标签: CFL

It’s well known that the performance and life of the traditional incandescent bulb performance are very sensitive and highly nonlinear in response to the nominal value of the AC line. Years of data on countless bulbs, plus some analytical work, has shown that for a supply voltage V near the rated voltage of the lamp: -Light output is approximately proportional to V3.4 - Power consumption is approximately proportional to V1.6 - Lifetime is approximately proportional to V-16 - Color temperature is approximately proportional to V0.42   Talk about parametric sensitivity: those are fairly significant exponential-driven variations around a nominal operating voltage setpoint (the Wikipedia entry has many reputable citations and links on this).   I’m sensitive to this problem because I have a small Datel (now Murata/Datel) AC-line voltage meter always in place on one of my outlets (Figure 1) . It’s handy because it’s small, unobtrusive, and has no settings or controls; it does only thing, and that is to read out the AC voltage. Mine line is usually at 123 to 135 VAC, thought I have seen it run as high as 128 to 129 VAC, and as low as 118 to 119 VAC, and both extremes are bad, for many reasons. In both the high and low cases, my local electric company blamed it on a problem with my AC line’s neutral connection at the meter box, not their source. (I rejected that rationalization but still paid for inspection by an electrician, who verified the integrity of my power feeds.)   This Datel AC voltage cube is a handy way to keep an eye on the AC line voltage, it truly is a "plug in and play" unit (note that the segments of the digits are starting to "wear out" and dim after 20+ years).   Still, the low and high-line scenarios made me think about the effect of line voltage on compact fluorescent lamps (CFLs) and light-emitting diode lamps (LEDs), Figure 2 . In contrast to the incandescent lamp, these light sources do not run directly from the AC line, of course, as there is an intermediate AC/DC driver for each of them. I’ve seen many of the reference designs from reputable vendors of the ICs which are at the core of these lamp drivers, and most specify a fairly wide AC-input range over which the driver design will maintain tight output regulation, typically to about 1%.   Three sources, with three very different power issues: the incandescent bulb operates directly from the AC line; the CFL needs an AC/DC voltage driver; while the LED lamp needs an AC/DC current driver.   But wait: isn’t 1% roughly the same variation that the incandescent bulb sees when the AC line is well-managed? That brings me to the core question: what is the performance and lifetime sensitivity of both CFL and LED bulbs themselves (the bulb is the actual illuminating source) to variations in their DC drive? I haven’t been able to find any solid data on this, and I doubt that any would be meaningful anyway. The reason is that it is so dependent on the specific manufacturer of the bulbs, which varies from lamp vendor to vendor and may even vary with a single vendor's between production runs.   There's another thing which bothers me about ratings for CFL: and LEDs. Since their performance is heavily dependent on the performance of the driver, consistency in the manufacture of that driver is critical. Yet we all have read credible stories of substandard and even counterfeit parts being used (knowingly or not) in circuits of this type. The overall unit may appear to even function to spec, at least for a while, but its tolerance for input-voltage variations and temperature-induced changes may be much less than the first-run batches which used quality parts, were fully tested, and then submitted for certification.   Do you have any insight into the performance of mass-market CFL and LED divers with respect to input-line variations or driver output? Have you had any experience with batch and unit variations among what should have been identical units from a given vendor?

本月初，美国环保署(EPA)分发了能源之星照明灯规范第1版(ENERGY STAR Lamps Version 1)最新草案。新规范从2011年年中开始制定，现在仍在制定之中，它的目的是替换现行的CFL和LED能源之星能效规范。 第4稿与上一稿相比包括许多变化： 更新了闪烁、流明维持率、全向灯、半定向灯、定向灯和装饰灯的定义 新增了闪烁指数、百分比闪烁和周期频率的定义 更新了可调光灯的测试要求 调整了可接受的闪烁指数范围 LED灯的大部分要求在新草案中都保持不变，它们包括调光器性能、功率因数（5 W以上照明灯为0.7或更高）以及发光效率（如表1所示）。尽管曾有利益相关者要求降低CRI* ≥ 90的照明灯的效率，但这一要求被EPA拒绝，因为测试数据显示市场上目前销售的照明灯能同时满足高CRI及高发光效率要求。 表 1. 所有照明灯的最低发光效率（资料来源：能源之星）     灯泡额定 功率 (W) 灯泡最低 发光效率 （初始， lm/W ） 全向灯 15 55 ≥15 65 定向灯 20 40 ≥20 50 装饰灯 15 45 15≤ W 25 50 ≥25 60   如果某款照明灯在市场宣传中声称是具有切相调光性能的可调光灯（例如，使用在大多数家庭都能看到的标准可控硅调光器），那么必须使用至少来自两家制造商的十款调光器来测试其兼容性。至少其中一款调光器必须宣称能兼容CFL或LED灯。 在新规范的制定过程中，闪烁问题始终是讨论话题之一。EPA已经调整了可接受的闪烁指数范围，并引入了一个频率依赖性方程式以解决与驱动器级中的PWM电路相关的问题（见下面表2）。 表 2. 所有 LED 灯的最低闪烁效率（资料来源：能源之星）   灯具类型 能源之星要求 所有标示为可调光的 照明灯 照明灯必须具有一个 ≥120 Hz的周期波形周期频率，并且闪烁指数必须小于等于下表中的值（在调光器的设置和已调光条件下进行评估）。   光波形  周期频率  （单位Hz） 闪烁指数 120-800 （周期频率乘以0.001） 大于800 不适用 频率未定的照明灯必须有个百分比调光值≤30%。 80%的照明灯/调光器组合都必须满足此要求。   未来版本的照明灯规范可以考虑照明灯集成了额外的耗能功能(wi-fi)、兼容Zhaga标准的LED灯引擎以及改进了照明灯的调光体验、色彩带质量和一致性。 Lamps Version 1规范将于最终要求发布12月后生效。有关第4稿规范和测试方法的详细信息，请单击此处。如想报名参加将于5月13日举行的旨在探讨修订提议的网络研讨会，请发送电子邮件至lamps@energystar.gov，并在主题行注明"Lamps Draft 4 webinar"字样。请务必在邮件中提供您的姓名、公司名、电话号码和电子邮件地址。 *CRI = 演色指数

