Airwalker16
Well-Known Member
I'm confused on these. So could I run 4 CXB 3070's on the HLG185's? And how do the cobs have to be wired?
DiY LEDs - How to Power Them
- Thread starter SupraSPL
- Start date
Bill Lidgate
Active Member
CXB 3070's run at 38.5 Vf and 1.9A (typically) 38.5 x 1.9 = 73.15 watts,
so the HLG-120H-48A can run a single CXB-3070 with almost 47w to spare.
The HLG-185H-48A can power 2 CXB-3070's (parallel) at 73.15w with 39w to spare.
I'd be tempted to run the CXB-3070's at 39.5Vf/ 2.175A = 86w, but the cooling would need to be very good to keep them below 55C
An HLG-185H-48A could run 4 x CXB-3070's, but you'd have to run them at about 36.5Vf and they'd only put out 70% of their rated output, a quite expensive way to get that amount of light IMHO.
Airwalker16
Well-Known Member
They are 36 Fv. Less at currents less than test 2800ma. No idea where you got FV of 38.5?
Bill Lidgate
Active Member
Sry I assumed Cree had the same Vf for a PN, but not the case
Airwalker16
Well-Known Member
So what say you now knowing it's 35-36?
insert username
Well-Known Member
Does anyone know what color of these wires are nuetral and positive/neg? Its just a cheap extension cord that I want to attach to my driver im in Australia if that makes a difference? I've got dark brown , green and dark.blue wires
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JorgeGonzales
Well-Known Member
Again, you are describing how literally 99% of people DIYing with cobs run their lights, and saying it's silly.
Look at the spreadsheet @REALSTYLES linked. That extra $60 you spend on two extra cobs gives you 28% more lumens per watt for the life of the fixture, and twice the spread.
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soooooooooooo why don't you care about efficiency ? You keep talking about how hard you can push a light, but I want to reduce electrical cost, reduce heat AND want a better spectrum (in order of priority).
How does running a cob full out at max manageable amperage achieve that ?
Bill Lidgate
Active Member
By all means run your COBs at typical (or lower) Vf and they will last forever, not overheat on the passive cooling favored here and allow you to run many COBs on a given PS.
Pushing a Vero 29 to 140w dissipation is tricky and not a good choice for many, especially if your goals are reduced electrical cost and reduced heat. I would say that the spectrum does NOT suffer unless there is phosphor breakdown due to inadequate cooling.
Pushing a Vero 29 to 140w dissipation is tricky and not a good choice for many, especially if your goals are reduced electrical cost and reduced heat. I would say that the spectrum does NOT suffer unless there is phosphor breakdown due to inadequate cooling.
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fine, but that doesn't answer my question ? why don't you care about efficiency ? You keep talking about how hard you can push a light ........ I asked cause I am curious of outliers.
Bill Lidgate
Active Member
the calculations above compares 3 under-voltage conditions and 3 over-voltage conditions for a combo of a Vero 29 Decor COB and a Mean Well HLG-185H PS. The extreme under-volt (-8% of Vf typ) allows you to run 5x more COBs (10) than the Vf typ (2) with this PS. The added up front expense of buying 8 more COBs makes the total cost in 1 year considerably higher and is not offset by the excellent efficiency of the under-volt (118 Lm/W) vs Vf typ. (99 Lm/W). In one years time the scenario of a single COB with a mild over-volt (+3% of Vf typ) seems to give the best value in Lm/$ and when you figure the expense and bother of mounting 2 COBs vs 1 COB this advantage could be even greater. Add the expense of reflectors/optics, wiring etc. and this advantage would only increase.
There are other things to consider, maybe you love the even light given by 10 COBs vs one, maybe your heatsinks cant keep the temp down on a COB dissipating >80W, or you plan on having your setup for >5 years and amortize the initial COB expense etc. etc. but there is a realistic argument to be made for a mild over-volt under some circumstances IMHO.
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ok I see! you are more interested in cost per lamp than running cost, understandable with cobs still being relatively expensive. I'm more interested in running costs, and do my best building my own to keep costs down. Considering that my own lights are already outlasting the throwaway chinese leds being replaced I'm way ahead.
the calculations above compares 3 under-voltage conditions and 3 over-voltage conditions for a combo of a Vero 29 Decor COB and a Mean Well HLG-185H PS. The extreme under-volt (-8% of Vf typ) allows you to run 5x more COBs (10) than the Vf typ (2) with this PS. The added up front expense of buying 8 more COBs makes the total cost in 1 year considerably higher and is not offset by the excellent efficiency of the under-volt (118 Lm/W) vs Vf typ. (99 Lm/W). In one years time the scenario of a single COB with a mild over-volt (+3% of Vf typ) seems to give the best value in Lm/$ and when you figure the expense and bother of mounting 2 COBs vs 1 COB this advantage could be even greater. Add the expense of reflectors/optics, wiring etc. and this advantage would only increase..
