led ground effects for car

Here's what we were discussing earlier.

Due to the difference in manfacturing of the LED's one led could draw more current than the others. so you need a seperate resistor for each LED (as shown in the "good design").
In my roof project, I had only one current limiting resistor for 20 LED's (60 total). there were quite a few that burned (about about 20 of them). I thought it could have been due to my poorly constructed circuit board, the soldering, or wiring. Now I think it's because of only having one resistor for 20 leds.

The advantage to the parallel set up is you can control each led individually, which is benificial for cool looking displays like the LED's in my roof.

I also included a picture of the series set up, but I dont have time to give an explination of it (I'm supposed to be working right now :wink: ).

How bout u just get a couple ultrabright led's??? then u dont gotta worry about 100's of leds, maybe just 20 or so . . . so how bout it?

Nigel Goodwin said:

genuis man said:

ok now i am officially lost someone said put the leds in parralell and the someone is tellin me if i do that ill burn em all out wtf i need help from someone!!!!!!!!!!!!!!!

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I would agree, it's very bad practice to put LED's in parallel, and not something that should ever be done!.

With a 12V supply I would suggest using four LED's in series, with their own series resistor. This then becomes a 12V LED 'block', you can put as many of those in parallel as you wish - so you need one resistor per 4 LED's.

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dangit, thats what i've been trying to say all along with 1 resistor per 4 LEDs. this is a common method of stringing up LEDs for computer case mods... tried and tested.

the most that will burn out in this case is one of the 4 LED blocks, which is maybe 2$ in components depending on the LEDs.

Here is some hookup info that is using white LEDs. https://www.otherpower.com/otherpower_lighting_leds.html
If you are using lower voltage LEDs of red, green, yellow, etc. you can use a few more in a string, at 12vdc. Also note on that site, the voltage fluctuation issue of automotive electric systems. Others here might give you some advice on that.

ok thanx alot u guyz have helped alot anywayz i will contact u all when i finish my dang project! 8)