LOSSES” in LEDs
Federal Document No.98-3967-1 dated June 24, 1998 (attached)
demonstrates the lack of technical aptitude of the employees at NHTSA who
wrote this 9 year old “Notice of Proposed Rulemaking” (NPRM).
nonsensical excuses are still being used by NHTSA employees to
avoid this heat loss fact.
Initially, in 1994 … that
is, 15 years ago …in another NPRM dated April 8, 1994, Federal
Document No. 94-23, NHTSA acknowledged the real life Candela output
losses involved with the heating of LEDs. This characteristic
produces a distinct safety problem if not properly compensated for.
However, to this day, NHTSA has done absolutely nothing to acknowledge
and require compensation for LED Heat Losses, particularly for “LED” use
in Brake/Turn and Lane Changing Signal Lights.
Even the mild LED warm up
exercise outlined in SAE 1889 is no where near stringent enough to
qualify a LED Brake/Turn Signal for outdoor use in fully exposed Trailer
applications, particularly when considering the fact that
exposed Trailer Brake/Turn Lights are most needed to do their job when
used on hot days in “close up” traffic while hanging out over very hot
In the 1998 NPRM (attached)
…NHTSA gives absurd and nonsensical excuses in order to obviously
avoid addressing the LED heat loss problem, and therefore,
pass it on to the next generation of employees …and still today …
nine years later …NHTSA still totally ignores this real
life safety problem.
Basically, in 1998, NHTSA’s
Rulemaking employees claimed it was too hard and too expensive to Test
(and compare) various LED outputs at increased ambient temperatures when
heated from room temperature while under full power up to ≈ 200°F Ambient
for 10, 20 and 30 minute “on” cycles, and at the same time, measuring their
Signaling Power losses. To this day, NHTSA employees
stick their heads in the sand on this issue, which is clearly a “dereliction of duty” and an
insult to NHTSA’s main reason for “being”.
Who and where are the
people who came up with such stupid excuses for not doing their job? … have
they been fired as they would have immediately faced in U.S. Industry?
Regardless, since 1994 …
the laws of Physics and Chemistry haven’t changed and it is still a
known fact that LEDs lose about 10% of their output for every ≈ 18°F
of increased “Junction temperature”. I’ve read in DOE reports
that the “junction temperature” is always ≈20°F more than surrounding
Therefore, a increase
of say … from 72° to ≈150°F… which represents an easily attained internal
temperature increase for a Trailer’s fully exposed Tail
Light Assembly when used consistently on a hot day in close up traffic
conditions while mounted only 15 inches from a hot, radiating pavement …
produces a real life Candela loss of at least ≈50%.
if allowed to heat more … the LEDs can be destroyed.
temperature is still acceptable to NHTSA as the official
“Qualifying” Test Temp for LEDs and you can bet this is what the
current, “walking the line”, cheapened LED Brake Lights are being tested at,
where in real life use, they’ll lose ≈50% when used on a hot day in tight
Ask any LED Manufacturer
about this subject and see what kind of answer you get!?
Last year, some of our
traffic lights in Livermore, CA became so dim on very hot days, they had to
be returned to the manufacturer. Think of the dangers this caused and
the recall cost to the manufacturer.
NHTSA ignoring these
realities produces a huge Public safety problem that can’t be ignored.
LOOK AT THE MILLIONS of “STAND IN” “LED” CHMSL FAILURES used on Caps/Shells,
Anywhere in the U.S., you can see “Stand In” LED Center High
Mounted Brake Lights (CHMSLs) mounted on the tops of “Caps/Shells/
Toppers/Canopies” that have accumulated over the past 10 years.
Observe the 50% of non working ones and note that half of the half left
LED types are only partially working and/or significantly dimmed.
*”Stand in” means a mandated Replacement CHMSL
for the Factory provided one … which replaces the “covered CHMSL”,
which results when a Cap/Topper/Shell/Canopy is mounted on a typical Pick
Of course, any up close,
bumper to bumper traffic represents conditions where
conspicuous Brake/Turn and Lane Changing Signals are needed the
Also, note that the half ± of the LED
Stand In CHMSLs remaining working … generally work only partially or poorly!
… and virtually all are “Effective Projected Luminous Lens Area”
(EPLLA) deficient as well …check it out! –
4-1/2in² of EPLLA is mandated!
Observe how many Cap/Shell/Canopy “LED” Stand In CHMSLs are still
“effectively” working in your area… and count up the Dim and Faded somewhat
working ones as well.
Can you imagine how many Rear End Crashes will be caused by non
working, dimmed, and EPLLA deficient Stand In LED
CHMSLs that are used on (I estimate) 30 million Pick Up Trucks produced over
the past 10 years? One-third have had Caps mounted on them and
80% of these used LED Stand In CHMSLs or 8 million, and 4 million don’t work
and aren’t getting fixed!
Also, consider that the
average following drivers’ brain is relying on using the CHMSL in front
of them as its primary conscience and subconscious source
telling their foot to
but since the CHMSL they’re counting on is Non Working or Dimmed … many more
than ordinary Rear Enders are bound to occur to this group.
The same scenario exists in
the case of “following drivers” directly behind (and in adjoining lanes)
with a Trailer, RV, or Big Rig in front of or to the sides in “up tight
traffic” … where the following driver’s attention will also consciously
and/or subconsciously affix on the ahead vehicle’s “Conventional”
Brake/Turn/Lane Changing Lights. If any Brake, Turn or Lane
Changing Signal Light is ineffective … or not working … then what? What
percent increase in Rear Ender and Clipping Collisions will take
place over the lifespan of these kinds of vehicles?
