New COB LED Design & Comparison

[verticalgrow]

g'day @GreenLED

Thx for the reply & did you use 2mm thickness sheetmetal for the case?

VG

 

[Airwalker16]

I dont know how nobody has asked yet. But you have 2 drivers in there so I'm assuming you've got 2 cxb3590's per. What brand and model are they?

 

[Rahz]

So you think the big fan should be pulling air IN TO the fixture then?

The PC build I was referring to, I cut a 10" hole in the side of a case and mounted a 10" industrial fan, something like 360 CFM, right over the CPU cooler. The problem was that the airflow over the cooler was so strong that the fan on the cooler wasn't able to pull air and temps actually went up. I had the 10" on a dimmer, but even turning it down didn't really help. Temps were lowest when the big fan was hardly running, and not much different than if the fan wasn't running at all.

So if you have a system where the intake is putting pressure on one side of the cooler it will be fighting the smaller fans. It can be the same in reverse, which is why I mentioned putting the holes between the coolers... but I don't know how it would work in practice, it would take testing.

 

[Airwalker16]

The PC build I was referring to, I cut a 10" hole in the side of a case and mounted a 10" industrial fan, something like 360 CFM, right over the CPU cooler. The problem was that the airflow over the cooler was so strong that the fan on the cooler wasn't able to pull air and temps actually went up. I had the 10" on a dimmer, but even turning it down didn't really help. Temps were lowest when the big fan was hardly running, and not much different than if the fan wasn't running at all.

So if you have a system where the intake is putting pressure on one side of the cooler it will be fighting the smaller fans. It can be the same in reverse, which is why I mentioned putting the holes between the coolers... but I don't know how it would work in practice, it would take testing.

Oh I see. Makes sense. Can you reply to my question in my other thread about running pcbs?

 

[sweetherb]

Ya I would do the same.

Me too. It's not just about managing heat in the fixture, but also the tent/room.

 

[GreenLED]

I know from experience playing with PC cases that fans with conflicting air patterns can work against each other. I would place the vents in-between the coolers so the big fan is pushing fresh air through without putting pressure on the fins exhaust... or enough holes that there's not a lot of pressure to begin with.

I agree, fans only work well in clean air. If there is too much turbulence the fans will be rendered ineffective. I'm going to play around with solidworks and see where the ideal hole placement should be to try and mitigate turbulence in the case.

Put a 4-6 inch vent connector on top so you can suck air out of the tent?

All these enclosed designs should have a way to pull air right out of the tent from the light.

Other wise why bother enclosing it at all? Btw I am serious.

If I wanted to sell more lights that is exactly what I would do.

It's would be quite easy to replace the top fan with a 9 to 6 reduction duct if you had to pull air out of the box.

g'day @GreenLED

Thx for the reply & did you use 2mm thickness sheetmetal for the case?

VG

The case is made from 18 gauge sheetmetal.

I dont know how nobody has asked yet. But you have 2 drivers in there so I'm assuming you've got 2 cxb3590's per. What brand and model are they?

Correct I do have 2 drivers but they both drive all 4 COB's. Drivers are meanwell hlg-320-1400, I wanted to leave some room to add more COB's when needed.

 

[Airwalker16]

I agree, fans only work well in clean air. If there is too much turbulence the fans will be rendered ineffective. I'm going to play around with solidworks and see where the ideal hole placement should be to try and mitigate turbulence in the case.

It's would be quite easy to replace the top fan with a 9 to 6 reduction duct if you had to pull air out of the box.

The case is made from 18 gauge sheetmetal.

Correct I do have 2 drivers but they both drive all 4 COB's. Drivers are meanwell hlg-320-1400, I wanted to leave some room to add more COB's when needed.

How are they wired??? I'm Confused. You got 2.8 amps by connecting the leads of the drivers together to 1 wire?

 

[GreenLED]

How are they wired??? I'm Confused. You got 2.8 amps by connecting the leads of the drivers together to 1 wire?

Correct. Drivers are wired in parallel and COB's are wired in series. System max 229VDC @ 2.8A total capacity of 641 Watts.

 

[Airwalker16]

Correct. Drivers are wired in parallel and COB's are wired in series. System max 229VDC @ 2.8A total capacity of 641 Watts.

That's fuckin cool. I don't think anyone else has done that here.

 

[SomeGuy]

I remember Supra using two drivers connected to cobs in series. He was suprised but I guess it does work just fine. Apparently you could even put a switch on each driver and shut one or the other down as a sort of dimming feature.

 

[GreenLED]

I remember Supra using two drivers connected to cobs in series. He was suprised but I guess it does work just fine. Apparently you could even put a switch on each driver and shut one or the other down as a sort of dimming feature.

Really? do you by chance know what his findings were? Did it not work for him? The only problem I could see is if you were to use drivers with different currents. Otherwise nothing according to Ohm's law would dictate a different outcome.

 

[Uberknot]

I agree, fans only work well in clean air. If there is too much turbulence the fans will be rendered ineffective. I'm going to play around with solidworks and see where the ideal hole placement should be to try and mitigate turbulence in the case.

It's would be quite easy to replace the top fan with a 9 to 6 reduction duct if you had to pull air out of the box.

The case is made from 18 gauge sheetmetal.

Correct I do have 2 drivers but they both drive all 4 COB's. Drivers are meanwell hlg-320-1400, I wanted to leave some room to add more COB's when needed.

welp I said my peace have fun hope you sell some.

 

[SomeGuy]

Really? do you by chance know what his findings were? Did it not work for him? The only problem I could see is if you were to use drivers with different currents. Otherwise nothing according to Ohm's law would dictate a different outcome.

all i remember is him retrofitting a regular house lamp with a cob driven by two identical drivers in parallel. he had a two stage switch so it was one driver or both. it was low amperage.. two 300ma drivers I think is what he was using. possible though and as long as they are identical im not sure there is really a pit fall or not.

 

[GreenLED]

all i remember is him retrofitting a regular house lamp with a cob driven by two identical drivers in parallel. he had a two stage switch so it was one driver or both. it was low amperage.. two 300ma drivers I think is what he was using. possible though and as long as they are identical im not sure there is really a pit fall or not.

Thanks for the reply! I am not aware of any problems with running 2 drivers and I like the idea of being able to switch one of them off for a dimming function. The only reason I chose to use 2 instead of 1 driver was strictly due to cost.

 

[Airwalker16]

Thanks for the reply! I am not aware of any problems with running 2 drivers and I like the idea of being able to switch one of them off for a dimming function. The only reason I chose to use 2 instead of 1 driver was strictly due to cost.

Those 310's are quite expensive

 

[GreenLED]

Those 310's are quite expensive

Yea it looks like they recently jumped in price. I paid $71.95/each but now they are going for $104.95 from my local supplier.
The HLG-600 might be a better option now.