Need information on 3w COB LED’s.

[SteveMM62Reef]

I need some information on this type of COB LED. What kind of Heat Dissipation would I need, thinking of an Aluminum Strips with the Fins. Can I attach the COB’s directly to the heat sink or do I need a base. Hoping to avoid a Fan, but will have enough room in an existing fixture if I should need one. BTW, I have a Fluke Inferred Thermometer and small K Junction Probes for checking the COB Temperatures.

 

[oreo54]

I need some information on this type of COB LED. What kind of Heat Dissipation would I need, thinking of an Aluminum Strips with the Fins. Can I attach the COB’s directly to the heat sink or do I need a base. Hoping to avoid a Fan, but will have enough room in an existing fixture if I should need one. BTW, I have a Fluke Inferred Thermometer and small K Junction Probes for checking the COB Temperatures.

First not sure why they call those cobs but whatever.
Normally those get attached to star boards or other pre-fab circuit boards.
Some have successfully just glued those to aluminum using thermal epoxy or thermal silicone glue such as "heatsink plaster".

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For passive cooling look for wide spacing of fins. Preferably also either anodized or a light black paint.
Increases radiative cooling.
For fans, doesn't matter. Most cooling is convective so paint doesn't help and may hinder.
anodizing, regardles of color just increases surface area.

Of course you need to keep the arms from touching metal.
They are a bit fragile so bending the arms up is err delicate work.

Fans are dependent on density and drive current.

Driver choice depends on how or if you want to control them.
Simplist is meanwell LDD-s and a switching power supply.
gives you 5V PWM dimming.
If Apex or like controllers outputting 0(1)-10V analog, well easiest to get drivers that respond to same.
There are ways to convert analog-pwm and vice versa. Just adds complications though.

They recommend their 600mA driver, I'd recommend no more than 500mA especially if passively cooled.
so 1.65 (approx) watts per led.

 

[oreo54]

Dang, missed edit time..
Example of boards:

257mm x 47mm Aluminium PCB Circuit Board for 14PCS x 1W,3W,5W LED In Series | eBay

1pcs 257mm 14x1-5w LED PCB board. Suit for 14pcs 1W 3W 5W high power LED. Circuit: 14pcs LED in serials. 1, We support our products. ( If slow, you can also receive within one month and. ).

www.ebay.com

 

[SteveMM62Reef]

It’s Easy to keep the arms insulated, cover the COB, with Silicone Sheet, a Silicone Pot Holder works great. Solder wires on, clean Flux off with 91% or above Isopropyl Alcohol. Slit Self Sealing Shrink Tubing, place over Solder Ears. Heat and Shrink with Solder Iron by bringing it close to the shrink tubing, but not touching it.