led ground effects for car

[genuis man]

hi,
i am in a pedicamit i need to find a schematic for a led ground effects for my car. i woul like the schematic to be parrelel to save battery power!! thanks alot!

 

[Oznog]

Parallel doesn't save power... if anything, series can save power, but it's hard to regulate their current when you have enough LEDs in series to approach the source voltage (2 or 3).

Typically those LED underbody kits have hundreds of LEDs inline underneath, and the physical construction is the difficult part. I don't even know if you can get a PCB mfg to make a 1" wide board several feet long.

 

[zevon8]

Another way is to use what is called "rope-light" powered from a small auto inverter to convert the cars 12 Volts to house current that the rope light uses. Since the rope light is basically a plastic cord with small lamps ( sometimes LED's ) encased inside, it is able to withstand the elements under your car. You get a small 12 Volt to 120 ( or 220 Volt depening on where you live ) inverter to power it. Since rope lights are used outdoors for lighting stairs, patios, etc it is pretty durable.

I realize this is what is refered to as "catalog engineering" but it may turn out to be easier and cheaper in the long run.

If you do a google search for rope light you can get some idea of what I mean.

 

[jrz126]

You are definitly better off to just go out and buy one that's already made.
What's the point in making your own when everyone will think that you bought it premade.
I suggest finding a more unique place to put the leds. for example: https://www.cardomain.com/memberpage/435572/2
That's a little project I've done. I'll bet no one could mistake that for being done by myself. I'm in the process of redoing it too.

 

[genuis man]

ya i know i can go out and buy one but i would like to make one my own way and tweak it ya know. leds is no matter i have a crap load of them and i have pretty much anything i need for the project i just need a good schematic!! thanks alot!

 

[plot]

put them in parallel, otherwise the current going through the first few will fry the hole lot. you'll need high wattage resistors for all the power that'll be flowing through them though.

 

[absolution]

plot do you even know what u are talking about. you have to remember that diodes get theirs first so if you put a few in series the 1.8-2.4 volts that an LED would be dropped leaving very little to go on that resistor so it wouldnt need to be that big. though it is true that for this project he would have to go parallel. now a question for the guy who posted the question. are you planning to make them run in any kind of pattern or just act as a low power undercarrage kit. if stationary with no fancy designs it would have to be a series parallel circuit and yes in that type of hookup some mildly high rated resistors would need to be used. LEDs generally run at an optimal 20mA.

 

[plot]

plot do you even know what u are talking about. you have to remember that diodes get theirs first so if you put a few in series the 1.8-2.4 volts that an LED would be dropped leaving very little to go on that resistor so it wouldnt need to be that big. though it is true that for this project he would have to go parallel. now a question for the guy who posted the question. are you planning to make them run in any kind of pattern or just act as a low power undercarrage kit. if stationary with no fancy designs it would have to be a series parallel circuit and yes in that type of hookup some mildly high rated resistors would need to be used. LEDs generally run at an optimal 20mA.

Well, i was thinking if he used the settup with a resistor in series with a bunch of LEDs in parallel, the drop would be equal over the LEDs, but they'd draw quite a bit of current... which the resistor would have to be able to handle. this does of course completely depends on how many LEDs he puts in parallel with each resistor... if he used multiple settups and say 4 LEDs per resistor, then there wouldn't be a problem. if he put 100 parallel LEDs in series with 1 resistor... well, somethings going to fry if that's not a high rated resistor.

Make more sense? Or am i completely missing something here?

 

[jrz126]

I recall reading somewhere that doing it that way isnt good, due to the manufacturing differences in the LED's, one LED could draw more current than another, and cause damage. You are supposed to have 1 resistor per LED. This is just what I think I read, so I could (and probably am) be wrong.

 

[JohnBrown]

LED's in parallel, bad idea. Either use a sepArate resistor for each LED or put the LED's in series. LED's in parallel bad; LED's in series good.

 

[genuis man]

yes i would like them to have a strobe effect and a fade effect thats probly it!

 

[genuis man]

:twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted:

hi its me again,
ok this is wut i want the led tube to be like dont mind the tube i have the tubing im gonna use here it is. i need a schematic though pleez. thanks alot for any advice in advance!


:twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted:

 

[genuis man]

opps srry computer messed up! here it is!

 

[absolution]

sorry plot but from the understanding i had from the way you wrote that reply you were trying to just hook up the LEDs in series so in that it woulda been wrong maybe just a misunderstanding on ur intent but well anyways putting the LEDs in parallel is a good idea but you would have to compensate for manufacturer differences and overall variations in doping so using some resistors in line with the LEDs may counteract those flaws though it will have to be tweaked for each segment.

 

[jrz126]

Is that only the case if you are driving the led's at Imax? What if I run the LED's at 15mA and their max rating is 20mA, would I be safe running say 62 of them in parallel with only a couple resistors?

Also, anyone know where I can find a good PSpice model of leds? I have some blue leds, 5000mcd.

 

[JohnBrown]

Listen very carefully. Don't put LED's in parallel. The one with the lowest forward voltage drop will take all the current and burn out, Then, the one with the next lowest forward voltage drop will take all the current and burn out (slightly faster than the first one did, probably). Can you see where this is going?

 

[jrz126]

They will burn out even if you arent anywhere near the max. current? Which value is it that varies from the manufacturer? the N value?

 

[genuis man]

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!!!!!!!!!!!!!!!

:twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted: :twisted:

 

[Nigel Goodwin]

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!!!!!!!!!!!!!!!

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.

 

[genuis man]

ok thank you but also would have a simple schematic by chance?
all the other peeps arnt that educated in electronics!! i am in vo-tech right now so if u can post me bak quik! thanks in advance!