A problem with LEDs

Dec 16, 2009 36 Replies

When used in traffic signals, the lights don't get warm enough to melt snow. The snow obscures the signal and people die.



"Cities around the country that have installed energy-efficient traffic lights are discovering a hazardous downside: The bulbs don't burn hot enough to melt snow and can become crusted over in a storm - a problem blamed for dozens of accidents and at least one death."



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Some cities are considering hiring midgets to sit atop the signals with hair-dryers and long extension cords to keep the traffic signals clear. (Some species of monkeys could be trained to do the job, but the training time would take too long to be effective this season.)


I can see a couple of ways to prevent the problem and one is to use the type of heater that is used in outdoor CCTV cameras. Another way would be a simple snap on clear plastic cover that would prevent snow from getting into the hooded area. Oh yea, teeny little windshield wipers.

TDD

Yes, that would work. Wouldn't need much heat at all, either, I suspect.

Problem might be designing something and getting it all properly safety tested before it can be used out in the wild; I expect LED lights have been in the pipeline for a few years and for some reason some idiot never thought of the cold-weather issues.

There are an awful lot of places where it simply isn't an issue.

I would expect it wouldn't be that difficult to install an optical sensor at the end of the hood looking back at the light and use that to switch on a heater if it did not detect sufficient brightness when the signal light was on. No extra energy use unless there actually was snow obscuring the signal. Probably around $20 manufacturing cost, so sell for $200, a fairly insignificant cost given what the signals themselves cost. Also only needed in climates that have blowing sticking snow.

Using the same material as used in the manufacture of self regulating heat tape, an inexpensive add on heater that worked automatically could be produced.

TDD

No point in heating all the time, or even just when it's cold. Much better to heat only when it's cold and something (snow) is obscuring the light. The minimal cost of the extra control components will be far outweighed by the lifetime power savings of only having the heater active during sticking snow events.

Birds have actually built nests in the lights so turning on a heater every time a bird lights in the light (pun) you would turn on heat.

TDD

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Yes, but that's an entirely different problem, and one that would afflict both LED and incandescent signals.

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If it's a Hippie bird, it would build its nest in a flashing light because it's psychedelic. *snicker*

TDD

But the heat would serve to incubate the eggs, leaving momma free to flirt with the flight. The chicks would then end up as unsupervised avians leading to the spread of "feather delinquency."

What the heck's wrong with the "midgets with hair-dryers" proposal?

The LED bulb people should make "Cold climate" bulbs. Which have a small heater filament in parallel with the LED.

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I think a Hippie bird would choose the red lights with the flashing white strobe light in it. Cool man. That's cool.

Not enough "midgets" to fill the job demand?

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Nah man, it's GROOVY.

TDD

You would have to find the cast of "Under the Rainbow" and put them to work.

TDD

sounds like a good project for obama to create jobs and put folks back to work. would it work better with tall people instead of short people on ladders? Maybe a Cash For Blinkers program.

Don't be silly, the "Cash for Caulkers" program is for tall people.

"Obama at Home Depot Declares Home Improvements Sexy"

"?Insulation is sexy stuff. Saving money is sexy stuff,? the Washington Times quoted the President as saying. "

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