Electronic – Powering Multiple LED Strips

breadboardled strippower supply

I'm new to EE in general and I've gotten myself a bit confused. My apologies if this is a stupid question, but my research isn't helping too much.

I am working on a project to control 7 LED strips with an Arduino and MOSFETs. The strips require 12V and say they use 24W. I was hoping to find a power supply to power all 7 strips, instead of one supply per strip (seems silly).

So if, 24W = I * 12V then each strip should need 2 amps. This means, to power all 7 strips, I need a 12V 14amp power supply. I'm noticing most power supplies deal in watts for some reason, so that means I need a 12V 168W supply, maybe 200W for safety.

So, with the backstory in check, 2 questions:

1) Do my 200W power supply calculations seem correct?

2) When I find this power supply, is it safe to put 14amps at 12V through a breadboard's power rails? That seems like a lot? Seems dangerous? I really have no idea…

Thank you in advance!

Best Answer

1) Do my 200W power supply calculations seem correct?

Yes. At 200W, as long as it's the 12V rail alone that has 200W, you are running it at 80% of it's total load capacity, which is a good target. The average PC supply should do this for you.

2) When I find this power supply, is it safe to put 14amps at 12V through a breadboard's power rails? That seems like a lot? Seems dangerous? I really have no idea...

As you can see from Breadboard max current/voltage or How much current can Solderless Breadboards handle? or https://www.eevblog.com/forum/projects/maximum-vac-and-amp-on-breadboard/ you shouldn't put even a 10th of that on a breadboard.

Your options are to dead-bug the mosfets, use terminal strips, use a heavy copper clad board. Or use led strip amplifiers, which are basically pre-built led drivers in a box:

enter image description here

Which comes to the second issue. You will most likely not want to wire all 7 Strips in series. You would need beefier mosfets, you will run into voltage drop along the FPC that the led strips are made of which means color drop and heat issues. You want to wire a few in parallel, or run wires from your supply to different sections of the strip. Like the picture above.

Related Topic