LEDs?
Incandescent bulbs produce light in a rahter wide range of wavelengths (shorter = purple; longer = red, other colors fall in between; mix = white, more or less). In order to get light of a certain color, a filter has to be used that only passes through the light of the desired wavelengths, blocking the rest of the spectrum.
LEDs, on the other hand, emit light of a very narrow spectrum - monochromatic, with no other (unwanted) colors present. Hence, no filter is need. But if you use, say, a red filter on an LED emitting red light, the light will pass through just like it were clear glass, since the filter is supposed to pass wavelenghts from this area of the spectrum.
I've been thinking of designing a specially tailored light conductor that would redirect the light from the LEDs to the lens - they can be made from clear plastic. The principle is the same as that used in fiber optics - the light reflects from the walls of such conductor, staying inside it. You can bend it, thereby directing light as you wish.
Those who deal with rack-mountable servers, probably, have seen those. A good example is the one used by Dell to replicate LEDs on detachable front panels.
Last edited by vadim; Dec 20, 2002 at 05:11 PM.
There are many online stores offering drop-in replacements for automotive incandescent bulbs:
http://www.trucknvans.com/bulbs/
http://www.theledlight.com/ledbulbs.html
http://www.stylinconcepts.com/parts....categoryid=198
They are darn bright when lit and the main point of getting these was that the bulbs would light up in tandem with the LED 3rd brake light, and not half a second slower. At 60mph (96 kph), that half a second equates to up to 20 feet of extra braking distance for the driver behind you.
Here's a picture that I just snapped 1/2 hour ago:
Last edited by Drew_ML; Dec 21, 2002 at 10:08 PM.
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The problem is, these LED bulbs are directional - they emit light in one direction, as opposed to regular incandescent bulbs. The brake light bulbs in the Coupe's rear light cluster are mounted vertically. Not a problem with a regular bulb - but this makes the light from the LEDs barely visible.
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Are the bulbs only mounted this way in the coupe? Because it sounds like Drew did it with no problem on his sedan. I guess we'll have to wait for your invention that you can sell to all us coupe owners. I like the LED taillight look. You can definitely tell how much quicker they light up.
I should add that not all LED bulbs are the same. I've tested all of those that I've been able to get a hold of, from Alpena, APC, to Polarg. The formymercedes.com LED bulbs are by far, the best out there. They are literally blinding when tested even with a 9 volt battery.
Here's the wagon:
Last edited by Drew_ML; Dec 21, 2002 at 10:15 PM.
I should add that not all LED bulbs are the same. I've tested all of those that I've been able to get a hold of, from Alpena, APC, to Polarg. The formymercedes.com LED bulbs are by far, the best out there. They are literally blinding when tested even with a 9 volt battery.
Actually, "brighter" isn't necessarily "better" in this case. A LED bulb can be easily made as bright as desired. There are LED-based headlight lamps out there already. As for the brake light - I wouldn't want it to be "blindingly" bright - it may actually work against you under certain conditions - rainy night, for example. If you blind a driver of a car behind you, it will hardly increase your safety.
However, in this case, brighter is better as it allows for more light to be diffused evenly through the fluted lenses + the reflectors. The result is a pattern which is very even, and not simply two points of bright light as many LEDs are. What I meant was that the exposed bulb, when held within a couple of feet to one's face, are blinding bright. Not all LEDs are that good. The Polarg & APC ones, in particular, were not very good.
In rainy conditions, and we get a hell of a lot of those in Vancouver, the LEDs are much more intense and vibrant than the regular incadescents. Not to the point of
Any chance you can give some specs on this equalisers. Are they just resistors? If yes what is the value? If not, then what do they consist of: if you know?
Thanx Drew,
Any chance you can give some specs on this equalisers. Are they just resistors? If yes what is the value? If not, then what do they consist of: if you know?
They are 6 Ohm resistors coupled with heat sinks. They have to be able to dissipate 30-40W, so your regular one from Radio Shack won't do.
This 6 ohm value; does it have to be exact? I mean, what range can it be in: i.e. 5 - 7 ohm? Is it different for every bulb? Sorry about all these questions. I have access to a lot of different power resistors, cheaper than Jerry @ formymercedes. And I know that a lightbulb is not a simple resistor.
Guess this is just the 'sparky' in me asking about all the details and then some that I have forgotten.
