提防LED十万小时使用寿命之说.pdf

提防LED十万小时使用寿命之说 - LED vs Cold Cathode 作者：Dan Watt 每次看到有关LED 的报道，总会注明它有十万小时的寿命，这意味你安装它后便可安枕无忧地连 续可使用超过11年了，这般通用的声言就让不少人习惯性地接受这是无可非议的事实。 但事实并非如此… 一颗抗UV环氧树脂5mm LED 二极管灯在全电流和高温下工作，在一千小时 内它的光输出将会缩减一半... 在建筑照明的应用上，工程维护和能源成本为最关键的因素，因此 使用冷阴极管仍是最理想的选择。 让我们以典型的白色LED与直径25mm暖白色冷极管在常规照明应用的情况下做个比较, 下图即 为我们展示实验得出的二者的表现。 LED标榜其专业灯光应用，但并不一定是所有灯光照明的最佳答案。当你分析LED 的技术规格或 说明书时，你会发现，没有写明的东西比写明的东西更为重要，一定要好好考虑清楚！ 冷阴极管已是很成熟和被技术得到证实有很多优点的产品, 因此当我们把所有关键问题都整合 在一起考虑，并需要在两者间做个选择的话，很明显地，冷阴极管仍然能提供比LED更多的好处。 注：本文借鉴 Dan Watt 先生相关观点和言论 Dan Watts 是美国一名灯光技术顾问和电路设计工程师，拥有 50 多年电气工程经验。主要专注于灯光行业应 用的电源设计，曾在著名的 Micro Lamps 公司(高级 LED 及灯光材料供应商) 担任 3 年技术总裁，常被受邀于 全美各重大灯光会议上演讲。 LED vs. Cold Cathode - Beware of the 100,000 hour LED myth Every time you see anything regarding LEDs, it is always stated that they have a 100,000 hour life expectancy. This implies that you can just install them and forget about them for more than 11 years of continuous use. This claim is so common that most people have come to accept it as hard fact. The reality is quite different… A 5mm epoxy UV LED working at full current and an elevated tem- perature, may have its output decreased to 50% in less than 1,000 hours… In architectural lighting applications, where maintenance and energy costs are important, a superior choice is still Cold Cathode lamps. Let’s compare typical white LEDs with 25m diameter warm white Cold Cathode lamps for general illumination applications. The table below shows the typical performance ranges for both. LEDs are here to stay for specialty lighting applications, but are not necessarily the best answer to most lighting needs. When looking at a data sheet or specifications for LEDs, what is left out can be more important than what is put in. Do your homework carefully. Cold Cathode lamps are