COB efficiency Spreadsheets

JorgeGonzales

JorgeGonzales

Well-Known Member
I'm with 80% guy in theory, not so much in practice. 100% driver utilization is a silly goal to have, way too much obsession here with that. Just pick what fits, if there's some left over on the driver, who cares? Fraction of a percent of efficiency gain, if any at all on some drivers, as @Spuzzum pointed out.

However, how do you run the CC/CV drivers in CC mode at anything less than 100%? You don't, but they also put out less power than the CC versions. 187W vs 200W in the HLG-185s. Built in derating.

And unlike apparently anybody in here, I've had shit die running close to 100% sitting in an unventilated cabinet.

Heat, that's the enemy. Keep the test point under 70C, and move on.

@Spuzzum these drivers really do happily provide 106-110% with open dimming wires. And most people have them in the open and well ventilated. Those that don't will probably have issues, eventually. Took my first one 3 years to kick it, but whatever. It was in a crap spot.

@BOBBY_G those test reports are not anything to rely on. @Malocan just ran into that trying to run CC mode with a CXB3590 that the test report said would work, data sheet did not. Data sheet won. Analog!
 
JorgeGonzales

JorgeGonzales

Well-Known Member
SaltyNuts said:
It's true that not all power supplies or drivers will reliably pump out 100% claimed power. Nor are all stereo amps equal, watt for watt. That's just to say yes there's variability out there in the land of electronics and different products get labeled differently. My impression, based purely on others reports, are that the Meanwell drivers will reliably run at 100%. Maybe they beef it up a little, hardware-wise, and their ratings are conservative, instead of the other way around like when a shady manufacturer will rate something too high through some bullshit testing procedure just so they can make a quick buck. There's an expectation of transparency with the Meanwell product and I think it's rubbing off on other manufacturers who are trying to compete in that space. That's just my impression. Lately some other driver OEMs have been getting screen time on RIU with the DIY kits and PLC has their driver. The Meanwell HLG series has been the gold standard for a while, and the first question is naturally "is this driver as good as the comparable Meanwell driver?". Anyway. I'm just saying. From peoples anecdotes, and the little I know about electronics, it appears that if the good-quality driver is adequately ventilated and the led's are run within their temperature specs it makes for a stable load on the driver up to 100% rated wattage, if the rating is realistic. And it's common for people here to run their cobs way below temperature spec. The driver stability is generally taken for granted. But, of course, electronics do sometimes fail. Usually it's related to excess heat. There's been no large scale spate of complaints about dying Meanwell drivers, or the newer players either. That would become apparent pretty quick. Not saying it can't happen though.
Click to expand...
Meanwell's best are probably the best, period. The HLG series is great, I have a couple open frame and laptop-style drivers from them as well to run various things. Linear drivers, I look elsewhere.

PLC's Meanwell clones shipped out with broken dimming. Now there's a company I'm going to trust to build drivers. Just as good as Meanwell, we swear. Jesus. I'd rather pay $10 more, thanks.
 
Rayne

Rayne

Well-Known Member
According to my understanding of "Headroom" it aught to be part of the overall build for the sake of anticipating sudden and extended power surges. If a power surge occurs a driver being pushed to it's limits is more than likely going to burn out.

Headroom is the electric variant of mechanical surge protectors known as circuit breakers or fuses. Except the electricity is not suddenly cut off, if the power surges beyond a specific point.

If headroom is accounted for in the build of a LED array or other electronics it would take an extended power surge to burn out a particular driver or electronic competent. Granted a circuit breaker is more likely to flip in the event of a massive power surge first.
 
Last edited:
SaltyNuts

SaltyNuts

Well-Known Member
JorgeGonzales said:
Meanwell's best are probably the best, period. The HLG series is great, I have a couple open frame and laptop-style drivers from them as well to run various things. Linear drivers, I look elsewhere.

PLC's Meanwell clones shipped out with broken dimming. Now there's a company I'm going to trust to build drivers. Just as good as Meanwell, we swear. Jesus. I'd rather pay $10 more, thanks.
Click to expand...
Same here, rather pay a little more for the proven quality.
 
Spuzzum

Spuzzum

Well-Known Member
JorgeGonzales said:
@Spuzzum these drivers really do happily provide 106-110% with open dimming wires. And most people have them in the open and well ventilated. Those that don't will probably have issues, eventually. Took my first one 3 years to kick it, but whatever. It was in a crap spot.
Click to expand...
I agree that they are top quality hardware, and they can be pushed to certain limits. But that doesn't mean they are invincible to failure. Mean Well's own suggested use says to give yourself 30% headroom. At least 1 driver has died on a riu member, as I linked, and another driver died on growmau5.. as he said in one of those tech talk videos on youtube. It's rare, but it does happen. this is only 1 site.. what about other sites and other users? I've read posts in the reef tank community in the past.. they've been using this stuff far longer than we have. That's where I learned most of this.. that and knna.. one of the godfathers of led growing. I'm pretty sure he'd be saying to give that headroom as well.

Basically.. if I can prevent it by spending a few extra dollars, to get a driver using the recommendations of the actual manufacturer.. then that's what I'd do. That's how I design everything I make.. I look at any and all scenarios, and what could go wrong. I then work around that.



cheers.
 
BOBBY_G

BOBBY_G

Well-Known Member
JorgeGonzales said:
I'm with 80% guy in theory, not so much in practice. 100% driver utilization is a silly goal to have, way too much obsession here with that. Just pick what fits, if there's some left over on the driver, who cares? Fraction of a percent of efficiency gain, if any at all on some drivers, as @Spuzzum pointed out.

