit that performs on / off control of the switching element, the feedback unit outputs a feedback signal in which the control information based on the on / off control and the winding voltage information are superimposed, and the control unit is, LED driving device provided, characterized in that performs the on-off control on the basis of the feedback signal for controlling the power based on said control information and said winding voltage information It is.

また、本発明の一態様によれば、少なくとも１つのＬＥＤを含むＬＥＤ負荷と、一次巻線、二次巻線及び三次巻線を有するトランスと該一次巻線に接続されるスイッチング素子とを有し、前記二次巻線を介して前記ＬＥＤ負荷に電力を供給する絶縁型の電力変換部と、前記三次巻線に接続され、制御情報を検出する制御情報検出部と前記三次巻線の巻線電圧情報を検出する電圧検出部とを有するフィードバック部と、前記スイッチング素子をオンオフ制御する制御部と、を備え、前記フィードバック部は、前記オンオフ制御に基づく前記制御情報と前記巻線電圧情報とが重畳されたフィードバック信号を出力し、前記制御部は、前記フィードバック信号に基づき前記オンオフ制御を行うとともに前記制御情報と前記巻線電圧情報とに基づき前記電力を制御することを特徴とするＬＥＤ照明装置が提供される。 According to one aspect of the present invention, there is provided an LED load including at least one LED, a transformer having a primary winding, a secondary winding, and a tertiary winding, and a switching element connected to the primary winding. And an insulated power converter that supplies power to the LED load via the secondary winding, a control information detector that is connected to the tertiary winding and detects control information, and a winding of the tertiary winding. A feedback unit including a voltage detection unit that detects line voltage information; and a control unit that performs on / off control of the switching element, wherein the feedback unit includes the control information based on the on / off control, and the winding voltage information. There outputs a feedback signal which is superimposed, wherein, before on the basis of said winding voltage information and the control information performs the on-off control on the basis of the feedback signal LED lighting apparatus is provided, characterized in that to control the power.

本発明によれば、トランスの三次巻線に接続されるフィードバック部がスイッチング素子のオンオフ制御に基づく制御情報と三次巻線の巻線電圧情報とが重畳されたフィードバック信号を出力し、制御部がフィードバック信号によりスイッチング素子のオンオフ制御を行うとともに制御情報と巻線電圧情報とに基づき電力を制御するため、小型且つ低コストに構成され、ＬＥＤ負荷の定電流制御を行うＬＥＤ駆動装置及びＬＥＤ照明装置を提供できる。

According to the present invention, the feedback unit connected to the tertiary winding of the transformer outputs a feedback signal in which the control information based on the on / off control of the switching element and the winding voltage information of the tertiary winding are superimposed, and the control unit An LED driving device and an LED lighting device that are configured in a small size and at low cost and perform constant current control of an LED load, because on / off control of a switching element is performed by a feedback signal and electric power is controlled based on control information and winding voltage information Can provide.

本発明の第１の実施例に係るＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。It is a circuit diagram which shows the structure of the LED drive device and LED lighting apparatus which concern on 1st Example of this invention. 本発明の第１の実施例に係るＬＥＤ駆動装置の特性を説明するためのＶＦ−ＩＬＥＤ特性図である。It is a VF-ILED characteristic view for explaining the characteristic of the LED drive device concerning the 1st example of the present invention. 本発明の第１の比較例に係るＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。It is a circuit diagram which shows the structure of the LED drive device and LED lighting apparatus which concern on the 1st comparative example of this invention. 本発明の第２の比較例に係るＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。It is a circuit diagram which shows the structure of the LED drive device and LED lighting apparatus which concern on the 2nd comparative example of this invention. 本発明の第２の実施例に係るＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。It is a circuit diagram which shows the structure of the LED drive device and LED lighting apparatus which concern on the 2nd Example of this invention. 本発明の第２の実施例に係るＬＥＤ駆動装置の特性を説明するためのＶＦ−ＩＬＥＤ特性図である。It is a VF-ILED characteristic view for explaining the characteristic of the LED drive device concerning the 2nd example of the present invention. 本発明の第３の実施例に係るＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。It is a circuit diagram which shows the structure of the LED drive device and LED lighting apparatus which concern on the 3rd Example of this invention. 本発明の第４の実施例に係るＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。It is a circuit diagram which shows the structure of the LED drive device and LED lighting apparatus which concern on the 4th Example of this invention. 本発明の第４の実施例に係るＬＥＤ駆動装置の特性を説明するためのＶｉｎ−ＩＬＥＤ特性図である。It is a Vin-ILED characteristic view for demonstrating the characteristic of the LED drive device which concerns on the 4th Example of this invention. 従来のＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。It is a circuit diagram which shows the structure of the conventional LED drive device and LED lighting apparatus.

次に、図面を参照して、本発明の実施形態を説明する。以下の図面の記載において、同一又は類似の部分には同一又は類似の符号を付している。また、以下に示す実施形態は、この発明の技術的思想を具体化するための装置や方法を例示するものであって、この発明の技術的思想は、特許請求の範囲において、種々の変更を加えることができる。 Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. The embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is subject to various modifications within the scope of the claims. Can be added.

（第１の実施例）
図１は、本発明の第１の実施例に係るＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。本実施例に係るＬＥＤ照明装置１００は、ＬＥＤ駆動装置１とＬＥＤ駆動装置１に接続されるＬＥＤ負荷２とを備える。 (First embodiment)
FIG. 1 is a circuit diagram showing a configuration of an LED driving device and an LED lighting device according to a first embodiment of the present invention. The LED lighting device 100 according to the present embodiment includes an LED driving device 1 and an LED load 2 connected to the LED driving device 1.

本実施例に係るＬＥＤ駆動装置１は、絶縁型のスイッチングレギュレータからなるＤＣ−ＤＣコンバータの構成を備え、商用電源等の交流電源又はバッテリ等の直流電源から供給される入力電力を所望の直流電力に変換し、出力端子を介してＬＥＤ負荷２に出力する。ＬＥＤ駆動装置１は、ＬＥＤ負荷２に接続される絶縁型の電力変換部３と、電力変換部３に接続される制御部４と、電力変換部３及び制御部４に接続されるフィードバック部５と、を備える。また、ＬＥＤ駆動装置１は、電力変換部３の一部を構成し制御部４及びフィードバック部５に接続される制御電源部６を備える。 The LED drive device 1 according to the present embodiment has a configuration of a DC-DC converter composed of an insulating switching regulator, and receives input power supplied from an AC power source such as a commercial power source or a DC power source such as a battery as desired DC power. And output to the LED load 2 via the output terminal. The LED driving device 1 includes an insulating power conversion unit 3 connected to the LED load 2, a control unit 4 connected to the power conversion unit 3, and a feedback unit 5 connected to the power conversion unit 3 and the control unit 4. And comprising. In addition, the LED driving device 1 includes a control power supply unit 6 that constitutes a part of the power conversion unit 3 and is connected to the control unit 4 and the feedback unit 5.

