I recently bought a 3528 SMD Flexible LED Strip, 300 LED for 5 M.

The Power Supply I have output 12V and 3A.

From what I found online, this seams okay, but it doesn't work. I managed to light them once, but the led strip doesn't light up until the end.

How can I know if my power supply is appropriate?

  • 1
    Do you have any specs or datasheets for either the strips or power supply you purchased? Many power supplies advertise their peak current, and not continuous load rating (which is lower). Additionally, cheap power supplies in particular tend to overstate their ratings, and will output a lower voltage as you get near their max ratings. With power supplies, as with many things, you typically get what you pay for.
    – gregmac
    May 12, 2013 at 0:23

1 Answer 1


Based on the LED strip that you have, your power supply will not be enough. You need a minimum of 4 amperes to fully power the strip.

  • Citation? The datasheets I found say a 3528 draws 2A on a 5m roll, or 3A per color for RGB strips.
    – gregmac
    May 12, 2013 at 0:12
  • 1
    The datasheet I found says that a 3528 draws .8 amps/m. ledii.com/pdf/3528smd%20120led%20ribbon%20series.pdf
    – Chris
    May 12, 2013 at 0:20
  • Because that's a 600 LED (120 LED/metre) strip. Yes, those are .8 amps/metre. Another way of thinking of it with 3528s is 0.4A per 60 LEDs or 1.0A per 150 LEDs. Given OP's 300-LED, 5M strip that should have drawn 2A and his power supply should've been fine. Feb 15, 2017 at 3:39

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