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JorgeGonzales
Well-Known Member
This is a bizarre chart. What is the point of comparing 7 different total wattages. Your costs all just scale with watts, or number of cobs, drowning out any subtler points about efficiency. There is a reason the whole world uses lumens/W.
the calculations above compares 3 under-voltage conditions and 3 over-voltage conditions for a combo of a Vero 29 Decor COB and a Mean Well HLG-185H PS. The extreme under-volt (-8% of Vf typ) allows you to run 5x more COBs (10) than the Vf typ (2) with this PS. The added up front expense of buying 8 more COBs makes the total cost in 1 year considerably higher and is not offset by the excellent efficiency of the under-volt (118 Lm/W) vs Vf typ. (99 Lm/W). In one years time the scenario of a single COB with a mild over-volt (+3% of Vf typ) seems to give the best value in Lm/$ and when you figure the expense and bother of mounting 2 COBs vs 1 COB this advantage could be even greater. Add the expense of reflectors/optics, wiring etc. and this advantage would only increase.
There are other things to consider, maybe you love the even light given by 10 COBs vs one, maybe your heatsinks cant keep the temp down on a COB dissipating >80W, or you plan on having your setup for >5 years and amortize the initial COB expense etc. etc. but there is a realistic argument to be made for a mild over-volt under some circumstances IMHO.
Let's simplify this. A lot. I'll use Supraspl's CXB3070 charts linked above.
2 x CXB3070 @ 1.05A = 12800lm and 73W
1 x CXB3070 @ 2.45A = 12500lm and 92.5W
Can we agree that's close enough, and a common sense way to compare?
That 19.5W difference is a savings of $15 a year with choice number one, using $.12/kWh. The CXB3070 pays for itself in two years, and cheaper cobs or pricier electricity breaks even much faster. There are $12 Citizens that outperform a Vero 29, and I wish I paid $.12kWh here.
It's definitely a pain to build up twice as many cobs, that's the truth. Cooling I would argue ends up costing the same per watt, regardless of # of cobs.
And I apologize in advance if you are a climate change denier, but thinking past my wallet it's better for the goddamned planet to run at higher lumens/W.
Editing to add after a relaxing shower: manufacturing environmental impact could overshadow any efficiency gains in a higher cob scenario. I'm my own devil's advocate.
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Bill Lidgate
Active Member
An extension of the above chart, if I subtly change the Vf I can get the most out of the PS finding the best value for 1yr operation gives it at 102% over-volt of Vf typical at 176W total (88w/COB)
(I always try to not get higher than 95% of a PS's rated output)
This is only valid because I am stuck with the HLG-185H and I like this Vero 29s output. The "best" Vf to use depends on many factors, obviously, but the Lm/watt is not the final word in this case.
Environmentally $ = carbon, whether you spend it on COBs or electricity IMHO.
(I always try to not get higher than 95% of a PS's rated output)
This is only valid because I am stuck with the HLG-185H and I like this Vero 29s output. The "best" Vf to use depends on many factors, obviously, but the Lm/watt is not the final word in this case.
Environmentally $ = carbon, whether you spend it on COBs or electricity IMHO.
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nevergoodenuf
Well-Known Member
Bill, you need to forget about the Vf. You don't really have control over that with the drivers we use. Most of us use full Constant Current drivers ( hlg185h-c2100b or similar) and the only reason you need to know Vf is to see how many COB will fit on a given driver.
The driver you are referring to is also a Constant Current driver ( hlg185h-48b or similar), but it has a voltage limit (48v) and will run CC 3.9Amps until you draw 48v then it converts to a CV and limits it at 48v. The hlg185-42 will run CC @ 4.4 amps and the hlg185-36 will run CC @ 5.2 amps. If you run the 36 volt, then the driver will limit you to 36v. If you buy the A version, then you can adjust the drivers voltage out between 33v and 40v.
Now when you do use a CC/CV driver you can add as many COBs as you want, but you must run in parallel to maintain the voltage.
The CC drivers your running in series and the driver will only give the set amperage to each and every COB until you run out of volts out.
The driver you are referring to is also a Constant Current driver ( hlg185h-48b or similar), but it has a voltage limit (48v) and will run CC 3.9Amps until you draw 48v then it converts to a CV and limits it at 48v. The hlg185-42 will run CC @ 4.4 amps and the hlg185-36 will run CC @ 5.2 amps. If you run the 36 volt, then the driver will limit you to 36v. If you buy the A version, then you can adjust the drivers voltage out between 33v and 40v.
Now when you do use a CC/CV driver you can add as many COBs as you want, but you must run in parallel to maintain the voltage.
The CC drivers your running in series and the driver will only give the set amperage to each and every COB until you run out of volts out.
Airwalker16
Well-Known Member
So how many cxb's can you run on an HLG185H-48A?
nevergoodenuf
Well-Known Member
At what wattage do they stop getting more efficient? That would be the best point to stop adding COBs
nevergoodenuf
Well-Known Member
Or when you run out of money!!!!
Airwalker16
Well-Known Member
I just don't understand the ground rules of how these work like I do the HLG-###H-C#### Models.At what wattage do they stop getting more efficient? That would be the best point to stop adding COBs