ＬＥＤ負荷２は、ＬＥＤ駆動装置１から供給される直流電力に応じて発光する直流発光負荷であり、Ｒ（赤）、Ｇ（緑）、Ｂ（青）又は短波長のＬＥＤ（Light Emitting Diode）を含む少なくとも１つの白色ＬＥＤから構成される。本実施例に係るＬＥＤ負荷２は、直列接続されたｎ個の白色ＬＥＤ２−１、２−２、・・・、２−ｎを備える。 The LED load 2 is a direct-current light-emitting load that emits light according to direct-current power supplied from the LED driving device 1, and is an R (red), G (green), B (blue), or short wavelength LED (Light Emitting Diode). Is composed of at least one white LED. The LED load 2 according to the present embodiment includes n white LEDs 2-1, 2-2, ..., 2-n connected in series.

電力変換部３は、トランスを有する周知のフライバックコンバータから構成され、入力電力を所望の直流電力に変換し、トランスを介してＬＥＤ負荷２に電力を供給する。一次巻線Ｐ、二次巻線Ｓ１及び三次巻線Ｓ２を有するトランス３３と、一次巻線Ｐに接続されるスイッチング素子３４と、を備える。また、電力変換部３は、交流電源３１とダイオードブリッジ３２と出力ダイオード３５及び出力コンデンサ３６からなる整流平滑部とを備える。なお、図１における一次巻線Ｐ、二次巻線Ｓ１及び三次巻線Ｓ２に示す●は、各巻線の極性を意味する。 The power conversion unit 3 includes a known flyback converter having a transformer, converts input power into desired DC power, and supplies power to the LED load 2 through the transformer. A transformer 33 having a primary winding P, a secondary winding S1, and a tertiary winding S2 and a switching element 34 connected to the primary winding P are provided. The power conversion unit 3 includes an AC power supply 31, a diode bridge 32, an output diode 35, and a rectifying / smoothing unit including an output capacitor 36. In FIG. 1, the black circles in the primary winding P, secondary winding S1, and tertiary winding S2 mean the polarity of each winding.

交流電源３１の両端は、ダイオードブリッジ３２の第１及び第２の端子に接続される。ダイオードブリッジ３２の第３の端子は、トランス３３の一次巻線Ｐの一端に接続され、第４の端子は、一次側グランドに接続される。一次巻線Ｐの他端は、例えばＭＯＳＦＥＴ（Metal-Oxide-Semiconductor Field-Effect Transistor）からなるスイッチング素子３４の一端（ドレイン端子）に接続される。スイッチング素子３４の他端（ソース端子）は、一次側グランドに接続され、制御端子（ゲート端子）は制御部４に接続される。トランス３３の二次巻線Ｓ１は、コアを介して一次巻線Ｐに対し逆極性に巻き回され、その一端は出力ダイオード３５のアノード端子に接続され、他端は二次側グランドに接続される。出力ダイオード３５のカソード端子は、出力コンデンサ３６の一端に接続され、電力変換部３の第１の端子を介してＬＥＤ負荷２の一端（アノード端子）に接続される。出力コンデンサ３６の他端は、二次巻線Ｓ１の他端と二次側グランドとに接続され、電力変換部３の第２の端子を介してＬＥＤ負荷２の他端（カソード端子）に接続される。 Both ends of the AC power supply 31 are connected to the first and second terminals of the diode bridge 32. The third terminal of the diode bridge 32 is connected to one end of the primary winding P of the transformer 33, and the fourth terminal is connected to the primary side ground. The other end of the primary winding P is connected to one end (drain terminal) of a switching element 34 made of, for example, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The other end (source terminal) of the switching element 34 is connected to the primary side ground, and the control terminal (gate terminal) is connected to the control unit 4. The secondary winding S1 of the transformer 33 is wound in a reverse polarity with respect to the primary winding P through the core, one end of which is connected to the anode terminal of the output diode 35 and the other end is connected to the secondary side ground. The The cathode terminal of the output diode 35 is connected to one end of the output capacitor 36, and is connected to one end (anode terminal) of the LED load 2 through the first terminal of the power conversion unit 3. The other end of the output capacitor 36 is connected to the other end of the secondary winding S1 and the secondary side ground, and is connected to the other end (cathode terminal) of the LED load 2 via the second terminal of the power conversion unit 3. Is done.

交流電源３１は、両端からＡＣ１００Ｖ等の交流電圧を出力する商用電源であって、ダイオードブリッジ３２は、正負の交流電圧を整流して正負いずれか一方向の直流電圧（脈流電圧）を生成し、第３の端子と第４の端子とを介して出力する。交流電源３１とダイオードブリッジ３２とは、直流電圧を出力するため、バッテリ等の直流電源と置き換えることができる。また、ダイオードブリッジ３２の第３の端子と第４の端子（一次側グランド）との間にコンデンサを接続しても良い。スイッチング素子３４がオン（導通）する期間、直流電流が、ダイオードブリッジ３２から一次巻線Ｐ及びスイッチング素子３４を流れる。スイッチング素子３４がオフ（遮断）する期間、巻線電圧（フライバック電圧）が二次巻線Ｓ１の両端に発生し、直流電流が二次巻線Ｓ１の一端から出力ダイオード３５を介して出力コンデンサ３６及びＬＥＤ負荷２に流れる。 The AC power supply 31 is a commercial power supply that outputs AC voltage such as AC100V from both ends, and the diode bridge 32 rectifies positive and negative AC voltage to generate DC voltage (pulsating voltage) in either positive or negative direction. , And output via the third terminal and the fourth terminal. Since the AC power supply 31 and the diode bridge 32 output a DC voltage, they can be replaced with a DC power supply such as a battery. Further, a capacitor may be connected between the third terminal and the fourth terminal (primary side ground) of the diode bridge 32. A DC current flows from the diode bridge 32 through the primary winding P and the switching element 34 while the switching element 34 is on (conductive). During the period when the switching element 34 is turned off (cut off), a winding voltage (flyback voltage) is generated at both ends of the secondary winding S1, and a direct current is output from one end of the secondary winding S1 through the output diode 35 to the output capacitor. 36 and LED load 2.

制御部４は、ＬＥＤ負荷２を所定の輝度で安定的に発光させるために、電力変換部３を構成するスイッチング素子３４をオンオフ制御する。制御部４は、フィードバック部５が出力するフィードバック信号（以下ＦＢ信号）に基づきスイッチング素子３４の制御端子に制御信号を出力するために、誤差増幅器４１と基準電圧源４２とコンデンサ４３と比較器４４と三角波発生器４５とを備える。制御部４は、例えば上記の構成素子を含む単一の半導体集積回路（ＩＣ）で構成され、少なくともＦＢ端子、ＯＵＴ端子及びＶｃｃ端子を備える。また、制御部４は、過電流保護機能や過電圧保護機能等の周知の保護機能を備えるが、図示及び説明を割愛する。 The control unit 4 performs on / off control of the switching element 34 constituting the power conversion unit 3 in order to cause the LED load 2 to emit light stably at a predetermined luminance. The control unit 4 outputs an error amplifier 41, a reference voltage source 42, a capacitor 43, and a comparator 44 in order to output a control signal to the control terminal of the switching element 34 based on a feedback signal (hereinafter referred to as FB signal) output from the feedback unit 5. And a triangular wave generator 45. The control unit 4 is constituted by, for example, a single semiconductor integrated circuit (IC) including the above-described constituent elements, and includes at least an FB terminal, an OUT terminal, and a Vcc terminal. The control unit 4 includes known protection functions such as an overcurrent protection function and an overvoltage protection function, but illustration and description thereof are omitted.

