Intrepid High Mount Stop Lamp LEDs?

If you're going to google the wrong threads, there's not much I can do for
you.

I haven't got a monopoly on the refs, y'know. They're readily available to
everyone, including you. I grew tired of typing them in again and again
and again, so I started pointing people in the right direction to find
them themselves, and I've grown tired of that, too. Use the resources at
your disposal to find my references and my reference sources, or find the
refs on your own.

 

Nope. Over to you.

- RWM

On the aviation side of the TRB house, sequenced and random flashing
strobes and landing lights (for pattern and low altitude use;
helicopters especially, but Southwest uses them as well) have been used
for years in anti-collision lighting (ACL) to good effect. Same for
fixed ACL use (towers, etc.). Seems aviation adopted Voevodsky's
theories for use against skyplane and groundplane lighting clutter.

- RWM

 

*shrug* OK, don't look 'em up, then. No skin off my nose.

DS

 

Here's one but it's pricy

http://autolumination.com/1156_1157.htm

 

Since you repeatedly choose not to cite the "rigorous studies" that you
claim validate your points, that places you in the "just my opinion"
category, no?

Here's that homework from December 2003 and January 2004 again. So far,
you have an "Incomplete".

Over to you. We're waiting. Maybe "Geoff" can rationalize the lack of
response.

On the aviation side of the TRB house, sequenced and random flashing
strobes and landing lights (for pattern and low altitude use;
helicopters especially, but Southwest uses them as well) have been used
for years in anti-collision lighting (ACL) to good effect. Same for
fixed ACL use (towers, etc.). Seems aviation adopted Voevodsky's
theories for use against skyplane and groundplane lighting clutter.

- RWM

 

Over to you. We're waiting. Maybe "Geoff" can rationalize the lack of

Still bitter about that head gasket, eh, RWM? Bought yourself a Toyota yet?

"over to you", bud...
--Geoff

 

That kill file isn't working very well, is it?

Or maybe you're reading DS' mail?

We're talking lights, by the way, in case you missed it.

 

Here's a secret for you: I spare myself the effort of creating a killfile
entry unlessI find myself dealing with a low-grade moron. Near as I can
tell, you're a high-grade moron, so I haven't bothered.

Have a nice day.

--Geoff

 

It's a marvelous idea to read the previous posts in a thread before you
make your own contribution, lest you post something that's already been
covered.

Here:

 

Introducing an ad hominem argument is generally viewed as a mark
of having
lost the debate.

That aside, same best wishes.

- RWM

 

Not too sure what you mean by debate, since you and I weren't having one.
Except, possibly, about your own mental faculties, but I think I've pretty
much got a slam-dunk on that one. Or are you answering Ted's email today?

Cheers,
--Geoff

 

There was just a newspaper article about this. I think the numbers were
50ms vs 250ms and would result in a surprising 24 feet of extra warning (I
assume at highway speeds) with the LED. That is what I remember from the
article but I would not bet my life on my memory or their calculations.

 

Well, let's see here. In many states, the speed limit on rural interstates
is 70MPH.

70MPH = (60 * 5280 feet/mile) = 369600 feet/hour.
369600feet/hour = (369600/ (60minutes * 60seconds)) = 102.67 feet/second.
(rounding off to two decimal places)

There are 1000 ms in 1 second, of course. (duh.)

If you travel 102.67 feet in 1 second, in 250ms you travel 1/4 the
distance:
(.25 * 102.67) = 25.67 feet covered as the incandescent lamp comes up to
full brightness

Again, travelling 102.67 feet in 1 second, in 50ms you travel 5/100ths the
distance:
(.05 * 102.67) = 5.13 feet. as the LED array comes up to full brightness

So, assuming:
o You first notice either type of lamp only when it's at full
brightness (debateable)
o Both lamps are of equal brightness
o Assume the same vehicle, one with an LED option and one without
(unlikely)
o You are the same distance away from the rear of the vehicle both
times (the same amount of light is available to your retina at full, equal
brightness)
o You react perfectly each time (hah!)
o There's perfect visibility both times (under whatever ideal
conditions that consists of)

At our hypothetical 70 MPH, the difference is (25.67 feet- 5.13 feet) =
you'd be warned 20.54 feet sooner. Somewhat longer than the typical
carlength. (I haven't run the numbers, but I suspect you'd have to be going
at least 80MPH to see 24 feet of difference.)

