New COB LED Design & Comparison

Airwalker16 said:

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

Click to expand...

Rahz said:

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.

Click to expand...

Airwalker16 said:

Ya I would do the same.

Click to expand...

Rahz said:

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.

Click to expand...

Uberknot said:

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.

Click to expand...

verticalgrow said:

g'day @GreenLED

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

VG

Click to expand...

Airwalker16 said:

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?

Click to expand...

GreenLED said:

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.

Click to expand...

Airwalker16 said:

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

Click to expand...

GreenLED said:

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

Click to expand...

SomeGuy said:

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.

Click to expand...

GreenLED said:

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.

Click to expand...

GreenLED said:

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.

Click to expand...

SomeGuy said:

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.

Click to expand...

GreenLED said:

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.

Click to expand...

Airwalker16 said:

Those 310's are quite expensive

Click to expand...