John Callahan wrote: > LED's, question. > 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?
It's unlikely they would replace an individual LED, they are soldered on to a circuit board. It would likely be cheaper to replace the whole thing than to repair it. The reason for switching to LED traffic lights, aside from power savings, is they out last incandescents by a factor of a hundred or more). Incandescent traffic light bulbs are extra long lasting, they have a thicker filament. My dad put one in the stairwell light and I don't think it ever burned out. But LED lamps are far longer lived. The cost of changing a lamp is probably a lot more than even the cost of the LED Lamp so not having to change them so much makes for quite a savings. Repeatedly turning incandescent lamps on as in traffic light use greatly shortens their life. LEDs aren't affected by turn on surge like this. Around here (San Francisco Bay Area) they have been changing traffic lights to LED for some time, 5 years at least. LEDs are even more efficient in traffic light applications for two reasons. First, when using incandescent bulbs their light is filtered to red, yellow or green. This wastes even more power than an incandescent alone. LEDs are inherently colored, no filtering needed. In left or right turn signals only enough LEDs to form the arrow are used rather than masking most of the light from an incandescent. -- 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 [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 -~----------~----~----~----~------~----~------~--~---
