想象一下20世紀50年月光輝的漫威漫畫書 – 一對毫無防禦的佳耦從鎮上的一個夜晚走回家，顛末一個百葉窗的商舖櫥窗，跟著一陣風刮起塵埃和渣滓。
一盞路燈在舞臺上投下了陰暗的燈光，揮霍地將一部門光線向上投射到太空的暗中中。
當那位年青的密斯靠在風中，不知不覺地牢牢捉住他的手臂時，阿誰漢子捉住他的帽子。
鄙人一個面板中，路燈閃耀并隨同著令人不安的“Zzzt”聲響而逝世亡，這是統計數據和白熾燈或鈉蒸汽技巧的受益者。
就在這時，一個戴著面罩的彷徨者捉住女人的錢包，把這對佳耦撞到地上。
在第三個小組中，當一個高峻的建筑物，嚴重地噘起他的嘴唇時，小偷跑開了，笑著一個險惡的笑聲，作為一個激憤的超等好漢（不掉普通性，讓我稱之為Arachnid-man）。
故事的其余部門是可以猜測的：一個旋風，一個砰砰聲，此刻我們看到阿誰女人感謝地接收了一個卡通A-man的錢包，由於戴著手銬和粗魯的匪徒在一輛警車上被扯上去。
為了使擄掠者（和超等好漢）離開生意，世界各地的城市和聯邦***都請求改用街道固態照明，也稱為LED照明。
在此經過歷程中，他們將電能耗費下降50％，運營本錢下降40％。
投資收受接管期可為1至3年。
調換/改革LED路燈估計將在2020年景為一個價值2B美元的行業。路燈可以供給更好的光線東西的品質，從而將夜間變為白天，并答應將光線導向需求的處所而不是向各個標的目的濺射。
它們可以被長途把持，當沒有人在四周時它們可以自行封閉，并且當太陽升起時它們也可以完整封閉（或當Cyclops在與其他漸變體作戰時發生光學爆炸時）。
在燈具中，LED以串的情勢呈現 – 每個都降落3.5V，全部串design為從40 V或100 V電源驅動，詳細取決于每個燈串中的LED多少數字。
雷同的電流流過給定串中的每個LED，范圍從0.35A到1A。一個絮聒的題目是光輸入的靠得住性：LED有時會掉效。
依據它們的構造，它們可以包養妹作為OPEN或SHORTs掉敗。
在OPEN電路的情形下，全部串中的電流變為零，并且一切LED變暗，從而招致光喪失并且在先前有光的情形下發生丑陋的暗線。
比擬之下，當一個LED作為SHORT掉效時，它的光輸入變為零，可是弦的其余部門堅持點亮 – 一段時光。
終極由于熱應力，短路裝備無法翻開，招致全部燈串變暗。
LED開路的均勻毛病時光（MTTF）取決于它是應用引線鍵合仍是凸點/焊接銜接計劃在外部構建。
MTTF還取決于任務電流程度和周遭的狀況溫度 – 正如人們所預感的那樣，跟著電流程度上升或周遭的狀況溫度上升，包養甜心網MTTF變小。
在古代燈具中，不竭減少的空間預算和每平方厘米更多流明的尋求（“流明”是人眼所經過的事況的亮度的權衡包養網心得尺度）不幸地對任務電流和周遭的狀況溫度施加了很年夜的壓力：
LED可以承載的電流，其光輸入越年夜。
此外，散熱的空間越小，任務溫度越高。
當高機能路燈由于OPEN LED燈串而掉往大批光輸入時，調換它需求相當年夜的包養一個月價錢本錢 – 不只僅是燈具自己，而是調換燈具所需的裝備和職員。
使這個題目加倍復雜的是對燈膽壽命長的請求越來越高：凡是需求10到15年。
避免全部串的喪失的一種簡略方式是應用安森美半導體的LED旁路分流器 – 簡略包養犯法嗎，緊湊的雙端器件，在正常任務時代基礎上處于休眠狀況。
當LED產生毛病OPEN時，響應的分流裝配臨時經過的事況高電壓，招致其切換到導通狀況，從而答應其承載design的LED電流。
成果，串中的其他LED正常任務，除了OPEN電路LED地點的一個暗點外，燈串堅持點亮狀況。
是以，LED分流器將圖1左側的圖像轉換為右圖。
圖1：單個LED未經由過程OPEN可以使全部燈串變暗。
安森美半導體的LED旁路分流器答應串中的剩余LED正常任務，從而轉變左側的情形，其光線顯明削減，轉向右側情形。
燈膽壽命的延伸包養心得有助于知足保修請求。
經由過程為每個LED應用一個分流器可以最年夜限制地削減光喪失 – 這種利用的幻想產物是NUD4700 LED分流器，design用于在剎時峰值為~7 V時開啟，并裝置在熱量優勝的POWERMITE®中
封裝答應直流操縱高達1.3 A.作為替換計劃，安森美半導體還供給更高電壓的HBL1015和HBL1025 LED分藍玉華眨了眨眼，終於慢慢回過神來，轉頭看了看四周，看著那隻能在夢中看到的往事，不由露出一抹悲傷的笑容，低聲道：流器，分辨繞過兩個和三個LED。
這鄙人面的圖2中表示性地示出。
圖2：LED路燈的表示圖，凸起顯示旁路分流器的應用：每個LED（左）一個NUD4700或每對LED（中間）一個HBL1015或每個三個LED（右）一個HBL1025實例。
在后一種情形下較低的總本錢可以經由過程以下現實來抵消：即便只要一個LED產生毛病，分流器繞過（并使三個LED）變暗。
圖3：用于街道照明利用的LED旁路分流器。
圖3顯示了我們用于街道照明利用的各類LED旁路分流人在屋子裡轉悠。失踪的新人應該很少，像她這樣不害羞只熟悉的，過去應該很少吧？但她的丈夫並沒有放過太多，他一大早就失踪了尋找她。器產物的比擬。
