1248886 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種具安全迴路且適用於低溫環境的車 燈控制電路，尤指一種運用於以發光二極體作為光源的車 燈之驅動電路。 【先前技術】 由於發光二極體具有低耗電、壽命長等優點，近來已 i渐被運用在照明用途，特別是白光發光二極體問世以後 ，及發光二極體大廠宣稱特定色光的發光二極體（如紅黃 光），其工作壽命可達五萬甚至十萬小時，而使發光二極 體k具儼然成為照明設備的明日之星。此股風潮亦吹向汽 車車燈’例如高級進口車雙B、國產車ALT|S才目繼採用發 光一極組作為車燈（尤其是車尾燈）。儘管發光二極體亮 度相較於以往已有顯著提升，但單顆仍不足滿足照明的需 要因此必須令複數發光二極體同時工作始能到達標準， 為確料尾燈正常的提供警示功能，交通法規對其亮度亦 -則發光二極體車燈為確保迴路上的單顆或 =極體損壞時，車燈仍可正常工作，乃採用如第四^ 的線路佈局，在該等以並聯作為基礎的線路佈局下， 即使迴路中有_ f g十— 、 顆或一顆以上的發光二極體損 仍然可以正當锺从,, a旱眉 作。然而從安全的角度觀之， 安全上的疑慮。 u然存名 1248886 二引述車燈迴路上有相當數量的發光二極體損壞時， 基於刖述的線路佈局’該車燈仍然可以正常運作，但其亮 度可能已經低於規定標準，而影響其警示效果，此時駕敬b 人仍渾然不知，影響安全之鉅即不言可喻。 #又某些電子元件之電氣特性常受低溫環境影響而使其 失书或失效，例如發光二極體在極低溫狀態下即可能無法 順利點亮，換言之，以發光二極體作為光源的車燈，在寒 帶地區可能無法正常工作。 【發明内容】 由上述可知，既有以發光二極體作為光源的車燈，可 能存在安全性及低溫環境下無法正常工作等問題。 本卷明主要目的即在提供一種具安全迴路設計 且適用於低溫環境的車燈控制電路，其可在車燈中有一定 數量的發光二極體損壞時，自動停止車燈的工作；另具有 -溫度監控反應功能’使發光二極體車燈即使處於低溫環 境下，仍可正常運作。 為達成則述目的採取的主要技術手段係令—啟動電路 具有-輸入端，供與電源連接，又具有一輸出端，供盘發 光二極體車燈連接，又啟動電路係在其輸入/輸出端間則 跨接有一限電流安全迴路，且另與一預熱電路連接；其中 :該限電流安全迴路包括有： 電子開關其一端係與輸出端的發光二極體車燈連 接； 4 1248886 、一電流檢測器，係透過電子開關連接輸出㈣，用以透 過電子開關檢測輸出端的負載電流； '一比較電路，係與前述電流檢測器連接1以判斷負 载電流是否低於一設定值； 、一維持電路’係設於電源輸入端與電子開關之間，用 以負載電流正常時’令電子開關維持導通，而持續供電予 發光二極體車燈； 八 以前述的限電流安全迴路設計，當發光二極燈車燈中 有:定數量的發光二極體損壞，使負載電流下降至一 ^定 值打，即令電子㈤關截纟，而停止對發光二極體車燈供電 ’避免因警示效果不良而影響安全。 又前述啟動電路因連接一預熱電路，當^二極體車 燈處於寒帶地區的低溫環境下，預熱電路將在未工作狀態 下透過啟動電路輸出_微量電流予發光二極體車燈，使其 先行預熱，以便在低溫環境下仍可正常運作。 ^ 前述電子開關為一 N通道場效電晶體，其以源茂極連 接於電源輸人端與輸“之間，其閘極分職維持電路及 比較電路的輸出端連接。 則述電流檢測器係以兩並聯的電阻串接於電源輸入端 與電子開關之間，兩並聯電阻的兩端係與一 pNp電晶體的 射基：構成迴路；又該電晶體的集極係連接至比較電路。 前述比較電路係以兩電阻的分壓節點與一 npn電晶 體的基極連接，其中—電阻的另端係與電流檢測器連接， 該電晶體的集極則連接至電子開關。 1248886 :述維持電路係以—pNp電晶體的射極連接電 ”集極則連接電子開關的閘極，以 ：入 時賦予雷子p卩M日日 月戮尾/现正常 開關的導通極-足以使其導通的電而維持電子 刖述啟動電路係以一 pN P電晶體 =入端與輸出端之間，其基極透過電阻連接到：接:: 門'電路❹-PNP f晶體連接於電源輸人端與路 便在車燈未啟動前，透過啟動電路輸出= 机予車燈使其預熱。 里晃 【實施方式】 有關本毛明之-可行貫施例，請參閱第一圖 包括有： # -啟動電路（10) ’其輸入端係連接電源， 端係供與發光二極體車燈（本圖中未示）連接，於本實施 例中，該啟動電路（10)係以一 PNP電晶體Q4的射/ 集極跨接於前述電源輸人端與輸出m其基極透過— 電阻R8連接到地； 一預熱電路（2〇)，係連接於電源輸人端與前述啟 動電路（1 G )之間’於本實施例中，該預熱電路（2 〇 )係由-電晶冑Q3與—溫度感測器（2工）組成，該溫 度感測器（2 1 )係串接於電源輸人端與啟動電路（]_ 〇 )中電晶M Q4的射極，又電晶體Q3係以射/集極分別 與電源輸人端與啟動電路（1 〇)之電晶冑Q4閘極連接 I248886 ’電晶體Q3基極連接至溫度感測器（2 1 )與電晶體Q4 的射極間；藉Λ，當環境溫度低於一定值以下，溫度感測 器（2 1 )將使電晶體Q3導通，使發光二極體車燈在未 啟動刖的一般狀態下，透過啟動電路（i 〇 )輸出一微量 電流予發光二極體車燈，由於電流小，發光二極體車燈光 電反應不明顯，就人類視覺而言係屬關閉狀態，惟藉此可 達成預熱的效果，俾使其低溫狀態下仍能被正常點亮；前 述溫度感測器（2 1 )可為各種溫度感測元件； -限電流安全迴路，係跨接於電源輸入端與輸出端之 間用以在負載電流低於_設定值時，自動切斷發光三極 體車燈的電源，以避免車燈在亮度低於標準的狀態下工作 而影響安全。 至於前述限電流安全迴路之具體組成，則包括有： 一電子開關U1 ’係連接於電源輸人端與輸出端之間 用以決定是否發光二極體車燈持續供電； 一電流檢測器 與電源輪入端之間 的負载電流； (3 0 )，係串接於電子開關⑴另端 ’用以透過電子開關U1檢測輸出端上 遠接較電路"〇)，係與前述電流檢測器（3.0) 判斷負載電流是否低於一設定值，從而決定是 否關閉電子開關U1 ; 一維持電路（5 0 )，俏Μ私Φ^ 又农電源輸入端與電子開關 u1之間’用以在負載電流正常時，八 ^ ^ 吊吋7電子開關U1維持導 通，而持續供電予發光二極體車燈；其中： 1248886 前述電子開關U1為一 N通道場效電晶體，其源洩極 係分別連接電源輪入端及輸出端，其閘極則與維持電路（ 5 〇 )連接，該維持電路（5 0 )係以一 PNP電晶體Q5 的射極連接電源輪入端，其集極則連接電子開關u1的閘 極，其基極則透過電阻R6連接到地，以便在負載電流正 常時賦予電子開關m極一足以使其導通的電位，而維 持電子開M U1的導通，使發光三極體車燈持續取得電源 供應。 該電流檢測器（3 0 )係以兩並聯的電阻R1/R2串接 於電源輸入端與電子„ W之間的電源迴路上，兩並聯 電阻R1/R2的兩端係與一 PNP電晶體Q1的射/基極構成 迴路’該電晶It Q1的集極係連接至比較電路（4 〇 )， 藉此可用以檢測輸出端上的負載電流。 而邊比較電路（4 〇 )係以兩電阻R3/R4的分壓 與一 N P^N電晶體Q 2的基極連接，其中一電阻r 3的另端 檢測β ( 3 〇 )連接’該電晶體Q2㈣ 接至電子開關U1的閘極。 a 在前m流安全迴路的電路設計下，在發光二極體 車文且工作時，電流檢測哭 赛雷、ώ 〇口 （ 3 〇 )將即柃檢測輸出端的負 載電机，當發光二極燈車 _ 、 於…… W且正常’或損壞的發光二極體低 、數，比較電路（4 〇 )不動作，而電 在維持電路（5 0 )提供導，s千y 开關U1 發光二極體車燈中有-定數量（一顆以上）的if; 扣壞，以致使負載電流下降至一 ° 口又疋值時，則比較電路（ 1248886 4 Ο )之電晶體Q2基極透過分壓電阻R3取得一電位而 導I Θ而使电子開關U ’ ~，極接地而截止，故電源迴路 虹P中斷並如止對發光二極體車燈供電，藉此，可避免發 光二極體在亮度偏低狀況下仍工作，而警示效果不佳的狀 況下影響安全。 