LEDs and the Viper

[I Bin Therbefor]

I get a weekly newletter from Co.Design Newsletters which had an interesting article on LEDs. In part, this article says:

"Those who’ve purchased LED lamps will find that the numbers on the box can lie. Such figures are based on technical estimates by the LED manufacturers themselves, not the companies sticking the LEDs into lamps and other fittings. LEDs are so tiny and power efficient that they can fit in almost any design you could imagine, but these same designs end up roasting the lights in their own heat. So lights that promise to last decades on the box--an environmental coup in terms of waste and energy savings--will degrade quickly, grow dim within a few years (or even months), and their color temperature shifts."

The article goes on to say:

“LEDs are semi conductors,” . . . “and semiconductors are used in computers. And the way they (The computer industy) cooled semiconductors in computers was using heat pipes.”

Simple question for the Viper design team, are you cooling the LEDs properly?

 

[2000_Black_RT10]

I get a weekly newletter from Co.Design Newsletters which had an interesting article on LEDs. In part, this article says:

"Those who’ve purchased LED lamps will find that the numbers on the box can lie. Such figures are based on technical estimates by the LED manufacturers themselves, not the companies sticking the LEDs into lamps and other fittings. LEDs are so tiny and power efficient that they can fit in almost any design you could imagine, but these same designs end up roasting the lights in their own heat. So lights that promise to last decades on the box--an environmental coup in terms of waste and energy savings--will degrade quickly, grow dim within a few years (or even months), and their color temperature shifts."

The article goes on to say:

“LEDs are semi conductors,” . . . “and semiconductors are used in computers. And the way they (The computer industy) cooled semiconductors in computers was using heat pipes.”

Simple question for the Viper design team, are you cooling the LEDs properly?

I've designed headlamps and tail lights one time in my career, and the entire assembly is designed to accommodate heat, as a system.

That newsletter quote tends to imply a scenerio when people install LED lights into an assembly that wasn't designed for them.

Projector lamps create quite a bit of heat also, as the assembly will typically have a thermoset plastic housing which can handle higher temps, metal reflectors, venting, heat sinks, some halogen lamps create less heat and do not require higher temp durable plastics and are not compatible with aftermarket LED lights. Some types of lighting creates less heat such as high intensity discharge, which creates a cold blue type of light, yet, sometimes that's not good either, because heat is actually needed to de-ice the headlamps, and there's been some headlamps that had a heater internally because the lights didn't keep the lens hot enough, otherwise driving in the winter you would get ice build-up on the lens not since having enough heat.

Lighting designers / engineers are fully aware of headlamp technology. There's really no sense instigating concerns based on stumbling across an article and expecting an answer from the Viper design team to address a question; basically asking them - if they knew how to do their job? The inquiry could have reworded, perhaps asking about the design if you were sincerely interested in how the headlamps are designed.

Cheers,
Mike

 

[I Bin Therbefor]

Thanks for the education, Mike.

The problem with written communication is even worse than verbal, I never know what the other person took to be my meaning. Thanks for the dialog.

My concern for the design team is that the LED application may well be a first time for them. Are they aware of the heat sink requirements for the LED application? Or better, did the LED supplier provide the necessary information. Given that the team is aware, I have every confidence that they did the right job. So my question would have been better phrased, did the supplier provide the LED heat output and cooling requirements?

Apparently some products with LEDs on the market do not take the heat issue into account properly and fail to live up to the life estimates, signs and bulbs among them. I will be looking at other cars that have been on the road with LEDs to see how well those applications last.

I haven't spent time in the auto industry, but I did spend time in the Navy, the railroad industry and the aerospace industry, always in computers. I am a senior member of the AIAA and IEEE in the computer sections. If I have a concern, I ask. IMO, better ask twice than miss once. Some day if we get together, I'll tell your about a water cooled supercomputer that was installed with the water flow in reverse with the result being a melted supercomputer or the six guys who were killed because a person in the group didn't feel free to ask a question or the space shuttle that exploded because no one listened and the investing committee was trying to sweep things under the table.

Communications is different than command and control. IMO, everyone should feel free to ask questions and make suggestions.

Anyone I question should consider I'm asking from a sincere concern and in my ignorance.

Thanks again for the education.

 

[2000_Black_RT10]

Hopefully it's not sarcasm, and you are welcome if not.

Many time folks don't appreciate the validation efforts in vehicle design, as there are many concerns regarding liabilities with higher volume products.

Cheers,
Mike

 

[Makara]

LEDs needing adequate cooling seems to be common knowledge with anyone not hiding under a rock. I would hope that anyone designing anything with them would know this. Two minutes of research on any DIY LED fixture of any kind will make that very clear so for someone who's job is to design anything with LEDs should be in the know. Then again, I am constantly amazed at what sort of things slip through the cracks.

 

[I Bin Therbefor]

Hi Makara,

Two separate incidents: (1) Challenger and (2) six killed in a different accident that shouldn't have happened.

I too am I am constantly amazed at what sort of things slip through the cracks.

Mike,

Not sarcasm, always appreciate adding to my body of knowledge.

"Many time folks don't appreciate the validation efforts in vehicle design, as there are many concerns regarding liabilities with higher volume products." Another story to be told. Had an acquaintence whose name I've forgotten working for Chrysler Electronics or Space Systems or something like that in Huntsville. Said acquaintence was part of the folks from Huntsville who were consulted on applying computers to Chrysler automobiles. She rapidly learned that she knew nothing about stress environments and reliability and volume products until she worked on getting computers to live in an automobile. A humbling experience.

 

[2000_Black_RT10]

Cool thanks, never know how to read replies at times and avoid making assumptions. Nice to read about your background too, lots of stuff I don't know about.

Cheers,
Mike

PS.. one unusual idea... decades ago working with an OEM, they wanted to have a single light source, as one light box centrally located in the vehicle and then run fiber optic lines to all the exterior lights including the headlamps, but it never made it into production.

 

[F8L SNK]

Great question to ask the amount of research the design team did on LED's. One problem I see with the original question is "are you cooling the LED's properly" is that LED's do NOT produce heat. Having said that, the heat from a light that is LED will come from the driver board to the LED (the connection point, not the LED) This is why I say it is a good question but wanted to clarify where the real issue is. It is fairly easy to design a new light with proper heat sinks and or cooling methods on a new lamp. It is not easy to retrofit an existing lamp with new LED's when this was not part of the original design. My guess is this is a non issue but worth asking anyway. I believe this should be more directly aimed at ALL auto manufacturer's as the true R&D comes from the supplier not necessarily the manufacturer (Dodge/Chrysler) They will most likely use suppliers that work with multiple manufacturers and most likely have addressed this.

Also, the fact that they say that they diminish in intensity (brightness) and color shift (temperature) is all related to the quality of the LED. This too would be a good question to ask of the design team.

Having brought up the above statements, LED technology is no longer in the dark ages (yes pun intended). LED is now mainstream and is much more controllable and known as a technology. So much so that they are now being used in Surgical and Operatory settings on a regular basis. I have a feeling that the new technology we see in the Viper is not new technology and very stable.

Again, I still agree that the design team should show validation if requested. Obviously it has been requested. Knowing what I do about LED's I am not concerned if they ever produce this information. I have confidence that LED's are mainstream and not an issue to be concerned about.