誤差増幅器４１の反転入力端子（−端子）は、制御部４のＦＢ端子を介してフィードバック部５に接続され、非反転入力端子（＋端子）は、基準電圧源４２の正極に接続され、出力端子は、比較器４４の非反転入力端子に接続される。基準電圧源の負極は一次側グランドに接続される。コンデンサ４３は、誤差増幅器４１の反転入力端子と出力端子との間に接続される。比較器４４の反転入力端子は、三角波発生器４５に接続され、出力端子は、制御部４のＯＵＴ端子を介してスイッチング素子３４の制御端子に接続される。 The inverting input terminal (− terminal) of the error amplifier 41 is connected to the feedback unit 5 via the FB terminal of the control unit 4, and the non-inverting input terminal (+ terminal) is connected to the positive electrode of the reference voltage source 42 for output. The terminal is connected to the non-inverting input terminal of the comparator 44. The negative electrode of the reference voltage source is connected to the primary side ground. The capacitor 43 is connected between the inverting input terminal and the output terminal of the error amplifier 41. The inverting input terminal of the comparator 44 is connected to the triangular wave generator 45, and the output terminal is connected to the control terminal of the switching element 34 via the OUT terminal of the control unit 4.

誤差増幅器４１は、フィードバック部５が出力するＦＢ信号の電圧値と基準電圧源４２の電圧値との誤差を増幅し、誤差信号としてその出力端子から出力する。比較器４４は、誤差増幅器４１から出力される誤差信号の電圧値と三角波発生器４５から出力される三角波信号（鋸歯状波信号）の電圧値とを比較し、誤差信号の電圧値が三角波信号の電圧値よりも大きい期間、Ｈ（High）レベルのパルス信号（制御信号）をスイッチング素子３４に出力する。また、比較器４４は、誤差信号の電圧値が三角波信号の電圧値よりも小さい期間、Ｌ（Low）レベルの制御信号をスイッチング素子３４に出力する。スイッチング素子３４は、制御信号がＨレベルの期間オンし、制御信号がＬレベルの期間オフする。本実施例に係る制御部４は、ＰＷＭ（Pulse Width Modulation）制御回路であり、フィードバック部５が出力するＦＢ信号が小さくなると制御信号のデューティ比（オン幅）は大きくなり、スイッチング素子３４のオン時間が長くなり、出力コンデンサ３６の両端電圧が高くなる。また、フィードバック部５が出力するＦＢ信号が大きくなると制御信号のデューティ比は小さくなり、スイッチング素子３４のオン時間が短くなり、出力コンデンサ３６の両端電圧が低くなる。即ち、本実施例に係る制御部４は、スイッチング素子３４をＰＷＭ（Pulse Width Modulation）制御する。 The error amplifier 41 amplifies an error between the voltage value of the FB signal output from the feedback unit 5 and the voltage value of the reference voltage source 42, and outputs the error signal from its output terminal. The comparator 44 compares the voltage value of the error signal output from the error amplifier 41 with the voltage value of the triangular wave signal (sawtooth wave signal) output from the triangular wave generator 45, and the voltage value of the error signal is a triangular wave signal. A pulse signal (control signal) of H (High) level is output to the switching element 34 for a period larger than the voltage value of. Further, the comparator 44 outputs an L (Low) level control signal to the switching element 34 during a period in which the voltage value of the error signal is smaller than the voltage value of the triangular wave signal. The switching element 34 is turned on while the control signal is at the H level and turned off while the control signal is at the L level. The control unit 4 according to the present embodiment is a PWM (Pulse Width Modulation) control circuit. When the FB signal output from the feedback unit 5 decreases, the duty ratio (ON width) of the control signal increases, and the switching element 34 is turned on. The time increases and the voltage across the output capacitor 36 increases. Further, when the FB signal output from the feedback unit 5 increases, the duty ratio of the control signal decreases, the ON time of the switching element 34 decreases, and the voltage across the output capacitor 36 decreases. That is, the control unit 4 according to the present embodiment controls the switching element 34 by PWM (Pulse Width Modulation).

フィードバック部５は、スイッチング素子３４のオンオフ制御に必要なＦＢ信号を制御部４に出力するために、三次巻線Ｓ２の巻線電圧情報を検出する電圧検出部と、オンオフ制御の情報を検出する制御情報検出部と、を備え定電流制御フィードバックループを構成する。フィードバック部５は、ダイオード５１とコンデンサ５２とツェナーダイオード５３とコンデンサ５４と平滑コンデンサ５５と抵抗５６、５７及び５８とを備える。ツェナーダイオード５３及び平滑コンデンサ５５は制御情報信号を出力する制御情報検出部を構成し、抵抗５８は電圧信号を出力する電圧検出部を構成する。 The feedback unit 5 detects the voltage information of the tertiary winding S2 and the information of the on / off control in order to output the FB signal necessary for the on / off control of the switching element 34 to the control unit 4. A constant current control feedback loop. The feedback unit 5 includes a diode 51, a capacitor 52, a Zener diode 53, a capacitor 54, a smoothing capacitor 55, and resistors 56, 57 and 58. The Zener diode 53 and the smoothing capacitor 55 constitute a control information detector that outputs a control information signal, and the resistor 58 constitutes a voltage detector that outputs a voltage signal.

ダイオード５１のアノード端子は、制御電源部６を構成するトランス３３の三次巻線Ｓ２の一端に接続され、カソード端子は、抵抗５７を介してツェナーダイオード５３のカソード端子に接続される。コンデンサ５２は、ダイオード５１のアノード端子とカソード端子との間に現れるダイオード５１の寄生容量である。ツェナーダイオード５３のアノード端子は、一次側グランドに接続され、カソード端子は、抵抗５６を介して平滑コンデンサ５５の一端に接続される。ツェナーダイオード５３は、本発明の電圧クランプ部に相当し、後述する効果を得るために、三次巻線Ｓ２に発生する巻線電圧のピーク値よりも低い電圧値によってツェナー降伏する。コンデンサ５４は、ツェナーダイオード５３のアノード端子とカソード端子との間に現れるツェナーダイオード５３の寄生容量である。平滑コンデンサは、本発明の電圧平滑部に相当し、平滑コンデンサ５５の一端は、電圧検出部を構成する抵抗５８に接続され、制御部４のＦＢ端子を介して誤差増幅器４１の反転入力端子に接続される。平滑コンデンサ５５の他端は、一次側グランドに接続される。抵抗５８の一端は、制御電源部６を構成する平滑コンデンサ６２の一端と制御部４のＶｃｃ端子とに接続され、他端は、平滑コンデンサ５５の一端に接続される。 The anode terminal of the diode 51 is connected to one end of the tertiary winding S <b> 2 of the transformer 33 constituting the control power supply unit 6, and the cathode terminal is connected to the cathode terminal of the Zener diode 53 via the resistor 57. The capacitor 52 is a parasitic capacitance of the diode 51 that appears between the anode terminal and the cathode terminal of the diode 51. The anode terminal of the Zener diode 53 is connected to the primary side ground, and the cathode terminal is connected to one end of the smoothing capacitor 55 via the resistor 56. The Zener diode 53 corresponds to the voltage clamp unit of the present invention, and in order to obtain the effect described later, the Zener breakdown occurs due to a voltage value lower than the peak value of the winding voltage generated in the tertiary winding S2. The capacitor 54 is a parasitic capacitance of the Zener diode 53 that appears between the anode terminal and the cathode terminal of the Zener diode 53. The smoothing capacitor corresponds to the voltage smoothing unit of the present invention. One end of the smoothing capacitor 55 is connected to the resistor 58 constituting the voltage detecting unit, and is connected to the inverting input terminal of the error amplifier 41 via the FB terminal of the control unit 4. Connected. The other end of the smoothing capacitor 55 is connected to the primary side ground. One end of the resistor 58 is connected to one end of the smoothing capacitor 62 constituting the control power supply unit 6 and the Vcc terminal of the control unit 4, and the other end is connected to one end of the smoothing capacitor 55.