It's not a surprise when components eventually fail even in normal use; engineers are used to that. We also understand the likely failure modes: filaments burn out, film capacitors dry out, and batteries lose their ability to be recharged after some number of cycles. But I recently had a modest failure experience which has me puzzled and a little worried. I smelled the classic odor of electronics getting a little too hot and starting to burn, but couldn't localise it. So, I went around closely sniffing my PCs, TVs, and other devices, looking like a slightly crazed escapee. A few hours later, a 13-watt compact fluorescent bulb (which had been in use for at least several thousand hours) burned out, which was not unusual by itself. I did not yet know there was a correlation between the smell (which had already disappeared) and the burned-out bulb. But when I went to change the bulb in the fixture, I saw that the merging where the CFL's glass tube meets the base of the bulb had actually melted and charred, also allowing the tube to tip from its original position:     This is worrisome. Somehow, this low-wattage bulb had managed to go "critical", getting hot enough to where, I assume, it could have started a fire if there was any easily combustible material nearby; it was also source of the smell I couldn't localise. Yes, the bulb has that UL label, but so what? As we know from a recent story on counterfeit electronics, false UL certifications are fairly common. Or sometimes, vendors substitute non-approved components into a product after it has been certified (unintentionally, or maybe not so unintentionally—shocking but true). I am still puzzled by what actually failed in my bulb and allowed a product of such low nominal dissipation to get so hot. On one hand, thirteen watts is not what I normally consider enough internal consumption and subsequent dissipation to start a fire; on the other hand, the bulb is connected to a 120Vac line and, hey, "stuff happens". Since I don't have access to the necessary forensic tools or bulb-design documentation, I can't determine exactly went wrong. Also, having the purported documentation probably wouldn't help, since the design, original BOM, and components (if they were ever approved) may not be the ones in the bulb as it actually shipped. Still, I am puzzled by details of the failure mode which allowed a 13W, AC-line CFL to go into modest meltdown. It's got me worried about things just a little more. Readers: Have you ever had a failure mode that not only surprised you, but that you were unable to adequately explain, whether due to lack of time, information, or insight on your part?  

Efficiency博士： 节能灯的市场看来前景广阔。针对此应用Fairchild有什么具体的方案吗？ - “Question Boy”   Question Boy, 你好： 节能灯CFL（Compact Fluorescent Lamp）市场前景确实非常广阔。与传统的白炽灯相比，CFL具有明显的节能优势，能降低高达80%的能耗。因此，节能灯在民用和商业领域广受欢迎，世界 各国也都在禁用白炽灯，大力推广CFL。据有关调研公司预测，各类CFL产品的年销量到2012年有望突破50亿件。   Fairchild在LED、CFL、LFL以及HID等照明类的应用上都有全面的、成熟的方案。针对CFL应用，我们有FAN7711和FAN7710V等 产品。前者是一颗专用的控制芯片，可以配合外部MOSFET来实现CFL Ballast系统的设计；后者是一颗控制芯片与两颗MOSFET集成的产品，相对来说，这种高度集成的产品可以减少外围元器件的数量并且节省空间。这对 CFL的设计是相当重要的，因为它们对体积都有着非常高的要求。   这些产品还有很多共同的特点：通过选择合适的CPH(preheating time set capacitor)电容来调整预热、启动时间，进而可以延长灯的寿命；在启动以后以ZVS模式工作；无需外围器件就可以实现“开灯”(open- lamp)状态的检测以实现保护等等。   另外，我们还有FAN7387V、PFC 控制芯片以及多种规格的MOSFET可供CFL设计选择.有兴趣见面一起讨论一下？   Efficiency博士

从今年1月1日起，加州开始实施了一项新的EISA要求，比预定时间提前了一年。新能效要求规定商店不得销售2010年12月31日之后生产的100瓦家用灯泡。更具体地说，新法案规定72瓦或更低瓦数的灯泡所产生的发光量必须等于100瓦灯泡（1500至1700流明）所产生的发光量。新法案虽然没有禁止白炽灯，但却将市场有效地限制在了卤素灯、紧凑型荧光灯(CFL)和LED灯。 加州能源委员会表示，新法案的实施在今年将避免1,050万个100瓦灯泡的销售，为消费者带来共计3,560万美元的电费节省。 接下来将会限用75瓦灯泡，然后是60瓦灯泡，最后是40瓦灯泡。接下来的几年中，所有灯泡都将采用类似的标准要求，参见下面的时间表： 如今的灯泡    标准实施后    生效日期 100 W    ≤ 72 W    2012年1月1日 75 W    ≤ 53 W    2013年1月1日 60 W    ≤ 43 W    2014年1月1日 40 W    ≤ 29 W    2014年1月1日 有趣的是，新法案一经出台便受到了零售商的大力拥护。  美国最大的照明零售商Home Depot用了数月的时间对其加州销售人员展开相关培训，以便加强客户对新法案的了解。Lowe's正在将所有100瓦白炽灯从其加州分店撤下。Ikea已全面停止销售白炽灯，停售决定不仅仅限于加州，还包括美国其他州和其他国家。 事情的发展虽然缓慢，但不容置疑的是，我们将逐渐告别爱迪生发明的灯泡 -- 估计就连爱迪生本人也会第一个为之欢呼的。