SJCguy From United States of America, joined Apr 2001, 579 posts, RR: 1 Posted (12 years 10 months 4 weeks 1 day 3 hours ago) and read 722 times:
I have noticed around here in the Bay Area they are installing new red/yellow/green light units on each stoplight. They are a single ball made up of tiny lights which look to be more true color and much brighter than the bulb and lense. They are installing them all around here in Los Gatos and San Jose. They almost seem too bright, are they doing it anywhere else?
LH423 From Canada, joined Jul 1999, 6501 posts, RR: 54
Reply 1, posted (12 years 10 months 4 weeks 20 hours ago) and read 713 times:
Yeah, they've done that to most of the red lights in Boston, and now seem to be working on getting the green lights done. I never really noticed a difference in lumination until about two weeks ago, I was driving at night, and stopped at a red light and noticed how bright it was.
The only thing I've noticed, is that over time, the individual lights go out, so you get left with little dark patches on the red light. Kinda strange to look at.
« On ne voit bien qu'avec le cœur. L'essentiel est invisible pour les yeux » Antoine de Saint-Exupéry
Aa737 From United States of America, joined Oct 1999, 849 posts, RR: 0
Reply 2, posted (12 years 10 months 4 weeks 19 hours ago) and read 709 times:
I think I read in the newspaper that these lights have to do with the whole power issue. I think they use less power then normal lights so towns have started to instal them. I haven't noticed any around San Mateo near my house, but there might be some and I just haven't seen them yet.
Sccutler From United States of America, joined Jan 2000, 5393 posts, RR: 26
Reply 3, posted (12 years 10 months 4 weeks 19 hours ago) and read 706 times:
Those are the new LED (Light Emitting Diode) signals; they use less power; they switch faster (turn on and off faster); and since they are an aray of many small lamps, they "fail soft," meaning there can be a number of individual LED's out but the signal still works.
LEDs are more costly to manufacture but the long-term cost is lower.
You'll also notice that many cars are beginning to have LED tail lamps.
...three miles from BRONS, clear for the ILS one five approach...
Turbulence From Spain, joined Nov 1999, 963 posts, RR: 21
Reply 4, posted (12 years 10 months 4 weeks 18 hours ago) and read 704 times:
Not only in Boston or California. Here in Barcelona, too. As Aa737 says, it has to do with the power needed. As Sccutler says, it has to do with both long term cost and less failure probabilities. Actually, LEDs have a very very very long useful life.
But there's also some other good points. For example, in very sunny places, like California in this case, or in Southern Europe, when sun is low, you can find yourself in front of a traffic light of the "bulb-and-lens" system, and be absolutely unable to guess which of the three lights is on. Some twenty years ago the municipality of Barcelona tried to solve this problem installing coloured bulbs behind transparent or smerilized glasses. But LEDs are being successfully used during the last two-three years. This way, the two "lights" off look grey, and the one on, brightly coloured.
As for the cars, you have only to look for one (there's quite a lot of them) that have the two "normal" brake lights with bulb, and the third one in the middle with LEDs. If you pay attention, you'll see the center one be fully lightened about 2/10ths of a second faster. This, if your car has one of these LED lights, means, expressed in distance covered at US limit speed 55mph (88kms/h), that the person driving the car behind yours is going to see your indication 2,44 metres sooner. At a limit probability, imagine the difference between he/she managing to stop his/her car, let's say 44 cms far behind, or... 2 metres inside yours!!!!
That's why some cars are starting to incorporate their three brake lights made of LEDs
N312RC From United States of America, joined Aug 2000, 2680 posts, RR: 17
Reply 5, posted (12 years 10 months 4 weeks 18 hours ago) and read 701 times:
Yeah, weve got those in the Detroit-Metro Area too... They are supposed to last like 5 times longer than normal traffic lights. They are way sharper (much crisper) and WAAAAY brighter. In Detroit, they also have sun shields on the lights, so you usually dont have a problem seeing them anyways.