Suggestions for LED strip power supply?

Hey guys!! I have a project I am working on that I am making for my nephew. I am hoping to make a wall mounted sign that has backlighting LEDs. I realize that I don’t have any clue where to start for knowing the right now power for these amounts of LEDs. Is there a affordable, safe and adjustable supply for power (either in a case or just as the chip)for this kind of thing? (bonus points if you can point me towards one that has a second knob for my sis/nephew to use to dim the LEDs!) I want to be able to sell things with these in them.

This is the project for reference! (I think I blew the LEDs when I plugged it in :joy:)


I have a reel of those same lights and I used this to power them (works for the whole reel):
Gxilee Power Supply 12V 2A US Plug with Inline on off Switch AC 100-240V to DC 12V Converter Adapter for 12V LED Light and Small Household Electronics, 24W Max ,US plug (1 Pack 24watts Power Adapter)

Alternatively, you could get a battery case that holds 8 AA batteries for a total of 12V. The case I have has a little switch on the side:
abcGoodefg 8 Slots AA 12V Battery Holder Case Plastic Battery Storage Box with DC Plug and ON/OFF Switch 2 Pack

About the dimmer, I have no idea.


That reel has 5050 LEDs. Each LEDs, there are three per unit, pulls a maximum of 20 mA, for a total of 60 mA per LED. There is a reduction diode in the circuit, but I can’t read it, so I don’t know what the light strip itself pulls.

You can’t blow them by using too much current - they will only pull their rated/design amount. If you connected too much voltage you could have blown them.

Count the LEDs, multiply by 0.020, and that will give you the number of amps you should use as a minimum.


It’s also printed on the back of the package. For a dimmer, you could use something like this:


I bought a bunch of these for various LED projects. I figure the cheap LED strips I use will last a bit longer if I run them under-volted (and I don’t need the full brightness, anyway):

FWIW, I’m not necessarily recommending this specific seller – it was just the link I had in my history. My first order arrived with a single unit (ordered 5) and it took several back/forth emails to get them to ship the rest of my stuff.


I went down to my local thrift store, and for $20 walked away with a big bag of power supplies. Maybe 10 or so at 12v and 7-8 at 5v to run various LED projects.

All power supplies are required to have the Voltage and the Amperage labeled on them. Just make sure that you see 12v DC.

Amperage needs vary depending on the LED strip your using. But the one I’ve got is something like 150ma per foot.


You will have to stay within the voltage range of the LEDs to run them at a lower voltage and you may have problems with uniform brightness. LED brightness should be controlled with current, not voltage.

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Make it easy on yourself just get a power supply that can handle the load of the project and get a PWM dimmer.

I’ve never used this but it looks like it could handle the whole string you have. There are smaller/cheaper power supplies than this if you don’t need a full 5A. Comes with the added benefit of RF remote.


I ordered 10) LPV-20-5 LED power supplies for a project. I paid 6.95 each, they are rated IP67, so nearly watertight. From Sager electronics. 3A output.


Thanks guys!!! I’ll look these over!

I used one of these when I made my gallery sign a few years ago.

Not a great picture of the sign but your can see I backlit a basic shadow box. The vignette is part of the image design, not due to a lack of light.


I have boxes of these!(can’t seem to toss them) Make sure you measure the actual voltage they output, They can vary a lot from what is marked, especially old ones that may have gotten hot at some point.

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