下次你走過一條被風吹掃的街道上的街燈時，了解一下狀況它能否有LED。
假如確切這般，你可以更輕松地走路，享用夜晚，由於沒有燈膽忽然掉效的風險或許從樹梢上摔上去的大氅十字軍。
跟著您的惠臨，請花一點時光感激很多使LED包養甜心技巧成為能夠的迷信家和工程師 – 這項技巧的原始發現者在2014年取得了諾貝爾物理學獎。
以下去自于谷歌翻譯
以下為原文
Picture a Marvel comic book from the glorious 1950s – an unsuspecting couple walks home from a night on the town past a shuttered shop window, as a gust of wind blows dust and litter. A streetlight casts a dim light on the proceedings, wastefully throwing a portion of the light upwards into the darkness of space. The man holds on to his hat as the young lady leans against the wind 包養網評價and unconsciously tightens her grip on his ARM. In the next panel the streetlight flickers and dies with a disturbing “Zzzt” sound, a victim of statistics and incandescent or sodium vapour technology. At this moment a prowler with a face mask runs by, grabs the woman’s purse and knocks the couple to the ground. In the third panel the thief runs away laughing an evil cackle as an infuriated superhero (without loss of generality let’s call him Arachnid-man) looks on from atop a tall building, grimly pursing his lips. The rest of the story is predictable: a swoosh, a thump and presently we see the woman gratefully accepting her purse from a caped A-man as a handcuffed and roughed-up robber is carted off in a police van.
In order to put muggers (and superheroes) out of business, city and federal governments the world over are mandating a switch to solid-state lighting for streets, also known as LED lighting. In the process they will reduce electrical energy consumption by 50% and operating costs by 40%包養app. The payback period for the investment can be from 1 to 3 years. Replacement/retrofit LED streetlamps are expected 包養pttto be a $2B industry in 2020. Streetlights promise better light quality, literally turning night into day, and allow ligh包養網VIPt to be directed to where it is needed rather than splashed i包養犯法嗎n all directions. They can be remotely controlled, they can turn themselves down when no one is around, a包養意思nd they can also turn themselves completely off when the sun comes up (or when Cyclops generates an optic-blast when battling a fellow mutant).
