Experimenting with COB LEDS (10W 12cm Strip)

Did some experimenting with a 10W COB LED 12cm Strip today. I used a power converter to power it. The LED is rated at 950-1050 lumens at 750mA 12V. The converter I have takes AC to DC 12V 900mA. So I am overdriving the LED some. But I was still surprised that the large computer CPU heatsink I used still gets quite hot after about 20 minutes. The power converter gets even hotter actually. Not sure if that is normal for the converter or not.
The output is really impressive though, I would say its at leas 1000 lumens. I chose a 3000K warm white LED which has a nice color temp to it. It puts out a perfect WIDE flood of light, with absolutely no artifacts.
I will have to play around with more of these LEDs, I love the output, but they do seem to require alot of heatsinking.
Here are the links to the LED and Converter.
http://dx.com/p/10w-1050lm-3000k-1-...spotlight-lamp-yellow-silver-dc-12-14v-195839
http://dx.com/p/10w-waterproof-led-power-driver-ac-90-264v-164916

I want to try out some of the other ones DX has, like the square or round ones, should mount to a newer square CPU heatsink well.
Anyone else mess with these kinda COB LEDs and have any advice?

I love working with COB leds. It has been great watching the evolution of LEDs, each new design is usually both cheaper and capable of higher powers. COB is so far the cheapest to manufacture (no more epoxy or domes!) and practically unlimited in how big you can make them. You can slap them on the side of anything, mounting and electrical hookup is very easy. As you've seen, ceiling/wall bouncing these units makes for a very soft illumination.

Do you have a multimeter? You might want to check how much current it is actually using. I am willing to bet it'll be way above 900 mA. Damage to the PSU is likely if you run it for extended times.

Get a regulator in there. The LED will run much cooler and so will the power supply. Avoid the AMC1735 junk. If you want to get cheap chinese regulators to match the cheap chinese LEDs, I've had very good luck with this model: http://dx.com/p/3256

It is meant for flashlights, but just solder some wires to the +/- terminals on the bottom and wire it between the PSU and the LED. Rated for max 1 amp output and you can decrease that by swapping in a larger sense resistor.

By doubling the resistor (from 0.27 ohms to 0.6 ohm) the output will be cut in half. A 10W COB led will now run at 5W. At half power the frame holding the LED will often provide sufficient cooling without any extra heat sinks.

Thanks for the advice!
When I first got the LED I was a bit worried about so much exposed "dome" but realized it was quite strong and seems durable.
I will have to check and see just how much current the LED is getting, I suspect you are right, that its getting too much.
Though I think its rated for 750mA normal, so figured 900mA shouldnt be all that bad on it. But as you said, it might be getting even more.
Not sure why the PSU gets as hot as it does either.
Definately will be getting a few more to play with. Also tempted to see what one of these is like in 15W. Simple home voltage solution.
http://www.aliexpress.com/item/COB-...E14-Home-Kitchen-High-Power-10/991348896.html
Thinking of getting a couple to use at the table I usually take photos at.

jtice said:

Thinking of getting a couple to use at the table I usually take photos at.

Click to expand...

I would not bother. If you want to spend $10-$15 on a high wattage bulb, do yourself a favor and get Cree's bulb. The direct-from-china bulbs are more expensive (per lumen) than Cree's bulb and they have nowhere near the quality or features. Plus you don't have to wait three weeks for shipping.

Yea buddy of mine mentioned that he saw those Cree bulbs the other day and was curious about them, asked me about them.
They are less lumen output, since they are 9.5W vs. 15W, but yes I dont doubt the quality is much better.
Still hard to beat spiral bulbs though for bang for buck decently efficient output, thats what I have used in the past for taking photos.

I'm thinking now after this post has been up for over 3 years if you guys have any advice on building an 8ft long strip using these COB lights?
I am wanting to replace my 110 watt fluorescent tubes I currently have now!

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