Cobs smoke

Budies 101

Budies 101

Well-Known Member
iHearAll said:
im thinking that since the driver is a constant current driver, it is trying to regulate something that is out of its range of reading. it says on the datasheet that it reads a range of 72-143vdc and you're one volt higher than you should be for a constant current driver. you need a constant voltage driver.

a constant voltage driver would work on a range of amps at a particular voltage.
a constant current would work on a range of voltage at a particular current.

make sense?

the drivers datasheet also say that at 146v it is an open circuit. i think this means that it is guaranteed to be unregulated currents up there. which may be past the 2800ma max of those chips.

http://www.trcelectronics.com/Meanwell/led-power-supply-erp.shtml
ERP-350-36 36VDC 9.7A 349.2W
Click to expand...
Well thank you, Kingbrite sent them to me and said it would all work. I hope that's not the issue but it might be =(

Sucks seeing as I bout 56 cobs and a bunch of drivers.
 
iHearAll

iHearAll

Well-Known Member
David Abrahamson said:
Well thank you, Kingbrite sent them to me and said it would all work. I hope that's not the issue but it might be =(

Sucks seeing as I bout 56 cobs and a bunch of drivers.
Click to expand...
youll be ok then. run 3 in series per driver. they should adjust the voltage automatically and the current should be at 1750mA as long as you stay below 143v and above 72v.

use your ammeter to measure that the driver is indeed putting out 1750 mA through 3 of the LEDs or you could try an incandescent bulb in place of an LED just to prove your driver works though. if your driver put out exactly 1750mA through an incandescent bulb then you should be golden.
 
Budies 101

Budies 101

Well-Known Member
iHearAll said:
youll be ok then. run 3 in series per driver. they should adjust the voltage automatically and the current should be at 1750mA as long as you stay below 143v and above 72v.

use your ammeter to measure that the driver is indeed putting out 1750 mA through 3 of the LEDs or you could try an incandescent bulb in place of an LED just to prove your driver works though. if your driver put out exactly 1750mA through an incandescent bulb then you should be golden.
Click to expand...
Ok, ill give 3 per driver a shot.

Thanks!
 
Budies 101

Budies 101

Well-Known Member
Ok, at about 150 watts I get smoke with just 3. I'm going to assume its either the Thermal goo or possibly the metal as a heatsink. Seems odd only because I have heard of guys running passive heat sinks past 45 watts and I have a fan per 2 cobs.
 
Budies 101

Budies 101

Well-Known Member
Is it possible the thermal grease is whats smoking? I see like this whispy smoke but I can't see where its coming from cuz it's like staring into the sun lol.
 
sixstring2112

sixstring2112

Well-Known Member
David Abrahamson said:
At first I did a small amount and I don't think it covered the whole led. Next I did a carp ton so it was pressing out the edges.
Click to expand...
i think you have too much paste on them maybe.should be no problem running 4 x 3590 off that driver per supras driver spread sheet.

take it apart and clean the chips and then spread a thin layer of paste and see how it goes.also what type of paste did you use ?
led Driver match.png
 
Budies 101

Budies 101

Well-Known Member
Pics are on main post.

I used TG-7 thermal Grease.

I also wonder if i drilled so close to the cob that the wires are burning when it gets hot.
 
iHearAll

iHearAll

Well-Known Member
well i guess your driver works. yea listen to those guys about the paste. but the paste shouldnt smoke though unless there's an electrical current burning it. make sure neither electrode is touching the paste....is there a protective film melting maybe?
 
S

Shugglet

Well-Known Member
What kind of metal is your frame/mount? Maybe it isnt conducting the heat efficiently enough. Like you said too, could be wires in contact with hot metal and melting the wire casing. If its getting that hot, that fast though I would think something isnt right.
 
Budies 101

Budies 101

Well-Known Member
OK, well I'll keep at it and let you guys know. I appreciate all the advise so far.

The Cobs seem fine is the strange thing, I let it sit there and puff smoke for about 3 min and after the chip does not look burnt in any way.

It has to be something somewhere.
 
CobKits

CobKits

Well-Known Member
popeyesailorman said:
Metal backing might not work as a heat sink.
Click to expand...
this - i cant make out what they are mounted to in your first post- doesnt look like an aluminum heatsink - what kind of metal and what dimensions?. it looks like thin gauge galvanized steel used for wall framing.which would be too thin apart from not being thermally conductive enough for any serious wattage
 
sixstring2112

sixstring2112

Well-Known Member
Try holding something in front of the cob les to block the light so you can look at it while its on,maybe you can see whats smoking?
 
Budies 101

Budies 101

Well-Known Member
CobKits said:
this - i cant make out what they are mounted to in your first post- doesnt look like an aluminum heatsink - what kind of metal and what dimensions?. it looks like thin gauge galvanized steel used for wall framing.which would be too thin apart from not being thermally conductive enough for any serious wattage
Click to expand...
Thats what it is, steel framing to build out walls.
 
Stephenj37826

Stephenj37826

Well-Known Member
David Abrahamson said:
Hello, I have built 2 led lights in the past and now am building out a bunch more for my grow.

I built a veg light with CXB3070's bd 5000k bin and the driver is Meanwell hlg-240H-C1750A and with 4 cobs I see a draw from the wall of 150watts or more and the cobs start to smoke. I have 2 fans on this light as well.

It takes about 20 seconds for them to start smoking. Has anyone had this issue?

I'm at a loss because I thought these 4 cobs should be able to handle 240watts fairly easily, yet at 200+ watts they instantly start to smoke. I was under the impression I'd be running the driver at near or max with no issues but it seems like I have to dim the driver almost all the way to not get burning.

I used a thermal paste between the cob and the metal backing as well.

I'm at a loss =(
Click to expand...

Is that a flat aluminum plate? Thickness?
 
You must log in or register to reply here.
Top