DiY LEDs - How to Power Them

No, I think that is correct. You have selected results for 6 leds. It is telling you the
total watts dissipated for the 6 leds at 2.0 amps. Watts=voltsxamps

I thought it was power applied at the COB(s).
Edit: as above.

OldGrower said:

No, I think that is correct. You have selected results for 6 leds. It is telling you the
total watts dissipated for the 6 leds at 2.0 amps. Watts=voltsxamps

Click to expand...

So that's not watts drawn from the wall, the ac side? It's the watts on the dc side?

Correct would not include driver losses or any thing else ie fans etc

OldGrower said:

Correct would not include driver losses or any thing else ie fans etc

Click to expand...

Thank you!

So if I'm not completely "filling up" a driver..say it can power up to 4 cxb3070's but I intend on running only 3 instead, am I really hurting efficiency that much and if not, what other consideration is there in doing this?

Check the data sheet of the driver you intend to use. The better quality Mean Wells will have a graph showing efficiency vs load.

sanjuan said:

Check the data sheet of the driver you intend to use. The better quality Mean Wells will have a graph showing efficiency vs load.

Click to expand...

I downloaded the data sheet but didn't know that was there. Thanks for that!

giantsfan24 said:

Even on 6 cob's? Or did I misunderstand what LED multiple means?

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I missed that part about 6. Then it is totally correct. String of 6 would be that many colts and that many watts.

The more "full" a driver is the more efficient it runs. It's in the data sheet for all drivers...usually called efficiency vs load.

Greengenes707 said:

I missed that part about 6. Then it is totally correct. String of 6 would be that many colts and that many watts.

The more "full" a driver is the more efficient it runs. It's in the data sheet for all drivers...usually called efficiency vs load.

Click to expand...

Yup! Saw that. It seems that once you're around 85% of driver capacity, with the 240 series anyway, the efficiency is minimally affected if at all. That answers a lot of questions for me and effects my build approach.

You've helped me a lot gg. Thank you very much.

Is there a formula to determine the watts drawn from the wall? I'm sure this is partially on the driver data sheet and cob spec sheet?

giantsfan24 said:

Is there a formula to determine the watts drawn from the wall? I'm sure this is partially on the driver data sheet and cob spec sheet?

Click to expand...

DC output amps x voltage to gets you the wattage of the load(your cobs power)

Then factor in the correlating driver efficiency.

200w of led dissipation on a 91% efficient driver is 200w x 1.09=218w.

And the same applies to fans and their power supplies. They usually have low 80% efficiencies to wall draw is more significant than just what the fan is using.

On a meanwell 240 driver is the Brown hot? So Brown to black and blue to white?

Or does it matter? I have it backwards and seems to be working.

What effect do the different driver series have on output?

For instance, what's the difference between the 120, 185 and 240? I understand that these numbers represent the wattage of the driver but how does that affect the output?

giantsfan24 said:

What effect do the different driver series have on output?

For instance, what's the difference between the 120, 185 and 240? I understand that these numbers represent the wattage of the driver but how does that affect the output?

Click to expand...

not really kinda sorta ... the 120 is ~150 watts, the 185 is ~200 watts, and the 240 I believe is ~250 watts .

PurpleBuz said:

not really kinda sorta ... the 120 is ~150 watts, the 185 is ~200 watts, and the 240 I believe is ~250 watts .

Click to expand...

Correct. The wattage, I think, probably represents a "mean" throughout the series.

The data sheet references that number as wattage.

After I asked that question, I looked up the cob/driver matching then compared the wattage and number of cobs for each driver series but that have the same amp output. Makes sense now.

Thanks!

Has anyone thought of buying the Cree high low bay retrofit kit and using it directly?
One can get a complete CXB fixture with 12-3590's in it,with driver,and white reflector for under 450.00,less with no reflector.All parts Cree.
Given tempatures are 4000k and 80cri and cobs are closer together,but it costs much less than buying components and assembling them.
This has nothing to do with powering but it could be modified for bloom or used for veg it has a very nice 450nm curve as is.

Zblade, do you have a retail source for the Cree kits? Edit: Platt.com. cesco.com.
There is only one COB, driven at 160W or 240W.

I'd rather spend $420 on this: http://www.tastyled.com/product-p/v4-200.htm

Here's the part number and several suppliers/retailers have in stock online.Its very close to plug and play or you can wire yourself like most high bay lights.

Here's a link and picture,which shows 12 CXB cobs.
http://www.beeslighting.com/product-p/cxb-a-hc-h-50k-8-ul-10v-l715p.htm?gclid=CJiu_5zulssCFQsDaQodGtgICw&gdftrk=gdfV27781_a_7c2325_a_7c10411_a_7cCXB_d_A_d_HC_d_H_d_50K_d_8_d_UL_d_10V_d_L715P

Or here is part number.

CXBAHCH50K8-UL10VL715P