12 volt star led's

[fun4four]

Just a general question for you do-it-yourselfer's out there.

Are there any 12 - 14 volt (car battery) high powered led's out there which are al ready soldered to a star PCB that have a 700 - 1000 MA range? I'm trying to eliminate the driver because I don't want to hook them up in series.

Some links would be greatly appreciated.

[email protected]

Thanks,

bob

 

[LukeA]

The DX 6090 and 11621 will work for this. They each have regulators that take automotive power to run a Cree at 1A. I have ten of them running in parallel in an installation.

 

[fun4four]

Thanks for the info LukeA.....

What is driving the LED? Can you buy the driver separate. I don't need the fancy housing/barrel.

Just out of curiousity, what are you doing with them on your car

Bob

 

[Oznog]

There are no 12V leds. No die has that at a forward voltage, 3-4V is common. In rare cases there are multi-die devices which put them in series to increase forward voltage.

Even IF you had a 3v@1000mA LED AND put 4 of them in series, you CANNOT use it without a driver for 2 reasons. A car's voltage can go from 12V to 14.6V when running, not even counting the spikes. Due to the low dynamic resistance, an increase of 22% in voltage could mean an increase in LED current of 100% or more. Meaning basically you've got no control over LED current. Adding series resistance moderates this effect but does not eliminate it, and the moderation is poor unless the resistor drops a lot of the voltage ( say only a 6v LED and 6v-8.6v on the resistor) and a lot of heat. That would be 8.6W in the resistor at 1A! This works great for 10mA indicator LEDs, but it's impractical for power LEDs.

Second, LEDs have a negative temp coefficient- as the die temp increases, the forward voltage decreases, and thus current will increase if run on a fixed voltage- which increases heat generation and further increases current until the device destroys itself (thermal runaway).

In short you MUST have a driver.