201212702 六、發明說明： 【發明所屬之技術領域】 本發明係關於發光二極體之技術領域，尤指_種發 光二極體驅動系統。 【先前技術】 發光二極體（Light Emitting Diode，LED)是利用電能 直接轉化為光能的原理，在半導體内正負極的兩個端子 施加電壓，當電流通過，使電子與電洞相結合時，剩餘 能量便以光的形式釋放，依其使用的材料的不同，其能 階高低使光子能量產生不同波長的光，而為人眼所能接 受到各種顏色的光。 圖1係發光二極體的電壓電流特性曲線，如圖i所 示’硃加於發光二極體的順向電壓Vf大於2.5伏特時，發 光二極體導通發光，順向電壓Vf小於0·〇伏特時不發光。 由圖1可知’順向電壓Vf較佳為2.5〜3.5伏特，此時發光二 極體的電流為20mA〜30mA。同時由圖1可知，當施加於 發光二極體的電壓太大時’會導致發光二極體損壞。故 在使用發光二極體時，常_接多個發光二極體，使每一 個發光二極體的順向電壓Vf介於2.5〜3.5伏特之間。由於 電壓電流及串接多個發光二極體之限制，故使用時，所 施加的外部電壓需大於一所謂的啟動電壓，整個串接發 光二極體才會發光。 201212702 圖2係一習知交流發光二極體使用的示意圖。其包含 一父流電源210、第一組發光二極體22〇及第二組發光二 極體230，且該第一組發光二極體22〇及第二組發光二極 體230的順向導通電壓為9〇伏特。 當交流電源210的輸出交流電壓等於或是大於 9〇伏特時，開始啟動點亮第一組發光二極體22〇 ^當 輸出交流電壓繼續上升後並再降回至9 〇伏特時，第— φ 。且發光一極體220被關閉。同理，輸出交流電壓等於或 疋小於-90伏特時，開始啟動點亮第二組發光二極體 230。當輸出交流電壓繼續下降後並再上升至_9〇伏特 時’第二組發光二極體230被關閉。 。月參閱圖3，係顯示圖2之交流發光二極體的電流波 型圖’其中，橫軸為時間，其係以電壓相位顯示，縱轴 為電流單位為mA(毫安培卜如圖3所示，在相位約3〇度 時，電壓開始大於90V，而點亮第一組發光二極體22〇。. 在相位約90度時，電壓達到最大值，流經第一組發光二 春極體220的電流約為5 2mA。在相位為15〇度〜2]〇度時電 壓小於90V且大於·9〇ν，此時第一組發光二極體22〇及第 二組發光二極體23〇被關閉，故電流為〇mA。在相位約21〇 度時，電壓開始小於_9〇v，而點亮第二組發光二極體 230。在相位約27〇度時，電壓達到最小值，流經第二組 發光二極體230的電流約為_5_2mA。在相位為33〇度〜36〇 度時，電壓小於9〇V且大於_9〇v，此時第一組發光二極體 220及第二組發光二極體23〇被關閉’故電流為〇mA。 201212702 由圖3可知’第一組發光二極體220及第二組發光二 極體2 3 0有時被點亮有時被關閉，此會產生閃爍現象，而 導致人眼之不舒服，故如圖2的習知技術並不適合使用於 照明設施。 圖4係另一習知交流發光二極體使用的示意圖。如圖 4所示其係由一交流電源210、一組發光二極體220及一全 橋整流器250所組成。其工作原理係將交流市電透過全橋 整流器250，將正負的交流弦波整流成只有正半週的波 形’再利用此波形直接驅動發光二極體22〇。但是，此種 · 波形卻會造成發光二極體220閃爍以及利用率低落的問 題。其中，在輸入電壓為低壓時，輸入電壓會小於發光 二極體220的導通電壓，所以發光二極體22〇為熄滅狀 態》在輸入電壓為高壓時，輸入電壓會大於發光二極體 220的導通電壓，發光二極體處於明亮狀態。整體而言， 發光一極體220隨著輸入電壓而有明有滅，此結果造成發 光二極體的利用率較低且易出現閃爍現象。故習知交流 發光二極體驅動電路仍有改善空間。 鲁 【發明内容】 本發明之主要目的係在提供一種發光二極體驅動系 •洗其係以一全新架構而提昇整體發光二極體的利用 率’同時將發光二極體的閃爍頻率提高，使人眼無法查 覺。 依據本發明之一特色’本發明提出一種發光二極體 驅動系..先，其使用一交流電壓以驅動發光二極體該 6 201212702 驅動系統至少包含一濾波電路、一整流電路、—填谷電 =、及一發光二極體發光電路。該濾波電路其接收該交 流電壓’並對該交流電壓與電流進行濾波，以濾 除該交流電壓與電流的高次諧波成分，並產生一 濾波父机電壓。該整流電路連接至該濾波電路，該整流 電路具有一第—輸出端及一第二輸出端，以對該濾波電 壓與電流進行整流，而產生一整流電壓與電流。 該填谷電路連接至該整流電路，該填谷電路改變該整流 電路之導通時間，以提升該整流電壓與電流的功率因 數及發光二極體的利用率。該發光二極體發光電路連 接至戎填谷電路，該發光二極體發光電路接收該整流電 壓而產生光源。 【實施方式】 圖5係本發明一種發光二極體驅動系統500的電路 圖。該發光二極體驅動系統5〇〇使用一交流電壓以驅動 發光二極體’該驅動系統50〇包含一濾波電路5 1〇、—整 流電路520、一填谷電路53〇、一發光二極體發光電路 540、及一控制電路55〇。 該濾波電路5 10其連接至一交流電源Vac，以接收交 流電壓與電流，並對該交流電壓與電流進行據 波’以濾除該交流電壓與電流的高次諧波成分， 並產生一濾波交流電壓Vac，filtered。 201212702 該濾波電路510由一濾波電感Li與一濾波電容Ci所 組成。該濾波電感Li的第一端503連接至該交流電壓源 Vac的第一端501，其第二端504連接至該濾波電容ci 之第一端505，該溏波電容Ci的第二端506連接至該 交流電壓源Vac的第二端502。 該整流電路520連接至該渡波電路5 1 〇，該整流電路 520具有一第一輸出端521及一第二輸出端522，以對該濾 波電峻與電流進行整流，而產生一整流電磨。該 第—輸出端5 2 2並迷接至一低電位。 該整流電路520由一第一至第四整流二極體dr丨、Dr 2、201212702 VI. Description of the Invention: [Technical Field] The present invention relates to the technical field of light-emitting diodes, and more particularly to a light-emitting diode driving system. [Prior Art] A Light Emitting Diode (LED) is a principle that directly converts electric energy into light energy. A voltage is applied to two terminals of the positive and negative electrodes in the semiconductor, and when the current passes, the electron and the hole are combined. The remaining energy is released in the form of light. Depending on the material used, the energy level of the photon enables the photon energy to produce light of different wavelengths, and the human eye can receive light of various colors. Fig. 1 is a voltage-current characteristic curve of a light-emitting diode. As shown in Fig. i, when the forward voltage Vf of the light-emitting diode is greater than 2.5 volts, the light-emitting diode is turned on, and the forward voltage Vf is less than 0· It does not illuminate when it is volts. As is apparent from Fig. 1, the forward voltage Vf is preferably 2.5 to 3.5 volts, and the current of the light-emitting diode is 20 mA to 30 mA. At the same time, as can be seen from Fig. 1, when the voltage applied to the light-emitting diode is too large, the light-emitting diode is damaged. Therefore, when the light-emitting diode is used, a plurality of light-emitting diodes are often connected so that the forward voltage Vf of each of the light-emitting diodes is between 2.5 and 3.5 volts. Due to the limitation of voltage and current and multiple LEDs connected in series, the external voltage applied must be greater than a so-called starting voltage during use, and the entire series of light-emitting diodes will emit light. 