CobKits
Well-Known Member
if you have a way of applying lower adjsutable voltage and current you can look at the dies ans see if any strings are burnet out.
needs to be like 10-50 mA for you to look at them
Cheap and Cheerful DIY using Citizen cobs
- Thread starter JorgeGonzales
- Start date
if you have a way of applying lower adjsutable voltage and current you can look at the dies ans see if any strings are burnet out.
needs to be like 10-50 mA for you to look at them
I stumbled on an easy method if you have a LOW VOLTAGE driver..... Connect one driver wire to the COB, hold the other driver wire in your hand and touch the other COB terminal. Your body will conduct a few mA to slightly light the COB. Not a good idea over 50 volts or so. If you don't have a low voltage driver a few 9v batteries can be snapped together in series.
greenballs
Member
Yes electrocution urself is way easier
KonopCh
Well-Known Member
Yea I know that. But I touched them because on surface was dust. I waiting for driver, hope they'll work.
MrTwist1
Well-Known Member
They will work. They can survive a light touch no problem.
The Dawg
Well-Known Member
When Assembling My Cob's I've had My Screwdriver Slips And Yep I Stabbed My Cob And It Still Worked
MrTwist1
Well-Known Member
I've dropped hot solder on mine before and it still worked. I also delaminated the corner of one resoldering it... still works lol.When Assembling My Cob's I've had My Screwdriver Slips And Yep I Stabbed My Cob And It Still Worked
KonopCh
Well-Known Member
That screw seems a little too big.
And what the hell have you done
Just found them at garage. Simple light, cheap. 180€ for 220W. All included- heatsinks, fans, drivers, COBs, wires, screws, 2x postage.
nevergoodenuf
Well-Known Member
If you hard on your equipment, you may want to use these COBs
BobCajun
Well-Known Member
I doubt you'd be able to tell the difference from the same wattage of a Cree COB, for instance, maybe slightly higher. I think you're over analyzing things though. Just hit em with about 50w/ sq ft of any brand of COB and you're gonna be alright. It's not really a precise science, just blast the fuckers with as much as they'll take without ill effects or excessive heat, is my advice. I guess the figures would be good for reference purposes though, to to know. I dimmed my lights from 50w to 75% with PWM and I just got reduced yield. Now I put em back on full power. So what if the top parts get a little bleached? The bottom parts also get more light, so you take the bad with the good. I wouldn't go over 50w though, because that's actually pushing it, at least in an enclosed chamber lined with mylar.
Actually, since I read in one report that pulsed light avoids light saturation I may try a duty cycle of something like 99%. Same amount of light, virtually, but never on for more than a few hundred microseconds at a time. Probably make no difference, the plants used in report were lettuce, as I recall, which probably saturates a lot easier than weed. Worth a shot though.
Actually, since I read in one report that pulsed light avoids light saturation I may try a duty cycle of something like 99%. Same amount of light, virtually, but never on for more than a few hundred microseconds at a time. Probably make no difference, the plants used in report were lettuce, as I recall, which probably saturates a lot easier than weed. Worth a shot though.
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CobKits
Well-Known Member
i generally design for 35W/SF if cobs are being run soft (1212@3W5, cxm or 1818@50W, 1825@75W), and would use 45W/SF if run hard (1212@75W, cxm or 1818@100W, 1825@150W). Its never a bad thing to buy more light and dim it its pretty easy to bump up 10% power every other day and watch the response. so thats pretty much the same conclusion, "design for 50W/SF and dim"
people like the science but unless youre spec'ing out a warehouse, rule-of-thumb is gonna work well for most people
BobCajun
Well-Known Member
That sounds like a good way, 50w then dim as required. I'm trying my revised PWM system now. I went with 98% duty cycle, 500 mics on and 10 mics off. I'll see how that turns out. Good thing about dimmers/Arduinos is that you can connect several drivers to one, you just parallel them.
Metacanna
Well-Known Member
My growing space is 4.5 sq ft, I'm using 5x 1212 driven at 1.4A. That gives 55W per sq ft. Initially I had some problems since the plants weren't big enough to handle it, after a few weeks my plants now seem to handle that amount happily, distance 10"-12". Once I realized my plants couldn't handle so much light, I dimmed the lights to a third and every two days I would increase by 5%-10%, they are now full blast, this way plants could adapt. PPFD is 1210, which in theory is bearable for MJ plants.
Are you actually measuring the draw from wall? I have exactly the same gear but I'm reading 240W from the wall when full blast.
Are you actually measuring the draw from wall? I have exactly the same gear but I'm reading 240W from the wall when full blast.
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