LDD powering questions

[Kairus]

I ordered two Meanwell LDD-1000HW and I have two AC adapters both 36V one is capable of 2.1a, the other is 1.7a. One is a Lite-On made for a printer, and the other is a Delta Electronics made for who knows what, but both are decent brands. I have two '30w' multichips rated between 33-35V @ 1a. So I should be within spec after voltage drop from the ldd.

What would be the best way to go about wiring them?

1) Wire both LDDs in series to the 2.1a supply?

2) Hook up each LDD to its own supply.

I have enough outlets and they're not going to be dimmed so it really doesn't matter if I use both supplies, but if I can run both off of one, then I have an extra power supply to do something else with. My concern would be that I would be maxing out the 2.1a supply for 8-10 hours a day.

Another question:
I have enough room in my fixture for another two 50w multichips, should I go with more 455nm or more 6500k? I have two 50w 445nm multichips currently, and two 30w 6500k multichips when my ldds get here.

 

[GiulianoM]

Wire both LDD's in parallel, not series, to the 2.1A power supply.

 

[Kairus]

Wire both LDD's in parallel, not series, to the 2.1A power supply.

I always mix up parallel/series, good to know.

 

[mcgyvr]

"personally" neither power supply is suitable.. You are very close to the limit.
You've got 70W of LED's and a 75W power supply..
I typically go 125% or more of the rated continuous load..
70 x 1.25 = 87.5W

A 2.5A or greater supply would be a better choice.. IMO

or use 1 LDD on each of those supplies..

 

[webslinger]

"personally" neither power supply is suitable.. You are very close to the limit.
You've got 70w of led's and a 75w power supply..
I typically go 125% or more of the rated continuous load..
70 x 1.25 = 87.5w

a 2.5a or greater supply would be a better choice.. Imo

or use 1 ldd on each of those supplies..

+1

 

[oreo57]

Or switch to 700mA drivers.. no need to always push them to the "limits".. just increases heating and losing efficiency.. Especially if you aren't planning dimming..

"personally" speaking of course.. \

And to complicate things a bit the more correct calculation involves dividing this :Vf x If = W
by the effeciency of the driver..
35v (which I believe is NOT the v drop @1000ma btw) x 1A= 35 X 2 = 70 divided by say 95 (.95) = 73.7W total needed from the ps

75.6 in your ps assuming rated output is correct

correct???

 

[Kairus]

"personally" neither power supply is suitable.. You are very close to the limit.
You've got 70W of LED's and a 75W power supply..
I typically go 125% or more of the rated continuous load..
70 x 1.25 = 87.5W

A 2.5A or greater supply would be a better choice.. IMO

or use 1 LDD on each of those supplies..

How is neither suitable? The LEDs want 33-35v @ 1a, each power supply is 36v @ 2.1a and 1.7a respectively.

My original plan was to drive each LED separately which is why I grabbed both of them.

Or switch to 700mA drivers.. no need to always push them to the "limits".. just increases heating and losing efficiency.. Especially if you aren't planning dimming..

"personally" speaking of course.. \

And to complicate things a bit the more correct calculation involves dividing this :Vf x If = W
by the effeciency of the driver..
35v (which I believe is NOT the v drop @1000ma btw) x 1A= 35 X 2 = 70 divided by say 95 (.95) = 73.7W total needed from the ps

75.6 in your ps assuming rated output is correct

correct???

Well I'm not sure what voltage drop the LDD will have, and obviously the power supplies either since they're not made for this purpose, I don't have data sheets from them. I'll just run each LDD off its own supply they should have more than enough power to power them individually. I didn't factor in efficiency, but separately they should be fine.

Eventually I may dim them when I get a controller which is why I grabbed the LDDs so I'd like to at least be able to run them at full power.

 

[mcgyvr]

How is neither suitable? The LEDs want 33-35v @ 1a, each power supply is 36v @ 2.1a and 1.7a respectively.

I should have said
"Neither is suitable to be used alone (aka one of those powering both LDD's).." Using both supplies with 1 LDD on each is fine.

or should have just said do #2