201212702 FIG. 2 is a schematic diagram of a conventional AC light emitting diode. The device includes a parent current source 210, a first group of LEDs 22 and a second group of LEDs 230, and the first group of LEDs 22 and the second group of LEDs 230 The turn-on voltage is 9 volts. When the output AC voltage of the AC power source 210 is equal to or greater than 9 volts, the first group of light-emitting diodes 22 is started to be turned on. When the output AC voltage continues to rise and then falls back to 9 volts, the first- φ. And the light-emitting diode 220 is turned off. Similarly, when the output AC voltage is equal to or less than -90 volts, the second group of light-emitting diodes 230 is started to be turned on. When the output AC voltage continues to drop and rises again to _9 volts, the second group of LEDs 230 is turned off. . Referring to FIG. 3, the current waveform pattern of the AC light-emitting diode of FIG. 2 is shown, wherein the horizontal axis is time, which is displayed by voltage phase, and the vertical axis is current mA (mA amp is shown in FIG. 3 It is shown that when the phase is about 3 ,, the voltage starts to be greater than 90V, and the first group of light-emitting diodes 22 illuminates. When the phase is about 90 degrees, the voltage reaches a maximum value and flows through the first group of light-emitting springs. The current of the body 220 is about 5 2 mA. When the phase is 15 〜 degrees to 2 〇 degrees, the voltage is less than 90 V and greater than · 9 〇 ν, at which time the first group of light-emitting diodes 22 〇 and the second group of light-emitting diodes 23〇 is turned off, so the current is 〇mA. When the phase is about 21〇, the voltage starts to be less than _9〇v, and the second group of light-emitting diodes 230 is lit. When the phase is about 27〇, the voltage reaches the minimum. The value of the current flowing through the second group of LEDs 230 is about _5_2 mA. When the phase is 33 〜 to 36 ,, the voltage is less than 9 〇V and greater than _9 〇 v. The polar body 220 and the second group of LEDs 23 are turned off, so the current is 〇mA. 201212702 It can be seen from FIG. 3 that the first group of LEDs 220 and the second group of hair The light diode 2 3 0 is sometimes turned on and sometimes turned off, which causes flickering, which causes discomfort to the human eye, so the conventional technique as shown in FIG. 2 is not suitable for use in a lighting facility. A schematic diagram of the conventional AC light-emitting diode is used. As shown in FIG. 4, it is composed of an AC power source 210, a group of light-emitting diodes 220, and a full-bridge rectifier 250. The working principle is to exchange AC power through the full bridge. The rectifier 250 rectifies the positive and negative AC sine waves into a waveform having only a positive half cycle. The waveform is directly driven by the illuminating diode 22 〇. However, such a waveform causes the illuminating diode 220 to flicker and the utilization rate is low. In the case where the input voltage is low, the input voltage is lower than the turn-on voltage of the LED 220, so the LED 22 is turned off. When the input voltage is high, the input voltage is greater than the LED. The turn-on voltage of the body 220 and the light-emitting diode are in a bright state. Overall, the light-emitting diode 220 is extinguished with