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warren@fourward.com
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Platinum
Re: Drive a billboard, not a car?
warren@fourward.com   2/17/2012 6:22:40 PM
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The total cost of the laser diodes would be minimal, only a few bucks, but the insurance for willingly blinding people would add additional costs.  Your only hope would be to skip town til the whole thing blew over once you use my brilliant lighting system...

Rob Spiegel
User Rank
Blogger
Re: Drive a billboard, not a car?
Rob Spiegel   2/17/2012 3:53:59 PM
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Good idea, Warren. What would that mean for cost? Is it something that could be done at a relatively equivalent cost?

bdcst
User Rank
Platinum
Re: Drive a billboard, not a car?
bdcst   2/10/2012 10:17:54 AM
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Right, but couldn't one go back to the traditional dual filament concept by building LED tail light fixtures with a combination of dispersion optics and LED chips with two power leads, one for powering, lets say only a few of segments of a multi-segment LED substrate.  Cheap LED chips could still be used but packaged so there was control over the number of chips powered at any moment and with proper dispersion optics so the pattern/beamwidth would remain the same.

My guess is the constant current sources would still end up being switchers for reasons of efficiency even though steady power levels would be required for each LED string.  And, of course, you'd require two different current source supplies so each string received the appropriate current.  Humbug!

And here's a retro idea, as LED efficiency continues to soar, why not continue to produce older, lower efficiency chips, bin them so they can be assembled on substrates offering two intensities both requiring the same current!  Only one constant current supply would be required alternately feeding the low or high intensity (filament) lines.

warren@fourward.com
User Rank
Platinum
Re: Drive a billboard, not a car?
warren@fourward.com   2/9/2012 9:14:22 PM
I think they should go to high intensity solid-state lasers instead of leds.  You can operate them at any consistent power level, as they have built-in photodetectors, and if the guy behind you refuses to lower his high beams, you can burn the retinas right of of his thoughtless eyeballs!

Just a thought...

LED MAC
User Rank
Gold
Re: Drive a billboard, not a car?
LED MAC   2/9/2012 8:26:38 PM
@bdcst:   I'm right there with you, annoyed by the flickering of LED taillights that are operated by a PWM switcher driver.   Unfortunately, if the lamp makers insist on using the cheapest LEDs, this is really the only approach to getting both STOP and TAIL out of the same LED, or to just get predictable and consistent lower intensities.  Most LEDs are only characterized at one drive current, that is, at a high drive current.  In order to get a consistent and repeatible lower intensity with one of these LEDs, the designer MUST use a PWM switcher.   If they used a constant (low) drive current, the flickering would be gone, but there would be too much intensity mismatch between LEDs on the same lamp...no good.   

There are other LEDs that are characterized at both high and low drive currents, which allows the designer to use simple constant current or even better the cheapest, simplest and most reliable resistive driver.  But again, if the lamp makers have their "cheap LED blinders" on,  it's best to stick to the flickering nuisance.

Maybe the folks who develop these lamps have burned their retinas so badly over the years that they can't notice the flickering anymore...so no problem!

William K.
User Rank
Platinum
light up the LEDS Dart?
William K.   2/9/2012 6:40:56 PM
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Actually there was some better body filler called "swiss" that I liked a lot more than Bondo. I used several quarts of it to rebuild a 1965 Barracuda, the very best handling car ever. OF course, that was after it had been set up for circle track racing. Much different springing, cheater slicks in back, and "roadmaster" tires in front. THis gave it a bit of oversteer that was predictable and smooth.

The "vent" from where the floor shift had been was never a source of cool air, it provided a hot blast of engine heated air whenever it popped open, so it got closed with a good sheetmetal plate. I did install an automatic when I replaced the "broken" raceing engine with a reliable Slant Six. 

Charles Murray
User Rank
Blogger
Re: LEDs light up the Dodge Dart
Charles Murray   2/9/2012 5:58:21 PM
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I haven't thought of Bondo in years. It used to be a post-crash automotive staple.

