June 5, 2006

Attached is a catalog sheet from Truck Lite’s ± recent catalog showing what we believe, to be the only “ECE” (European Union) Approved Stop/Turn (Tail) Signal Lamp made by an American Company!  This model costs ≈ $120 Retail. You’ll note it uses 50 LEDs plus incorporates “Cone Reflectors” (we call them), which if correctly designed, increases the EPLLA by qualifying the walls of the Cones for EPLLA additions.  Several American and Japanese Auto Manufacturers are now using this same EPLLA increase approach to achieve the USA and Canadian mandated  FMVSS #108 required 7-3/4in² EPLLA* necessary for single Brake/Turn Signals used on all under 80” width SUVs, Pick Ups and Autos.  Further, note that they are using LEDs in conjunction with Incandescents.            

*Effective Projected Luminous Lens Area (“EPLLA”)

European Engineers and Designers are very conscious of what EPLLA “is” and its safety importance and they know what it takes in their designs to accumulate proper amounts of Effective Projected Luminous Lens Area so human recognition and responses are optimized.

Assuming the entire large end of 50 Truck Light’s “Cone Reflectors” can be considered as entirely Effective Projected Luminous Area, the “EPLLA” for this 50 “LED” arrangement is:

“Effective Projected Luminous Lens Area” for each = Pi (3.14) x (.22)²* = .152in² each.

                * “Scaled Radius “estimated” from the Truck Lite photo attached

For these 50 LEDs and “Cone Reflectors” Areas altogether … they produce an estimated 50 X .152 = 7.60in² of Total “EPLLA”, which is very close to the U.S.A. required 7-3/4in² “EPLLA” that’s mandated for all Under 80” Brake and Turn Signals.  

If this Lamp were required to have 11-5/8in² of “EPLLA” … which is what’s mandated by FMVSS #108 for

Over 80” width uses … it would need:

                11-5/8 = QTY LEDs?

                  7.6              50                ≈ 77 LEDs used with “Cone Reflectors” similar to shown in the Photo

Note that 77 of these Cones would not fit into a ≈standardized 4” Round* or 6” Oval* used by most Big Rigs today … necessitating significantly  larger Area Lamps than the 4” Round and 6” Oval represents if 11-5/8in² of EPLLA is needed.

 (*which are ≈exactly 11-5/8in² in lens area only

77 “Unlensed” LEDs are a long, long way from one to ten, which “Peterson”, “Optronics”, “Innovation” and other LED Lamp Manufacturers’ of LED Brake/Turn lamps have been directly or indirectly supplying for public use while inferring, or actually claiming, their designs are totally compliant to all the mandates of FMVSS #108.  According to our observations, most 3 and 7 Function LED Lights being used today are very far from being compliant to the many mandated requirements of FMVSS #108 … Check it out!

The LED “Cone Reflectors” provided by the Cadillac as a sort of “Interim Lens” in their 2003/4? Designs, is the same in concept to the “ECE” Approved Truck Lite discussed above, because this Cadillac Lamp uses the same approach as Truck Lite to assure that the inherently limited Output of each LED used is reflected (and/or refracted in Fresnel Designs) so that most of this limited Conal Output is corralled and projected rearwards within the required 20° Left to 20° Right; 10° Up to 10° (5°) Down mandated Test Pattern.  This is primarily accomplished by “lighting up” the walls of the Cones by projecting this light within this mandated Test Pattern.

Using this approach, nearly all the “Effective Light Omitting Surface” seen at the end of each “Cone Reflector”, officially qualifies as “Effective Projected Luminous Lens Area”.   Of course, this area depends on the spread of the “LED” due to added interim lenses or other arrangements.  Within limits, this approach only allows the Areas at the Cone’s “Ends” to qualify for EPLLA while any subsequent “Transparent Outer Lenses” … whether positioned near or far from the Cone’s End …“does not” add any more EPLLA to the Total because it’s “Transparent”- and therefore doesn’t qualify for EPLLA addition … a fact conveniently ignored by most LED designers!

If Cadillac used, say, 12 large high powered LEDs properly matched along with 12 fairly long “Cone Reflectors” that were say, 3/4” in diameter at the large ends … the EPLLA would be -

                “EPLLA” = 12 x P x (3/8)² = 5.3in² - which is ≈ 1.5in² short of the mandated 7-3/4in² for under 80” Wide Vehicles

If Cadillac used say, Ten (10) LEDs, 1” Diameter “Cone Reflectors” –

“EPLLA” would then be 10 x P x (1/2)² = 7.79in² … which would give the Designer just enough “EPLLA” to meet the mandated requirement of 7-3/4in² for under 80” width (auto) type vehicles – but not for over 80” vehicles.

For Over 80” Trailers, RVs and Big Rigs –

The Designer would need 11-5/8in² / 7-3/4in² or 150% as many … or ≈15, one inch Diameter Cones powered by

15 expensive?, high powered LEDs.

Bottom Line – Everyone involved in an “EPLLA Liability Situation” should be asking any and all “LED” Lamp Suppliers trying to sell lighting that will be used by the public … “What proof can you produce to show that your “Effective Projected Luminous Lens Area” meets the mandated 11-5/8in² required by State and Federal FMVSS #108 Law using the FMVSS #108 definition of “Effective Projected Luminous Lens Area” from FMVSS #108. 

SEE WHAT THEY SAY and CHECK THEIR EXPLANATION WITH NHTSA EMPLOYERS!