the input voltage, which results in low utilization of the light-emitting diode and easy It is now flickering. Therefore, there is still room for improvement in the conventional AC light-emitting diode driving circuit. [Invention] The main object of the present invention is to provide a light-emitting diode driving system and a new architecture to enhance the overall structure. The utilization ratio of the light-emitting diodes simultaneously increases the blinking frequency of the light-emitting diodes, making it impossible for the human eye to detect. According to one feature of the present invention, the present invention provides a light-emitting diode driving system. The AC voltage is used to drive the light emitting diode. The 201212702 driving system includes at least a filter circuit, a rectifier circuit, a valley charge=, and a light emitting diode light emitting circuit. The filter circuit receives the AC voltage and The AC voltage and current are filtered to filter out the higher harmonic components of the AC voltage and current and generate a filter parent voltage. The rectifier circuit is coupled to the filter circuit, the rectifier circuit having a first output terminal and a second output terminal for rectifying the filter voltage and current to generate a rectified voltage and current. The valley filling circuit is connected to the rectifying circuit, and the valley filling circuit changes the on-time of the rectifying circuit to increase the power factor of the rectified voltage and current and the utilization ratio of the light-emitting diode. The light emitting diode lighting circuit is coupled to a germanium valley filling circuit, and the light emitting diode lighting circuit receives the rectified voltage to generate a light source. [Embodiment] FIG. 5 is a circuit diagram of a light emitting diode driving system 500 of the present invention. The LED driving system 5 uses an AC voltage to drive the LEDs. The driving system 50 includes a filter circuit 5 1 , a rectifier circuit 520, a valley filling circuit 53 , and a light emitting diode. The body light emitting circuit 540 and a control circuit 55A. The filter circuit 510 is connected to an AC power source Vac to receive an AC voltage and current, and performs a wave on the AC voltage and current to filter out the harmonic components of the AC voltage and current, and generate a filter. AC voltage Vac, filtered. 201212702 The filter circuit 510 is composed of a filter inductor Li and a filter capacitor Ci. The first end 503 of the filter inductor Li is connected to the first end 501 of the AC voltage source Vac, and the second end 504 is connected to the first end 505 of the filter capacitor ci. The second end 506 of the chopper capacitor Ci is connected. To the second end 502 of the AC voltage source Vac. The rectifier circuit 520 is coupled to the wave circuit 5 1 〇. The rectifier circuit 520 has a first output end 521 and a second output end 522 for rectifying the filter current and current to generate a rectified electric grinder. The first output terminal 52 is connected to a low potential. The rectifier circuit 520 is composed of a first to fourth rectifying diodes dr, Dr 2
Du、Du所組成。第一整流二極體]〇111的正極連接至該 濾波電感Li之第二端504及該濾波電容Ci之第一端5〇5， 其負極連接至該第一輸出端521。第二整流二極體Du的 正極連接至該交流電壓源Vac的第二端5〇2及該濾波電 容Cl的第二端506 ’其負極連接至該第一輸出端521。第 三整流二極體Du的正極連接至該第二輸出端522，其負 極連接至該第整流一極體DR |的正極。第四整流二極體 _ DR4的正極連接至該第二輸出端522，其負極連接至該第 二整流二極體DR2的正極。 前述填谷電路530連接至該整流電路520,用以改變該 H電路520之導通時間，以提升該整流電壓與電流的 功率因數。該填谷電路包含—第-電容C1 第一二極 容C2。 體D1、一第二二極體叫、一第三二極體D3、及一第二電 8 201212702 該第一電容Cl之第一端59丨連接至該整流電路52〇的 第一輸出端52卜該第一二極體⑴之負極連接至該第一電 谷C1的第一端592，其正極連接至該整流電路52〇的第二 輸出端522。該第二二極體D2之負極連接至該整流電路 520的第一輸出端521。 〇亥第 極體D3之負極連接至該第二二極體的 正極，其正極連接至該第一電容(^的第二端592及該第一 一極體D1的負極。该第一電容C：2之第一端593連接至該第 二二極體D3的負極及該第二二極體]；^的正極，其第二端 594連接至該整流電路52〇的第二輸出端522。