Furthermore, since “LED”
Brake Lights all produce only a narrow output of effective light, and
their output is still allowed by NHTSA to drop to zero output
at a mere 10° Up angle, the safety potential of low mounted Conventional
Brake/Turn and Lane Changing Lights are greatly reduced – Example:
A Brake Light on a Trailer that has its 10° Up Limited “LED” Brake Signals
located only 15 inches off the pavement is not at all seen at closer than
16 feet by the average Auto driver. And also consider that at
the 10° Up observation angle, the Signal’s intensity only is required to
be 15 CP, where it could be as much as 300 CP. *How
dumb is this?
This narrow output of
LED Brake/Turn/Lane Changing Signal light is a great detriment to
road safety no matter how you look at the situation. More LEDs pointing
in varying directions are needed to accomplish what the Incandescent Brake
light has always provided the public. More on this subject later!
Bottom Line, LED
Brake/Turn Lights must be, at the least, as large, reliable, conspicuous and
as effective as typical Incandescent
Brake/Turn/Lane Changing lights…
no matter how hot the day or no matter how “close up” the traffic is.
“FILL and DRAIN” SUBMERSIBLES DESTROY all Inside Reflex and Lens FACETING
Head Lights have
always been required by NHTSA to be extensively tested using strict,
detailed FMVSS #108 Physical Testing Mandates, so the Public is guaranteed
their Headlights can’t collect degrading internal dust and grime,
nor are they dimmed from internally trapped moisture precipitants.
And when they burn out … after a reasonably long lifespan … a
standardized, reliable, new Headlight bulb can be easily found
anytime, anywhere by anybody!
It’s a known Physics fact
that any Dust, Grime or Precipitation put on any inside Lens or Reflex
surfaces decimate the light output. This is true of Headlights as
well as for Brake Lights and Reflectors. Therefore, we have to ask …
“Aren’t Brake/Turn and Lane Changing Signal Lights just as important for our
road safety as Headlights”?
Referring to the Society of
American Engineers on this issue:
SAE J1398, Section
6.2.4. says on this matter:
it is expected that lamps must perform an extremely severe environments,
such as off-highway, mining, or fuel haulage, or where it is expected that
they will be totally immersed in water, the user should specify lamps
specifically designed for such use.
For NHTSA to allow a
so-called, “Submersible Tail Light Assembly” to fill-up with
typical oily, silty, Launch Ramp water during the launching of a
typical Trailered boat at a typical American Launch Ramp … makes no
sense, whatsoever. Repetitive submersions, each leave an
“accumulated layer” of a grimy, silty conglomeration upon all
the not washable inside surfaces thereby ruining all
the operating refraction and reflection facet surfaces. And this is
happening while NHTSA employees stand by … oblivious to what’s happening.
This kind of head in the sand … ignoring of fact … is absolutely
ridiculous and an insult to intelligent road safety reasoning.
“AIR TRAPPING” DESIGNS must always PROTECT the REAR REFLECTOR from Grime and
Multi Function, “Air Trapping”* Light Designs must provide
Grime and Dust protection for any bottom positioned Reflector used
in an Air Trapping, Submersible Design because the “Compression Water
Column” in a typical Air Trapping, multi function light always
travels ≈ 1” to 2+” up into the sealed Air-Trapping Chamber;
therefore, wetting all unprotected lower located Reflex Lens Facets
thus allowing accumulated Grime to significantly deplete the
effectiveness of any “unprotected” bottom located rear pointing Reflector. *We pioneered the “Air-Trapping”, Submersible,
idea 30 years ago
Over the past 20 years,
we have always provided a separate, clear protective
window in our all “SP” Air Trapping Designs. This makes sure
the important Rear Reflector doesn’t degrade from Grime or Dust deposits
and therefore become a Safety Hazard for public use.
You will not find this
“Fail Safe, Protective Feature” built
into Peterson®, Wesbar® (Cequent®) or Optronics® so-called “exact copies” of
our 3-1/2 x 6, road proven “SP” Models used on first class Shoreland’r, E-Z
Loader, Magic Tilt, Water-Land, etc. over the past 20+ years.
Many years ago, I was
getting my hand bandaged for a chemical burn at our small town Livermore
hospital when Ambulances brought in a whole family that had pulled off onto
the shoulder of a local highway and “crashed” into a “left behind Boat
Trailer” that had a flat tire. They were all hurt and bleeding and
I could hear the father saying “I didn’t see the trailer because I didn’t
see any reflectors”.
I’ve told this story over
the years to all boat trailer manufacturers that would listen
… trying to warn them of the Liability involved with allowing Reflectors
to degrade below FMVSS #108 minimal mandated requirements.
These kinds of liability
circumstances can produce large jury awards and large out of court
Settlements you’ll never read about. You should always think about the
unexpected when selecting your Lighting. Yes! currently FMVSS #108
does not address inner lens and inner reflex grime and dust degradation
problems … but, of course, it should! However, you should be aware
that NHTSA is under obligation to Recall any kind of apparent safety
hazard on our roadways covered by Federal Motor Safety Standards or
not … using the
main objective statement of the 1966 Vehicle Safety Act – check it out!
This means if the Lights
and Reflectors you use are not designed to take Submersion* and Dusty
Roads without dropping below the minimal outputs spelled out in FMVSS
#108 – your Liability is greatly increased.
To knowingly or
unknowingly ignore these realities and facts produces liabilities
that should be avoided.
Back to Index