スイッチング素子３４がオフ（遮断）する期間、巻線電圧（フライバック電圧）がトランス３３の三次巻線Ｓ２に発生し、ツェナーダイオード５３の両端に印加される。ツェナーダイオード５３のツェナー電圧は、巻線電圧のピーク値よりも低い電圧値によってツェナーダイオード５３がツェナー降伏し、ツェナーダイオード５３の両端電圧をクランプするように設定される。そのため、ツェナー電圧とスイッチング素子３４のオンオフ動作とに応じた、又は、ツェナー電圧とＬＥＤ負荷２への電力供給期間とに応じた、パルス状の電圧波形がツェナーダイオード５３の両端に発生する。平滑コンデンサ５５は、上述の電圧波形を平滑化するため、平滑コンデンサ５５の両端電圧は、制御部４が出力する制御信号のデューティ比又は二次巻線Ｓ１を介したＬＥＤ負荷２への電力供給期間に応じて電圧レベルが変化する制御情報信号となる。また、制御部４のＶｃｃ端子電圧に応じた電圧が、電圧情報として抵抗５８の両端に発生し、平滑コンデンサ５５の両端電圧に重畳される。平滑コンデンサ５５の両端電圧と抵抗５８の両端電圧とは、制御情報信号と電圧信号とが重畳されたＦＢ信号として、制御部４のＦＢ端子を介して誤差増幅器４１に出力される。 During the period when the switching element 34 is turned off (shut off), a winding voltage (flyback voltage) is generated in the tertiary winding S2 of the transformer 33 and applied to both ends of the Zener diode 53. The Zener voltage of the Zener diode 53 is set such that the Zener diode 53 breaks down due to a voltage value lower than the peak value of the winding voltage, and the voltage across the Zener diode 53 is clamped. Therefore, a pulsed voltage waveform is generated at both ends of the Zener diode 53 according to the Zener voltage and the ON / OFF operation of the switching element 34 or according to the Zener voltage and the power supply period to the LED load 2. Since the smoothing capacitor 55 smoothes the voltage waveform described above, the voltage across the smoothing capacitor 55 is the power supply to the LED load 2 via the duty ratio of the control signal output by the control unit 4 or the secondary winding S1. The control information signal changes in voltage level according to the period. A voltage corresponding to the Vcc terminal voltage of the control unit 4 is generated as voltage information at both ends of the resistor 58 and is superimposed on the voltage across the smoothing capacitor 55. The both-ends voltage of the smoothing capacitor 55 and the both-ends voltage of the resistor 58 are output to the error amplifier 41 through the FB terminal of the control unit 4 as an FB signal in which the control information signal and the voltage signal are superimposed.

制御電源部６は、スイッチング素子３４をオンオフ制御するために必要な駆動電力を制御部４に供給するために、三次巻線Ｓ２とダイオード６１及び平滑コンデンサ６２からなる整流平滑部とを備える。 The control power supply unit 6 includes a tertiary winding S 2, a rectifying and smoothing unit including a diode 61 and a smoothing capacitor 62 in order to supply the control unit 4 with drive power necessary for on / off control of the switching element 34.

トランス３３の三次巻線Ｓ２は、コアを介して一次巻線Ｐに対し逆極性に巻き回され、その一端はダイオード５１及びダイオード６１のアノード端子に接続され、他端は一次側グランドに接続される。ダイオード６１のカソード端子は、平滑コンデンサ６２の一端と制御部４のＶｃｃ端子とに接続され、フィードバック部５の抵抗５８の一端に接続される。平滑コンデンサ６２の他端は、トランス３３の三次巻線Ｓ２の他端と一次側グランドとに接続される。 The tertiary winding S2 of the transformer 33 is wound in reverse polarity with respect to the primary winding P through the core, one end of which is connected to the anode terminals of the diode 51 and the diode 61, and the other end is connected to the primary side ground. The The cathode terminal of the diode 61 is connected to one end of the smoothing capacitor 62 and the Vcc terminal of the control unit 4, and is connected to one end of the resistor 58 of the feedback unit 5. The other end of the smoothing capacitor 62 is connected to the other end of the tertiary winding S2 of the transformer 33 and the primary side ground.

スイッチング素子３４がオフ（遮断）する期間、上述のように、巻線電圧が三次巻線Ｓ２に発生し、ダイオード６１を介して平滑コンデンサ６２が充電される。平滑コンデンサ６２の両端電圧は、制御部４の制御電源として、Ｖｃｃ端子を介して制御部４の各部に供給される。 As described above, the winding voltage is generated in the tertiary winding S <b> 2 and the smoothing capacitor 62 is charged via the diode 61 during the period when the switching element 34 is turned off (cut off). The voltage across the smoothing capacitor 62 is supplied to each part of the control unit 4 via the Vcc terminal as a control power source for the control unit 4.

次に、本実施例に係るＬＥＤ駆動装置１及びＬＥＤ照明装置１００の作用について説明する。図２は、本発明の第１の実施例に係るＬＥＤ駆動装置の特性を説明するためのＶＦ−ＩＬＥＤ特性図である。なお、図２に示す特性図のＸ軸（ＶＦ）はＬＥＤ負荷の順方向電圧を示し、Ｙ軸（ＩＬＥＤ）はＬＥＤ電流を示す。 Next, the operation of the LED driving device 1 and the LED lighting device 100 according to the present embodiment will be described. FIG. 2 is a VF-ILED characteristic diagram for explaining the characteristics of the LED driving apparatus according to the first embodiment of the present invention. In the characteristic diagram shown in FIG. 2, the X axis (VF) indicates the forward voltage of the LED load, and the Y axis (ILED) indicates the LED current.

本発明の発明者は、本実施例に係るＬＥＤ駆動装置１と従来のＬＥＤ駆動装置と後述する第１及び第２の比較例に係るＬＥＤ駆動装置とを用意し、各ＬＥＤ駆動装置に対し交流電源としてＡＣ１００Ｖを供給し、各ＬＥＤ駆動装置を駆動させた。次に、各ＬＥＤ駆動装置から電流が供給される各ＬＥＤ負荷のＶＦを中央値から±２０％程度変動させ、変動時におけるＩＬＥＤの定常値を測定した。なお、例えばＬＥＤ駆動装置１におけるＬＥＤ負荷２のＶＦとは、各ＬＥＤ２−ａ、２−ｂ、・・・、２−ｎのＶＦを合計した値を意味する。また、ＩＬＥＤは、各ＬＥＤ負荷のＶＦが中央値であるときに測定された電流値を基準としてパーセンテージで示される。 The inventor of the present invention prepares an LED driving device 1 according to the present embodiment, a conventional LED driving device, and LED driving devices according to first and second comparative examples, which will be described later. AC100V was supplied as a power supply, and each LED drive device was driven. Next, the VF of each LED load supplied with a current from each LED driving device was varied by about ± 20% from the median, and the steady value of ILED at the time of variation was measured. For example, the VF of the LED load 2 in the LED driving device 1 means a value obtained by adding up the VFs of the respective LEDs 2-a, 2-b, ..., 2-n. The ILED is indicated as a percentage based on the current value measured when the VF of each LED load is the median value.

