CleanCL

i've been putting this together for over 6 months doing a lot of testing and fitting. at this point i'm pretty set on this setup. this is going in 97+ tails and the cover is not on, so the red will be diffused a lot better.

aliga

iTrader: (147)

looks good, cant wait to see the finished product.

CleanCL

yea, the only thing that wont be LEDs is the top running lights bc the LEDs just dont disperse as much light as some fat wedge bulbs. but i think it will blend nicely since the big lower portions that are LEDs arent on most of the time.

you can be the judge once its all put together since your the master of SCs. ;]

ki_soarer

looks great jose! cant wait to see the end result.

p.s.: im still trying to get ahold of some bi-xenons at work. lol.

O. L. T.

iTrader: (17)

It has a cadillac feel to it.

Pain in the *** to build them, isn't it? I made ONE set..... and quit

Beware of heat on the tracers, the big led boards for the tails tend to overheat and melt tracers and solder at the final load point.

These were a huge pain. I never even finished the design, too much work involved.





This triangle tapering was supposed to be on the other side at the end, but I didn't have the other tail open when I took this pic. (pointing to the corner and tapering off).

Hil

iTrader: (61)

cool

CleanCL

haha tell me about it. i could probly do it in a week now. but like i said, i started this project over 6 months ago.

O. L. T.

iTrader: (17)

Like I say, just watch the final load points. The math doesn't add up when looking it over and checking for current, but the problem lies in the heat produced by the current that is actually there where H=I/T (current V/S time).

Any time you add more than 20 led's together the heat factor at the final load point surpasses the solder's melting point where it becomes more malleable and rather than roasting off in a blaze of glory it simply melts enough to limp off the connections and creates a cold solder joint. (threshold, commonly known as the "fence" where time/current make up for lack of amperage. The reason why things fail if left on for a longer period of time. A build up of energy in the form of heat)

If you know how much of a pain it is to go inside a tail light one time, think of constantly having to do it to repair cold solder joints.

It's not the current initially, as in an overload. It's the energy (heat) produced by the current passing at the final load point. The thresh hold for cold solder joints produced by overheating the solders melting point is past the 20 led mark. I see the cadillac brake and high step lights going out all the time. You'll see them going down the road with only like 1/3 of them lit when they hit the brake.

booja

iTrader: (1)

wow that looks good!

CleanCL

wow, you brave man, you did a resistor for every LED?

im doing 1 resistor for every 5 LEDs. and im using 20 LEDs for the turn signal and 30 LEDs for the brake lamp.

my design is slightly different than yours and it disperses the load across different points. but if i have to open the tail again, ill just pull the LEDs out because as you said its not worth it.

i'm also using the same LEDs that are used in all the newer cars like nissan/infiniti/bmw.

O. L. T.

iTrader: (17)

naw man, FINAL LOAD POINT. No matter how you configure the led's, they have to meet up somewhere for a source at the final load point. Watch THAT area closely. It won't matter how you wire them to get to that point the final load will be determined strictly by the number of led's sucking off the final load point.

Same reason there. It's not that the resistor can't handle the current, it's that the time factor of increased resistance as heat rises over time (heat V/S ohm / time) makes that 1/4 watt resistor needing to be a 1/2 watt past a certain "on time". It's all about how much time passes under load. Resistance increases with heat, heat increases over time rapidly. More ON time, more heat, more resistance, in that order. It makes a simple circuit with practically no resistance become choked with large amounts of resistance as the heat rises.

CleanCL

gotcha. i did a lot of testing and math so that the whole array would be sucking power at safe levels of heat according to the LED specs, so im not worried about that, but ill have to check out my source points.

also in the 97+ lights, those lower lights dont run all the time like the 92-94 tails. they will only be on during turn signals and pressing the brake, so in all theory it shouldnt get TOO hot unless its on for an extended period of time.

but of course this is all just a project so i'll see how it works out. you sound like you have an electrical engineering degree. i have an EE helping me, and i'm also in the field. to be honest, i'm expecting to have to open them up again. haha.

O. L. T.

iTrader: (17)

You've worked so hard on them, I hate to see ya kill them. Two heads are better than one

I'm not really worried at all about your primaries. Even a 1/2 watt resistor can handle 5 led's for a small amount of time. The chances of heat failure in the primaries (5 led bundles) would only rise to "possible" in heavy traffic. It depends on where you live I guess. Here traffic is sporadic and clears out quickly, other metro areas practically never get a break in the traffic.

It's that final load point heading to the source where your primaries all meet that would be more classified as "quite potentially fail-able" as you sit in traffic and the heat increases. Your heat/resistance curve is going to rise dramatically over the 30 second mark of "on time".

I'm sure you've studied the well debated heat, time, resistance curve for live circuits under load. I'm just trying to make sure you pay attention to the final load points where the REAL load will be taking place. The "math" says the circuit can handle it the way it is designed, but nearly no one pays attention to the final load point, not the circuit, AFTER it has an on time resistance.

Most 5mm led's don't create enough current to worry with even when grouped in 5's unless you sit in traffic for like 15 minutes of "on time". However if your final load point has.... what was it... 30 on the brake then the final load will be 30 led's @ a starting point of (i'll just throw out the number 500 ohms for each led) 500 ohms, but as the heat rises the current will choke from the resistance and create even more heat faster. The chain reaction after that set point of time is very rapid. More heat making more resistance, making more heat, making more resistance.

Now you're not at 500 ohms, you've had "on time" for 3 minutes and the temp was 98 degree's, but now it is 108 and the resistance has increased (insert number here) to let's say 620 ohms of resistance because of the heat in the circuit path. The longer you sit there, the more heat, the more resistance, but it multiplies itself so it does not climb steady, it leaps by a factor of (insert number here) depending on the total on time and total resistance of the original 500 ohms and the extra 108 ohms from the heat which will advance until the solder joint fails into a cold solder joint when the heat meets the solders thresh hold for becoming malleable.

See originally you're concern might be for the resistors to dissipate the heat. That works until you throw in the time curve and the heat makes the final load increase. THAT is where your final load point fails...... even though the circuit handled the load like it was supposed to. Don't watch the current, watch the heat at the final load point. Screw the rest of the circuit, it'll handle it.

Blah, blah blah..... watch your final load points

SUPRMSC

iTrader: (7)

If there is a problem with load points, cant you simply split each section into, lets say 10's and then split them off onto difference sources on the 12v? Creating somewhat of an alternating current rather then a direct one?

O. L. T.

iTrader: (17)

There are several ways to do it, but he's already wired the boards. To split it right now he'd have to go back and break the circuit up into partitions. I'm sure after 6 months of work he'd rather just beef the load points and cross his fingers.