DiY LEDs - How to Power Them

insert username said:

anyone know a cheap driver to power 2x cxb3590"s 36v , ive got two active cooled heatsinks rated to cool 109watts each if that makes a difference

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A Mean Well HLG-185H-36* would suit this perfectly, best practice is to wire the COBs parallel with small value resistors off the negative side, but many leave the Rs off.

*several flavors at Jameco, B type does dimming, A type is most flexible. If you go A all of the following could work:
HLG-185H-36A
HLG-185H-42A
HLG-185H-48A
HLG-185H-54A

as they'll all put out 36Vf

Man that would make me nervous running two cobs that hard in parallel. On the other hand, not sure how else you could do it from one driver if you wanted to run higher than 1400ma.

On the other other hand, why spend the coin on CXB3590s and then run them so hard they underperform cheaper options?

JorgeGonzales said:

On the other other hand, why spend the coin on CXB3590s and then run them so hard they underperform cheaper options?

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The stock Vf for CXB3590s is 36Vf, I believe, so that's not running them hard at all unless they're allowed to get over 55C. They are rated to a max of 39Vf at 4A (156w) although that would be expected to knock their lifespan down considerably.

Airwalker16 said:

So what you'd just put blue and white dimming leads into those screw terminals and done? What's the dofference between that and just a potentiometer with a resistor inline?

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no no no all the dimming circuits in LED PSs are already PWM circuits internally, only requiring a variable resistor to set the PW (or a two other signals in the fancy PSs) The PWM unit I posted can be fed with raw DC voltage from a dumb PS and be used to give pulsed power to a DC motor or DC LED COBs whatever.

There are even cheaper circuits for DC motors, SCR based units which chop AC power up and directly feed DC circuits, without any AC/DC conversion before hand. A typical $80 SCR DC motor controller can power a 1100w 90/180v DC motor from straight wall power. No one has adapted these to LEDs though to my knowledge.

The direct AC powered Acrich2 units from Seoul Semi may do something like this but are only 17w (1$/watt)

http://www.mouser.com/ds/2/363/SMJD2V16W2P3-482084.pdf

Bill Lidgate said:

The stock Vf for CXB3590s is 36Vf, I believe, so that's not running them hard at all unless they're allowed to get over 55C. They are rated to a max of 39Vf at 4A (156w) although that would be expected to knock their lifespan down considerably.

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Most DIYers seem to run 50W or under on the CXB3590, to take advantage of the efficiency gains in the nether regions.

JorgeGonzales said:

Most DIYers seem to run 50W or under on the CXB3590, to take advantage of the efficiency gains in the nether regions.

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There are no real reason to under-volt COB LEDs, IME.

As an example the Vero 29 run:

1. at 38Vf makes 100Lm/w and dissipates 80w to make -> 7800Lm at 55C
2. at 39.5Vf makes 90Lm/w and dissipates 124w to make -> 11000Lm at 55C

So the efficiency (Lm/w) drops by only 10% while the Lm output is up by 41%

And the plants don't care, they want more photonic energy and do not care one whit how much electricity you use to give it to them!

The above argument is predicated on robust cooling as efficiency and lifespan suffer greatly if the COBs are overheated; active cooling is usually required to over-volt, but is well worth it IMO.

Bill Lidgate said:

There are no real reason to under-volt COB LEDs, IME.

As an example the Vero 29 run:

1. at 38Vf makes 100Lm/w and dissipates 80w to make -> 7800Lm at 55C
2. at 39.5Vf makes 90Lm/w and dissipates 124w to make -> 11000Lm at 55C

So the efficiency (Lm/w) drops by only 10% while the Lm output is up by 41%

And the plants don't care, they want more photonic energy and do not care one whit how much electricity you use to give it to them!

The above argument is predicated on robust cooling as efficiency and lifespan suffer greatly if the COBs are overheated; active cooling is usually required to over-volt, but is well worth it IMO.

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Well, yeah. The plants might not care how much electricity I use, but my wallet sure as hell does. And multiple cobs running at lower power spreads light more evenly of course.

Your 90lm/w is literally half the efficiency many people are getting with their CXB3590s running at 50W, as a point of comparison.

Actually, are you sure about those numbers? I am positive a Vero 29 doesn't need 124W to make 11000 lumens. And 90lm/w is atrocious, real talk. Might want to double check your math there.

About to pull the trigger but still have a few questions:
If I get the HLG-185H-C1400A, can I use it to power 2 CXB3590 (3000k)? Later down the road I plan to add 2 more to it to run all 4 at 50w. Or should I go with a LPC-100-1400 to power the 2 and then upgrade to the C1400A when I purchase the other 2 CXB3590s?
Also, it seems most people buy the B version of the HLG instead of the A. Is there a reason for that? The A has the pot built in...is it more difficult to dim?
Thanks in advance!

palmetto420 said:

About to pull the trigger but still have a few questions:
If I get the HLG-185H-C1400A, can I use it to power 2 CXB3590 (3000k)? Later down the road I plan to add 2 more to it to run all 4 at 50w. Or should I go with a LPC-100-1400 to power the 2 and then upgrade to the C1400A when I purchase the other 2 CXB3590s?
Also, it seems most people buy the B version of the HLG instead of the A. Is there a reason for that? The A has the pot built in...is it more difficult to dim?
Thanks in advance!

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Just a pain in the ass. It's under a rubber stopper and it's done by screwdriver. B VERSION you just wire a potentiometer and a resistor to the blue and white wire. Done. Get a B version or you'll regret it.