Staber Dearth
User Rank
Silver
Re: LEDs light up the Dodge Dart
Staber Dearth   2/9/2012 4:09:05 PM
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Ozark (one of my fave groups, Ozark Mountain Daredevils). Too many cars of today are soulless appliances. Even my 1983 Pontiac 6000STE (I called it the primitive racer, since the technology in it was definitely carryover early 70's) was the front end of the appliance car era in my opinion. The sad part was, it was about the only sports sedan you could buy at the time(actually it was the derivative of the Chevy Citation X-11) and even that was a stretch (I used to laugh at my buddy's Audi 5000 that had the ill deserved feature that I called the auto accelerative option, another buddy had a turbo Saab that never seemed to be anywhere but in the shop to fix that turbo spinner). The Pony-ac, worked first time every time, had it until 2000 with over 190,000 miles and in fine condition when those nagging uv attached parts started to fail and even the last of the remaining A bodies the Buick could not be found intact in the junkyards. I donated the car and a week later, before the state got the title transfer file, I got a call from the staties telling me "my" car was found as a burned out totalled hulk on the Schuylkill expressway. Next car? 98 Pony-ac Grand Prix GT in black (this model only looked good in black) mostly an appliance car, no emotional attachment, gave it to my oldest son. Now, a 2010 Fusion Hybrid. I like... but once again...appliance. Gotta find a car with some soul!

Ozark Sage
User Rank
Silver
Re: LEDs light up the Dodge Dart
Ozark Sage   2/9/2012 12:53:28 PM
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Hey Staber Dearth Good Read!  Reminds me of my fitrst purchase in '59 of a '29 Model "A", Black, of course and of a much heavier guage metal than your's and easier to maintain....used black spray paint, made it look brand new!  I installed a Wolf Whistle and Ahooga Horn for effects.  No AC but GOOD ventelation at speed as the shifter floor plate cover would rise UP the Shift shaft....NOT SO GOOD in RAIN but, interesting when with a female companion; as were the MANUAL Brakes too.

If you ever rebuild one of these DON'T use anything but STAINLESS steel cotter pins on the brake actuation linkage!  IF the main crossbar pin comes out it IS A HAIR RAISING EXPERIENCE especially if you're going down hill AT THE TIME WHICH IS TYPICALLY THE CASE.

Oh, one last comment.  Be alert that you passenger doesn't kick the under dash fuel valve to OFF at an oppertune moment just to have some fun at your expense. 

PS Paid $200, used it 2+ yrs, Maint Cost under $50... SOLD for $3000 at college in short one of the best fun buys of my life!



Staber Dearth
User Rank
Silver
Re: LEDs light up the Dodge Dart
Staber Dearth   2/9/2012 9:36:41 AM
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First impression?  Looks like a Neon with LED's... 

First thoughts (stream of consciousness...)?  Going back to the three Plymouth Valiants we owned immediately post college days.  A 71 two door Scamp with a black vinyl top that lasted longer and looked far better than any on even more expensive cars. 

Two 72's - all slant sixes, one a butt ugly slime green color with, cold as the arctic, vinyl seats in the winter and an egg fryer in the summer.  All had AC units that could freeze ice cubes and would startle a pedestrian at any cross walk when they kicked in.  You could tell your parking space by the oil spill as tightening up any gaskets only squeezed then out of their place and the oil leaks only continued). 

Quarter panels?  We don't need no stinking metal in the quarter panels!  That's what Bondo is for!  Steering?  Plus or minus a jerk left or right kept you on the road, radial retrofits after bias ply did nothing for the car! 

But these cars were reliable as hell!  Could fix them with your bare hands for the most part.  The trunk?  Bigger than any car in its price range had any right to be.  And those vent windows and under dash air gates that you got adept at opening with a flick of your foot.  Once I gave up my 71 Scamp, I saw it around town, overladen with a handyman's tools in the back seat and trunk for a good decade beyond 1983!  It was no longer white but a tinged bleed through shade of iron oxide.  The vinyl top still looked showroom new!  It had to be made of cockroach shell extract.

The new Dart?  Eh...I've got LED lights on my deck, they are not novel anymore and in this case a marketing hype.  Just put 'em on and be done with it!  Why not use neon lights since the car looks like a frikkin' new version of a Dodge Neon!  Put back those wing vents...then we're talkin'!

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