於本實施例 中，s玄第一電容ci的電容值與該第二電容C2的電容值相 同。 前述發光二極體發光電路540連接至該填谷電路 530,以接收該整流電壓而產生光源。該發光二極體發 光電路540包含一第一發光二極體模組D6、一第一開關 Q1、一第一發光二極體模組D4、一第二開關Q〗、及—二 極體D5。 該第一發光二極體模組D6和該第一開關Q1係串聯 連接，該第一發光二極體模組D6和該第一開關Q1係電連 接於該整流電路520的該第一輸出端52卜第二輸出端522 之間，該第一開關Q1可受控制於導通與不導通之間切換。 泫第二發光二極體模組D4和該第二開關q2係串聯 連接，該第二發光二極體模組D4和該第二開關Q2係電連 接於該整流電路520的該第一輸出端521、第二輸出端522 之間，忒第二開關Q2可受控制於導通與不導通之間切換。 201212702 该一極體D5之負極連接於該第一發光二極體模組 D6與該第—開關連接點，其正極接於該第二發光二 極體模組D4與該第二開關（^2的連接點之間。 β亥控制電路550連接至該填谷電路530及該發光二極 體發光電路540,依據該整流電壓大小，以控制該發 光二極體發光電路540。 圖6係本發明發光二極體驅動系統之控制電路55〇的 電路圖。控制電路550藉由電壓Vc及¥]8控制該第一開關 Q 1及第二開關q2於導通與不導通之間切換。 控制電路550包括一第一電阻尺丨、一第二電阻R2、 第二電阻R3 ' —第四電阻R4、一第五電阻R5、一第一 N型金氧半導體場效電晶體]^]^〇31、及一第二N型金氧半 導體場效電晶體NMOS2。 該第一電阻R1係由電阻Rla及Rlb所組成，以避免 當第二N型金氧半導體場效電晶體NMOS2導通時，過 咼的電壓直接跨在該第一開關Q】的閘極與源極 之間。該電阻Rla的一端電連接於該第一輸出端521，其 另—端連接該電阻Rib的一端及該第一開關qi的閘極，並 藉由電壓VC以控制該第一開關Q1導通或不導通。該電阻Du, Du is composed. The anode of the first rectifier diode 〇111 is connected to the second terminal 504 of the filter inductor Li and the first terminal 5〇5 of the filter capacitor Ci, and the cathode thereof is connected to the first output terminal 521. The anode of the second rectifier diode Du is connected to the second terminal 5〇2 of the AC voltage source Vac and the second terminal 506' of the filter capacitor C1 has its cathode connected to the first output terminal 521. The anode of the third rectifying diode Du is connected to the second output terminal 522, and the anode thereof is connected to the anode of the first rectifying body DR |. The anode of the fourth rectifying diode _DR4 is connected to the second output terminal 522, and the cathode thereof is connected to the anode of the second rectifying diode PD2. The valley filling circuit 530 is connected to the rectifier circuit 520 for changing the on-time of the H-circuit 520 to increase the power factor of the rectified voltage and current. The valley filling circuit includes a first capacitor C1 of the first capacitor C1. The first end 59丨 of the first capacitor C1 is connected to the first output end 52 of the rectifier circuit 52A. The body D1, the second diode body, the third diode D3, and the second battery 8 201212702 The anode of the first diode (1) is connected to the first end 592 of the first valley C1, and the anode thereof is connected to the second output 522 of the rectifier circuit 52A. The cathode of the second diode D2 is coupled to the first output 521 of the rectifier circuit 520. The anode of the anode body D3 is connected to the anode of the second diode, and the anode thereof is connected to the second terminal 592 of the first capacitor and the cathode of the first body D1. The first capacitor C The first end 593 of the second terminal 593 is connected to the cathode of the second diode D3 and the second terminal of the second diode, and the second end 594 is connected to the second output end 522 of the rectifier circuit 52A. In this embodiment, the capacitance value of the first capacitor ci is the same as the capacitance value of the second capacitor C2. The light emitting diode lighting circuit 540 is connected to the valley filling circuit 530 to receive the rectified voltage to generate a light source. The LED device 540 includes a first LED module D6, a first switch Q1, a first LED module D4, a second switch Q, and a diode. D5. The first LED module D6 and the first switch Q1 are connected in series, and the first LED module D6 and the first switch Q1 are electrically connected to the first of the rectifier circuit 520. Between the output terminal 52 and the second output terminal 522, the first switch Q1 can be controlled to switch between conduction and non-conduction. The photodiode module D4 and the second switch q2 are connected in series, and the second LED module D4 and the second switch Q2 are electrically connected to the first output end 521 and the second of the rectifying circuit 520. Between the output terminals 522, the second switch Q2 can be controlled to switch between conduction and non-conduction. 