4 ms·
The issue was already discovered a month ago and it's not 'consequences' but one single consequence. Also the statement > None of the proposed solutions are fo
by zyb09 17y ago
The issue was already discovered a month ago and it's not 'consequences' but one single consequence.
Also the statement
> None of the proposed solutions are foolproof
is just simply wrong. Traffic lights will be upgraded with little heating systems (coil/wires) and everything will be fine.
- itistoday 17y agoThanks, you beat me to it. The sensationalism in this article is incredible. This is a simple engineering problem that does not justify an article titled "The Unintended Negative Consequences of LEDs". Put in a coil connected to a thermometer to melt snow if necessary. Problem solved, and energy is still conserved.
- mnemonicsloth 17y agoUnless we're talking about relativistic quantum traffic lights, energy will conserved regardless ;-)
- maw 17y agoIf so, will they still be cheaper to operate? I can buy that they'll still use less energy on net, but that isn't the only concern here.
- wildwood 17y agoIf the heating element is thermostat-driven, and not on all the time, then yes.
- ars 17y agoHopefully not a thermostat but rather a proximity or a frost sensor.
- evgen 17y agoNo, use a thermostat. It is much simpler, less prone to errors, you only need one per light housing, and the energy cost required to keep the shrouds above 34 degrees is quite insignificant.
- pavel_lishin 17y agoYou could probably get away with having one per block; aren't most traffic lights all connected? Or have I just been watching too many movies where hackers take over streetlights?
- evgen 17y agoPutting one per light housing means it gets added at the manufacturer and you don't need to do any additional wiring or setup at installation time.
- phil 17y agoWhat if it's dry but cold?
- aplusbi 17y agoPresumably they wouldn't turn the heating coils on in the winter.
- eli 17y agoMoreover, LED traffic lights with heated lens already exist. They've been around for over a decade. This is a case of stingy municipalities, not a failure of engineering.
- notauser 17y agoFTA> Heating up the LEDs would help defeat the purpose of saving energy. This will only be true if it snows every day! Or are they really proposing switching bulbs twice a year? (There are plenty of people in MA who keep their incandescents year round 'for the free heating' - ignoring the fact that they have their air conditioning on for 6 months a year. People can be perplexing at times.)
- brk 17y agoAnd ignoring the fact that the heat wouldn't really be "free". It would be generated by excess energy consumption. Electric heat (in any form or format in homeowner applications) is generally the most expensive way to turn a given quantity of dollars into a given amount of heat. The only MORE expensive option is burning the dollar bills themselves to produce heat.
- ismarc 17y agoYou could burn the checks that can be converted into the dollar bills, but that's just getting excessive.
- marze 17y agoOn the shroud over each light, a number of LED/photodiode pairs should be placed. The LED can be blinked every few seconds. The photodiode will detect significanly more light during the blink if there is snow packed into the shroud. If the controller detects packed snow it turns on a heater to melt it. Similar LED/photodiode pairs are used to detect paper in copiers and other similar situations. Even though this may sound complex, the parts required are cheap, especially compared to the cost of the traffic light as a whole. Of the ~40000 traffic fatalities in the US each year perhaps 0.01% are due to this problem, but the fix is easy.
- cakesy 17y agoCan't they just put a bigger lid over the led traffic lights, and no ledge under the light for snow to build up? Or would there still be a problem (not so familiar with snow, coming from Oz).