原本对广州附近的旅游点兴趣不大，但白水寨的感觉很好。
光是蓝蓝的天，星光灿烂的夜，就让我不相信这里还属于广州地区。
广州的天空，灰灰的；国庆的沪宁高速，灰灰的；旅游经过的成都，同样是灰灰的。
印象中，稻城和映秀的天空，让我有种舒服的感觉。
居然，在白水寨，也有这种天空。
2009年11月23日星期一
纪念《建筑电气辅导站》
才出去玩了2天，回来就发生大事了。
又过了2天，《建筑电气辅导站》解散了。
工作了几年，以前很少进论坛，163也很少去，平时都是和同事们讨论讨论。
后来进了《建筑电气论坛》，不久 有一篇关于 配合的讨论
http://www.jzdq.net.cn/bbs/Show.asp?BoardID=14&ID=2676&TB=1&page=4
，认识了" 治学以诚 "也就是老鹰，就入了《建筑电气辅导站》。
看看时间，大概是在2008年11月，也就是我考注册后的2个月。
这是我加的第一个电气群，认识了很多朋友，长了很多见识。《建筑电气辅导站》让我收获了很多。
现在，很多群友转到了另一个群，延续着《建筑电气辅导站》。。。。。。
无论以后再变成什么群号，什么群名，《建筑电气辅导站》都应该被记住。
现在仔细想想，刚加入《建筑电气辅导站》的情景，里面聊的的确更多是专业的东西，大家熟了以后，聊天的内容更广了。。。。。。
实际上，群适合聊天，实时性好；论坛适合探讨技术，就是实时性差，很多论坛没有邮件通知；MailList 邮件列表 适合探讨技术，实时性中等。
我前一段时间发现，QQ的群邮件比上面3种更有优势，但现在更多用于 分享文件。
2009年11月9日星期一
热辐射光源
Schneider Electrical Installation Guide 2008
照明电路选择与设计 技术手册 Schneider Electrical
http://en.wikipedia.org/wiki/Incandescent_light_bulb
由电源直接供电的白炽灯 [电气装置应用(设计)指南第二版 翻译错误]
由于灯丝在工作时温度非常高 (达到 2500 °C)，因此开灯与关灯时的电阻差别特别大。因为其冷态电阻很低，电流会在点亮时几毫秒或数毫秒内达到峰值，高达其额定电流的 10 ~ 15 倍。
这种制约对普通灯和卤素灯都有影响：使得遥控开关、模块化电流接触器和总线中转的继电器等装置带动的灯的最大数量降低。
Incandescent lamps with direct power supply
Due to the very high temperature of the filament during operation (up to 2,500 °C),its resistance varies greatly depending on whether the lamp is on or off. As the cold resistance is low, a current peak occurs on ignition that can reach 10 to 15 times the nominal current for a few milliseconds or even several milliseconds.
This constraint affects both ordinary lamps and halogen lamps: it imposes a reduction in the maximum number of lamps that can be powered by devices such as remote-control switches, modular contactors and relays for busbar trunking.
特低电压 (ELV) 卤素灯
部分低功率卤素灯通过变压器或一台电子变换器由 12 V 或 24 V 低压供电。通过变压器，磁化现象与合闸时灯丝电阻变化现象结合起来。涌流在几毫秒内可达到额定电流的 50 ~ 75 倍。使用安装在上游的调光器开关可以大大地降低这种制约。
电子变换器要比使用相同额定功率的变压器更加昂贵。这个商业障碍可由安装很方便的设备系统来补偿，因为其散热较低而可以安装在易燃的支架上。另外，它们还装有内置的热保护器。
底座安装有变压器的新型特低压卤素灯现在已经问世。它们可直接由低压线路电源供电，不需要任何特殊适配就可以代替普通灯。
Extra Low Voltage (ELV) halogen lamps
Some low-power halogen lamps are supplied with ELV 12 or 24 V, via a transformer or an electronic converter. With a transformer, the magnetization phenomenon combines with the filament resistance variation phenomenon at switch-on. The inrush current can reach 50 to 75 times the nominal current for a few milliseconds. The use of dimmer switches placed upstream significantly reduces this constraint.
Electronic converters, with the same power rating, are more expensive than solutions with a transformer. This commercial handicap is compensated by a greater ease of installation since their low heat dissipation means they can be fixed on a flammable support. Moreover, they usually have built-in thermal protection.
New ELV halogen lamps are now available with a transformer integrated in their base. They can be supplied directly from the LV line supply and can replace normal lamps without any special adaptation.
(Regular) Incandescent lamps (普通)白炽灯
Incandescent lamps are nearly pure resistive loads with a power factor of 1. This means the actual power consumed (in watts) and the apparent power (in volt-amperes) are equal. The actual resistance of the filament is temperature-dependent. The cold resistance of tungsten-filament lamps is about 1/15 the hot-filament resistance when the lamp is operating. For example, a 100-watt, 120-volt lamp has a resistance of 144 ohms when lit, but the cold resistance is much lower (about 9.5 ohms) [66][67]. Since incandescent lamps are resistive loads, simple triac dimmers can be used to control brightness. Electrical contacts may carry a "T" rating symbol indicating that they are designed to control circuits with the high inrush current characteristic of tungsten lamps. For a 100-watt, 120 volt general-service lamp, the current stabilizes in about 0.10 seconds, and the lamp reaches 90% of its full brightness after about 0.13 seconds.[68]
halogen Incandescent lamp 卤素(白炽)灯
A halogen lamp is an incandescent lamp in which a tungsten filament is sealed into a compact transparent envelope filled with an inert gas and a small amount of halogen such as iodine or bromine. The combination of the halogen gas and the tungsten filament produces a chemical reaction known as a halogen cycle (see below) that increases the lifetime of the bulb and prevents its darkening by redepositing tungsten from the inside of the bulb back onto the filament. The halogen lamp can operate its filament at a higher temperature than a standard gas filled lamp of similar power without loss of operating life. This gives it a higher efficacy (10-30 lm/W). It also gives light of a higher color temperature compared to a non-halogen incandescent lamp. Alternatively, it may be designed to have perhaps twice the life with the same or slightly higher efficacy. Because of their smaller size, halogen lamps can advantageously be used with optical systems that are more efficient.
Magnetic transformer for Low-voltage (12V) halogen incandescent lamp 给低压(12V)卤素(白炽)灯供电的电感变压器
Electronic transformer for Low-voltage (12V) halogen incandescent lamp 给低压(12V)卤素(白炽)灯供电的电子变压器
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