在運用_象方Φ，本發明可運用在各種車燈上，如方 向燈或行車燈/刹車燈，首先請第二圖所示，係本發明運 用在驅動方向燈的線路不意’其設於一電源轉換器（61248886 IX. Description of the Invention: [Technical Field] The present invention relates to a vehicle lamp control circuit having a safety circuit and suitable for use in a low temperature environment, and more particularly to a driving circuit for a lamp used as a light source using a light emitting diode . [Prior Art] Since the light-emitting diode has the advantages of low power consumption and long life, it has recently been used in lighting applications, especially after the introduction of white light-emitting diodes, and the large-scale light-emitting diodes claim specific color light. The light-emitting diode (such as red-yellow light) has a working life of 50,000 or even 100,000 hours, and the light-emitting diode k has become a shining star of lighting equipment. This trend has also been blown to the car lights. For example, the high-end imported car double B, the domestic car ALT|S has adopted the light-emitting pole group as the headlights (especially the taillights). Although the brightness of the light-emitting diode has been significantly improved compared with the past, the single piece is still insufficient to meet the needs of the illumination. Therefore, the plurality of light-emitting diodes must be operated at the same time to reach the standard, and the warning function can be provided for the normal tail light. The regulations are also for their brightness - the light-emitting diode lamp ensures that the single or the pole body on the circuit is damaged, the lamp can still work normally, and the line layout such as the fourth ^ is used, in parallel Under the basic line layout, even if there are _fg ten, one or more LED damage in the loop, it can still be justified. However, from a security perspective, security concerns. u, the name is 1248886. When a considerable number of LEDs are damaged on the lamp circuit, the lamp layout can still operate normally, but its brightness may be lower than the specified standard, which affects its The warning effect, at this time, the people who are respectful are still ignorant, and the impact on safety is self-evident. #The electrical characteristics of some electronic components are often affected by the low temperature environment, causing them to lose books or fail. For example, the light-emitting diode may not be able to light up smoothly under extremely low temperature conditions, in other words, a car with a light-emitting diode as a light source. Lights may not work properly in cold areas. SUMMARY OF THE INVENTION As described above, there is a problem that a vehicle lamp having a light-emitting diode as a light source may have problems such as safety and failure to operate normally in a low-temperature environment. The main purpose of this document is to provide a vehicle lamp control circuit with a safety loop design and suitable for low temperature environment, which can automatically stop the operation of the lamp when a certain number of light-emitting diodes are damaged in the lamp; -The temperature monitoring reaction function enables the LED light to operate normally even in a low temperature environment. The main technical means adopted to achieve the stated purpose is that the start-up circuit has an input terminal for connection to the power supply and an output terminal for the connection of the light-emitting diode lamp, and the start-up circuit is connected to its input/output. The terminal is connected to a current-limiting safety circuit, and is connected to a preheating circuit. The current-limiting safety circuit includes: an electronic switch connected at one end to the LED of the output terminal; 4 1248886 The current detector is connected to the output through the electronic switch (4) for detecting the load current of the output terminal through the electronic switch; 'a comparison circuit is connected with the current detector 1 to determine whether the load current is lower than a set value; The circuit is disposed between the input end of the power supply and the electronic switch, and is used to maintain the conduction of the electronic switch when the load current is normal, and continuously supply power to the LED lamp of the light-emitting diode; In the two-lamp lamp, there is a certain amount of light-emitting diode damage, so that the load current drops to a certain value, that is, the