図中の実線Ａは、図１に示す本実施例に係るＬＥＤ駆動装置１により測定された特性を示す。図中の破線Ｂは、図７に示す従来のＬＥＤ駆動装置により測定された特性を示す。図中の破線Ｃは、図３に示す第１の比較例に係るＬＥＤ駆動装置により測定された特性を示す。第１の比較例に係るＬＥＤ駆動装置は、三次巻線Ｓ２の巻線電圧情報のみを検出するために、本実施例に係るＬＥＤ駆動装置１からツェナーダイオード５３及び平滑コンデンサ５５からなる制御情報検出部を除いて構成される。また、図中の破線Ｄは、図４に示す第２の比較例に係るＬＥＤ駆動装置により測定された特性を示す。第２の比較例に係るＬＥＤ駆動装置は、三次巻線Ｓ２から得られる制御情報のみを検出するために、本実施例に係るＬＥＤ駆動装置１から抵抗５８からなる電圧検出部を除いて構成される。 A solid line A in the figure indicates characteristics measured by the LED driving device 1 according to the present embodiment shown in FIG. A broken line B in the figure indicates characteristics measured by the conventional LED driving device shown in FIG. A broken line C in the figure indicates characteristics measured by the LED driving apparatus according to the first comparative example shown in FIG. The LED driving device according to the first comparative example detects control information including the Zener diode 53 and the smoothing capacitor 55 from the LED driving device 1 according to this embodiment in order to detect only the winding voltage information of the tertiary winding S2. Consists of all parts. Moreover, the broken line D in a figure shows the characteristic measured by the LED drive device which concerns on the 2nd comparative example shown in FIG. The LED drive device according to the second comparative example is configured by removing the voltage detection unit including the resistor 58 from the LED drive device 1 according to the present embodiment in order to detect only control information obtained from the tertiary winding S2. The

従来のＬＥＤ駆動装置（破線Ｂ）は、ＬＥＤ電流を直接検出して定電流制御を行うため、ＶＦの変動に対してＩＬＥＤの変動が最も少なく、ＩＬＥＤはＶＦが中央値の８０％又は１２０％となった場合でも基準値と略等しくなった。第１の比較例に係るＬＥＤ駆動装置（破線Ｃ）は、僅かなＶＦ変動に対してＩＬＥＤの変動が大きく、ＶＦが中央値から数％変動するとＩＬＥＤは基準値の１０％から２５０％程度に変化した。第２の比較例に係るＬＥＤ駆動装置（破線Ｄ）は、ＶＦの変動に対するＬＥＤの変動が第１の比較例よりも低減され、ＶＦが中央値の９０％又は１１０％となった場合、ＩＬＥＤは基準値の９０％から１１０％程度に制御された。本実施例に係るＬＥＤ駆動装置１（実線Ａ）は、ＬＥＤ電流の代替特性によって定電流制御を行うため、ＶＦの変動に対するＩＬＥＤの変動は、従来のＬＥＤ駆動装置よりも大きい。詳細には、ＶＦが中央値の８０％のときＩＬＥＤは基準値の９７％程度であり、ＶＦが中央値の１２０％のときＩＬＥＤは基準値の９２％程度であった。また、ＶＦが中央値の９０％のときＩＬＥＤは基準値と略等しく、ＶＦが中央値の１１０％のときＩＬＥＤは基準値の９７％程度であり、本実施例に係るＬＥＤ駆動装置１及びＬＥＤ照明装置１００は、一般的な照明用途において実用的な精度要求を十分に満足することを示す結果が得られた。 Since the conventional LED driving device (broken line B) directly controls the LED current by directly detecting the LED current, the fluctuation of the ILED is the smallest with respect to the fluctuation of the VF, and the ILED is 80% or 120% of the median VF. Even when it became, it became substantially equal to the reference value. The LED driving device according to the first comparative example (broken line C) has a large fluctuation of ILED with respect to slight VF fluctuation, and when VF fluctuates several percent from the median, ILED is reduced from 10% to 250% of the reference value. changed. The LED driving device according to the second comparative example (broken line D) is configured so that the LED variation with respect to the VF variation is less than that of the first comparative example, and the VF is 90% or 110% of the median value. Was controlled from 90% to 110% of the reference value. Since the LED drive device 1 (solid line A) according to the present embodiment performs constant current control based on the alternative characteristics of the LED current, the variation of the ILED with respect to the variation of VF is larger than that of the conventional LED drive device. Specifically, when the VF is 80% of the median value, the ILED is about 97% of the reference value, and when the VF is 120% of the median value, the ILED is about 92% of the reference value. Further, when VF is 90% of the median value, ILED is substantially equal to the reference value, and when VF is 110% of the median value, ILED is approximately 97% of the reference value. The result which showed that the illuminating device 100 fully satisfy | fills practical precision requirements in a general illumination use was obtained.

本発明の第１の実施例に係るＬＥＤ駆動装置１及びＬＥＤ照明装置１００は、以下の効果を有する。 The LED driving device 1 and the LED lighting device 100 according to the first embodiment of the present invention have the following effects.

（１）ＬＥＤ電流に代わり、トランス３３の三次巻線Ｓ２に発生する巻線電圧とこの巻線電圧から得られる制御情報とに基づきＬＥＤ負荷２に供給する直流電力を制御することで、ＬＥＤ駆動装置１はＬＥＤ負荷２を定電流制御することができる。 (1) Instead of the LED current, the LED drive is controlled by controlling the DC power supplied to the LED load 2 based on the winding voltage generated in the tertiary winding S2 of the transformer 33 and the control information obtained from this winding voltage. The device 1 can perform constant current control of the LED load 2.

（２）ＬＥＤ負荷２の順方向電圧の変動に対しＬＥＤ電流が安定に制御されるため、ＬＥＤ照明装置１００は、ＬＥＤ負荷２の光がちらつくことを防止できる。 (2) Since the LED current is stably controlled against fluctuations in the forward voltage of the LED load 2, the LED lighting device 100 can prevent the light of the LED load 2 from flickering.

（３）定電流制御フィードバックループとしてのフィードバック部５がトランス３３の一次側に接続されるため、フォトカプラのような絶縁型の信号伝達素子を設ける必要がなく、ＬＥＤ駆動装置１及びＬＥＤ照明装置１００を小型且つ低コストに構成することができる。 (3) Since the feedback unit 5 as a constant current control feedback loop is connected to the primary side of the transformer 33, it is not necessary to provide an insulating signal transmission element such as a photocoupler, and the LED driving device 1 and the LED lighting device 100 can be made small and low cost.

（４）フィードバック部５が制御部４とともにトランス３３の一次側に接続されるため、フィードバック信号に対する制御部４の応答性が高速化され、ＬＥＤ電流を良好に制御することができる。 (4) Since the feedback unit 5 is connected to the primary side of the transformer 33 together with the control unit 4, the responsiveness of the control unit 4 with respect to the feedback signal is increased, and the LED current can be favorably controlled.