201212702 The negative pole of the one-pole body D5 is connected to the first light-emitting diode module D6 and the first switch connection point The anode is connected between the second LED module D4 and the connection point of the second switch (^2). The β-axis control circuit 550 is connected to the valley filling circuit 530 and the LED light-emitting circuit 540. According to the magnitude of the rectified voltage, the LED output circuit 540 is controlled. Fig. 6 is a circuit diagram of the control circuit 55A of the LED driving system of the present invention. The control circuit 550 controls the voltage by Vc and ?8 The first switch Q 1 and the second switch q2 are switched between conducting and non-conducting. The control circuit 550 includes a first resistor 丨, a second resistor R2, a second resistor R3 ′, a fourth resistor R4, and a fifth Resistor R5, a first N-type MOS field effect transistor]^]^〇31, a second N-type MOSFET field-effect transistor NMOS 2. The first resistor R1 is composed of resistors R1a and R1b to avoid over-voltage when the second N-type MOS field effect transistor NMOS2 is turned on. Directly across the gate and the source of the first switch Q. One end of the resistor R1a is electrically connected to the first output end 521, and the other end is connected to one end of the resistor Rib and the first switch qi a gate and controlling the first switch Q1 to be turned on or off by a voltage VC. The resistor
Rib的另一端連接該第二N型金氧半導體場效電晶體 NMOS2的汲極。 該第二電阻R2的一端電連接於該第一輸出端521，該 第三電阻R3的一端電連接於該第二電阻R2,其另一端電 連接於該該第二輸出端522。 201212702 該第四電阻R4的一端電連接於該第一輸出端521，該 第五電阻R5的一端電連接於該第四電阻R4，其另一端電 連接於該該第二輸出端522。 泫第一 N型金氧半導體場效電晶體?<]^〇31其汲極連 接至5玄第二開關Q2的閘極及第二N型金氧半導體場效電 晶體NMOS2的閘極，並藉由電壓VB以控制該第二開關Q2 導通或不導通，其源極連接至該第二輸出端522，其閘極 φ 連接至該第四電阻R4及該第五電阻R5的連接端。 該第二N型金氧半導體場效電晶體NM〇S2其汲極連 接至s亥電阻Rib，其源極連接至該第二輸出端522，其閘 極連接至該第二電阻R2及該第三電阻幻的連接端及該第 一 N型金氧半導體場效電晶體nm〇S1的汲極。 其中’當該第一N型金氧半導體場效電晶體nm〇S 2 導通時，該第一電阻Rla的跨壓足以使該第一開關Q1導 通，而當該第二N型金氧半導體場效電晶體nM0S2不導 通時，該第一電阻R1的跨壓不足，而使該第一開關（^截 ♦ 止。 該控制電路550在該整流電路520的第一輸出端521 的電壓Vo介於第一及第二參考電壓之間時，使該第二開 關Q2及該第二N型金氧半導體場效電晶體nm〇S2導通， 且使該第一開關Q1導通，此會使該第二發光二極體模組 D4及s亥第一發光一極體模組D6為並聯狀態。否則，使該 第二開關Q2及該第二Ν型金氧半導體場效電晶體nm〇S2 不導通，會導致該第一開關Q1不導通。 201212702 其中，該第一參考電壓大於該第二參考電壓，該第 -參考電壓由該第二與第三電阻R2、㈣電阻值及該第 二開關Q2及該第二1^型金氧半導體場效電晶體NMos2的 臨界電壓決定，該第二參考電壓由該第四與第五電阻 R4、R5的電阻值及該第一N型金氧半導體場效電晶體 NMOS 1的臨界電壓決定。 該驅動系統500的工作原理如下列所述· 當該濾波交流電壓Vac，fntered小於濾波交流電 壓Vac，mtered的1/2電壓峰值時，該整流電路52〇為不 導通狀態，當該濾波交流電壓Vac，fntered大於濾波交 流電壓Vac，filtere<^ 1/2電壓峰值時，該整流電路52〇 為導通狀態。 ^ /慮波父流電壓V a c，f丨丨t e r e d由〇漸增至該漶波交 流電壓Vac, m,ered之1/2電壓峰值時，該第一二極體叫 及該第二二極體D2導通，該第三二極體D3戴止，此時該 第一電容C1及該第二電容c 2為並聯對該發光二極體發光 電路540釋放能量，該整流電路52〇的第一輸出端521的電 壓Vo被該第一電容C1及該第二電容C2箝位於1 /2的渡波 交流電壓V a c，f i 11 e r e d的峰值電壓。 此時，該控制電路550控制該第一開關Q1及該第二開 關Q2導通，該二極體D5截止，該第二發光二極體模組〇4 及該第一發光二極體模組D6為並聯狀態。 12 201212702 由於此時的濾波交流電壓Vac，filtered小於該濾波 交流電壓Vac，fUtered之1/2電壓峰值，故該第二發光二 極體模組D4及該第一發光二極體模組£>6為並聯狀態，以 降低該第二發光二極體模組D4及該第一發光二極體模組 D6的順向導通電壓’以提昇此時整體發光二極體模組的 利用率。 當該渡波交流電壓Vac, filtered介於濾波交流電 壓乂仏⑴…以之^電壓峰值與濾波交流電壓^。 filtered之電壓峰值時，該第一二極體D1、該第二二極體 D2、及該第三二極體D3截止，該第一電容C1及該第二電 容C2停止放電，該整流電路520的第一輸出端52〇之電壓 Vo隨著該濾波交流電壓Vac，fUtered變動。 此時’該控制電路550控制該第一開關Q丨及該第二開 關Q2戴止，該二極體D5導通，該第二發光二極體模組D4 及該第一發光二極體模組〇6為串聯狀態。 s a玄渡波交流電壓Vac，fntered為濾波交流電壓 Vac，filtered之電壓峰值時，該第一二極體〇1 '該第二 二極體D2截止，該第三二極體！^導通，該第一電容^及 該第二電容C2呈串聯狀態且受濾波交流電壓充電，該整 流電路520的第一輸出端521之電壓v〇隨著該濾波交流 電壓 Vac, filtered 變動。 13 201212702 此時’該控制電路550控制該第一開關Q1及該第二開 關Q2戴止’該二極體〇5導通’該第二發光二極體模組以 及該第一發光二極體模組D6為串聯狀態。 由於此時的濾波交流電壓Vac，fntered等於濾波交 電壓Vac, filtered之電壓峰值，故該第二發光二極體 模組D4及該第一發光二極體模組為串聯狀態，有較高 的順向導通電壓’以防止因為第一輸出端521之電壓v〇 過高’而導致該第二發光二極體模組D4及該第一發光二 極體模組D6燒毀。 圖7係本發明第一輸出端521之電壓Vo及電流的模擬 示意圖。