Instrument LIGHTS experiment - Part 2
 

The second round of of tests are done, and we are getting somewhere [but not fast, I know].

The first experiment showed that there were a few problems to solve, and that there was a decent chance of a result that would be much better than the dull glow of the stock gauge lights....for those who want it.

I've tried LED products from around ten vendors. The original plan was to locate a stock array which could be grafted onto the european bayonet base. As TRE's work confirmed, thats a dead end. Light tubes are duds as well - major instrument mods required to the to make that work.

Turns out that suitable LEDs need to be set up in an array [I'm using 4 per 'bulb']. These LEDS need to be massaged to improve their beam spread. Its all a bit labor intensive at present.


So, the results so far:

http://forums.pelicanparts.com/uploa...hite Panel.jpg

The coverage of the most instruments is far better than before, but the speedo and clock are not there yet. The problem stems from the obvious fact that VDO built their instruments first, then tried to find a spot to drop in a bulb or two. Lighting design is a primary design goal for contemporary auto instrument panels, but it was a poor cousin back in the 50s when VDO designed these babys.

Did somebody say RED?? Since so many people mentioned red as an alternative, I decided to include red in this set of tests. They really look good [subjective, I know] and appear to provide a far more even light spread.

http://forums.pelicanparts.com/uploa... Red Panel.jpg

http://forums.pelicanparts.com/uploa...2 Red Tach.jpg

So, whats next? A few things, actually.
First, I'm trying to find a source for the european bases so I can quit de-glassing stock bases for each of these test LEDS.
Second, the next test will feature LED arrays specifically set up for a particular gauge. The Tach array will be slightly different to the Speedo array - beam alignment, spread etc. Should finally get a nice even coverage this way.

Finally, I'm determined to get this right before much longer. Not sure if it will ever be a DIY project, but will be trying to make it so.

Now I know how the Prince of Darkness felt.

AAARRRGGGHHHH ... sorry about the wide screen bungle - my bad.

wow.......i like the red, keep up the good work :)

Tony.. you deserve a bottle on this one.. I was worthless on helping you.. so will slow mail you a merry christmas.......Ron

Tony, looks *****in man. Keep up the good work, I'll definitely be looking forward to the final masterpiece.

Fantastic work! Looks great, what excites me the most about it is the reduction in current draw. I feel I get enough light, but reduced current draw would be nice. a setup for the exterior lights would be cool.
Something like this, http://www.vintageled.com/LEDs.html
If you look at the raw photo's of the led arrays in this link you'll notice a couple of things, one is that there is a slew of resistors on the boards, and in one of them you see what looks like three adjustable somethings and a couple of chips. Any one of you electrical guys out there have an idea what/why this stuff is necessary? So you couldn't just stick a bunch of led's in a board and then wire them in parallel to the socket. I don't know miuch about leds, but I can imagine that since they don't draw much current you might need a resistor to simulate the bulbs presence to keep from blowing fuses, but at that point are you using the some amount of current??

Looks awesome, Tony.

I like the red, but the super-bright white is my preference!

Keep up the good work Tony. I will stay tuned!

Both alternatives already look better than my stock situation! I'm really looking forward to the final results. Great work!

Both look good..... I like the Red

Both look really good, I personally like the white better if the dispersion would be a little better but both loook really good right now.

Steve....the problem with LED's....they don't like too much current (amps).
So...they are rated at voltage and current.
For the sake of argument say one is rated at 2.5V and 30ma Max.....so you have to feed not more than 2.4V and limit the current to 25ma with a resistor.
Some cheapo units use a bunch of LEDs in series (6 or 7) and put them straight across the 12V line.
This is OK if the 12V does not go too high...but we all know the positive in these cars can sometimes get up to 14 to 15 Volts....so you over-power the LEDs.
With a good array...there are resistors....with an expensive array they use current limiting chips (integrated circuits).
There is is in a nutshell.
Bob

Really NICE! I can't decide either. My car is red and my stereo lights up red, but the white is just so clean and bright.

Okay, what if you could choose what color you wanted by a small switch on the dash. Years ago a buddy of mine had a car stereo that allowed you to switch between green and red lighting to match your car's gauges. What type of bulbs/leds would allow you to do that?

Answers
 

Steve,
LED performance curves are current sensitive - the resistors effectively set the operating current for each LED for optimal output. The vintage tail light assemblies are nicely done. If you take a closer look, their circuit appears to include on-board voltage regulation, which goes to the point HawgRider made about keeping the supply voltage constant.

On a related point, dimming incendescent bulbs is easy - just drop the voltage via a variable resistance [the dimmer knob]. Dimming LEDS requires a switching approach - switching them off several hundred times a second to reduce the 'effective' brightness.

Johhnyo,
There are several ways to do this, but they have problems. There are some multi-chip LEDS that can be switched [eg green to red] but their output is really low. There is not enough space to fit a red and a white set of LEDs without severely hacking the instrument cases. Best bet is to have tow sets, and change 'em when the mood strikes.

Tony--

Great work. I like the red. Sounds like you're really close. I've got a pre-embargo Cuban double corona for you to celebrate with when it's done.

Man, this looks like a LOT of work and research. Question: Why does the red light thing up more evenly? Something about wavelengths of light?

Tony,
Regarding the bulb bases, you may want to give Stoddard Imports a call. They seem to be able to get the smallest of parts easily. They may also provide a bulk discount. They extended one to me when I built Turbo mirror electrical conversion harnesses.

http://www.*************/

Good luck.
Rick

I'm bummed. For some reason, the pics aren't coming through on my computer. All i see on the screen is an icon.
Anyone have suggestions on how to view these pics?
thanks
Mike
'86 coupe

non-expert- try refresh.. on top toolbar on my windows.. it looks like a legal size paper w/2 curved arrows in it........Ron

Tony, does the red look that much more uniform in real life, or does it just photograph better due to lower contrast between red-black and white-black? My wife has a Pontiac Montana with red instruments and I think they are horribly difficult to read. Maybe it's just my eyes are aging??? -- Curt

Curt,
I should have re-shot the red pics, because it is nice and uniform in real life. The human factors geeks preferred red for instrument lighting because it preserved night vision. The more recent humfac favorite is blue. I understand that the navy has spent bazillions changing its shipboard combat command centers from red to blue lighting. Sounds like a contractor's windfall, right?

I prefer the higher contrast of the white lighting, but others prefer the red [or even other colors found in sushi rolls].

Mike,
The pics are standard jpegs - hope you are seeing them now.