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Hopefully easy question for those of you into electronics, but as software person bit out of my depth.

What power supply should I be getting for the following LED strip for nice even light single color strip with dimmer attached? (that's not going to blow up/burn out)

Length: 10 meter (2 joined 5 meter strips)

Color: Red

Led per meter: 60

Wattage: 14.4 per meter

Voltage: 12v

Dimmer: LED dimmer mini RF 12-24V 12A

Been checking and calculating (12v /5A? ) but so confused by watts volts, amps starting to doubt every answer I come up with


marked as duplicate by Daniel Grillo, Leon Heller, JYelton, laptop2d, Bence Kaulics Aug 31 '16 at 7:40

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  • \$\begingroup\$ @Transistor: I'm still kind of new to EE.SE, but I'm really beginning to feel a need for a growing book of carefully crafted pages on frequently asked questions, where each crafted page has been well-vetted and hammered out by experienced engineers on EE.SE and at the same time targeted by good writers who can write well towards educational content. Something as permanent as EE.SE itself is and just as applicable to common questions, but where it can replace "waving a hand towards hundreds of old questions." I'm I alone in feeling that need? (Apologies for the side-bar.) \$\endgroup\$ – jonk Aug 30 '16 at 17:25
  • \$\begingroup\$ @jonk - I think you might be asking for an electronics version of stack-overflow documentation blog.stackoverflow.com/2016/07/… \$\endgroup\$ – gbulmer Aug 30 '16 at 17:39
  • \$\begingroup\$ "so confused by watts volts, amps" - hyperphysics.phy-astr.gsu.edu/hbase/electric/elepow.html#c1 \$\endgroup\$ – Bruce Abbott Aug 30 '16 at 17:43
  • \$\begingroup\$ @gbulmer: Maybe so. I need to read that better. But on first blush, it seems to be in a direction towards where I'm heading. The short moment I gave it so far does leave me wondering if anything yet exists for EE.SE, though. I'll read more and see. But if you already know, I wouldn't mind a clue about it, too. EDIT: Never mind. It seems to be for software. Oh, well. \$\endgroup\$ – jonk Aug 30 '16 at 17:43
  • \$\begingroup\$ @jonk: You're right. I think there's actually a need for LEDs.stackexchange.com. \$\endgroup\$ – Transistor Aug 30 '16 at 17:46

If the strips are 14.4 watts per metre, 10 metres will be 144 watts. At 12 volts, that requires 12 Amps, so you need a 12 Volt power supply that can deliver at least 12 Amps.

You should use several pairs of wires from the power supply to various points along the LED strips, rather than depending on the copper tracks on the strips to carry the full current.


Your options are CV or constant current, CC with PWM or built-in dimmer control. This is a shopping question. PWM cards are avail with 10 or 15A for CV supplies. You need at least 150W.

LED strips are designed with a series R on parallel arrays of 3 or 4 LEDs in series, so dim or off is 8-9V and they are design for cars operating at 14.2V for max power where 12V is nominal brightness. If you run in series, shop for PWM 15A cards with 24-28V power supplies

You can use an old 350W PC PSU with 12V if run in parallel fixed moderate brightness or add PWM with a dummy load for stability reasons.

No more than two parallel 5m strings can be cascaded due to bus current limits. Series requires following string end to end with power cable.

I like to use universal 150W laptop chargers with switch options for 14V, or 16V in // or 26-28V in series, if cable is long AWG16 for this application may be just enough.

Meanwell brand LED supplies are a good choice for online purchase for constant current supplies used in LEDs 144W / 28Vmax ~= 6A max for Margin or 144W/14Vmax = 12A max with margin if in parallel.

Depending on your budget, lots of shopping solutions, and cable drop voltage will affect brightness so must be heavy wire if long using constant voltage (CV)


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