Yeah, I'd expect that could make a difference in the outcome of a collision
avoidance opportunity. Of course, the actual outcome (do you avoid the
crash?) is going to vary due to a whole lot of other criteria -- if you're 5
feet off the back of the leading car's bumper when the lead driver hits the
brakes, LED warning isn't gonna save you, for example. Drag racers do well
to react in 500ms, so there's got to be a law of diminishing returns
somewhere factored in this as well. Finally, the lead vehicle could
decelerate at different rates, you could decel at different rates, etc.,
etc., etc.

But, at least hypothetically, it could make a difference.

--Geoff

 

70MPH = (60 * 5280 feet/mile) = 369600 feet/hour.

Uh, that would more correctly be stated (70 * 5280). I fat-fingered it.
Calculation is right for 70MPH, though.

--Geoff

 

LEDs may lead to new car lighting Los Angeles Times
(LED headlamps)

Light-emitting diodes, or LEDs, are almost as old as transistors. But
technological advances in recent years have paved the way for a new generation
of high-powered LED headlamps that will change auto styling and possibly
improve safety.

Lumileds Lighting, a Silicon Valley firm that has pioneered high-intensity
LEDs, announced last month that it would provide LEDs for daytime-running
lights in the new Audi A8.

LED headlamps will begin appearing by 2006 or 2007 on new vehicles, most
probably luxury and other high-end models, said Doug Silkwood, director of
marketing at Lumileds.

Because LEDs are so much thinner than traditional headlamps, they will give
automotive stylists new flexibility in designing front ends. Already, concept
cars are being designed with all-LED lamps for exterior uses.

LEDs would offer several other advantages. Typically, they operate many times
longer than traditional lights before needing replacement, and they are about
twice as energy efficient. Japanese automakers have estimated that LED
headlights alone could improve fuel efficiency by half a mile per gallon; I
take that with a grain of salt because some people rarely drive at night.

Still, one big benefit of LEDs could come in the area of glare reduction,
though they are such an unknown commodity that it's probably much too soon to
say they will solve the growing safety problem of nighttime glare.

Full Story
http://www.latimes.com/classified/automotive/highway1/la-hy-wheels25feb25,1,2713748.story

 

Of course, most of the collisions take place at significantly slower
speeds than this.

There's not much more it seems that
can be done to uglify the ass-end of cars with more, faster, bigger,
lights, no matter how many statistical studies have been done - the
ass end of modern cars already looks like a travelling Christmas tree
going down the road, they can't find space to hang any more lights.

This is like the seat belt laws. A few years back the do-gooder
crowd became utterly convinced that getting the states to pass a
bunch of seat belt laws was going to save millions of lives because
magically everyone was going to start buckling up just because a
law was passed. They comissioned study after study and caused
a lot of trouble. In the end it was easier to just let them have their
way and of course, seatbelt use is still no better than it was before
the laws, that's why they went to full restraint airbags.

Ted

 

I would change that to "statisitically, it would make a difference"
because statistics is based on the assumption that over thousands of
potential rear-end situations ***ALL*** of those variables that you
mention would average out in the two groups of vehicles with
incandescents and with LED's, and the one fixed difference (the time
delay from contact closure to effective brightness) would show up as a
correlation in the results (accident vs. no accident).

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

Uh, sorry, Ted, wrong again. It wasn't a random group of "do-gooders"; it
was the insurance industry that was tired of paying out claims to stupid
folks who consistently greased themselves against their A-pillars by
refusing to buckle up and then crashing. And the fact is, the compliance
with the law increased to over 80% once it became a primary enforcement law
here in MI, which is a big jump from the 70% usage that prevailed before the
law was enacted. Not that I agree with the law, mind you, I don't. I don't
think the average legislator is capable of the abstract thought necessary to
enact laws that only limit freedom reasonably, and I'm pretty sure that the
gene pool won't miss the idiots out there too stupid to buckle up.

But there's identifiable reasons why it came into being, and
widely-circulated statistics on its effect. Go poke around the Michigan
government website and you'll get facts and figures to spout off about
rather than blather. Try: http://tinyurl.com/36zu9

Sorry to confuse you with the facts along your way to (yet) another rant,
though.
--Geoff

 

Dan, servers are not mirrored all at the same time. Some may be hours or
even days behind. The previous post you referred to may not have been
available to him when he made his post.

 

Ordinarily I'd agree with you. But, the post he failed to read was the one
he responded to (with full text quoted!) to make his own post.