（５）例えば、抵抗５８の抵抗値を小さくしＦＢ信号に対する電圧信号の影響を大きくすることで、ＬＥＤ負荷２に供給される電力を定電力制御することができる。 (5) For example, the power supplied to the LED load 2 can be controlled at a constant power by decreasing the resistance value of the resistor 58 and increasing the influence of the voltage signal on the FB signal.

（第２の実施例）
図５は、本発明の第２の実施例に係るＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。本実施例に係るＬＥＤ照明装置２００は、ＬＥＤ駆動装置１０１とＬＥＤ駆動装置１０１に接続されるＬＥＤ負荷２とを備える。 (Second embodiment)
FIG. 5 is a circuit diagram showing the configuration of the LED driving device and the LED lighting device according to the second embodiment of the present invention. The LED lighting device 200 according to the present embodiment includes an LED driving device 101 and an LED load 2 connected to the LED driving device 101.

本実施例に係るＬＥＤ駆動装置１０１は、ＬＥＤ負荷２に接続される絶縁型の電力変換部１０３と、電力変換部１０３に接続される制御部１０４と、電力変換部１０３及び制御部１０４に接続されるフィードバック部５と、を備える。また、ＬＥＤ駆動装置１０１は、制御部１０４、フィードバック部５に接続される制御電源部６及び制御電源部６に接続される共振信号検出部７を備える。 The LED drive device 101 according to the present embodiment is connected to the insulated power conversion unit 103 connected to the LED load 2, the control unit 104 connected to the power conversion unit 103, and the power conversion unit 103 and the control unit 104. Feedback section 5 to be provided. The LED driving device 101 includes a control unit 104, a control power supply unit 6 connected to the feedback unit 5, and a resonance signal detection unit 7 connected to the control power supply unit 6.

本実施例に係るＬＥＤ駆動装置１０１及びＬＥＤ照明装置２００は、電力変換部１０３が周知の擬似共振方式フライバックコンバータから構成され、制御部１０４が共振信号検出部７から電圧共振信号を受けて電力変換部１０３を制御するように構成される点で第１の実施例に係るＬＥＤ駆動装置１及びＬＥＤ照明装置１００と異なる。その他の構成は、実質的に同一に構成されるため、詳細な説明を省略する。 In the LED driving device 101 and the LED lighting device 200 according to the present embodiment, the power conversion unit 103 is configured by a well-known pseudo-resonance flyback converter, and the control unit 104 receives the voltage resonance signal from the resonance signal detection unit 7 and receives power. The LED driving device 1 and the LED lighting device 100 according to the first embodiment are different in that they are configured to control the conversion unit 103. Since other configurations are configured substantially the same, detailed description thereof is omitted.

電力変換部１０３は、スイッチング素子３４がオフする期間、スイッチング素子３４の両端電圧を自由振動させるために、スイッチング素子３４に並列接続された共振コンデンサ３７を有する。スイッチング素子３４がオフする期間、共振コンデンサ３７と共振リアクトルＬｒとで共振する。共振リアクトルＬｒはトランス３３の一次巻線Ｐと二次巻線Ｓ２との間のリーケージインダクタンスである。共振信号検出部７は、スイッチング素子３４がオフする期間にトランス３３の三次巻線Ｓ２に発生する巻線電圧情報を検出し、共振コンデンサ３７と共振リアクトルＬｒとで共振したときの電圧共振信号として制御部１０４に出力する。共振信号検出部７は、制御電源部６と制御部１０４とに接続され、三次巻線Ｓ２の巻線電圧を整流平滑するように構成される。制御部１０４は、制御情報検出部５の制御情報信号と共振信号検出部７の電圧共振信号とに基づきスイッチング素子３４をオンオフ制御させるために、制御判定部４６とＡＮＤ回路４７とを備える。 The power conversion unit 103 includes a resonance capacitor 37 connected in parallel to the switching element 34 in order to freely oscillate the voltage across the switching element 34 during a period in which the switching element 34 is turned off. During the period when the switching element 34 is turned off, the resonance capacitor 37 and the resonance reactor Lr resonate. The resonant reactor Lr is a leakage inductance between the primary winding P and the secondary winding S2 of the transformer 33. The resonance signal detection unit 7 detects winding voltage information generated in the tertiary winding S2 of the transformer 33 during the period when the switching element 34 is turned off, and as a voltage resonance signal when the resonance capacitor 37 and the resonance reactor Lr resonate. Output to the control unit 104. The resonance signal detection unit 7 is connected to the control power supply unit 6 and the control unit 104, and is configured to rectify and smooth the winding voltage of the tertiary winding S2. The control unit 104 includes a control determination unit 46 and an AND circuit 47 for performing on / off control of the switching element 34 based on the control information signal of the control information detection unit 5 and the voltage resonance signal of the resonance signal detection unit 7.

制御判定部４６は、共振信号検出部７と三角波発生器４５とＡＮＤ回路４７とに接続される。また、制御判定部４６は電圧共振信号の電圧レベルを判定した結果に基づき、三角波発生器４５の発振を制御するとともに、ＡＮＤ回路４７を介してスイッチング素子３４を制御する。詳細には、三次巻線Ｓ２の巻線電圧が低下し電圧共振信号の電圧レベルが所定の値よりも低いとき、Ｈレベルの判定信号を出力し、電圧共振信号の電圧レベルが所定の値よりも高いとき、Ｌレベルの判定信号を出力する。ＡＮＤ回路４７の第１の入力端子は比較器４４の出力端子に接続され、第２の入力端子は制御判定部４６に接続され、出力端子はスイッチング素子３４の制御端子に接続される。ＡＮＤ回路４７は、比較器４４の制御信号と制御判定部４６の判定信号とがともにＨレベルのとき、スイッチング素子３４をオンさせる。三角波発生器４５は、制御判定部４６の判定信号がＨレベルのとき発振し、三角波信号を出力する。 The control determination unit 46 is connected to the resonance signal detection unit 7, the triangular wave generator 45, and the AND circuit 47. The control determination unit 46 controls the oscillation of the triangular wave generator 45 and the switching element 34 via the AND circuit 47 based on the result of determining the voltage level of the voltage resonance signal. Specifically, when the winding voltage of the tertiary winding S2 decreases and the voltage level of the voltage resonance signal is lower than a predetermined value, an H level determination signal is output, and the voltage level of the voltage resonance signal is lower than the predetermined value. Is also high, an L level determination signal is output. The first input terminal of the AND circuit 47 is connected to the output terminal of the comparator 44, the second input terminal is connected to the control determination unit 46, and the output terminal is connected to the control terminal of the switching element 34. The AND circuit 47 turns on the switching element 34 when both the control signal of the comparator 44 and the determination signal of the control determination unit 46 are at the H level. The triangular wave generator 45 oscillates and outputs a triangular wave signal when the determination signal of the control determination unit 46 is at the H level.

