I bought 50 red l.e.d.* from a guy i know for 25 bucks. They are 3.3 volt or something like that. I want to mount them in a board and use it as my third brake light. When I am done this will snap right into where the original light bulbs go. All I need is the board. This it just a preliminary. I havent started building it yet. Any opinions or suggestions are more than welcome

unless you have a drill press i wouldnt bother, if you hand dril the holes for them no matter how precise you are they wont perfectly lined up and it will look like crap, my friend tried it once, i would actually like an LED brake light in that gap in the back of the spoiler, anyway unless you have 100% precise tools dont even try it cuz itll be a waste of time

Radio Shack sells pre-drilled boards for various electronics projects, but you will have to make extensive use of jumper wires, and see if you can get the mA draw on those LEDs, as you will need that to determine what size resistor you will need. In case you don't know it, remember: Visit Rhode Island (V=R/ I, V=Volts, R=resistance, I=current). Works every time

ACtually I do have a drill press, but I was planning to put the LEDs behind the original plastic cover, or that plastic light diffusing stuff they have for flourescent lighting. You wont actually see the leds directly. The amp draw is 30 mA or something like that. Ohms law isnt a problems seeing as im training to be an electronics technician in college Im going to check out radio shack soon to see if i can get that circuit board stuff you guys are talking about. Those leds are pretty cool so Im going to change as many lights as I can with them.

Sounds sorta neat. I like implementing LED'* wherever I can! Your best bet would be to try and hook up 4 in series and see if they throw enough light (12v +/- ~.5v into 4 LED'* would be on average 3.0v instead of 3.3v, so if they're really sensitive, they might not be bright). That would eliminate the resistor headache.

Otherwise, make sure you select the proper wattage resistors, or they'll get warm when used for extended periods of time!!!

Just buy a circuit board from rat shack. Make sure it has the right dimentions [you can always cut it], and then you have a perfect board to start out with. You will need a lot of jumper wires, but i'm sure you were planning for that anyways. I had a similar board made with 25LED'* spread out, over my old keyboard, and what happened was because the power from the PS/2 port wasn't all that great, I had the lights dimming on the other end of the power source. To remedy this problem, I just spliced the wire going from the one side, to the other, along with one going in the center. This way it evens out all the power, and everybody is happy. And, they 3rd brake light, does have that weird plastic, with the bumps on the back, that will kill the look of the LED'*. You may want to look into getting something made, or cutting one from some other car.


-justin

I went to radio shack and they had some boards there. They had 3 sizes, two of them has places to solder to but they were too small. The other one was 8x11 or somethig but it only had holes with no metal tabs to slder to:* Ill go to an electronics store over the weekend to see what else is available. As far as the resistor, I tried hooking them up without one using series/parallel combinations. It worked fine but it is really sensitive to voltage fluctuations (+-v1V) I was thinking of putting all of the LEDs in parallel and then putting a resistor that is 3 times higher than the resistance of the leds. With a resistor, the LEDs are far less sensitive to voltage changes. I burnt out 3 of them just testing them out I bought red and blue ones. The blue ones are 3 volts or so and theyre pretty bright, but the red ones are 2 volts or something and arent as bright so Im going to have to add more. Theres a great thread on LEDs around here somewhere, I think glanghus wrote it, but I may be wrong. Ill see if I can dig it up.

Here that page I was talking about
http://www.public.iastate.edu/~glang...nie/bonnie.htm

Glanghus, I linked this page from a previous post, If there is a problem just let me know and Ill change it

When you're using those red LED'*...if you think they're around 2V, go ahead and hook 6 up in a row. If they're not very bright at their full brightness (less than, let'* say 20 or 30 mcd) then slight varances in the car'* voltage system won't affect them that much (theoretically).

If you want to save the number of resistors you use, you could hook up several LED'* in series and just use, let'* say, one 1/2 watt resistor as opposed to one 1/4 watt resistor for every LED.

Your application might pull over 1/4 watt per single LED (depending on LED'* current draw) so make sure you test whatever design you're going use...I suggest leave it on for several hours, and make sure it [the resistor] doesn't get warm. As a rule, I always leave my designs on over night to burn them in, weather for the car or not.

Tonight Im going to try putting all of the leds in parallel and then put a potentiometer in series and adjust it till i get the right brightness and replace it with a resistor of that value. a half watt resistor. Ill try some series/parallel connections too and Ill choose the best one. I want to replace the light cover because you wont be able to see the LEDs through the original one. Ive got some clear red 1/8 inch plexiglass at home and my dads going to take it to work and mill it out to fit exactly. As far as spacing of the leds, whatwould look best? I can either make one row of leds or two rows staggered. What sucks is that I have to put the led board INSIDE the aluminum casting so that it will still be sealed. If anyone has any suggestions on how I should mount them....

Glanghus: When you put the LEDs in your interior lights, what mcd bulbs did you use? 20000mcd is the highest ive found for 5mm. (the white ones)