Power supply for led strips

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1

Hi guys!

I’ve just purchased 26metres of the 5M RGB LED Strip - WS2812B 60 Per Meter.

I’m wondering how I power these and how many amps I need.

Will 2x Mean Well - 130W 5VDC Switchmode Power Supply be enough?

Finally I need to know how many amps this will draw from the mains in my studio. Is it just the amount drawn from the power supply?

I am new to this world and very confused.

Thanks!

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Hi Felix,

Welcome to the forum!!

Before jumping into the calculations I’d check out some
I’d check out the Uberguide for Neopixels. A couple key points:

Taking each supply being able to send 13A each (130 W/ 5 V) and a nominal current of each LED is 20 mA (60 mA at max brightness) - the total draw of all 26m would be about 31.2 A, just short of the total 26A that both power supplies are able to provide. In software, you can tone down the brightness a bit but that also doesn’t leave too much headroom (since no motors are involved it isnt quite as essential but still definitely desired).

Just a heads up regarding the power supplies, make sure a licensed electrician is installing them. Mains power isn’t just lethal, it’s lethal!

When talking about different voltages its better to convert everything to Watts then divide through to get current. A total of 260 W between both power supplies and an efficiency of 75% we’d be looking at about 350 W, RMS of 240V thats about 1.5 A. I’d check out this excellent tutorial on Ohms law: Ohm's Law - Practical Examples for Makers - Tutorial Australia

Liam.

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Hi Liam,

So in your opinion I should get two of the big power supply or should I get one to power 20 metres and a smaller one to power 6 metres?

I will absolutely be making sure the electrician installs the power supply.

Thanks for your help. Is there another smaller power supply you can point me to?

Cheers,
Felix

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Hi Felix,

Just to clarify each LED will draw around 20 Milliamps, with each meter drawing about 1.2 A. So each power supply is able to provide power (and still at 20mA each not the maximum 60mA per pixel) for about 10.5m. Divvying up the strips amongst 3 power supplies would probably be your best bet.

Liam.

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5

Hi Felix,

Just to add to Liam’s points, the traces on the flexible PCB that the strip consists of can only take so much current, so it’s usually a good idea to split the supplies across the strip not only for the sake of using small supplies, but also to keep the current along the strip low.

Good luck with the project, and let us know if anything else comes to mind!
-James

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