electron (five) is cut off, and Stop for light-emitting diode lamp power 'to avoid the adverse affect safety warning effect. In addition, the start-up circuit is connected to a preheating circuit. When the diode lamp is in a low temperature environment in a cold zone, the preheating circuit will output a small amount of current to the light emitting diode lamp through the starting circuit in an inoperative state. Let it warm up first so that it can still operate normally in low temperature environments. ^ The aforementioned electronic switch is an N-channel field effect transistor, which is connected between the input terminal and the input of the power source, and the gate of the gate is connected to the output of the sustain circuit and the comparison circuit. Two parallel resistors are connected in series between the power input end and the electronic switch. The two ends of the two parallel resistors are combined with the emitter of a pNp transistor: forming a loop; and the collector of the transistor is connected to the comparison circuit. The comparison circuit is connected to the base of an npn transistor by a voltage dividing node of two resistors, wherein the other end of the resistor is connected to the current detector, and the collector of the transistor is connected to the electronic switch. 1248886: Maintaining The circuit is connected to the emitter of the -pNp transistor. The collector is connected to the gate of the electronic switch to: give the lightning pole p卩M day and month tail / the normal conduction switch - enough to make it conductive The electric circuit maintains the electronic description starting circuit with a pN P transistor = between the input terminal and the output terminal, and its base is connected through the resistor to: connect:: gate 'circuit ❹-PNP f crystal is connected to the power input end And the road is before the lights are turned on, Through the start circuit output = machine to warm the lights.里晃 [Embodiment] For the local example of the Maoming, please refer to the first figure including: # -Starting circuit (10) 'The input terminal is connected to the power supply, and the end is for the LED light ( In the present embodiment, the starting circuit (10) is connected to the power input end and the output m through a base/output of a PNP transistor Q4. The base is transmissive - the resistor R8 Connected to the ground; a preheating circuit (2〇) is connected between the power input end and the aforementioned starting circuit (1 G ). In this embodiment, the preheating circuit (2 〇) is made of - electric crystal胄Q3 and - temperature sensor (2 workers), the temperature sensor (2 1) is connected in series with the emitter of the power supply input terminal (] _ 〇), the emitter of the electric crystal M Q4, and electricity The crystal Q3 is connected to the gate of the power supply input terminal and the start-up circuit (1 〇), and the gate of the transistor Q4 is connected to the I248886 'the base of the transistor Q3 is connected to the temperature sensor (2 1 ) and the transistor Q4. Between the emitters; when the ambient temperature is below a certain value, the temperature sensor (2 1 ) will turn on the transistor Q3, so that the light-emitting diode lamp is In the general state of starting 刖, a small amount of current is output to the illuminating diode lamp through the starting circuit (i 〇). Due to the small current, the lighting reaction of the illuminating diode is not obvious, and it is closed in terms of human vision. However, the effect of preheating can be achieved, so that it can be normally illuminated under low temperature conditions; the temperature sensor (2 1 ) can be various temperature sensing components; - current limiting safety circuit, bridging Between the input end and the output end of the power supply, when the load current is lower than the _ set value, the power supply