Looking for a specific DC CC driver for LEDs

karimwassef

Active member
I can usually find these things, but this time, I'm stumped.

I'm looking for a DC-DC driver with constant current at 120W:

DC in = 36VDC
DC out = 32-34VDC
Constant Current
I max = 3500mA (or higher)
P max = 120W (or higher)
Dimmable 0-10V (preferred but any electronic dimming is ok)

I can go with any multiple of 12VDC for the input too (12V or 24V or 36V or 48V). I prefer the 36VDCin since that should be the most efficient with 36Vin, 34Vout (max duty cycle).

I think these should be ~$10 based on the description and the components I could do it for. The AC input versions run $30-$50 depending on the vendor, so just having the DC CC driver section should be less.

Anyone know where to get these things? Does anyone make them? I need 20 - assuming they're not fictional.
 
don't see one there, but it sure looks like you want something similar to those that I posted to put out 3x the mA they do.

i'll dig some more.
 
Do you really need to run all the way to 3.5A? Derating curves usually make that less appealing.

Don't worry, my build has 32 drivers ;)
 
Yes. I have forced liquid cooling to maintain the LED temperature at ~40C even at a full load of 34V 3.5A. I will only be running 100W really at 34V = 2950mA. But if the driver is only rated to 3000mA, I would need to derate its application to 2700mA...

There's 10-12 on each fixture for 1000W-1200W.
 
The 3A limit is over the speced temp range. With good thermal control 4A operation could be possible.
 
Thanks theatrus. Maybe I can buy their demo boards. I need 20, so I don't see making 20 circuits.

Yes. Each feeds a multichip LED.

In case this helps... I have a constant voltage AC/DC supply that generates 36V at 75A (2700W).

I have 20 multichip LEDs that need 34V at 3A each (100W) = 2000W total.

I'm missing the constant current DC-DC drivers in between. I would like each to be individually controllable.
 
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For a DC/DC solution a driver can be pretty easily built on the Allegro A6211 up to 3A, which is the highest current integrated switch controller I've seen (external switch is always possible with more design effort).

http://www.allegromicro.com/en/Products/Regulators-And-Lighting/LED-Drivers-For-Lighting/A6211.aspx

What LEDs are you planning - multichip?
This might work, but it is up to you to translate the geek speek..

http://cds.linear.com/docs/en/datasheet/3955fb.pdf
 
This might work, but it is up to you to translate the geek speek..



http://cds.linear.com/docs/en/datasheet/3955fb.pdf


Note that it's a boost topology, so Vin would have to below the target. Linear makes awesome parts at a nice premium.

For more plug and play, Meanwell HLG series supplies would be more plug and play but not cheap for the number of required channels. They come in various powers, here is the 150W:

http://www.mouser.com/ds/2/260/HLG-150H-SPEC-806071.pdf
 
Note that it's a boost topology, so Vin would have to below the target. Linear makes awesome parts at a nice premium.

For more plug and play, Meanwell HLG series supplies would be more plug and play but not cheap for the number of required channels. They come in various powers, here is the 150W:

http://www.mouser.com/ds/2/260/HLG-150H-SPEC-806071.pdf
But can it output 3.5A constant current..?

Besides:
Drives LEDs in Boost, SEPIC, CUK, Buck Mode,
Buck-Boost Mode, or Flyback Configuration

you didn't read it very well..
And they're $5 each...
http://www.linear.com/purchase/LT3955
 
Note that it's a boost topology, so Vin would have to below the target. Linear makes awesome parts at a nice premium.

For more plug and play, Meanwell HLG series supplies would be more plug and play but not cheap for the number of required channels. They come in various powers, here is the 150W:

http://www.mouser.com/ds/2/260/HLG-150H-SPEC-806071.pdf

Yes - see above. This is what I was going to do if I needed to start from AC input. I already have 36V DC.

The 120W version I was going to use is ~$50. For 20 channels, that's $1000.

Since I already have the AC-DC part, I just need the DC-DC CC driver.
 
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