However, how do you run the CC/CV drivers in CC mode at anything less than 100%? You don't, but they also put out less power than the CC versions. 187W vs 200W in the HLG-185s. Built in derating.
Click to expand...
those pots turn up to 220W, see my post above
 
JorgeGonzales

JorgeGonzales

Well-Known Member
BOBBY_G said:
those pots turn up to 220W, see my post above
Click to expand...
Sure, mine does the same. I was just pointing out that people should not actually rely on test reports to make purchasing decisions. If it says CC region 50-100V, and you try to run at 40V because the test driver managed it...don't be suprised if you need to order a different driver.
 
BOBBY_G

BOBBY_G

Well-Known Member
yes but i guess my point is if the nameplate says 3.9A, you should feel relatively comfortable running it right up to that as it certainly can handle it without breaking a sweat. im all for conservative design. but when theres yield on the line, to turn your drivers down at all with the false hope of it maybe living 18 years instead of 15 just doesnt make sense for most people in our application
 
JorgeGonzales

JorgeGonzales

Well-Known Member
Spuzzum said:
I agree that they are top quality hardware, and they can be pushed to certain limits. But that doesn't mean they are invincible to failure. Mean Well's own suggested use says to give yourself 30% headroom. At least 1 driver has died on a riu member, as I linked, and another driver died on growmau5.. as he said in one of those tech talk videos on youtube. It's rare, but it does happen. this is only 1 site.. what about other sites and other users? I've read posts in the reef tank community in the past.. they've been using this stuff far longer than we have. That's where I learned most of this.. that and knna.. one of the godfathers of led growing. I'm pretty sure he'd be saying to give that headroom as well.

Basically.. if I can prevent it by spending a few extra dollars, to get a driver using the recommendations of the actual manufacturer.. then that's what I'd do. That's how I design everything I make.. I look at any and all scenarios, and what could go wrong. I then work around that.



cheers.
Click to expand...
And my reef is exactly where I had Meanwell HLG die. In under three years.

I once had a bench supply go on me, and when it died it took the entire project I was working on out in a puff of smoke, caps exploded, resistors burnt, literal fire.

Sure wouldn't be happy if that was my COBs going "poof".

So rock on my man. I'm on your side. I know very well how fickle analog electronics are, how everything can operate outside of specs, until it can't. You got good advice with the 80% rule.
 
JorgeGonzales

JorgeGonzales

Well-Known Member
BOBBY_G said:
yes but i guess my point is if the nameplate says 3.9A, you should feel relatively comfortable running it right up to that as it certainly can handle it without breaking a sweat. im all for conservative design. but when theres yield on the line, to turn your drivers down at all with the false hope of it maybe living 18 years instead of 15 just doesnt make sense for most people in our application
Click to expand...
Hey I never said nothing about turning no cobs down. Eff dat.

You know, it's really time you started your own thread. Then I will have a new outdated top post to bitch about, and we can all get caught up on the latest and greatest Bobby datas in one spot.
 
SaltyNuts

SaltyNuts

Well-Known Member
I've become used to thinking of the Meanwell drivers as good for 100+% because that's been the received wisdom around these parts. But just because you can push an electrical component to the limit doesn't mean you should. But I do. But the 80% rule is completely logical and sane. Reliability and SAFETY are not irrelevant.

If that's flame fuel then let's go for another few pages, I got nothing better to do. But something tells me I just stole the last word. So I'm a dick, but I'm right. Ha! PS: everyone knows you can't grow shit with LED's.
 
Last edited:
Organic Miner

Organic Miner

Well-Known Member
BOBBY_G said:
theres no "may". every meanwell 185HLG that leaves the factory can push 220W, period. i just grabbed a new-in-the-box hlg-185h-48A and threw 2 cobs on it and maxed out the current. the two i grabbed were efficient but if i grabbed less efficient ones that ran at a higher voltage, they woulda maxed out the driver over 220W

View attachment 3732642

note that the rated output = 3.9A
actual max output = 4.26A

theres your built in 10%
Click to expand...
Hey @BOBBY_G where did you get that cool voltage/current/power meter? I want one (or maybe more than one)! ;-)
 
Abiqua

Abiqua

Well-Known Member
I want headroon on the AC side for surge and amperage [leading to overvoltage], this is different than headroom on the DC side..... :)
 
wietefras

wietefras

Well-Known Member
Spuzzum said:
Mean Well's own suggested use says to give yourself 30% headroom.
Click to expand...
I agree with you that you should have some headroom, but Mean Well also tests the HLG-185 driver at 220W. So when we load them up to around 200W we have 10% extra room from the actual maximum already.

They might fail a little sooner than when running them at 20% under that 220W, but how much would it really matter? Again from that test report, if they last 14 years, how much would that be decreased to when you load them a little bit more?
 
Last edited:
P

PurpleBuz

Well-Known Member
In principle I agree with allowing headroom for drivers to operate. BUT the amount of headroom allowed varies depending on the driver.

For example I have been recycling a bunch of constant voltage fan drivers from some china leds that have failed.

The recycled Chinese fan drivers I allow > 40% headroom.
The recycled CC led drivers I allow > 30% headroom.
Also using some meanwell APV drivers for fans I allow >20% headroom. Note these have only a 2 year warranty.

BUT HLG drivers with a 7 year warranty I will run over 90% as long as I can assure the heat is under control. There is a big difference in a 7 year warranty driver than a 2 year warranty. I'm pretty sure meanwell has run the numbers with history before upgrading the already lengthy 5 year warranty to 7 years.

So yeah In principle I agree with 20% headroom for the average driver. But you really need to base the headroom on the driver in question.
 
You must log in or register to reply here.
Top