of the light-emitting triode body lamp is automatically cut off to prevent the lamp from working under the condition that the brightness is lower than the standard, thereby affecting safety. The specific composition of the current-limiting safety loop includes: an electronic switch U1 'connected between the power input end and the output end to determine whether the LED light is continuously supplied; a current detector and a power source The load current between the wheel terminals; (3 0 ) is connected in series with the electronic switch (1) at the other end 'for detecting the remote terminal through the electronic switch U1 to detect the remote circuit "〇), and the current detector ( 3.0) Determine whether the load current is lower than a set value, thereby deciding whether to turn off the electronic switch U1; a maintenance circuit (5 0), a good Φ ^ and between the agricultural power input terminal and the electronic switch u1 'for the load current Normally, the eight ^ ^ 吋 7 electronic switch U1 maintains conduction, and continues to supply power to the LED light; wherein: 1248886 The electronic switch U1 is an N-channel field effect transistor, and the source and drain are connected to the power supply respectively. The wheel terminal and the output terminal are connected to a sustain circuit (5 〇). The sustain circuit (50) is connected to the power supply wheel terminal by the emitter of a PNP transistor Q5, and the collector is connected to the electronic switch. The gate of u1, The base is connected to the ground through a resistor R6, so as to give the electronic switch m a potential sufficient to conduct it when the load current is normal, and maintain the conduction of the electronic opening M U1, so that the light-emitting triode lamp continues to obtain power supply. . The current detector (30) is connected in series with the two parallel resistors R1/R2 on the power supply circuit between the power input terminal and the electron „W. The two parallel resistors R1/R2 are connected to a PNP transistor Q1. The emitter/base constitutes a loop 'The collector of the transistor It Q1 is connected to the comparison circuit (4 〇), which can be used to detect the load current at the output. The side comparison circuit (4 〇) is a two-resistor The divided voltage of R3/R4 is connected to the base of an NP^N transistor Q 2, wherein the other end of a resistor r 3 detects a β ( 3 〇) connection 'the transistor Q2 (4) is connected to the gate of the electronic switch U1. In the circuit design of the front m-flow safety circuit, when the LED is working and the LED is working, the current detection is crying, and the 〇 ( (3 〇) will be the load motor of the detection output, when the LED is illuminated Car _, ...... W and normal 'or damaged LED low, number, comparison circuit (4 〇) does not work, and electricity provides guidance in the maintenance circuit (50), s thousand y switch U1 light two In the polar body lamp, there is a certain number (more than one) of if; the buckle is broken, so that the load current drops to one ° and the value is depreciated. Then, the base circuit of the transistor Q2 of the comparison circuit (1248886 4 Ο) obtains a potential through the voltage dividing resistor R3 and conducts the I Θ to make the electronic switch U ' ~, the pole is grounded and cut off, so the power circuit rainbow P is interrupted and stopped. The light-emitting diode lamp is powered, thereby avoiding the operation of the light-emitting diode under the condition of low brightness, and affecting the safety under the condition of poor warning effect. The invention can be applied to various uses in the image Φ On the headlights, such as the direction lights or the running lights/brake lights, please first show the second picture. The line used in the driving direction of the present invention is not intended to be set in a power converter (6).
