# DC-DC 70+ Watt LED Driver?



## SCM_Crash (Aug 26, 2011)

Hey guys,

I'm dabbling with LEDs lately and what I've noticed is that there aren't high power DC-DC LED drivers.

I've got a couple 60w DC-DC LED drivers on the way matched to a couple 60w LEDs (supposed to be 4800-5400 Lumen).

Is there a specific reason that nobody builds them any higher? To be honest, I haven't found anyone other than ledwv.com that builds anything higher than 30w. Current Logic seems to have the right idea about building them, but they don't have exactly what I need and they haven't returned any of my emails to them.

It's odd to say the least. I'm not an electronics engineer. The LED drivers I'm getting will pull 4.5A @ 13.5 Volts and convert it to 1.8A @ 32V.

Current Logic has some boost DC-DC converters that take 12VDC input and turn it into 24V+ with super high current levels supporting 72, 100 and 200 watts. Why couldn't this be modified into a constant-current LED driver?

I guess I'm new to LEDs and I'm not quite understanding why there aren't higher wattage DC/DC LED drivers out there. Seems to be just AC/DC drivers.


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## blasterman (Aug 26, 2011)

You kind of answered your own question :thumbsup:

Super high current drivers like that would be excluded to fairly custom portable lighting applications where the designer is going to fab their own specific driver. Also realize that DC lighting applications tend to be more limited by absolute power draw requirements than AC applications. Last, a 60watt LED, unless it's Bridgelux, is going to be terribly inefficient and defeat the purpose of using it in the first place. In this respect it's cheaper and more efficient to use off the shelf 12-24volt regulated drivers that costs pennies to build in the 10-15 watt range.


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## SemiMan (Aug 29, 2011)

No market would be why they do not exist.

Anything of volume for automotive, trains, etc. is going to either be custom, or subject to significant regulatory approval (for transportation).

Been involved in a lot of LED stuff ... very rare to have a request for off the shelf high current DC\DC. They are quite easy to roll your own unlike an AC supplies.

Semiman


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## xul (Aug 29, 2011)

If you have several LEDs in series it will considerably relax the specs on the current source driver. When power loss is not a consideration you can make an LED driver from line voltage using a heat sinked diode bridge and a large high wattage voltage dropping resistor.


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## MikeAusC (Aug 31, 2011)

SCM_Crash said:


> . . . Current Logic has some boost DC-DC converters that take 12VDC input and turn it into 24V+ with super high current levels supporting 72, 100 and 200 watts. Why couldn't this be modified into a constant-current LED driver? . . . .


 
I'm testing a simple mod to a $10 12v - 30v 100 watt Inverter that will make it constant-current.

One of these days I'll find the time to write up the results here.

Dx sells 85-250 v AC drivers for 30v 100watt LEDs.


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## blasterman (Sep 1, 2011)

There was some discussion in the flashlight forums recently about a 9000mA driver.


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## MikeAusC (Dec 9, 2011)

I finally got around to documenting the $12 100 watt 12volt-in Constant Current Driver.
http://www.candlepowerforums.com/vb/showthread.php?327770-100-watt-CC-LED-Driver-for-12


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## mux (Dec 9, 2011)

Seems kind of obvious to me. If you need thát much light in one spot from a DC source, you're dealing with a very specialist application and you might as well roll your own. I even build my own drivers for much simpler loads, because then I can simulate and test it to get the best performance and efficiency. Not to mention that for some odd reason, some fairly obvious applications like triac dimmable ac drivers are still hard if not impossible to come by (but that's a whole different discussion).


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## ramicio (Apr 18, 2015)

Some people can build the mechanical part of a setup like this, but it doesn't mean that can build their own power supply. Yeah, I can dabble with linear power supplies that make a few amps, but there is no way in hell I could ever design and build a DC-DC boost converter to run something like a CXA from a 12v automotive system. Building the physical setup is fine, it's the lack of an existing LED driver that is screwing me, and making me just not even try this endeavor.


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