coloradodream...@united.net wrote: > > On Jan 29, 2009, at 9:49 AM, Dan wrote: > >> At 9:09 AM -0500 1/29/2009, Charles Davis wrote: >>>>> My company recently announced that we are going to retrofit LED >>>>> lighting in all our refrigerated and frozen coolers, we've already >>>>> started building new locations with motion sensor LED cases on the >>>>> sales floor. >>> LEDs ~ CF >>> Completely different animals!! >> Tell me about these LED lights please. I've just started to notice >> them. My housemate bought one ... I didn't take it seriously because >> the light seemed very blue-gray. >> >> - Dan. >> -- >> - Psychoceramic Emeritus; South Jersey, USA, Earth >> > An oversimplfied definition is that they are a bunch of little lights > grouped together to give off a larger light. > they used to need three different diodes each giving off a portion of > the spectrum (via different electric currents) to get a whitish > light, now they have combined it into one with a blueish chip as the > base( thus the blue-grey tint). That's why they aren't so expensive > now and do last a lot longer than either of the two aforementioned > alternatives and are more robust. But they eventually wear out, > putting out less and less light, rather than the "pop" of an > incandescent but the tint doesn't bother me on those as much as the > newer car headlamps with their Halogen/Xenon/ > can'tseewhentheystareyouintheface-on bulbs > Steve
I don't think three LEDs were used much at any time. They tend to be rather obvious, you can see the individual colors. White LEDs are actually UV LEDs with a phosphor coating that converts the UV into many wavelengths of visible light. There are no actual white Light Emitting Diodes (LEDs) as LEDs are monochromatic and white light is made up of several wavelengths of light. White LED lights function much as a fluorescent lamp. The difference is that white LED lights use an LED to produce UV light where as a fluorescent uses a mercury vapor tube, the LED is more efficient. White LED lights can be made in different colors, from blue white to a yellowish white. -- Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting "I'm a designated driver on the Information Super Highway" --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to Low End Mac's iMac List, a group for those using G3, G4, G5, and Intel Core iMacs as well as Apple eMacs. The list FAQ is at http://lowendmac.com/imac/list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to imaclist@googlegroups.com To unsubscribe from this group, send email to imaclist-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/imaclist?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
