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UPDATE : LED's for lighting (LONG)

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Old 11-21-2002 | 10:38 PM
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Always better to undervolt them. The brightness diffrence between 500ohm and 1Kohm is nothing, but that extra little bit of resistance could save $135 in bulbs (in my car) if there is a high voltage surge from a bad regulator or whatever else there may be.

Matt - The stock rheostat does not have enough resolution to dim them very much. I am going to see if I can find a way to work one into the system that will cut the voltage further. My setup at full voltage is like you having one of Ice Sharks light cannons in your gauge pod. With the dimmeer all the way down, it is a little bit better.

I will let you know. Also, I have not found time (or a way) to make molds for the reflectors yet. Still working on it, and over the winter, I am sure I will make some progress.
Old 11-21-2002 | 10:42 PM
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LOL. FWIW, the proper way to control brightness with LEDs is with an oscillator. Vary the duty cycle from 0 to 100% to vary the brightness from zero to max. This can be done with a simple 555 timer and a power transistor.
Old 11-22-2002 | 12:13 AM
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Okay, sorry if this has already been discussed in detail (I saw the dash light part earlier but didn't read on), but could you use several of these in your dash lights? And could you use them in sequence to indicate green for normal, yellow for not too bad, and red for redline/danger? They have them for my bike (it is all LED gauges, just swap LEDs) but I can't find the pics for them. It looks great, because this guy uses green from 0-6500, blends orange and green for a short time, then yellow and green (etc) from 6500-9000, then blends into red at 9000-tach limit. Looks great. Just wondering if it were possible, sorry if it was already mentioned/discussed.
Old 11-22-2002 | 12:34 AM
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It could be done. You would need an LED driver assembly to turn them on at the given RPM.

You would have to drill holes in the gauge face and backing plate to mount them, then there is the wiring... too much for me.
Old 11-22-2002 | 02:44 AM
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Perry, when you get your car done I think it is safe to say that it is going to be the ultimate 944. I'm jealous, but you deserve it.
Old 11-22-2002 | 08:48 AM
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[quote]Originally posted by mouse [CTY]:
<strong>Perry, when you get your car done I think it is safe to say that it is going to be the ultimate 944. I'm jealous, but you deserve it.</strong><hr></blockquote>

Agreed.

Brian, I have another idea. Would you need the same type of resistors to run LEDs for your brake lights? I'm going to work on this over Christmas... I think the stock lights aren't bright enough. I think some red LEDs in there would be awesome. In a matrix pattern, stuck in there somehow. Do you think this is doable?

-Matt
Old 11-22-2002 | 11:01 AM
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You can do anything, but most likely, they will look like the LED arrays in the tail lights of city busses.

You would have to rig up something to mount the bulbs to, or drill holes. After that, it is all wiring and soldering.
Old 11-22-2002 | 11:22 AM
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You better be careful monkeying around putting LEDs in the BRAKE lights.

The way light rays are emmitted from a LED is totally different than from a filament bulb. Your reflector and lens are designed for a filament bulb to get the appropriate intensity and angle distribution. Stick a few LEDs in there and you may be asking to be rear ended.

If your current brake lights are dim, get some new halogen bulbs (bulbs do wear out before they actually burn out) and make sure you are getting full voltage to them.

LED brake lights on the newer vehicles were designed from scratch and are better than filament in several ways, one way is they light up to full intensity faster ... which is a good thing for brake lights.

Bottom line: leave your brake light source alone if you are going to keep your OEM lens assembly.
Old 11-22-2002 | 12:53 PM
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What about replacing the bulbs in the glove box, hood, trunk, and map lights? What specs for the resistors and bulbs do you think would be best?
Old 11-22-2002 | 12:57 PM
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I did. Every bulb in the cars interior is a White LED. The amount of resistance you need depends on the working voltage of the LED. Not all LED's work off the same voltage.
Old 11-22-2002 | 01:01 PM
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Oh.. and for you newer listers who have not read the zillion posts on this, the info is on my site.

<a href="http://home.fuse.net/porsche951/led.htm" target="_blank">LED Install</a>
Old 11-22-2002 | 01:26 PM
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I wouldn't mess around with changing out interior/underhood lighting with LEDs. There really isn't any benefit to get equivalent illumination, only drawbacks like more money and work effort. You hardly ever use these lights so power draws and long life are not issues.

Long life and different colors or fashion statements in the dash and ***** are a different matter that could make sense.

BTW, you can overdrive LEDs over design voltage to get more intensity. People are doing this all the time for flashlights. Does cut way down on the LED life, though.



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