本実施例に係るＬＥＤ駆動装置１０１における制御情報信号は、擬似共振方式フライバックコンバータの特性上、制御信号のデューティ比及び周波数、又は、ＬＥＤ負荷２への電力供給期間に応じて電圧レベルを変化させる。 The control information signal in the LED drive device 101 according to the present embodiment varies in voltage level according to the duty ratio and frequency of the control signal or the period of power supply to the LED load 2 due to the characteristics of the quasi-resonant flyback converter. Let

図６は、本実施例に係るＬＥＤ駆動装置１０１及びＬＥＤ照明装置２００と実施例１に係るＬＥＤ駆動装置１及びＬＥＤ照明装置１００とのＬＥＤ負荷のＶＦ変動に対するＩＬＥＤの変化を示す特性図である。 FIG. 6 is a characteristic diagram showing changes in ILEDs with respect to VF fluctuations of LED loads of the LED driving device 101 and the LED lighting device 200 according to the present embodiment and the LED driving device 1 and the LED lighting device 100 according to the first embodiment. .

図中の実線Ｅは、図５に示す本実施例に係るＬＥＤ駆動装置１０１により測定された特性を示す。図中の破線Ａは、図２の実線Ａで示した第１の実施例に係るＬＥＤ駆動装置１により測定された特性を示す。本実施例に係るＬＥＤ駆動装置１０１（実線Ｅ）は、第１の実施例に係るＬＥＤ駆動装置１と同様に良好な電流制御特性を示し、一般的な照明用途において実用的な精度要求を十分に満足することを示す結果が得られた。 A solid line E in the figure indicates characteristics measured by the LED driving device 101 according to the present embodiment shown in FIG. A broken line A in the figure indicates the characteristic measured by the LED driving device 1 according to the first embodiment shown by the solid line A in FIG. The LED drive device 101 (solid line E) according to the present embodiment exhibits good current control characteristics similarly to the LED drive device 1 according to the first embodiment, and sufficiently satisfies the practical accuracy requirement in general lighting applications. The result which shows that is satisfied is obtained.

本発明の第２の実施例に係るＬＥＤ駆動装置１０１及びＬＥＤ照明装置２００は、第１の実施例に係るＬＥＤ駆動装置１及びＬＥＤ照明装置１００と同様の効果を有する。 The LED driving device 101 and the LED lighting device 200 according to the second embodiment of the present invention have the same effects as the LED driving device 1 and the LED lighting device 100 according to the first embodiment.

（第３の実施例）
図７は、本発明の第３の実施例に係るＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。本実施例に係るＬＥＤ照明装置１００ａは、ＬＥＤ駆動装置１ａとＬＥＤ駆動装置１ａに接続されるＬＥＤ負荷２とを備える。 (Third embodiment)
FIG. 7 is a circuit diagram showing the configuration of the LED driving device and the LED lighting device according to the third embodiment of the present invention. The LED lighting device 100a according to the present embodiment includes an LED driving device 1a and an LED load 2 connected to the LED driving device 1a.

本実施例に係るＬＥＤ駆動装置１ａは、図１に示す第１の実施例に係るＬＥＤ駆動装置１の構成に、さらに、一端がトランス３３の一次巻線Ｐの一端とダイオードブリッジ３２の出力端子とに接続され、他端が抵抗５６，５８の一端とコンデンサ５５の一端とに接続される交流入力補正用の抵抗７１を設けたことを特徴とする。 The LED drive device 1a according to the present embodiment has the same structure as that of the LED drive device 1 according to the first embodiment shown in FIG. 1, but one end of the primary winding P of the transformer 33 and the output terminal of the diode bridge 32. And an AC input correcting resistor 71 having the other end connected to one end of resistors 56 and 58 and one end of a capacitor 55.

まず、例えば、ＶＦが増加した場合には、制御部４での制御信号のパルスオン幅を広げるような動作をフィードバック信号に重畳させる必要がある。ＶＦが上昇すると、三次巻線（補助巻線）Ｓ２の電圧も上昇することを利用して、整流平滑された三次巻線Ｓ２の電圧をＶＦ変動補正用の抵抗５８により検出して、ＶＦ変動補正電圧信号として誤差増幅器４１に出力する。三次巻線Ｓ２の電圧が上昇すると、電力変換部３のスイッチング素子３４のパルスオン幅を広げるように制御することで、ＶＦバラツキがあっても定電流制御が行える。 First, for example, when VF increases, it is necessary to superimpose an operation that widens the pulse-on width of the control signal in the control unit 4 on the feedback signal. When the VF rises, the voltage of the tertiary winding (auxiliary winding) S2 also rises, and the rectified and smoothed voltage of the tertiary winding S2 is detected by the resistance 58 for VF fluctuation correction, and the VF fluctuation is detected. The correction voltage signal is output to the error amplifier 41. When the voltage of the tertiary winding S2 rises, constant current control can be performed even if there is VF variation by controlling the switching element 34 of the power conversion unit 3 to widen the pulse-on width.

しかし、交流入力変動が大きい場合には、三次巻線Ｓ２の電圧から生成されるデューティ信号のみでは定電流特性を維持することはできない。そこで、ダイオードブリッジ３２の出力端子とトランス３３の一次巻線Ｐの一端とにおける交流入力電圧を、交流入力補正用の抵抗７１により交流入力補正用の電圧信号として誤差増幅器４１に出力する。 However, when the AC input fluctuation is large, the constant current characteristic cannot be maintained only by the duty signal generated from the voltage of the tertiary winding S2. Therefore, the AC input voltage at the output terminal of the diode bridge 32 and one end of the primary winding P of the transformer 33 is output to the error amplifier 41 as an AC input correction voltage signal by the AC input correction resistor 71.

第３の実施例に係るＬＥＤ駆動装置１ａによれば、ＶＦバラツキや広範囲の交流入力変動があっても、抵抗５８によるＶＦ変動補正と抵抗７１による交流入力補正をかけることにより実使用上において支障のない定電流特性を得ることができる。また、電流検出抵抗やオペアンプなどで構成される定電流回路、フィードバック信号を送るフォトカプラなどが不要となる。このため、安価なＬＥＤ駆動装置及びＬＥＤ照明装置を提供することができる。なお、電力変換部３は、フライバック方式に限定されるものではなく、フォワード方式などでも良い。 According to the LED driving device 1a according to the third embodiment, even if there is a VF variation or a wide range of AC input fluctuations, the VF fluctuation correction by the resistor 58 and the AC input correction by the resistance 71 are hindered in actual use. The constant current characteristic without any can be obtained. Further, a constant current circuit composed of a current detection resistor and an operational amplifier, a photocoupler for sending a feedback signal, and the like are not required. For this reason, an inexpensive LED drive device and LED lighting device can be provided. The power conversion unit 3 is not limited to the flyback method, and may be a forward method or the like.

（第４の実施例）
図８は、本発明の第４の実施例に係るＬＥＤ駆動装置及びＬＥＤ照明装置の構成を示す回路図である。本実施例に係るＬＥＤ照明装置２００ａは、ＬＥＤ駆動装置１０１ａとＬＥＤ駆動装置１０１ａに接続されるＬＥＤ負荷２とを備える。 (Fourth embodiment)
FIG. 8 is a circuit diagram showing the configuration of the LED driving device and the LED lighting device according to the fourth embodiment of the present invention. The LED lighting device 200a according to the present embodiment includes an LED driving device 101a and an LED load 2 connected to the LED driving device 101a.