由圖7可知’在圓圈A處及圓圈B處，由於該第一 電谷C1及該第二電容C2放電，第一輸出端521之電壓Vo 的位準及電流位準均可維持在一定值，而使該第二發光 一極體模組D4及該第一發光二極體模組導通而產生 光源。反觀習知技術，往柱在此時段由於電流趨近於〇安 培或電壓過低，發光二極體無法導通，而使發光二極體 產生閃爍現象。 綜上所述’本發明發光二極體驅動系統利用電容與 二極體的特性，使得輸入電壓在低壓時，電容並聯對發 光二極體放電，維持發光二極體的導通電壓。再搭配後 端各式發光二極體驅動電路，以提昇整體發光二極體的 利用率。另外’同時將發光二極體的閃爍頻率提高，使 人眼無法查覺。 201212702 當輸入交流電壓較低時，透過控制訊號使該第一開 關Q1及s玄第二開關Q2導通，該第二發光二極體模組〇4及 該第一發光二極體模組D6並聯導通，此時第一電容(^與 第二電容C2並聯對該第二發光二極體模組D4及該第一發 光二極體模組D6放電且使其導通。當輸入交流電壓較高 時，透過控制訊號使該第一開關…及該第二開關以截 止，此時該第二發光二極體模組D4及該第一發光二極體 模組D6串聯導通，由輸入電源對該第二發光二極體模組 D4及該第一發光二極體模組D6提供能量使其導通，而提 高發光二極體的利用率，以及將其閃爍頻率提高至人眼 不易查覺的程度。透過本發明使該第二發光二極體模組 D4及s玄第一發光二極體模組D6皆處於導通的狀態’亦藉 此減緩燈源閃爍對人眼的影響。 由上述可知，本發明無論就目的、手段及功效，在 在均顯示其迥異於習知技術之特徵，極具實用價值。惟 應注意的是，上述諸多實施例僅係為了便於說明而舉例 而已’本發明所主張之權利範圍自應以申請專利範圍所 述為準，而非僅限於上述實施例。 【圖式簡單說明】 圖1係發光二極體的電壓電流特性曲線。 圖2係一習知交流發光二極體使用的示意圖。 圖3係圖2之電流波型之示意圖。 圖4係又一習知交流發光二極體使用的示意圖。 圖5係本發明一種發光二極體驅動系統的電路圖。 15 201212702 圖6係本發明發光二極體驅動系統之控制電路的電路圖 圖7係本發明第-輸出端之電壓及電流的模擬示意圖。 【主要元件符號說明】 交流電源2 10 第二組發光二極體230 發光二極體驅動系統5〇〇 整流電路520 發光二極體發光電路54〇 渡波電感Li 第一整流二極體DR1 第三整流二極體dR3 第一電容Cl 第二二極體D2 第二電容C2 第一開關Q1 第二開關Q2 端 501-506, 591-594 第一電阻R1 第三電阻R3 第五電阻R5 第一組發光二極體220 全波整流器250 濾波電路5 10 填谷電路530 控制電路550 濾波電容Ci 第二整流二極體Dr2 第四整流二極體dR4 第一二極體D1 第三二極體D3 第一發光二極體模組D6 第二發光二極體模組D4 二極體D5 第二電阻R2 第四電阻R4The other end of the Rib is connected to the drain of the second N-type MOS field effect transistor NMOS2. One end of the second resistor R2 is electrically connected to the first output end 521. One end of the third resistor R3 is electrically connected to the second resistor R2, and the other end thereof is electrically connected to the second output end 522. One end of the fourth resistor R4 is electrically connected to the first output end 521. One end of the fifth resistor R5 is electrically connected to the fourth resistor R4, and the other end thereof is electrically connected to the second output end 522.泫The first N-type MOS field effect transistor?<]^〇31 has its drain connected to the gate of the 5th second switch Q2 and the gate of the second N-type MOS field effect transistor NMOS2, And controlling the second switch Q2 to be turned on or off by the voltage VB, the source thereof is connected to the second output terminal 522, and the gate φ is connected to the connection end of the fourth resistor R4 and the fifth resistor R5. The second N-type MOS field effect transistor NM〇S2 has its drain connected to the s-up resistor Rib, its source connected to the second output terminal 522, and its gate connected to the second resistor R2 and the first A three-resistive connection terminal and a drain of the first N-type MOSFET field-effect transistor nm〇S1. Wherein when the first N-type MOS field effect transistor nm 〇 S 2 is turned on, the voltage across the first resistor R1 is sufficient to turn on the first switch Q1, and when the second N-type MOSFET When the transistor nM0S2 is not turned on, the voltage across the first resistor R1 is insufficient, and the first switch is turned off. The voltage Vo of the control circuit 550 at the first output terminal 521 of the rectifier circuit 520 is between When the first and second reference voltages are between, the second switch Q2 and the second N-type MOSFETs 〇S2 are turned on, and the first switch Q1 is turned on, which causes the second The LED module D4 and the first LED module D6 are in a parallel state. Otherwise, the second switch Q2 and the second germanium MOS transistor 〇S2 are not turned on. The first reference voltage Q1 is not turned on. The first reference voltage is greater than the second reference voltage, the first reference voltage is determined by the second and third resistors R2, (4) and the second switch Q2. The threshold voltage of the second NMOS-type MOS field effect transistor NMos2 is determined, and the second reference current The resistance values of the fourth and fifth resistors R4 and R5 and the