12v power source to power high power LED

[seanyiya]

Is there way to power the 100W High Power Led (30-36v input, 3.2A) from 12v car power??

[justDIY]

HV9910(b?) might be up to the challenge... possibly other switching controllers that use an external switch.  You might have to get creative in sensing the led current however, or aim for a constant voltage?

[seanyiya]

This is the bad boy I want to mount on the car..

http://www.lck-led.com/p478/Extreme-Bright-100W-High-Power-Led---White,-30-36v,-3.2A,-6000lm/product_info.html
Is this even possible?? I'm trying to use this as flood lights..

[justDIY]

4000 lm typical with 100 watts power input? 40lm/watt is awful!  But 40lm per $1 is pretty good. Alternately you could purchase 26x 160lm rebels at a cost of about $125, add a 48v power supply and two simple linear drivers , run two series strings (44v each) with a draw of roughly 1.4a off the psu.

Driving the 100w beast using a 12VDC to 120VAC "inverter" you have more options:
(list order: easiest and most expensive to hardest and least expensive)
Easiest way to drive it would be to buy their AC driver and call it done!
Less easy, buy a 36V 4a power supply, a few 100+ watt halogen light bulbs (as series resistors) and you're done.
Less easy still, build your own "offline" switcher, Supertex HV9910.

To generate 100w at 36v you'll need to take in roughly eight to ten amps at 12-14v - that's a pretty beefy boost converter!

[seanyiya]

I guess I'll have to stick with 12v input LED bulb to make it more practical.
There were 30w 1800lm with 1.5ma
I can probaby use 4 of those...

[cadstarsucks]

oy,  100W boost is not all that difficult IF you have the skill to deal with the heat.  It is actually stupid to boost it up just so you can buck it down again.

The problem here is that you need a custom transformer to achieve real good efficiency.  With a simple inductor you need 10A average with a 66% duty cycle and a peak current of 30A on the power switch.  A transformer changes the duty cycle allowing the conversion to run at less than 50%, but this is more critical on higher conversion ratios.

Dan