There's a letter to the editor in the January 2011 edition of "Auto Restorer" from Michael Pickholz of MaterialWerks, LLC in Oxford, Michigan that touts three LED 7" round headlights.

One is by Truck-Lite and is available through JC Whitney for $299 each.

The url is http://www.jcwhitney.com/7-round-led-he ... lterid=j1-

SKU number is 1JA 244491, manufacturer number 27250C.

The other two are from JW Speaker and "...were developed with the U.S. military in mind, which experienced many field failures in Iraq/Afghanistan with the ...glass tungsten sealed beams...".

The url given is http://www.jwspeaker.com/products/headlights/ with particular emphasis on items 6130 and 8700.

He says that automotive LED lighting is his specialty.

Comments?

--Walt Jackson

Junk. If you've just got to have have LED headlamps because they're cool (which they are), and you can afford the $300 each, then buy these. They perform okeh, not great. They are still handily outperformed by well-made conventional headlamps...that is, a $20 H6024NH GE NightHawk sealed beam gives objectively (much) better beam performance. This LED headlamp was designed, photometrically, to replace the 24-volt military 7" round sealed beam, which has awful performance, much worse than even the nastiest 12v unit. A few more years of LED revisions and optic evolution are needed before LED headlamps fulfill the promise of better-than-standard
performance with lower-than-standard power consumption. Also, this headlamp has a polycarbonate lens. Those haven't ever held up well in the long haul in automotive headlamp lens service — raise your hand if you can't think of a car model with costly major-brand OE polycarbonate headlamps that nevertheless age fast and badly — so we have here an expensive headlamp with a "forever" light source and an age-prone, non-replaceable lens. The military doesn't care about cost of replacement headlamps! A year's service out of a polycarbonate lens is more than adequate as far as the military is concerned.

Then there is the fact that we're dealing with a multiple-emitter headlamp here. Multiple emitters w/multiple optics to create the different parts of the beam work fine when everything's aligned as it's meant to be, but if the various components are out of alignment — almost certainly the case in a mass-market, mass-produced lamp at this price point at this time — the beam formation and focus go all to hell. Two or three months ago, one of Truck-Lite's engineers told me this product is on optical revision 6.2 and would continue to improve. That kind of statement bears listening between the lines, what do you think it means?
Good but costly headlamp.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Wow!!

Thanks.

--Walt Jackson

p.s. I corrected the spelling.

I ran every variant of "MaterialWerks" I could think of thru Google. No relevant hits.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Just a note on military acquisition:

Military stuff is often not what you want.

Like Dan said, the lighting is pretty bad on ground vehicles. I got out before they started looking at LED lighting, but they probably just spec'ed it to match some performance measure from way back, but last a bit longer.

The military does like things that don't break easily, and that stand up to rocks, dust, vibration, moisture, heat, cold, and the like. Their requirements often lead to heavy, clunky items rather than slick, light, state of the art performance. Because there's often little market for true milspec stuff, production is relatively low and prices are high.

As we used to say: That green paint is darned expensive!

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

Even if LED headlamps were up to par with good halogen lamps, there's still a strong argument against them for people like me: they don't produce heat, and as a result snow and frost will build up on them in the winter.

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

LED headlamps *do* produce heat. Plenty of it, on a per-lumen-of-light basis. Most of us think of LEDs as cold-running devices because our greatest exposure to them is as low-power indicators and displays. Illumination takes much higher power, and there's definitely heat involved. Unlike traditional light sources in which the light and heat are emitted in the same direction, LEDs push light out the front and heat out the back. If this heat is not moved off the back of the emitters, they quickly cook to death. The only good 7" LED headlamp on the market, the JW Speaker Model 8700, uses an internal fan to move the heat forward for dissipation through the finned aluminum housing and secondarily through the glass lens. Other LED headlamps (Cadillac Escalade Platinum, various Lexus hybrids, various Audis and Mercedes) use various mixes of ducts, fans, heat pipes, and passive cooling to get the heat off the emitters. The complexity, bulk, and cost of thermal management systems is trending downward in step with the wattage required to obtain any given amount of light from LEDs.

As for the "frost will build up" thing: No, mostly not. Yes, lens thawing is a concern with any present headlamp lens, but only because they get warm at all. The idea of frost building up is largely an urban myth resulting from a disinformation/scare campaign started deliberately by a lawyer whose client ran a red light and caused a big crash. His line of defence was imaginative: his client didn't see the red light because it was blocked by snow, because it was an LED red light that didn't heat up and melt off the snow. There was a flurry of news reports about "dangerous" LED traffic signals not melting off the snow. The whole thing was (and is) a crock.

Fact is, in the early stages of snowfall, the lens of an operating incandescent or xenon headlamp on a car can easily grow just warm enough to melt snowflakes that touch it. Then the light turns off (and to help things along, perhaps the wind picks up or the car speeds up and/or the ambient temperature begins dropping), and the droplets that were snowflakes freeze. It wouldn't take too many iterations of this sequence for the lens to build up a tenacious crust of white ice, to which additional snow would readily stick.

Compare that to an always-cold lens which is not heated at all; rather than sticking, snowflakes will tend to bounce off just as they do on any other subfrozen vertical smooth surface. Only if the snow itself is marginally frozen (i.e., wet, sticky) will adhesion to lenses be a significant issue. That doesn't mean it can't happen, it just means it's not especially likely.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Up in southern Michigan I often saw heavy, wet snow coat stick and cover signs and tail lights, but I've never ever seen it stick to a running sealed beam headlight. I've recently in Virginia seen such snow obscure a new (LED?) traffic light, but can't recall ever seeing it obscure an old traffic light up in Michigan. Just my experience.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.