On Jan 29, 2009, at 11:50 AM, John Callahan wrote:
> New York State has recently converted our traffic lights to LED at a > cost of countless millions of dollars. Part of the pitch was that as > the LED lights burn out they will only have to change one of the > small LED's rather than the entire light. Is this true? Depending on the construction of the lamp module, yes. Also LED's last a lot longer, which is why our city has started replacing the incandescent ones with LEDS as the old ones burn out. Finally LED's consume significantly less power, they're vastly more efficient at turning electricity into light, in low power applications LED's can approach 90% efficiency, even at lighting levels of power, they're a lot more efficient than incandescent lamps, which convert more power into heat than light. An example: I ride my bike to work daily, from about the middle of November to the middle of February, it's dark enough that I need to use the headlight on my bike. My old headlight, with an incandescent lamp, used up two C-cell batteries every week and a half or so. My new headlight which is a LOT brighter, and flashes, to make me much more visible, is still running on a single set of 3 AAA cells, and it's still bright enough that when I ride at night I can see the light bouncing off of road signs two blocks away. -- Bruce Johnson University of Arizona College of Pharmacy Information Technology Group Institutions do not have opinions, merely customs --~--~---------~--~----~------------~-------~--~----~ 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 [email protected] To unsubscribe from this group, send email to [email protected] 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 -~----------~----~----~----~------~----~------~--~---
