Need help matching power supply to LED project.

tedoro · May 18, 2020

Hello,

I am an artist in Portland Oregon and I need to power an array of 3 watt cob leds (9-12vdc 260-280ma)

10x 50x 1W 3W 5W 7W SMD COB LED Chip High Power Beads Light Warm/Cool White Lamp | eBay

Low consumption, high brightness. Light Color:Cool White6000-6500K/Neutral White4000-4200K/Warm white3000-3200K/Yellow2000-2200K/Red/Blue/Green/Purple. Type:SMD/COB LED Chip. LED Strip Light. Pets Self Ball.

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They need to be strung in strands of 8 (12 total strands) 96 total leds.

I would like to run them a little underpowered to reduce the heat and make things a bit safer and perhaps last longer? I've tested them on a small constant current power supply at about 2.5 watts strung in parallel and that seems about right.

How would you design the power for this, with safety and affordability being important. I am decent at following instructions...

Many thanks, Tor

Marvo · May 20, 2020

So you want 12 strings of 8 LED modules in parallel. Do you want all the strings to operate together with a single driver (power supply) or are the strings far away from each other and better suited to 3 separate drivers?

Current and wiring size becomes a big factor when you've got a total load of 250 watts at 12V, you need substantially sized conductors to carry that current if all the strings are on a single driver.

The reliability and longevity of the LED modules will be greatly affected by how you mount them and how effectively they're heatsinked by the substrate they're sitting on.

From the safety aspect I'd suggest using a good quality driver like a Meanwell and ensure your wiring sizes are appropriate for the current.

**edit. Not sure if the word 'heatsink' is a verb or not, if not apologies for the poor English..