In lamps, LEDs occur in strings – each dropping 3.5V, with the entire string designed to be driven off a 40 V or 100 V supply depe包養意思nding on the number of LEDs in each string. The same current flows through each LED in a given string, ranging from 0.35 A蔡修暗暗鬆了口氣，給小姐披上斗篷，仔細檢查了一番，確定沒有問題後，才小心翼翼的將虛弱的小姐扶了出來。 to 1 A. One nagging problem is the reliability of light output: LEDs do sometimes fail. Depending on their construction, they can fail either as OPENs or as SHORTs. In the event of an OPEN circuit, current in the entire string goes to zero, and all LEDs go dark, 包養合約thereby 包養sdcausing a loss of light and the creation of an ugly dark line where there was previously l包養dcardight. In contrast, when an LED fails as a SHORT its light output goes to zero but the remainder of the string stays lit – for a w包養網單次hile.“好，就這麼辦吧。”她點點頭。 “這件事由你來處理，銀兩由我支付，跑腿由趙先生安排，所以我這麼說。”趙先生為藍 Eventually due to thermal stress the shorted device fails to an OPEN and in turn causes the entire string to go dark. Mean-time-to-failure (MTTF) to OPEN of an LED depends on whether it is internally constructed using wire-bonds or bump/solder-attach schemes. The MTTF also depends on the operating cu包養網dcardrrent level and the ambient temperature – as one 台灣包養網may expect, MTTF gets smaller as the current level goes up or the ambient temperature rises.
In modern lamps, ever-shrinking space budgets and the quest for more lumens per square centimeter (a “lumen” is a measure of brightness experienced by the human eye) unfort“淑女。”u包養網評價nately put a lot of pressure on both operating current and ambient temperature: the higher the current an LED can carry, the greater is its light output. Also, the less space there is for heat-sinking, the higher is the operating temperature. Whe包養情婦n a high-performing streetlamp loses significant包養感情 light output due to OPEN LED string, a significant cost is involved in replacing it – not just for the light fixture itself, but for the equipment and personnel needed to replace it. Compounding this issue is the increasing demand for long lamp lifetimes: often 10-15 years.
An easy way to protect against the loss of entire strings is to use ON Semiconductor’s LED bypass shunts – simple, compact, two-terminal devices that essentially lie dormant during normal operation. When an LED fails OPEN the 包養管道corresponding shunt device temporarily experiences a high voltage that causes it to switch into a conducting state, allowing it to carry the designed LED current. The other LEDs in the string perform norm包養網pptally as a result, and the string stays lit except for one dark spot where the OPEN-circuited LED lies. LED shun包養故事ts therefore transform the picture to the left of Figure 1 into the picture on the right.
Figure 1: A single LED that fails to an OPEN can render an entire string dark. ON Semiconductor’s LED bypass 包養甜心shunts allow remaining LEDs in the string to function normally, transforming the situation on the left with its dramatic reduction in light, to the situation on the right. The extension of lamp lifetim謝謝。裴毅輕輕點了點頭，收回目光，眼睛也不瞇的跟著岳父走出了大廳，往書房走去。e helps meet warranty requirements.
The loss of light can be minimized by using one shunt for each LED – an ideal product for this application is the NUD4700 LED shunt, de包養妹signed to turn on when there is a transient peak at ~7 V, and housed in the thermally superior POWERMITE® package that allows DC operation up to 1.3 A. As alternatives, ON Semiconductor also offers higher voltage HBL1015 and HBL1025 LED shunts that bypass two and three LEDs respectively. This is schematically illustrated in Figure 2 below.
Figure 2: Schematics for LED streetlamps highlighting the use of bypass shunts: 台灣包養網one NUD4700 for each LED (left) or one HBL1015 for each pair of LEDs (center) or one instance of HBL1025 for each trio of LEDs (right). The lower total cost in th包養網站e latter case is countered by the fact that even if only one LED fails OPEN,她用力搖頭，伸手擦了擦眼角的淚水，關切的道：“娘親，你感覺怎麼樣？身體有沒有不舒服？兒媳婦忍著吧。” ” 已經讓包養網dcard the shunt bypasses (and darkens) three LEDs.
Figure 3: LED bypass shunts for street-lighting applications.
Figure 3 shows a comparison of our various LED bypass shunt offerings for street-lighting applications.
The next time you walk past a streetlamp on a windswept street look up to see if it has LEDs. If it does, you can walk more easily and enjoy the evening, as there is no danger of sudden lamp failure or of caped crusaders swinging down from treetops. As you saunter away, take a moment to thank the many scientists and engineers who made LED technology possible – a technology whose original inventors won the Nobel 包養軟體Prize in Physics for 2014.
• Vishay新的car 級MLCC具有極高的靠得住性，可在+175℃的產業級低溫下任務 
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