How to connect the LUXEON LED to 12v ?

Hi

i got luxeon star 1watt LED that i`m gonna use in my car !
I notice that the led need 6v ??
If so, can i then use 2xluxeon LED toghether (in serial) and use it perfect in the car ?

or do i got to have some resistors ? /ubbthreads/images/graemlins/smile.gif


thanx.. i`m new on this luxeon stuff...

guys... i still need help /ubbthreads/images/graemlins/blush.gif)

Which Luxeon LED do you have ?

You need to lower the voltage to the LED, if you have a single White - assume 3.5v, then you would need to get rid of 8.5v (12-3.5), and assuming 350ma operating current (.35A)

R=E/I
R=(12-3.5)/.350
R=8.5/.350
R=24 Ohms

Unfort - the resistor will be dissipating a lot of energy

P=I^2R
P=.350^2*24
P=2.94W

So, you will need at least 3w resistor

It would be better to "burn up" the extra voltage using more Luxeons, then the formula would change to whatever voltage is left

For example, 2x3.5v LEDs would be

R=E/I
R=(12-7)/.350
R=5/.350
R=14

For 3 Luxeons

R=E/I
R=(12-10.5)/.350
R=1.5/.350
R=4.2 Ohms

Watts would be .35^2R, or about .5W

If you search some of the truck forums, you may find what you are looking for. There was a guy that posted here a few years ago that was making boards that you could hook up a luxeon to your dome lights and also your door lights. Sorry I could not be more exact but most people here did not have much interest in step down devices.

LED cannot use with 'Voltage Source' such as battery.
LED need 'Current Source' to supply power.
But that source must have minimum voltage to operate LED.

Luxeon I ,II ~3.5-4 volt
Luxeon V ~6-8 volt

LED circuitry like Fluorescent lamp circuitry tht need ballast to limit current.
If you connect LED to car lamp socket directly, that is voltage source without current limitter, you will kill your LED in a few millisecond.!!!!

Look no further: http://www.taskled.com/

Best 12V drivers going. I use them in every car, for many applications.

Hi.

I agree with NaCl.

Unlike AAA,AA, c, d and lithium bateries. Automobile batteries are designed to output large amounts of power in a very short time, usualy 500+amps. This is also true for those portable battery/booster packs one can purchase any NAPA/UAP or Canadian tire stores, even if they are only 300 amps.

Hense the easy way to burn out your led lights in a blink of an eye.

I 'm not certain if this will help, however.

I make LED lighting for hunting camps and chalets , for solar kits or battery packs.

I use the standard 10 grouped led heads (lamps) that are used to replace incandescent bulbs in an automobile's head lamps, or the 10-12led sandwiches (cheaper but requires better power regulation).

Basicaly it is 2 or 3 led lamps slaved to a box with individual switches with individual power regulators.

I opted for isolated/individual power regulators as the lamps will be used in an environment that has very large changes in temperature,humidity, e.t.c., and didn't care for any trouble with auto regulating IC chip based circuits. Therefore the power regulation is solid state, as well as Slow start (power's up slowly).

I'l I honestly do not know how a luxeon (1 watt) will fair
as a dome panel light. However it's a given that you will without a doubt need a good power regulator.

Also I had a thought about the automobile battery power regulator on a single 1 watt luxeon. The resistance circuit needed to regulate the charge will probably get quite hot.

However I could be wrong about the regulator heat.

Good luck

Thanx alot /ubbthreads/images/graemlins/smile.gif
and thanx INRETECH for all the info /ubbthreads/images/graemlins/cool.gif

I use noral LED in my car, but was not sure if the Luxeon is workin the same way as "normal" led !

Soon getting the luxeons, then out and testing on my car /ubbthreads/images/graemlins/smile.gif

i will post some pic`s when done...

I think you could get a downboy converter from dat2zip and that would work for one luxeon and give it the voltage and current it needs.If the Luxeon is the star and not a bare emitter you could run it at spec that way.

Also the power in a car is very unregulated and can have very high transient voltage spikes; especially during starting when the starter pulls large amounts of current

The Sandwich Shoppe forum has some current regulating "downboy" solutions to supply a stable powersource to the leds.

There also are some very good driver circuits from leddynamics and CPF r georges80. Both are proven, efficient, clean builds, which will take in the "real voltage range" of a car battery.