Thanx Vadim,
This 6 ohm value; does it have to be exact? I mean, what range can it be in: i.e. 5 - 7 ohm? Is it different for every bulb? Sorry about all these questions. I have access to a lot of different power resistors, cheaper than Jerry @ formymercedes. And I know that a lightbulb is not a simple resistor.
Guess this is just the 'sparky' in me asking about all the details and then some that I have forgotten.
Thanx Vadim,
This 6 ohm value; does it have to be exact? I mean, what range can it be in: i.e. 5 - 7 ohm? Is it different for every bulb? Sorry about all these questions. I have access to a lot of different power resistors, cheaper than Jerry @ formymercedes. And I know that a lightbulb is not a simple resistor.
Guess this is just the 'sparky' in me asking about all the details and then some that I have forgotten.
Surely if you can afford a Mercedes-Benz, you can afford the price of the load equalisers!
The load equalisers are specificially designed by the manufacturer of the LED bulbs to complement the bulbs and to dissipate the heat effectively. I would not recommend using some other sort of resistor to achieve the same results.
Surely if you can afford a Mercedes-Benz, you can afford the price of the load equalisers!
These load equalizers are nothing more than just 6 Ohm 50W resistors coupled with heat sinks. 6 Ohm is about what the stock bulb's resistance is, but it doesn't have to be exactly the same - it is only needed to fool the computer, nothing else. If, say, a 15 Ohm resistor would do the trick - use it by all means. Just make sure it is powerful enough, with Watt rating above ( 196/R ), where R = resistance in Ohms; 196=14*14 - square of the voltage supplied by the car's electrical system. 14 Volts is on a higher side, but it never hurts to have some room.
Now if what Drew said
His other point
Drew
Now your other point
I don't take your response as a flame the same as mine is not. We are all here on this forum to learn about our cars and capabilities; i.e. cost effective mods, etc. Why go with tires from the tirerack when you can buy the same from your stealer? Cost effectiveness is the answer. OK its a bad example but it holds true nevertheless. Or better yet. Why buy mods like wheels, springs, sways, etc. from a third party instead directly from the original manufacturer? Same answer. Get the most bang for your buck because you can get it below MSRP most of the time.
These load equalizers are nothing more than just 6 Ohm 50W resistors coupled with heat sinks. 6 Ohm is about what the stock bulb's resistance is, but it doesn't have to be exactly the same - it is only needed to fool the computer, nothing else. If, say, a 15 Ohm resistor would do the trick - use it by all means. Just make sure it is powerful enough, with Watt rating above ( 196/R ), where R = resistance in Ohms; 196=14*14 - square of the voltage supplied by the car's electrical system. 14 Volts is on a higher side, but it never hurts to have some room.
What I meant about using formymercedes' load equalisers was that one should not use a simple off the shelf resistor without the proper heat sink, etc as the unit gets quite hot after a short duration of the bulbs being illuminated. I've seen a few people solder in regular (tiny) 6 ohm resistors and the long term results were not too nice
I have found it to be very sensitive. I currently have a bulb out indicated for the front right turn signal. This didn't start happening until I shorted the brake wear sensor but went away until it rained last week and I thought it would go off again, as the bulb is good, apparently to the eye anyway, and now it is stuck on.
Anyway, I still think it definitely would be possible to trick the computer with the proper off the shelf resistor and an old IC or CPU heat sink, maybe even a muffin fan to get really nerdy ;-) We use to install these are selves on CPUs way before anyone sold or OEMed such a device.
But on the other hand, like, I believe, the xenon setting in the computer, if I could get a copy of that star program, I could probably figure out a way to disable the bulb burnout sensing on each individually sensed bulb which would be a lot more efficient.
Bug, I digress, as I haven't gotten any responses to my inquiry about the Star program. *sigh* May just have to get employed there ;-)
Actually vadim, you have to be careful about that because the bulb out system seems to be very sensitive and you can easily blow a couple of fuses or not be able to trick the system into thinking that a regular incandescent bulb is there.
But on the other hand, like, I believe, the xenon setting in the computer, if I could get a copy of that star program, I could probably figure out a way to disable the bulb burnout sensing on each individually sensed bulb which would be a lot more efficient.
Bug, I digress, as I haven't gotten any responses to my inquiry about the Star program. *sigh* May just have to get employed there ;-)










