LED Signals?

[fuzion]

Sooo... i'd like to make my own custom LED turn signals for my car.. I took an electronics course .. a while ago & am a bit confused about the voltage issues w/ it.

Does anyone happen to know off hand what resistors to use to drop the voltage low enough so it doesn't fry the LEDs the second it gets power?

Thanks

[allthrottlenobottle]

i did an led setup but not for turn signals. I had to use a voltage regulator from radio shack. It took 12volts and converted it down to 1.5 which was what i needed but they have other ratios as well. good luck

[s14db]

You can buy 12v LEDs. many electronic supply houses have them and mini boards with regulators on them.Are you gonna just put some LED's were the bulb used to be? Becase you can just by those pre made. But, haveing them intigrated into the lens caddy style would be cool.

[AzurE]

a lot of those drop in led replacements are not DOT approved. they are usually very directional, ie; if someone is not directly behind you at exctly the right height...they wont see them. also they dont illuminate the lense like a bulb does, they just make little dots on the inside of the lense.

[fuzion]

I tried some of those premade LED brake lamps.. they didn't work.. wouldn't even light up

I was thinking for my turn signals to start out.. would be pretty spiffy I think, something custom that I did on my own.. would even be cool to have '2 stage' turn singles that alternated the blinker was on.. o_O

[Supafly]

The formula for figuring out what resistor value you need for a given LED, or LED array, is simple. It's basically just Ohm's Law.

Ohm's Law tells you exactly how any simple DC circuit like this will behave. It can be stated as V=IR - voltage (in volts) equals current (in amps) times resistance (in ohms).

Shuffled around to solve for R, this is R=V/I.

To find your series resistance value, you make V equal to the difference between the supply voltage, Vs, and the voltage you want across your LEDs, Vr. So here's that formula:

(Vs-Vr) / I = R

Let's say you've got a chain of three 2.2 volt LEDs (so Vr is 6.6) that you want to run at 25 milliamps (so I is 0.025, because there are a thousand milliamps in an amp) from a 12 volt supply (so Vs is 12). Now, the equation works out as

(12-6.6)/0.025=R

and R equals 216 ohms. 216 ohms isn't a standard resistor value, but 220 is; you can use resistors in series or parallel to exactly make up a non-standard value, but a 220 ohm resistor will work fine, here. The difference is small enough that it won't affect the numbers much.

hope that helped.

edit: most LED's have the voltage and amperage printed on the packaging so you know what values to plug into the equation above.

[fuzion]

*jaw open*

o_O

I need to read that 10 more times and itll lock in =p

[wangless]

http://autolumination.com/194_marker.html

get the leds that are 'inverted' that way it wont just give you a do

they also have led tail lights i believe

i have the inverted leds in my dash...

http://www.nissaninfiniticlub....73905