Bill Lidgate said:

There are no real reason to under-volt COB LEDs, IME.

As an example the Vero 29 run:

1. at 38Vf makes 100Lm/w and dissipates 80w to make -> 7800Lm at 55C
2. at 39.5Vf makes 90Lm/w and dissipates 124w to make -> 11000Lm at 55C

So the efficiency (Lm/w) drops by only 10% while the Lm output is up by 41%

And the plants don't care, they want more photonic energy and do not care one whit how much electricity you use to give it to them!

The above argument is predicated on robust cooling as efficiency and lifespan suffer greatly if the COBs are overheated; active cooling is usually required to over-volt, but is well worth it IMO.

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you make a good argument for the veros indeed- cree doesn't perform like that at higher current(or perhaps I should say vero doesnt perform as well at lower current)

however keep in mind that 100L per watt is no better than HPS, at those currents why bother with LED at all?

insert username said:

is a tad expensive for 2 lights, what would happen if i put 2x cxb 3590 36v onto a
LSD driver LCN200W140T its a 200 watt led driver at 1400 ma drive Current.

Output voltage is 87-145V, would the minimum output voltage need to be 72v?

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You need to drop 15v still. The lights would survive otherwise but not repeatedly day in day out. There are ways to drop it cheaply. You could use a 10.7 ohm resistor in series with your LEDs. Thatd be if running from 87v. Increase the resostance if you increased that drivers output. The resistor would need to be a minimum of 21watts, which isnt a stock value and neither is the 10.7ohms. Id bump it to 25 watts or get creative with low resistance-high powered resistors to add up to 21 watts and 10.7ohms.

This is cheaper but needs to be rectified and a parallel supply capacitor. http://m.ebay.com/itm/VINTAGE-TRANSFORMER-B131-6B-5156048-120-V-INPUT-36-V-OUTPUTS-USED-/301939124243?nav=SEARCH

http://m.ebay.com/itm/2PCS-50A-1000V-Metal-Case-Single-Phases-Diode-Bridge-Rectifier-KBPC5010-/221950605426?nav=SEARCH

Youd have to measure the transformer output

Bill Lidgate said:

There are no real reason to under-volt COB LEDs, IME.

As an example the Vero 29 run:

1. at 38Vf makes 100Lm/w and dissipates 80w to make -> 7800Lm at 55C
2. at 39.5Vf makes 90Lm/w and dissipates 124w to make -> 11000Lm at 55C

So the efficiency (Lm/w) drops by only 10% while the Lm output is up by 41%

And the plants don't care, they want more photonic energy and do not care one whit how much electricity you use to give it to them!

The above argument is predicated on robust cooling as efficiency and lifespan suffer greatly if the COBs are overheated; active cooling is usually required to over-volt, but is well worth it IMO.

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LEDs will have "off" sections if under volted. It'll make ya think ya broke them haha

dionysus4 said:

you make a good argument for the veros indeed- cree doesn't perform like that at higher current(or perhaps I should say vero doesnt perform as well at lower current)

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You are right, Cree doesn't perform like that at high currents, it performs a lot better. There is something very off with those Vero numbers.

Airwalker16 said:

Just a pain in the ass. It's under a rubber stopper and it's done by screwdriver. B VERSION you just wire a potentiometer and a resistor to the blue and white wire. Done. Get a B version or you'll regret it.

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A version is simpler the rubber stopper is no big deal all you need is a #0 phillips screwdriver. I run the A version and have made over 15 lights 16 to be exact.

REALSTYLES said:

A version is simpler the rubber stopper is no big deal all you need is a #0 phillips screwdriver. I run the A version and have made over 15 lights 16 to be exact.

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to each his own. Try a b
You've never dimmed below 50%

The B version is just much more flexible and convenient, at the expense of needing to solder on a pot or switch I guess. I actually think I might use a switch to go between 25, 50, and 100 percent. Dimming by eye doesn't really seem like a good way to stay consistent.

JorgeGonzales said:

The B version is just much more flexible and convenient, at the expense of needing to solder on a pot or switch I guess. I actually think I might use a switch to go between 25, 50, and 100 percent. Dimming by eye doesn't really seem like a good way to stay consistent.

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You use a knob... it tells you whats up.

Airwalker16 said:

You use a knob... it tells you whats up.

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I don't understand this response. I was agreeing with you, and saying you can use a switch instead of a knob as well.

Thanks gentlemen! Will I be able to run only 2 off of the driver I mentioned because the volts would only come to around 70v. The 185 min volts is 72v. So I would be under volting it, correct?
I guess I could add a 3rd one (cxb3590 3500k) to get the volts were it needs to be, but it might be too much light, even dialed down, in my little space (10"x18"x36").
I really like the thought of the A version because it's like a "set it and forget it" deal and I also wouldn't have to purchase a pot.

palmetto420 said:

Thanks gentlemen! Will I be able to run only 2 off of the driver I mentioned because the volts would only come to around 70v. The 185 min volts is 72v. So I would be under volting it, correct?
I guess I could add a 3rd one (cxb3590 3500k) to get the volts were it needs to be, but it might be too much light, even dialed down, in my little space (10"x18"x36").
I really like the thought of the A version because it's like a "set it and forget it" deal and I also wouldn't have to purchase a pot.

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If it's not a money thing, you could add 3 or all 4 now, and easily run at a lower power until you expand. You can dim down to 10% with the B version, it's really not an issue, and you'd have good spread.

Because yes, two cobs won't get you comfortably in the constant current region above 71V, and I have no idea what the driver does when that happens. Probably not worth exploring.