threshold voltage of the first N-type MOS field effect transistor NMOS 1. The operating principle of the driving system 500 is as follows: When the voltage Vac, fntered is smaller than the filtered AC voltage Vac, mtered 1/2 voltage peak, the rectifier circuit 52 is non-conducting state, when the filtered AC voltage Vac, fntered is greater than the filtered AC voltage Vac, filtere < ^ 1/2 voltage At the peak value, the rectifier circuit 52 is turned on. ^ / The wave parent voltage V ac,f丨丨tered is gradually increased from 〇 to the 1/2 voltage peak of the chopping AC voltage Vac, m, ered, The first diode is connected to the second diode D2, and the third diode D3 is worn. At this time, the first capacitor C1 and the second capacitor c 2 are connected in parallel to the LED light-emitting circuit. 540 releases energy, and the voltage Vo of the first output terminal 521 of the rectifier circuit 52 is clamped by the first capacitor C1 and the second capacitor C2 to a peak voltage of the AC voltage V ac, fi 11 ered of 1 /2. The control circuit 550 controls the first switch Q1 and the second switch When the Q2 is turned on, the diode D5 is turned off, and the second LED module 〇4 and the first LED module D6 are in parallel. 12 201212702 Due to the filtered AC voltage Vac at this time, the filtered is smaller than The second alternating current diode module D4 and the first light emitting diode module £>6 are in a parallel state to reduce the second light emitting diode by the 1/2 voltage peak of the alternating current voltage Vac and fUtered. The forward-facing voltage ' of the polar body module D4 and the first light-emitting diode module D6 is used to improve the utilization ratio of the overall light-emitting diode module at this time. When the wave AC voltage Vac, filtered is between the filtered AC voltage 乂仏 (1) ... and the voltage peak and the filtered AC voltage ^. When the voltage peak is filtered, the first diode D1, the second diode D2, and the third diode D3 are turned off, and the first capacitor C1 and the second capacitor C2 stop discharging, and the rectifier circuit 520 stops. The voltage Vo of the first output terminal 52〇 varies with the filtered AC voltage Vac, fUtered. At this time, the control circuit 550 controls the first switch Q丨 and the second switch Q2 to be worn, the diode D5 is turned on, the second LED module D4 and the first LED module. 〇6 is in series. s a quenching wave AC voltage Vac, fntered for filtering AC voltage Vac, filtered voltage peak, the first diode 〇 1 'the second diode D2 cut off, the third diode! The first capacitor ^ and the second capacitor C2 are in series and are charged by the filtered AC voltage. The voltage v〇 of the first output terminal 521 of the rectifier circuit 520 varies with the filtered AC voltage Vac, filtered. 13 201212702 At this time, the control circuit 550 controls the first switch Q1 and the second switch Q2 to be worn, the diode 〇5 is turned on, and the second LED module and the first LED module are Group D6 is in a series state. The second LED module D4 and the first LED module are in series, which is higher than the filtered AC voltage Vac, fntered is equal to the filtered AC voltage and the filtered voltage peak. The second LED module D4 and the first LED module D6 are burned by the forward voltage [to prevent the voltage of the first output terminal 521 from being too high. Fig. 7 is a schematic diagram showing the voltage Vo and current of the first output terminal 521 of the present invention. It can be seen from FIG. 7 that at the circle A and the circle B, since the first electric valley C1 and the second capacitor C2 are discharged, the level and current level of the voltage Vo of the first output terminal 521 can be maintained at a certain value. The second light-emitting