本実施例に係るＬＥＤ駆動装置１０１ａは、図５に示す第２の実施例に係るＬＥＤ駆動装置１０１の構成に、さらに、一端がトランス３３の一次巻線Ｐの一端とダイオードブリッジ３２の出力端子とに接続され、他端が抵抗５６，５８の一端とコンデンサ５５の一端とに接続される交流入力補正用の抵抗７１を設けたことを特徴とする。 The LED driving device 101a according to the present embodiment has the same configuration as that of the LED driving device 101 according to the second embodiment shown in FIG. 5, and one end of the primary winding P of the transformer 33 and the output terminal of the diode bridge 32. And an AC input correcting resistor 71 having the other end connected to one end of resistors 56 and 58 and one end of a capacitor 55.

第４の実施例に係るＬＥＤ駆動装置１０１ａによれば、第２の実施例に係るＬＥＤ駆動装置１０１の効果が得られるとともに、さらに、交流入力補正用の抵抗７１を設けたので、広範囲の交流入力変動があっても、抵抗７１による交流入力補正をかけることにより実使用上において支障のない定電流特性を得ることができる。また、電流検出抵抗やオペアンプなどで構成される定電流回路、フィードバック信号を送るフォトカプラなどが不要となる。このため、安価なＬＥＤ駆動装置及びＬＥＤ照明装置を提供することができる。 According to the LED driving device 101a according to the fourth embodiment, the effect of the LED driving device 101 according to the second embodiment can be obtained, and the AC input correction resistor 71 is further provided. Even if the input fluctuates, by applying AC input correction by the resistor 71, a constant current characteristic that does not hinder actual use can be obtained. Further, a constant current circuit composed of a current detection resistor and an operational amplifier, a photocoupler for sending a feedback signal, and the like are not required. For this reason, an inexpensive LED drive device and LED lighting device can be provided.

図９は、本発明の第４の実施例に係るＬＥＤ駆動装置の特性を説明するためのＶｉｎ−ＩＬＥＤ特性図である。図９において、Ｖｉｎは交流入力電圧であり、ＩＬＥＤはＬＥＤに流れる電流である。ＬＥＤ負荷２のＶＦを中央値（ＶＦ１００％）に設定した構成及びＶＦを±２０％の範囲で設定した構成において、Ｖｉｎを切り替えたときの負荷電流ＩＬＥＤを測定する実験を行った。図９では、ＡＣ１００Ｖ±１０％〜ＡＣ２３０Ｖ±２０％の範囲では、ＩＬＥＤは、３２３ｍＡｍｉｎ〜３６０ｍｔｙｐ〜４０４ｍＡｍａｘ＝−１０％〜＋１２％である。 FIG. 9 is a Vin-ILED characteristic diagram for explaining the characteristics of the LED driving apparatus according to the fourth embodiment of the present invention. In FIG. 9, Vin is an AC input voltage, and ILED is a current flowing through the LED. In the configuration in which the VF of the LED load 2 is set to the median value (VF 100%) and the configuration in which the VF is set in a range of ± 20%, an experiment was performed to measure the load current ILED when switching Vin. In FIG. 9, in the range of AC100V ± 10% to AC230V ± 20%, the ILED is 323 mAmin to 360 mtyp to 404 mAmax = −10% to + 12%.

以上の実施形態で説明された構成、形状、大きさおよび配置関係については、本発明が理解・実施できる程度に概略的に示したものにすぎない。従って本発明は、説明された実施形態に限定されるものではなく、特許請求の範囲に示される技術的思想の範囲を逸脱しない限り様々な形態に変更することができる。 The configurations, shapes, sizes, and arrangement relationships described in the above embodiments are merely schematically shown to the extent that the present invention can be understood and implemented. Therefore, the present invention is not limited to the described embodiments, and can be variously modified without departing from the scope of the technical idea shown in the claims.

例えば、制御部４（制御部１０４）とスイッチング素子３４とを含めて単一のＩＣで構成することができる。また、制御部４（制御部１０４）とフィードバック部５とを含めて単一のＩＣで構成することができる。また、各実施例は、トランス３３が一次〜三次巻線を有する場合についてのみ説明したが、ｎ次巻線（ｎは３以上の自然数）を有するトランスを用いてＬＥＤ駆動装置及びＬＥＤ照明装置を構成することができる。 For example, the control unit 4 (control unit 104) and the switching element 34 can be configured as a single IC. Further, the control unit 4 (control unit 104) and the feedback unit 5 can be configured as a single IC. Moreover, although each Example demonstrated only the case where the transformer 33 has a primary-tertiary winding, an LED drive device and an LED lighting device were used using the transformer which has an n-order winding (n is a natural number of 3 or more). Can be configured.

１、１０１ＬＥＤ駆動装置
２ＬＥＤ負荷
３、１０３電力変換部
４、１０４制御部
５フィードバック部
６制御電源部
７共振信号検出部
３３トランス
３４スイッチング素子
５８ＶＦ変動補正用の抵抗
７１交流変動補正用の抵抗
１００、２００ＬＥＤ照明装置 DESCRIPTION OF SYMBOLS 1,101 LED drive device 2 LED load 3, 103 Power conversion part 4, 104 Control part 5 Feedback part 6 Control power supply part 7 Resonance signal detection part 33 Transformer 34 Switching element 58 Resistor for VF fluctuation correction 71 For AC fluctuation correction Resistance 100, 200 LED lighting device

Claims

Insulated power having a transformer having a primary winding, a secondary winding and a tertiary winding, and a switching element connected to the primary winding, and supplying power to the LED load via the secondary winding A conversion unit;
A feedback unit connected to the tertiary winding and having a control information detecting unit for detecting control information and a voltage detecting unit for detecting winding voltage information of the tertiary winding;
A control unit for controlling on / off of the switching element,
The feedback unit outputs a feedback signal in which the control information based on the on / off control and the winding voltage information are superimposed,
The LED driving device , wherein the controller performs the on / off control based on the feedback signal and controls the power based on the control information and the winding voltage information .

The control information detection unit detects at least one of a duty ratio of the on / off control and a period of supplying power to the LED load via the secondary winding. LED drive device of description.

The LED control device according to claim 2, wherein the control information detection unit detects a control frequency of the on / off control.

The control information detecting unit includes a voltage clamping unit that clamps the winding voltage of the tertiary winding, and a voltage smoothing unit that smoothes the winding voltage that is connected in parallel to the voltage clamping unit and clamped. The LED driving apparatus according to claim 1, wherein the LED driving apparatus is characterized in that:

5. The LED driving device according to claim 1, further comprising a control power supply unit connected between the tertiary winding and the control unit. 6.

6. The feedback unit according to claim 1, wherein the feedback unit outputs a feedback signal in which the control information based on the on / off control, the winding voltage information, and the AC input voltage information are superimposed. LED drive device of description.

An LED load comprising at least one LED;
A transformer having a primary winding, a secondary winding and a tertiary winding, and a switching element connected to the primary winding, and supplying an electric power to the LED load via the secondary winding. A power converter,
A feedback unit connected to the tertiary winding and having a control information detecting unit for detecting control information and a voltage detecting unit for detecting winding voltage information of the tertiary winding;
A control unit for controlling on / off of the switching element,
The feedback unit outputs a feedback signal in which the control information based on the on / off control and the winding voltage information are superimposed,
The control unit performs the on / off control based on the feedback signal and controls the power based on the control information and the winding voltage information .