0 )與以發光二極體作為光源的方向燈（γ 〇 )上，其 中方向义且（70)係由複數的發光二極體並聯而成。又 如第三圖所示，係本發明運用在驅動行車燈/刹車燈的線 路示意圖，其設於一電源轉換器（6 0)肖一以發光二極 體作為光源的行車燈（8Q)(或剎車燈）上，其中，行 車燈（8 〇 )係由複數的發光二極體串聯而成。 由上述可知，本發明係在發光二極體車燈的控制電路 中加入-預熱電路及一限電流安全迴路，前者在發光二極0) and a directional light (γ 〇 ) using a light-emitting diode as a light source, wherein the direction (70) is formed by connecting a plurality of light-emitting diodes in parallel. As shown in the third figure, the present invention is applied to a circuit diagram for driving a running light/brake light, which is disposed in a power converter (60), a driving light with a light-emitting diode as a light source ( 8Q) (or brake light), wherein the running light (8 〇) is made up of a plurality of light-emitting diodes connected in series. It can be seen from the above that the present invention incorporates a preheating circuit and a current limiting safety circuit in the control circuit of the LED light, the former being in the light emitting diode
體車燈在接通電源前即透過預熱電路給予一微量電流供其 預熱’以確保發光二極體車燈能在低溫環境下正常運作； 後者則確保發光二極體車燈在亮度標準以上始能正常 運作，以避免因警示效果不良而影響安全；以前述設計確 已具備突出的技術特徵與顯然的進步，並符合發明專利要 件。 【圖式簡單說明】 9 1248886 第一圖：係本發明之詳細電路圖。 第二圖：係本發明運用在方向燈之線路示意圖。 第三圖：係本發明運用在行車燈或剎車燈之線路示意 圖。 第四圖A〜C :係習用發光二極體車燈的各種線路示 意圖。 【主要元件符號說明】 (1 0 )啟動電路Before the power is turned on, the body lamp gives a small amount of current through the preheating circuit for preheating 'to ensure that the LED lamp can operate normally in a low temperature environment; the latter ensures the brightness standard of the LED lamp The above can be operated normally to avoid the impact of safety due to poor warning effect; the above design has already had outstanding technical features and obvious progress, and is in line with the invention patent requirements. BRIEF DESCRIPTION OF THE DRAWINGS 9 1248886 The first drawing is a detailed circuit diagram of the present invention. The second figure is a schematic diagram of the circuit used in the directional lamp of the present invention. Fig. 3 is a schematic diagram of the circuit of the present invention applied to a running light or a brake light. The fourth figure A to C: is a schematic diagram of various lines of the conventional light-emitting diode lamp. [Main component symbol description] (1 0 ) Startup circuit
(2 0 )預熱電路 （2 1 )溫度感測器 (3 0 )電流檢測器 （4 0 )比較電路 (5 0 )維持電路 （6 0 )電源轉換器 (7 0 )方向燈 （8 0 )行車燈(2 0 ) Preheating circuit (2 1 ) Temperature sensor (3 0 ) Current detector (4 0 ) Comparison circuit (5 0 ) Maintenance circuit (60) Power converter (7 0) Directional lamp (8 0 Driving lights
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