diode module D4 and the first light-emitting diode module are turned on to generate a light source. On the other hand, in the conventional technique, the light-emitting diode cannot be turned on due to the current approaching the ampere-ampere or the voltage is too low, and the light-emitting diode is caused to flicker. In summary, the LED driving system of the present invention utilizes the characteristics of the capacitor and the diode such that when the input voltage is at a low voltage, the capacitor is discharged in parallel to the light-emitting diode to maintain the on-voltage of the light-emitting diode. It is also equipped with various LED driving circuits at the rear to improve the utilization of the overall LED. In addition, the flashing frequency of the light-emitting diode is increased at the same time, making it impossible for the human eye to detect. 201212702 When the input AC voltage is low, the first switch Q1 and the second switch Q2 are turned on by the control signal, and the second LED module 〇4 and the first LED module D6 are connected in parallel. When the first capacitor (^ and the second capacitor C2 are connected in parallel, the second LED module D4 and the first LED module D6 are discharged and turned on. When the input AC voltage is high The first switch and the second switch are turned off by the control signal. At this time, the second LED module D4 and the first LED module D6 are connected in series, and the input power is used for the first The two-light diode module D4 and the first LED module D6 provide energy to conduct, improve the utilization ratio of the LED, and increase the flicker frequency to a level that is not easily detectable by the human eye. Through the invention, the second LED module D4 and the S-first LED module D6 are both in a conducting state, thereby reducing the influence of the light source flicker on the human eye. The invention shows its differences in terms of purpose, means and efficacy. The features of the prior art are of great practical value. It should be noted that the above-described embodiments are merely for the purpose of illustration and description, and the scope of the claims of the present invention shall be The present invention is limited to the above embodiments. [Fig. 1 is a diagram showing the voltage-current characteristic of a light-emitting diode. Figure 2 is a schematic diagram of a conventional AC light-emitting diode. Figure 3 is a current waveform of Figure 2. Figure 4 is a schematic diagram of another conventional AC light-emitting diode. Figure 5 is a circuit diagram of a light-emitting diode driving system of the present invention. 15 201212702 Figure 6 is a control circuit of the light-emitting diode driving system of the present invention. Circuit diagram Figure 7 is a schematic diagram of the voltage and current at the first output of the present invention. [Main component symbol description] AC power supply 2 10 Second group of light-emitting diodes 230 Light-emitting diode drive system 5 〇〇 Rectifier circuit 520 Light-emitting two Polar body light-emitting circuit 54 〇 wave inductor Li first rectifier diode DR1 third rectifier diode dR3 first capacitor C2 second diode D2 second capacitor C2 first switch Q1 second open Q2 terminal 501-506, 591-594 first resistor R1 third resistor R3 fifth resistor R5 first group of light-emitting diode 220 full-wave rectifier 250 filter circuit 5 10 valley-fill circuit 530 control circuit 550 filter capacitor Ci second rectifier Diode Dr2 Fourth rectifying diode dR4 First diode D1 Third diode D3 First LED module D6 Second LED module D4 Diode D5 Second resistor R2 Four resistor R4
第一N型金氧半導體場效電晶體NMOS1 第二N型金氧半導體場效電晶體NMOS2 16The first N-type MOS field effect transistor NMOS1 The second N-type MOS field effect transistor NMOS2 16