LED-lit signals?

[M636C]

Mike,

I've seen some of the older LED road traffic signals here with single LEDs blacked out, or more correctly, with a few adjacent LEDs blacked out (one you would never see!). I assume that this is most likely caused by a local wiring failure, because the probability of adjacent LEDs failing in a big array is just to high to consider. Importantly, unless I was looking for it and paying attention, I wouldn't see it because the signal's meaning was still quite clear from the many remaining LEDs.

Peter

[Anonymous]

In the trucking industry, we're having a problem with LED tail lights on the back of trailers. Snow whips around the back of trailers and covers 'em up. LED signals along the track will have to be hooded in a very fool-proof way, 'cause you're not getting much help from lamp heat.

[rrnut282]

Is snow build-up their Achillies Heel? Or can they still be seen through snow?

[mloik]

QUOTE: Originally posted by railman

It's, the "wave of the future!"

Since we're talking about electromagnetic radiation, it is also the "particle of the future"...

[rich747us]

Hey Eric,

They are already using the LED lights in railway signals. I recently was passing through Chicago Union station on my way down to Texas a couple of weeks ago, and during my rides on the Late....uh, I mean Lake Shore Limited (LOL) and the Texas Eagle, I noticed some of the new LED style bulbs lit up in some of the signals along some of the station trackage, and at a few interlockings south of the station.

-Rich

[jkeaton]

Maybe it just goes with being the Silicon Valley of the North, but here in Ottawa the new trackside dwarf signals they've put in for our experimental 'light-rail' train all appear to be LEDs - and the city is in the midst of converting all its traffic control signals and bus turn and stop lamps to LEDs. All of our newer garbage trucks have them too. And, as another poster pointed out, Cadillacs have LEDs in their rear signals - as do some Acuras, Lexuses, and Mercedes.

A trucker friend of mine is all for LED brake lights on cars - apparently it takes a conventional incandescent brake lamp 0.3 seconds to achieve full brightness, while an LED is at full brightness in 0.001 seconds - that 0.3 seconds translates into 18 feet at 60 mph, a useful addition to the braking safety margin on crowded highways!

Jim

[tree68]

QUOTE: Originally posted by Fuzzyfocus

In the trucking industry, we're having a problem with LED tail lights on the back of trailers. Snow whips around the back of trailers and covers 'em up. LED signals along the track will have to be hooded in a very fool-proof way, 'cause you're not getting much help from lamp heat.

Emergency services is embracing LEDs in a big way for warning lights. I've also heard of the problem with brake/tail lights not melting the snow. I would imagine that the problem will be solved through design alterations - either placement or construction of the device itself. One possibility would be some sort of mini-heater, but that would defeat one of the features of the LED - low current draw....

[Puckdropper]

QUOTE:
One possibility would be some sort of mini-heater, but that would defeat one of the features of the LED - low current draw....

If you set a heater to come on about 38 degrees (ferenheit) you still would save power overall vs having it on all the time.

Or you could install "horsetails" over the lights... They just start swatting the snow away...lol

[eastside]

In practice I'd think a heating device, if it were necessary, would rarely have to be switched on in the context of railroad use. Snow and ice are highly translucent or transparent permitting a rather thick coating. As for crossing signals, incandescent lights have no advantage over LEDs because they're on intermittently. Having lived all my life in Northern climes, I don't think I've ever seen a traffic light covered by snow or ice. If that happens to a railroad, they're got other things to worry about.

[Anonymous]

Puckdropper- horsetails... is that a real thing? Is that slang for some sort of passive wiper? If you just made that up, you have a great idea. I might just steal it from you and try some kind of hanging rope or something that could blow around and keep the tail light lenses clean.

eastside- yeah, I guess your right. Come to think of it, I've never seen an LED traffic light snowed over either. I was thinking of street signs, etc, that simply become white when we have that sticky wet snow.

[tree68]

QUOTE: Originally posted by Fuzzyfocus

Puckdropper- horsetails... is that a real thing? Is that slang for some sort of passive wiper? If you just made that up, you have a great idea. I might just steal it from you and try some kind of hanging rope or something that could blow around and keep the tail light lenses clean.

eastside- yeah, I guess your right. Come to think of it, I've never seen an LED traffic light snowed over either. I was thinking of street signs, etc, that simply become white when we have that sticky wet snow.

Don't know if I've seen them either, but I have no problem picturing them... Great idea!

The hoods on most stoplights are open on the bottom. Only a really sticky, wet, wind-driven snow is going to get where it needs to be to block the light. I have seen stoplights with hoods that go all the way around with snow accumulations.

[Puckdropper]

Yes, horse tails are real things... I know where you can get some horse tails, but you'll have a hard time getting the horse to give them up!

Now, I thought we were talking about brake lights. Those things do get covered by snow. I figured the tiny (!) brake lights on a truck would need a heater to keep them clear. If you're getting a wet slushy type of snow you may have to stop and clean your lights off anyway...

[Modelcar]

...If the issue is snow covering up brake lights on trucks....maybe we could have the rear lights burning as the headlights do now on many vehicles when the vehicle is operated...day or night and the tail light bulbs would keep the lens clear from their heat and ready so one could see the applied brake lights. As for LED type lights, I don't know what value of heat they put out and if the same logic would apply.

[Anonymous]

No, there's no heat there, even when the LEDs are lit. At night, in a snow storm, just when visibility is at it's worst, just when you need taillights the most, they're completely covered up! By the way, they have LED headlights now, too. Same problem.