Lighting for Life

　　LED照明技術(shù)在工業(yè)和商業(yè)應(yīng)用中的進(jìn)步，需要低成本，堅(jiān)固耐用，可靠的電源，以提供長(zhǎng)期的使用壽命，往往在極端條件下。為了實(shí)現(xiàn)這些目標(biāo)，必須了解所有部件的可靠性和壽命特性，并在設(shè)計(jì)過(guò)程中應(yīng)用適當(dāng)?shù)目紤]因素。

　　氣體放電照明多年來(lái)一直是商業(yè)和工業(yè)環(huán)境中的主要照明技術(shù)。然而，LED照明現(xiàn)在已經(jīng)成為一個(gè)嚴(yán)重的競(jìng)爭(zhēng)對(duì)手。LED照明的兩大優(yōu)點(diǎn)是使用壽命長(zhǎng)，維護(hù)成本低。由于這些優(yōu)點(diǎn)證明了它們的價(jià)值，隨著全世界推出更多的系統(tǒng)，電燈背后的電子驅(qū)動(dòng)程序必須可靠并能夠運(yùn)行多年。LED驅(qū)動(dòng)程序設(shè)計(jì)需要平衡許多妥協(xié)，但一個(gè)糟糕的組件選擇可能會(huì)產(chǎn)生災(zāi)難性的后果。

　　An LED-based lighting system consists of the power supply， LED light emitter， and fixture （Figure 1）。 The lifetime of the system is determined by the shortest lifetime of any component within that system.

　　The power supply is constructed of many components， each of which has its own wear-out mechanism and consequent lifetime limitation. Figure 2 gives a breakdown of the lifetimes for the major components in an LED system.

　　For all practical purposes， the controller and other semiconductor components do not exhibit a lifetime limit. The life of the LED system is determined primarily by the LEDs and capacitors; this article will focus on those components.